This species' favored habitats are sphagnum bogs, grassy areas surrounding beaver ponds, and deciduous or mixed forests rich with mosses. The four-toed salamander will use the sphagnum bogs during reproduction, but uses the forest habitat during the summer. It overwinters in terrestrial habitat, using old burrows or cavities created by rotting roots, below the freezing depth. It will frequently overwinter in groups, sometimes with other amphibians such as the red-backed salamander.
In Canada, the four-toed salamander can be found in southern Ontario and Quebec, in Nova Scotia, and a single population was found in New Brunswick in 1983. In the United States, it can be found from Maine to Minnesota and as far as Alabama in the south. They have also been found in eastern Kentucky.
The home range of the species is not known. It was believed that the different elements of its habitat (breeding, summer and overwintering) had to be within 100 m of each other, but recent observations might suggest this to be an underestimation.


The four-toed salamander can be recognized by its white underbelly sprinkled with black dots. Its back varies from orange-brownish to red-brownish; its flanks are grayish. The body and the limbs are elongated. The snout is short, and the eyes are prominent. The tail color is usually brighter than the back, and you can observe a constriction at the body/tail junction. The posterior limbs have four toes (hence its name), a good identification criterion but hard to use in the field. This species rarely exceeds 10 cm (3.9 in) in length. The sexes are alike except for the shape of the head. Males have elongated and almost square snouts, whereas the females' snouts are short and round. The juveniles show a tail shorter than the body.
The four-toed salamander can be easily mistaken for the redback salamander (Plethodon cinereus) in the wild. The Four-toed salamander's underbelly is more of a "salt and pepper" color. There is no constriction at the tail, and posterior limbs show five digits.


Pike are found in sluggish streams and shallow, weedy places in lakes and reservoirs, as well as in cold, clear, rocky waters. They are typical ambush predators; they lie in wait for prey, holding perfectly still for long periods, and then exhibit remarkable acceleration as they strike. They inhabit any water body that contains fish, but suitable places for spawning are also essential. Because of their cannibalistic nature, young pike need places where they can take shelter between plants so they are not eaten. In both cases, rich submerged vegetation is needed. Pike are seldom found in brackish water, except for the Baltic Sea area, here they can be found spending time both in the mouths of rivers and in the open brackish waters of the Baltic Sea. It is normal for pike to return to fresh water after a period in these brackish waters. They seem to prefer water with less turbidity, but that is likely related to their dependence on the presence of vegetation.


The northern pike (Esox lucius) is a species of carnivorous fish of the genus Esox (the pikes). They are typical of brackish and fresh waters of the Northern Hemisphere (i.e. holarctic in distribution). They are known simply as a pike in Britain, Ireland, and most of Eastern Europe, Canada and the United States.
Pike can grow to a relatively large size: the average length is about 40–55 cm (16–22 in), with maximum recorded lengths of up to 150 cm (59 in) and published weights of 28.4 kg (63 lb). The IGFA currently recognizes a 25 kg (55 lb) pike caught by Lothar Louis on Greffern Lake, Germany, on 16 October 1986, as the all-tackle world-record northern pike. Northern pike grow to larger sizes in Eurasia than in North America, and typically grow to larger sizes in coastal than inland regions of Eurasia.


The young, free-swimming pike feed on small invertebrates starting with daphnia, and quickly move on to bigger prey, such as the isopods asellus or gammarus. When the body length is 4 to 8 cm (1.6 to 3.1 in), they start feeding on small fish.
A pike has a very typical hunting behaviour; it is able to remain stationary in the water by moving the last fin rays of the dorsal fins and the pectoral fins. Before striking, it bends its body and darts out to the prey using the large surface of its caudal fin, dorsal fin, and anal fin to propel itself. The fish has a distinctive habit of catching its prey sideways in the mouth, immobilising it with its sharp, backward-pointing teeth, and then turning the prey headfirst to swallow it. For larger prey, the pike will usually attempt to drown the prey before carrying it off to be consumed. It eats mainly fish and frogs, but also small mammals and birds fall prey to pike. Young pike have been found dead from choking on a pike of a similar size, an observation referred to by the renowned English poet Ted Hughes in his famous poem "Pike". Northern pike also feed on insects, crayfish, and leeches. They are not very particular and eat spiny fish like perch, and will even take fish as small as sticklebacks if they are the only available prey.
Pike have been observed hunting and attempting to eat larger waterbirds, such as an incident in 2016 when an individual was observed trying to drown and eat a great crested grebe, as well as an incident the previous year where an attack by a large pike between three and four feet long was implicated as a possible cause for the injury and death of an adult mute swan on Lower Lough Erne, Northern Ireland, but it is generally believed that such attacks are only rare occurrences.
The northern pike is a largely solitary predator. It migrates during a spawning season, and it follows prey fish like common roaches to their deeper winter quarters. Sometimes, divers observe groups of similar-sized pike that cooperate some to start hunting at the same time, so "wolfpack" theories are given. Large pike can be caught on dead immobile fish, so these pike are thought to move about in a rather large territory to find food. Large pike are also known to cruise large water bodies at a few metres deep, probably pursuing schools of prey fish. Smaller pike are more of ambush predators, probably because of their vulnerability to cannibalism. Pike are often found near the exit of culverts, which can be attributed to the presence of schools of prey fish and the opportunity for ambush. Being potamodromous, all esocids tend to display limited migration, although some local movement may be of key significance for population dynamics. In the Baltic, they are known to follow herring schools, so have some seasonal migration.


This species occurs in forests, chaparral, meadow margins, and sagebrush, especially in areas with many rocks or forest litter that provides shelter. It is associated with many kinds of coniferous trees, aspen, and manzanita.
It is omnivorous, feeding on pine nuts, acorns, herbs and shrubs, fungi, many kinds of insects, eggs, young birds, lizards, carrion, and human foods when available. This species caches food near its burrow, especially during the late summer and fall. The squirrel has also been known to "beg" for human food at the wildlife urban interface.
This species hibernates over the winter. During the summers they gain extra weight in order to prepare for hibernation. The squirrels hibernate in dens that can reach up to 100 feet in length although they are typically shallow in depth. The breeding season commences when males and females emerge from hibernation in the spring. Most broods are born in July. A female has two to eight young per litter, with an average of five. There is no paternal care of the offspring. Juveniles resemble adults by 40 days of age. The life span of this ground squirrel is up to about seven years.
Most adults are independent, rarely cooperating, and usually competing for resources. They may assemble at sites with abundant food but develop a group hierarchy. Adults reside alone in burrows, creating nests for hibernation or rearing of young. This species has been known to nest in structures, such as roofs. This species becomes vocal when it feels threatened, making squeaking noises or growling. However, it is generally not a very vocal species.
Predators of this squirrel include snakes, foxes, weasels, and bears. It may carry the Rocky Mountain wood tick, a vector of Rocky Mountain spotted fever and other diseases.


The golden-mantled ground squirrel (Callospermophilus lateralis) is a ground squirrel native to western North America. It is distributed in the Rocky Mountains of British Columbia and Alberta, and through much of the western United States.


The cane toad (Rhinella marina), also known as the giant neotropical toad or marine toad, is a large, terrestrial true toad native to South and mainland Central America, but which has been introduced to various islands throughout Oceania and the Caribbean, as well as Northern Australia. It is a member of the genus Rhinella, which includes many true toad species found throughout Central and South America, but it was formerly assigned to the genus Bufo.
The cane toad is an old species. A fossil toad (specimen UCMP 41159) from the La Venta fauna of the late Miocene in Colombia is indistinguishable from modern cane toads from northern South America. It was discovered in a floodplain deposit, which suggests the R. marina habitat preferences have long been for open areas. The cane toad is a prolific breeder; females lay single-clump spawns with thousands of eggs. Its reproductive success is partly because of opportunistic feeding: it has a diet, unusual among anurans, of both dead and living matter. Adults average 10–15 cm (4–6 in) in length; the largest recorded specimen had a snout-vent length of 24 cm (9.4 in).
The cane toad has poison glands, and the tadpoles are highly toxic to most animals if ingested. Its toxic skin can kill many animals, both wild and domesticated, and cane toads are particularly dangerous to dogs. Because of its voracious appetite, the cane toad has been introduced to many regions of the Pacific and the Caribbean islands as a method of agricultural pest control. The common name of the species is derived from its use against the cane beetle (Dermolepida albohirtum), which damages sugar cane. The cane toad is now considered a pest and an invasive species in many of its introduced regions. The 1988 film Cane Toads: An Unnatural History documented the trials and tribulations of the introduction of cane toads in Australia.


The common name "marine toad" and the scientific name Rhinella marina suggest a link to marine life, but cane toads do not live in the sea. However, laboratory experiments suggest that tadpoles can tolerate salt concentrations equivalent to 15% of seawater (~5.4‰), and recent field observations found living tadpoles and toadlets at salinities of 27.5‰ on Coiba Island, Panama.  The cane toad inhabits open grassland and woodland, and has displayed a "distinct preference" for areas modified by humans, such as gardens and drainage ditches. In their native habitats, the toads can be found in subtropical forests, although dense foliage tends to limit their dispersal.
The cane toad begins life as an egg, which is laid as part of long strings of jelly in water. A female lays 8,000–25,000 eggs at once and the strings can stretch up to 20 m (66 ft) in length. The black eggs are covered by a membrane and their diameter is about 1.7–2.0 mm (0.067–0.079 in). The rate at which an egg grows into a tadpole increases with temperature. Tadpoles typically hatch within 48 hours, but the period can vary from 14 hours to almost a week. This process usually involves thousands of tadpoles—which are small, black, and have short tails—forming into groups. Between 12 and 60 days are needed for the tadpoles to develop into juveniles, with four weeks being typical. Similarly to their adult counterparts, eggs and tadpoles are toxic to many animals.
When they emerge, toadlets typically are about 10–11 mm (0.39–0.43 in) in length, and grow rapidly. While the rate of growth varies by region, time of year, and gender, an average initial growth rate of 0.647 mm (0.0255 in) per day is seen, followed by an average rate of 0.373 mm (0.0147 in) per day. Growth typically slows once the toads reach sexual maturity. This rapid growth is important for their survival; in the period between metamorphosis and subadulthood, the young toads lose the toxicity that protected them as eggs and tadpoles, but have yet to fully develop the parotoid glands that produce bufotoxin. Only an estimated 0.5% of cane toads reach adulthood, in part because they lack this key defense - but also due to tadpole cannibalism. Although cannibalism does occur in the native population in South America, the rapid evolution occurring in the unnaturally large population in Australia has produced tadpoles 30x more likely to be interested in cannibalising their siblings, and 2.6x more likely to actually do so.  They have also evolved to shorten their tadpole phase in response to the presence of older tadpoles. These changes are likely genetic, although no genetic basis has been determined.
As with rates of growth, the point at which the toads become sexually mature varies across different regions. In New Guinea, sexual maturity is reached by female toads with a snout–vent length between 70 and 80 mm (2.8 and 3.1 in), while toads in Panama achieve maturity when they are between 90 and 100 mm (3.5 and 3.9 in) in length. In tropical regions, such as their native habitats, breeding occurs throughout the year, but in subtropical areas, breeding occurs only during warmer periods that coincide with the onset of the wet season.
The cane toad is estimated to have a critical thermal maximum of 40–42 °C (104–108 °F) and a minimum of around 10–15 °C (50–59 °F). The ranges can change due to adaptation to the local environment. Cane toads from some populations can adjust their thermal tolerance within a few hours of encountering low temperatures. The toad is able to rapidly acclimate to the cold using physiological plasticity, though there is also evidence that more northerly populations of cane toads in the United States are better cold-adapted than more southerly populations. These adaptations have allowed the cane toad to establish invasive populations across the world. The toad’s ability to rapidly acclimate to thermal changes suggests that current models may underestimate the potential range of habitats that the toad can populate. The cane toad has a high tolerance to water loss; some can withstand a 52.6% loss of body water, allowing them to survive outside tropical environments.


The skin of the adult cane toad is toxic, as well as the enlarged parotoid glands behind the eyes, and other glands across its back. When the toad is threatened, its glands secrete a milky-white fluid known as bufotoxin. Components of bufotoxin are toxic to many animals; even human deaths have been recorded due to the consumption of cane toads.  Dogs are especially prone to be poisoned by licking or biting toads. Pets showing excessive drooling, extremely red gums, head-shaking, crying, loss of coordination, and/or convulsions require immediate veterinary attention.
Bufotenin, one of the chemicals excreted by the cane toad, is classified as a schedule 9 drug under Australian law, alongside heroin and LSD. The effects of bufotenin are thought to be similar to those of mild poisoning; the stimulation, which includes mild hallucinations, lasts less than an hour. As the cane toad excretes bufotenin in small amounts, and other toxins in relatively large quantities, toad licking could result in serious illness or death.
In addition to releasing toxin, the cane toad is capable of inflating its lungs, puffing up, and lifting its body off the ground to appear taller and larger to a potential predator.
Since 2011, experimenters in the Kimberley region of Western Australia have used poisonous sausages containing toad meat in an attempt to protect native animals from cane toads' deadly impact. The Western Australian Department of Environment and Conservation, along with the University of Sydney, developed these sausage-shaped baits as a tool in order to train native animals not to eat the toads. By blending bits of toad with a nausea-inducing chemical, the baits train the animals to stay away from the amphibians.


Abudefduf saxatilis is found in the Atlantic Ocean. Populations in the western part of the Atlantic Ocean are found from the north eastern coast of the United States south to the Gulf of Mexico, the Bahamas, islands around the Caribbean Sea, the eastern coast of Central and South America all the way to Uruguay. In the eastern Atlantic Ocean, they are found from Portugal, Azores, the Canary Islands, Cape Verde, and western Africa. Juveniles are common in tide pools while adults are found over coral reefs. Sergeant majors are found at depths of 0 to 40 metres (0 to 131 ft). It has been recorded in the Mediterranean Sea in both eastern and western areas, it was originally thought to be the Red Sea species Abudefduf vaigiensis which was thought to be a Lessepsian migrant from the Red Sea through the Suez Canal but it has been found that the majority, if not all, of the specimens from the Mediterranean are of A. saxatilis.


This fish feed upon the larvae of invertebrates, zooplankton, smaller fish, crustaceans, and various species of algae. It is also known to feed on the waste and vomit of spinner dolphins.


Predators of this fish include Plectropomus leopardus, Thalassoma bifasciatum, Cephalopholis cruentata, Epinephelus striatus, Mycteroperca venenosa, and Rachycentron canadum.


The sergeant major or píntano (Abudefduf saxatilis) is a species of damselfish. It grows to a maximum length of about 22.9 centimetres (9.0 in).


The yellow-bellied marmot lives in southwestern Canada and western United States, including the Rocky Mountains and the Sierra Nevada. Northwards, its range extends into the southern British Columbia and goes eastwards up to the montane and basin regions of Wyoming, eastern Montana, Colorado, and southern Alberta. Southwards, its range extends into northern New Mexico. It inhabits steppes, meadows, talus fields, and other open habitats, sometimes on the edge of deciduous or coniferous forests. In Colorado, they are found from as low as 1,600 m (5,400 ft) to over 4,300 m (14,000 ft) of elevation. In central and eastern Washington, they are common at low elevations.
They are found in valleys, meadows, and foothills, and tend to occupy open areas which are free of vegetation. Their territory is about 2.5 hectares (6 acres) around a number of burrows dug during the summer. They choose to dig burrows under rocks, as it is less likely to be visible to predators. These predators include foxes, dogs, coyotes, wolves, and eagles. Upon seeing a predator, the yellow-bellied marmot whistles to warn the others in the area, after which it typically hides in a nearby rock pile until there is no more threat.


The yellow-bellied marmot (Marmota flaviventris), also known as the rock chuck, is a large, stout-bodied ground squirrel in the marmot genus. It is one of fourteen species of marmots, and is native to mountainous regions of southwestern Canada and western United States, including the Rocky Mountains, Sierra Nevada, and Mount Rainier in the state of Washington, typically living above 2,000 metres (6,500 feet). The fur is mainly brown, with a dark bushy tail, yellow chest and white patch between the eyes, and they weigh up to approximately 5 kilograms (11 pounds). They live in burrows in colonies of up to twenty individuals with a single dominant male. They are diurnal and feed on plant material, insects, and bird eggs. They hibernate for approximately eight months starting in September and lasting through the winter.


Marmots reproduce starting at around two years of age, and may live up to an age of fifteen. They reside in colonies of about ten to twenty individuals. Each male marmot digs a burrow soon after it wakes from hibernation, and starts looking for females to reproduce. By summer, it may have up to four female mates. Litters usually average three to five offspring per female. Only about half of those pups survive and become yearlings. Marmots have a "harem-polygynous" mating system in which the male reproduces with two or three females at the same time. Female offspring tend to stay in the area around their home, while male offspring typically leave when they are yearlings and will defend one or more females.
Yellow-bellied marmots spend about 80% of their lives in their burrows, 60% of which is spent hibernation. They often spend mid-day and night in a burrow as well. These burrows are usually constructed on a slope, such as a hill, mountain, or cliff. The hibernating burrows can be up to 5–7 m (16–23 ft) deep; however, the burrows constructed for daily use are usually only 1 m (3 ft 3 in) deep. Their hibernation period varies on elevation, but it is typically from September to May. Occasionally, they climb trees and other flora, though they are usually terrestrial.


Although tolerant of most conditions, common carp prefer large bodies of slow or standing water and soft, vegetative sediments. As schooling fish, they prefer to be in groups of five or more. They naturally live in temperate climates in fresh or slightly brackish water with a pH of 6.5–9.0 and salinity up to about 0.5%, and temperatures of 3 to 35 °C (37–95 °F). The ideal temperature is 23 to 30 °C (73–86 °F), with spawning beginning at 17 to 18 °C (63–64 °F); they easily survive winter in a frozen-over pond, as long as some free water remains below the ice. Carp are able to tolerate water with very low oxygen levels, by gulping air at the surface.


The Eurasian or European carp (Cyprinus carpio), formerly known as the common carp, is a widespread freshwater fish of eutrophic waters in lakes and large rivers in Europe and Asia. The native wild populations are considered vulnerable to extinction by the International Union for Conservation of Nature (IUCN), but the species has also been domesticated and introduced (see aquaculture) into environments worldwide, and is often considered a destructive invasive species, being included in the list of the world's 100 worst invasive species. It gives its name to the carp family, Cyprinidae.


Common carp are omnivorous. They can eat a herbivorous diet of aquatic plants, but prefer to scavenge the bottom for insects, crustaceans (including zooplankton), crawfish, and benthic worms. Common carp feed throughout the day with the most intensive feeding at night and around sunrise.


A single carp can lay over a million eggs in a year. Eggs and fry often fall victim to bacteria, fungi, and the vast array of tiny predators in the pond environment. Carp which survive to juvenile are preyed upon by other fish such as the northern pike and largemouth bass, and several birds (including cormorants, herons, goosanders, and ospreys) and mammals (including otter and mink).


The carp has a robust build, with a dark gold sheen most prominent on its head. Its body is adorned with large conspicuous scales that are very shiny. It has large pectoral fins and a tapering dorsal fin running down the last two thirds of its body, getting progressively higher as it nears the carp’s head. Its caudal and anal fins may either be a dark bronze or washed with a rubbery orange hue. The mouth of the carp is downwards-turned, with two pairs of barbels, the ones on the bottom being larger. Wild common carp are typically slimmer than domesticated forms, with body length about four times body height, red flesh, and a forward-protruding mouth. Common carp can grow to very large sizes if given adequate space and nutrients. Their average growth rate by weight is about half the growth rate of domesticated carp They do not reach the lengths and weights of domesticated carp, which (range, 3.2–4.8 times) can grow to a maximum length of 120 centimetres (47 in), a maximum weight of over 40 kilograms (88 lb), and an oldest recorded age of 38 years. The largest recorded carp, caught by British angler, Colin Smith, in 2013 at Etang La Saussaie Fishery, France, weighed 45.59 kilograms (100.5 lb). The average size of the common carp is around 40–80 cm (16–31 inches) and 2–14 kg (4.4–30.9 lb).


The magpie perch is found in Australia and New Zealand. In Australia is can be found from Albany, Western Australia along the southern coast and northwards on the eastern coast as far as Sydney, it can also be found off the islands in the Bass Strait and northern Tasmania. The epipelagic larvae and small juveniles drift with the currents from Australia across the Tasman Sea accounting for the infrequent records from northern and eastern New Zealand. It can be found on sheltered and exposed coastal reefs, often encountered in caves and below overhangs, at depths between 0 to 25 m (0 to 82 ft).


The magpie perch feeds on benthic invertebrates which it draws through its mouth by sucking them up from the sediment and from algal turfs. They often use caves and overhangs to shelter in, frequently as small groups.


The magpie perch has a robust, oval, compressed body The dorsal profile of the head is concave and there is a pair of small bony protuberances in front of the eyes. It has thick, fleshy lips. The ventral pectoral fin rays are robust and elongated. The dorsal fin contains 18 spines and 24-28 soft rays while the anal fin has 3 spines and 10 soft rays. The magpie perch attains a maximum total length of 41 cm (16 in).Thisfish is marked with three wide black bands, the first is on the head, the second girdles the body to the rear of the head and the third runs from the anal fin to the soft rayed part of the dorsal fin. In some individuals the central band is dark and in others it is pale grey. The juveniles have a reddish tail which darkens as they mature. The magpie morwong is able to change its appearance by "turning off" its central black band almost instantly.


They can be found in the Ochlocknee River and waters east and in peninsular Florida in medium to large lowland streams, canals, and lakes with muddy or sandy bottoms near underwater vegetation. They are often found in medium to shallow waters.  They use an air bladder to breathe air which helps them survive in poorly oxygenated water.
they sometimes will hide in weeds in 4-10 feet. usually when you find them here, they will have there head in the weeds and will only show a small portion of the body. some times they will be hiding on the edge of weeds. here they will be about 6-10 inches below the surface. usually the bottom will be 10 feet or more.


The Florida gar (Lepisosteus platyrhincus) is a species of gar found in the US from the Savannah River and Ochlockonee River watersheds of Georgia and throughout peninsular Florida. Florida gar can reach a length over 3 ft (91 cm). The young feed on zooplankton and insect larvae, as well as small fish. Adults mainly eat fish, shrimp, and crayfish. Although edible, they are not popular as food. The roe is highly toxic to many animals, including humans and birds.


This is a mid-sized species of gar. It measures from 51.7 to 132.2 cm (20.4 to 52.0 in) long and typically weighs 1.36 to 4.36 kg (3.0 to 9.6 lb). According to the IGFA, the record weight for this species is 10 kg (22 lb). This species has irregular round, black spots on the top of its head and over the entire body including the anal fin. The distance of the eyes is less than two-thirds the length of the snout. Also, it has a shorter, broad snout with a single row of irregularly spaced sharp teeth on the upper and lower jaws. No bony scales are on the throat. Their color is olive-brown on the back and upper sides, with a white to yellow belly. The young may have dark stripes on the back and sides.


The banded mongoose (Mungos mungo) is a mongoose species native from the Sahel to Southern Africa. It lives in savannas, open forests and grasslands and feeds primarily on beetles and millipedes. Mongooses use various types of dens for shelter including termite mounds. While most mongoose species live solitary lives, the banded mongoose live in colonies with a complex social structure.


Banded mongooses live in mixed-sex groups of 7–40 individuals with an average of around 20 individuals. Groups sleep together at night in underground dens, often abandoned termite mounds, and change dens frequently (every 2–3 days). When no refuge is available and hard-pressed by predators such as African wild dogs, the group will form a compact arrangement in which they lie on each other with heads facing outwards and upwards.There is generally no strict hierarchy in mongoose groups and aggression is low. Sometimes, mongooses may squabble over food. However, typically, the one who claims the food first wins. Most aggression and hierarchical behavior occurs between males when females are in oestrus. Female are usually not aggressive but do live in hierarchies based on age. The older females have earlier estrous periods and have larger litters. When groups get too large, some females are forced out of the group by either older females or males. These females may form new groups with subordinate males.
Relations between groups are highly aggressive and mongooses are sometimes killed and injured during intergroup encounters. Nevertheless, breeding females will often mate with males from a rival groups during fights. Mongooses establish their territories with scent markings that may also serve as communication between those in the same group. In the society of the banded mongoose there is a clear separation between mating rivals and territorial rivals. Individuals within groups are rivals for mates while those from neighboring groups are competitors for food and resources.


The banded mongoose is found in a large part of East, Southeast and South-Central Africa. There are also populations in the northern savannas of West Africa. The banded mongoose lives in savannas, open forests and grassland, especially near water, but also in dry, thorny bushland but not deserts. The species uses various types of dens for shelter, most commonly termite mounds. They will also live in rock shelters, thickets, gullies, and warrens under bushes. Mongooses prefer multi-entranced termitaria with open thicket, averaging 4 m from the nearest shelter, located in semi-closed woodland. In contrast to the den of the dwarf mongoose, banded mongoose dens are less dependent on vegetation cover and have more entrances. Banded mongooses live in larger groups than dwarf mongooses and thus more entrances means more members have access to the den and ventilation. The development of agriculture in the continent has had a positive influence on the number of banded mongooses. The crops of the farmland serve as an extra food source.
The banded mongoose lives in many of Africa's protected areas. The Serengeti of Tanzania, has a density of around three mongooses per km². In southern KwaZulu-Natal, mongoose numbers are at a similar density at 2.4 km². Queen Elizabeth National Park has much higher mongoose densities at 18/km².


Unlike most other social mongoose species, all females in a banded mongoose group can breed. They all enter oestrus around 10 days after giving birth, and are guarded and mated by 1–3 dominant males. The dominant males monitor the females and aggressively defend them from subordinates. While these males do most of the mating, the females often try to escape from them and mate with other males in the group.  A dominant male will spend 2–3 days guarding each female. A guarding male will snap at, lunge at or pounce on any males that come near. A non-guarding male may follow a guarding male and his female and may face this aggression. Non-guarding males mate in a more secretive way. This kind of "sneaking" behavior is similar to what subordinate males of the fish species Neolamprologus pulcher do; they also try to mate with females that are guarded by the dominant males.
Gestation is 60–70 days. In most breeding attempts, all females give birth either on the same day or within a few days. Litters range 2–6 pups and average 4. For the first four weeks of life, pups stay in the dens where they form an exclusive relationship with a single helper or escort, whose genetic relationship with the pups is unknown. These helpers are generally young nonbreeding males or breeding females who have contributed to the current litter and they help to minimize competition over food allocation among pups. During this time they are guarded by these helpers while the other group member go on their foraging trips. After four weeks, the pups are able to go foraging themselves. Each pup is cared for by a single adult "escort" who helps the pup to find food and protects it from danger. Pups become nutritionally independent at three months of age.


The American pika can be found throughout the mountains of western North America, from central British Columbia and Alberta in Canada to the US states of Oregon, Washington, Idaho, Montana, Wyoming, Colorado, Utah, Nevada, California, and New Mexico. Of the 30 existing species of pika, it is one of only two which inhabit North America, along with the collared pika (O. collaris). In relation to the distribution of the American pika, the collared pika is located farther north of those regions and is separated by a gap of about 500 miles (800 km) extending across British Columbia and Alberta.
Pikas inhabit talus fields that are fringed by suitable vegetation on alpine areas. They also live in piles of broken rock.  Sometimes, they live in man-made substrate such as mine tailings and piles of scrap lumber. Pikas usually have their den and nest sites below rock around 0.2–1 m in diameter, but often sit on larger and more prominent rocks. They generally reside in scree near or above the tree line. Pikas are restricted to cool, moist microhabitats on high peaks or watercourses. Intolerant of high diurnal temperatures, in the northern portion of their range, they may be found near sea level, but in the south they are rare below 2,500 m (8,200 ft). Pikas rely on existing spaces in the talus for homes and do not dig burrows. However, they can enlarge their homes by digging.


The American pika is a generalist herbivore. It eats a large variety of green plants, including different kinds of grasses, sedges, thistles, and fireweed. Although a pika can meet its water demand from the vegetation eaten, it does drink water if it is available in its environment.
Pikas have two different ways of foraging; they directly consume food (feeding) or they cache food in haypiles to use for a food source in the winter (haying). They feed throughout the year while haying is limited to the summer. Since they do not hibernate, pikas have greater energy demands than other montane mammals. They also make 13 trips per hour to collect vegetation when haying, up to a little over 100 trips per day. The timing of haying seems to correlate to the amount of precipitation from the previous winter. Pikas start and then quit haying earlier in years following little snow and early spring. In areas at lower elevations, haying begins before the snow has melted at high altitudes; at higher elevations, haying continues after it ends in lower elevations.
When haying, pikas harvest plants in a deliberate sequence, corresponding to their seasonal phenology. They seem to assess the nutritional value of available food and harvest accordingly. Pikas select plants that have the higher caloric, protein, lipid, and water content. Forbs and tall grass tend to be hayed more than eaten directly. Haypiles tend to be stored under the talus near the talus-meadow interface, although they may be constructed on the talus surface. Males generally store more vegetation than females and adults usually store more than juveniles. Pikas deposit two kinds of fecal droppings: Hard, brown, round pellets and pellets that are soft black shiny strings that form in the caecum. Caecal pellets have more energy value than stored plant food and the pika may consume them directly or store them for later.


The American pika (Ochotona princeps), a diurnal species of pika, is found in the mountains of western North America, usually in boulder fields at or above the tree line. They are herbivorous, smaller relatives of rabbits and hares. Pikas have two different ways of foraging; they either directly consume food or they cache food in piles for the winter (haying).
Pikas are vocal, using both calls and songs to warn when predators are nearby and during the breeding season. Predators of the pika include eagles, hawks, coyotes, bobcats, foxes, and weasels.
Recent studies suggest some populations are declining due to habitat loss and global warming. They generally cannot tolerate temperatures above 25.5 °C (77.9 °F). Currently the American pika is considered a species of least concern.


The American Pika is diurnal. The total area of land that an American Pika uses is known as a home range. About 55% of its home range is territory that the Pika defends against intruders. Territory size can vary from 410–709 m² and is dependent on configuration, distance to vegetation, and quality of vegetation. The home ranges of Pikas may overlap, with the distances of the home ranges of a mating pair being shorter than that of the nearest neighbors of the same sex. Spatial distances between adults of a pair is greatest during early and midsummer and reduces during late summer and early autumn. Pikas defend their territories with aggression. Actual aggressive encounters are rare and usually occur between members of the same sex and those unfamiliar with each other. A Pika may intrude on another's territory, but usually when the resident is not active. During haying, territorial behavior increases.
Adult Pikas of the opposite sex with territories adjacent form mated pairs. When more than one male is available, females exhibit mate choice.  Pikas are reflex ovulators; ovulation only occurs after copulation, and they are also seasonally polyestrous. A female has two litters per year and these litters average three young each. Breeding takes place one month before the snow melts and gestation lasts around 30 days. Parturition occurs as early as March in lower elevations, but occurs from April to June at higher elevations. Lactation significantly reduces a female's fat reserves and they only nurse the second litter if the first does not survive, despite exhibiting postpartum estrus. Pikas are born slightly altricial, being blind, slightly haired, and having fully erupted teeth. They weigh between 10 and 12 g at birth. At around nine days old, they are able to open their eyes. Mothers forage most of the day and return to the nest once every two hours to nurse the young. Young become independent after four weeks, around the same time they are weaned. Young may remain in their natal or an adjoining home range. When in their home range, young occupy areas away from their relatives as much as possible. Dispersal appears to be caused by competition for territories.
Pikas are vocal, using both calls and songs to communicate among themselves. A call is used to warn when a predator is lurking nearby, and a song is used during the breeding season (males only), and during autumn (both males and females). Predators of the Pika include eagles, hawks, coyotes, bobcats, foxes, and weasels.


The Sierra newt, with scientific name Taricha sierrae, is a newt found west of the Sierra Nevada, from Shasta county to Tulare County, in California, Western North America.
Its adult length can range from 5 to 8 in (13 to 20 cm). Its skin produces a potent toxin.


Sierra newts exist primarily in the Sierra Nevada, because they prefer less humid climates than the rough-skinned newts. Outside the breeding season, the newts are land-dwelling, preferring rock crevices and logs.


The closely related Taricha torosa, the California newt, is currently a California Special Concern species (DFG-CSC). Some populations have been greatly reduced in southern California coastal streams due to the introduction of non-native, invasive species and human habitation. The mosquitofish (Gambusia affinis) and red swamp crayfish (Procambarus clarkii) have caused the greatest reduction in newt populations.


Reproduction occurs generally between December and early May. Typically, the adult newts will return to the pool in which they hatched. After a mating dance, the male mounts the female and rubs his chin on her nose. He then attaches a spermatophore to the substrate, which she will retrieve into her cloaca.
The egg mass released by the female contains between seven and 30 eggs, and is roughly the consistency of a thick gelatin dessert.  Typically, the egg masses are attached to stream plant roots or to rocky crevices in small, pools of slow-moving water, but they have also been known to be attached to underwater rocks or leaf debris. While shallow in a wide sense, these pools are rather deep relative to the average depth of a Southern California stream, varying in depth from about 1–2 metres (3.3–6.6 ft).
Adult newts will stay in the pools throughout the breeding season, and can be occasionally found well into the summer. Larvae hatch sometime in early to midsummer, depending on local water temperature. Larvae are difficult to find in streams, as they blend in well with the sandy bottom, to which they usually stay close.


Like other genus Taricha members, the glands in the skin of Taricha sierrae secrete the potent neurotoxin tetrodotoxin, which is hundreds of times more toxic than cyanide. This is the same toxin found in pufferfish and harlequin frogs. Researchers believe bacteria synthesize tetrodotoxin, and the animals that employ the neurotoxin acquire it through consumption of these bacteria. This neurotoxin is strong enough to kill most vertebrates, including humans. However, it is dangerous only if ingested.
Due to their toxicity, Sierra newts have few natural predators. Garter snakes are the most common, and some species have developed a genetic resistance to tetrodotoxin. The mutations in the snake's genes that conferred resistance to the toxin have resulted in a selective pressure that favors newts that produce more potent levels of toxin. Increases in newt toxicity then apply a selective pressure favoring snakes with mutations conferring even greater resistance. This evolutionary arms race has resulted in the newts producing levels of toxin far in excess of what is needed to kill any other conceivable predator.


The common eland (Taurotragus oryx), also known as the southern eland or eland antelope, is a savannah and plains antelope found in East and Southern Africa. It is a species of the family Bovidae and genus Taurotragus. An adult male is around 1.6 metres (5') tall at the shoulder (females are 20 centimetres (8") shorter) and can weigh up to 942 kg (2,077 lb) with an average of 500–600 kg (1,100–1,300 lb), 340–445 kg (750–981 lb) for females). It is the second largest antelope in the world, being slightly smaller on average than the giant eland. It was scientifically described by Peter Simon Pallas in 1766.
Mainly an herbivore, its diet is primarily grasses and leaves. Common elands form herds of up to 500 animals, but are not territorial. The common eland prefers habitats with a wide variety of flowering plants such as savannah, woodlands, and open and montane grasslands; it avoids dense forests. It uses loud barks, visual and postural movements and the flehmen response to communicate and warn others of danger. The common eland is used by humans for leather, meat and milk, and has been domesticated in many areas. Eland milk contains more butterfat than cow milk, and can keep longer without pasteurising.
It is native to Angola, Botswana, the Democratic Republic of the Congo, Eswatini, Ethiopia, Kenya, Lesotho, Malawi, Mozambique, Namibia, Rwanda, South Africa, South Sudan, Tanzania, Uganda, Zambia and Zimbabwe but is no longer present in Burundi. While the common eland's population is decreasing, it is classified as of Least Concern by the International Union for Conservation of Nature (IUCN).


Common elands are nomadic and crepuscular. They eat in the morning and evening, rest in shade when hot and remain in sunlight when cold. They are commonly found in herds of up to 500, with individual members remaining in the herd anywhere from several hours to several months. Juveniles and mothers tend to form larger herds, while males may separate into smaller groups or wander individually. During estrus, mainly in the rainy season, groups tend to form more regularly. In southern Africa common elands will often associate with herds of zebras, roan antelopes and oryxes.
Common elands communicate via gestures, vocalizations, scent cues and display behaviors. The flehmen response also occurs, primarily in males in response to contact with female urine or genitals. Females will urinate to indicate fertility during the appropriate phase of their estrous cycle, as well as to indicate their lack of fertility when harassed by males. If eland bulls find any of their predators nearby, they will bark and attempt to attract the attention of others by trotting back and forth until the entire herd is conscious of the danger. Some of their main predators include lions, African wild dogs, cheetahs and spotted hyenas. Juvenile elands are more vulnerable than adults to their predators.


Females are sexually mature at 15–36 months and males at 4–5 years. Mating may occur anytime after reaching sexual maturity, but is mostly seen in the rainy season. In Zambia, young are born in July and August, while elsewhere it is the mating season. Mating begins when elands gather to feed on lush green plains with plentiful grass, and some males and females start mating with each other in separate pairs. Males chase the females to find out if they are in estrus. They also test the female's urine. Usually, a female chooses the most dominant and fit male to mate with. Sometimes she runs away from males trying to mate, causing more attraction. This results in fights between males, in which their hard horns are used. It is 2–4 hours before a female allows a male to mount. Males usually keep close contact with females in the mating period. The dominant male can mate with more than one female. Females have a gestation period of 9 months, and give birth to only one calf each time.
Males, females and juveniles each form separate social groups. The male groups are the smallest; the members stay together and search for food or water sources. The female group is much larger and covers greater areas. They travel the grassy plains in wet periods and prefer bushy areas in dry periods. Females have a complex linear hierarchy. The nursery and juvenile group is naturally formed when females give birth to calves. After about 24 hours of the delivery, the mother and calf join this group. The calves start befriending each other and stay back in the nursery group while the mother returns to the female group. The calves leave the nursery group when they are at least two years old and join a male or female group.


Common elands are spiral-horned antelopes. They are sexually dimorphic, with females being smaller than the males. Females weigh 300–600 kg (660–1,320 lb), measure 200–280 cm (79–110 in) from the snout to the base of the tail and stand 125–153 cm (49–60 in) at the shoulder. Bulls weigh 400–942 kg (882–2,077 lb), are 240–345 cm (94–136 in) from the snout to the base of the tail and stand 150–183 cm (59–72 in) at the shoulder. The tail is 50–90 cm (20–35 in) long. Male elands can weigh up to 1,000 kg (2,200 lb).
Their coat differs geographically, with elands in northern part of their range having distinctive markings (torso stripes, markings on legs, dark garters and a spinal crest) that are absent in the south. Apart from a rough mane, the coat is smooth. Females have a tan coat, while the coats of males are darker, with a bluish-grey tinge. Bulls may also have a series of vertical white stripes on their sides (mainly in parts of the Karoo in South Africa). As males age, their coat becomes more grey. Males also have dense fur on their foreheads and a large dewlap on their throats.
Both sexes have horns with a steady spiral ridge (resembling that of the bushbuck). The horns are visible as small buds in newborns and grow rapidly during the first seven months. The horns of males are thicker and shorter than those of females (males' horns are 43–66 centimetres (17–26 in) long and females' are 51–69 centimetres (20–27 in) long), and have a tighter spiral. Males use their horns during rutting season to wrestle and butt heads with rivals, while females use their horns to protect their young from predators.
The common eland is the slowest antelope, with a peak speed of 40 kilometres (25 mi) per hour that tires them quickly. However, they can maintain a 22 kilometres (14 mi) per hour trot indefinitely. Elands are capable of jumping up to 2.5 metres (8 ft 2 in) from a standing start when startled (up to 3 metres (9.8 ft) for young elands). The common eland's life expectancy is generally between 15 and 20 years; in captivity some live up to 25 years.
Eland herds are accompanied by a loud clicking sound that has been subject to considerable speculation. It is believed that the weight of the animal causes the two halves of its hooves to splay apart, and the clicking is the result of the hoof snapping together when the animal raises its leg. The sound carries some distance from a herd, and may be a form of communication.


The southern leopard frog (Lithobates sphenocephalus or Rana sphenocephala) is a medium sized anuran in the family Ranidae (The True Frogs). It is native to eastern North America from Kansas to New York to Florida. It is also an introduced species in some areas. This species lives in cool, clear water in the north, whereas in the south it occurs in warmer turbid and murky waters of coastal and floodplain swamps, twilight zones of caves, and abandoned mines.


This frog is up to 13 cm long. It is green or brown in color with a yellowish ridge along each side of the back. Rounded dark spots occur on the back and sides; a light spot is seen on each eardrum. The male has larger fore limbs than the female. The breeding male's vocal sacs are spherical when inflated. The call is described as a "ratchetlike trill", "chuckling croak", or a "squeaky balloon-like sound".
The larva is mottled, and the eyes are positioned on the top of the head. It grows to 7.6 cm in length before maturing. The female lays an egg mass that is "baseball-sized" when close to hatching time, and contains up to 1500 eggs.


The bowfin (Amia calva) is a bony fish, native to North America. Common names include mudfish, mud pike, dogfish, grindle, grinnel, swamp trout, and choupique. It is regarded as a relict, being the sole surviving species of the Halecomorphi, a group of fish that first appeared during the Early Triassic, around 250 million years ago. The bowfin is often considered a "primitive fish" because they have retained some morphological characteristics of their early ancestors. The closest living relatives of bowfins are gars, with the two groups being united in the clade Holostei.
Bowfins are demersal freshwater piscivores, commonly found throughout much of the eastern United States, and in southern Ontario and Quebec. Fossil deposits indicate Amiiformes were once widespread in both freshwater and marine environments  across North and South America, Europe, Asia, and Africa. Now, their range is limited to much of the eastern United States and adjacent southern Canada, including the drainage basins of the Mississippi River, Great Lakes, and various rivers exiting in the Eastern Seaboard or Gulf of Mexico. Their preferred habitat includes vegetated sloughs, lowland rivers and lakes, swamps, and backwater areas; they are also occasionally found in brackish water. They are stalking, ambush predators known to move into the shallows at night to prey on fish and aquatic invertebrates such as crawfish, mollusks, and aquatic insects.
Like gars, bowfin are bimodal breathers – they have the capacity to breathe both water and air. Their gills exchange gases in the water allowing them to breathe, but they also have a gas bladder that serves to maintain buoyancy, and also allows them to breathe air by means of a small pneumatic duct connected from the foregut to the gas bladder. They can break the surface to gulp air, which allows them to survive conditions of aquatic hypoxia that would be lethal to most other species.


A common parasite of bowfin is the anchor worm (Lernaea). These small crustaceans infest the skin and bases of fins, with consequences ranging from slowed growth to death. The mollusk Megalonaias gigantea lays eggs in the bowfin gills, that are then externally fertilized by sperm passing in the water flow. The small glochidia larvae then hatch and develop in the gill tubes.
Bowfin with liver cancer and with fatal leukemia have been reported.


Bowfin spawn in the spring or early summer, typically between April and June, more commonly at night in abundantly vegetated, clear shallow water in weed beds over sand bars, and also under stumps, logs, and bushes.
Optimum temperatures for nesting and spawning range between 16–19 °C (61–66 °F). The males construct circular nests in fibrous root mats, clearing away leaves and stems. Depending on the density of surrounding vegetation there may be a tunnel-like entrance at one side. The diameter of the nests commonly range between 39–91 cm (15–36 in), at a water depth of 61–92 cm (24–36 in).
During spawning season, the fins and underside of male bowfin often change in color to a bright lime green. The courtship/spawning sequence lasts one to three hours, and can repeat up to five times. Courtship begins when a female approaches the nest. The ritual consists of intermittent nose bites, nudges, and chasing behavior by the male until the female becomes receptive, at which time the pair lie side by side in the nest. She deposits her eggs while he shakes his fins in a vibratory movement, and releases his milt for fertilization to occur. A male often has eggs from more than one female in his nest, and a single female often spawns in several nests.
Females vacate the nest after spawning, leaving the male behind to protect the eggs during the eight to ten days of incubation. A nest may contain 2,000 to 5,000 eggs, possibly more. Fecundity is usually related to size of the fish, so it isn't unusual for the roe of a large gravid female to contain over 55,000 eggs. Bowfin eggs are adhesive, and will attach to aquatic vegetation, roots, gravel, and sand. After hatching, larval bowfin do not swim actively in search of food. During the seven to nine days required for yolk-sac absorption, they attach to vegetation by means of an adhesive organ on their snout, and remain protected by the parent male bowfin. Bowfin aggressively protect their spawn from the first day of incubation to a month or so after the eggs have hatched. When the fry are able to swim and forage on their own, they will form a school and leave the nest accompanied by the parent male bowfin who slowly circles them to prevent separation.
Bowfin reach sexually maturity at two to three years of age. They can live ten to twelve years in the wild, and 30 years in captivity. Females are longer-lived than males.


In some areas of the United States where aquatic environments have tested positive for elevated levels of toxins, such as mercury, arsenic, chromium, and copper, there are posted signs with warnings about the consumption of fish caught in those areas. Concentration of mercury biomagnifies as it passes up the food chain from organisms on lower trophic levels to apex predators. It bioaccumulates in the tissues of larger, long-lived predatory fish. When compared to smaller, short-lived fish, bowfin tend to concentrate mercury at higher levels thereby making them less safe for human consumption.


The typical length of a bowfin is 50 cm (20 in); females typically grow to 65–70 cm (26–28 in), males to 50–65 cm (20–26 in). They can reach 109 cm (43 in) in length, and weigh 9.75 kg (21.5 lb). Young of the year typically grow to 13–23 cm (5.1–9.1 in) by October. Females tend to grow larger than males.
The body of the bowfin is elongated and cylindrical, with the sides and back olive to brown in color, often with vertical bars and dark reticulations or another camouflaged pattern. The dorsal fin has horizontal bars, and the caudal fin has irregular vertical bars. The underside is white or cream, and the paired fins and anal fin are bright green. During larval stage, hatchlings from about 7–10 mm (0.28–0.39 in) total length are black and tadpole-like in appearance. At approximately 25 mm (0.98 in) total length they have been described as looking like miniature placoderms. They grow quickly, and typically leave the nest within 4 to 6 weeks after hatching. Young males have a black eyespot on the base of the tail (caudal peduncle) that is commonly encircled by an orange-yellowish border, while the female's is black, if present at all. It is thought the purpose of the eyespot is to confuse predators, deflecting attacks away from the head of the fish to its tail, which affords the bowfin an opportunity to escape predation. The bowfin is so named for its long, undulating dorsal fin consisting of 145 to 250 rays that runs from the middle of the back to the base of the tail.
The skull of the bowfin is made of two layers of skull, the dermatocranium and the chondrocranium. The chondrocranium layer cannot be seen because it is located below the dermal bones. The bowfin skull is made up of 28 fused bones, which compose the dermatocranium. The roof of the mouth is made up of three bones, the ectopterygoid, the palantine, and the vomer. They have two sets of teeth, including one set of larger sharp teeth coming out of the mandibular and premaxillary bones to grasp and control the prey. The other set of teeth, located posteriorly and connected to the hyomandibular bone, is made up of pharyngeal tooth patches, which are used for sorting out nutrients and grinding down larger pieces of food.   Another three bones make up the lower jaw: the dentary, the angular, and the surangular. The cranial surface of the skull is made up of the nasals, the antorbital, the lacrimal, the parietal, the intertemporal, the post parietal, the supratemporal, the extra scapular, the post temporal, and the opercular. The entirety of the skull is attached to the girdle through another set of bones.
Bowfin are often referred to as "living fossils", or "primitive fish" because they retained some of the primitive characters common to their ancestors, including a modified (rounded externally) heterocercal caudal fin, a highly vascularized gas bladder lung, vestiges of a spiral valve, and a bony gular plate. The bony gular plate is located underneath the head on the exterior of the lower jaw between the two sides of the lower jaw bone. Other distinguishing characteristics include long, sharp teeth, and two protruding tube-like nostrils. Unlike all of the most primitive actinopterygians, the scales of bowfin differ in that they are not ganoid scales, rather they are large, single-layered cycloid scales closer in similarity to more derived teleosts.


The platypus is semiaquatic, inhabiting small streams and rivers over an extensive range from the cold highlands of Tasmania and the Australian Alps to the tropical rainforests of coastal Queensland as far north as the base of the Cape York Peninsula.
Inland, its distribution is not well known. It was considered extinct on the South Australian mainland, with the last sighting recorded at Renmark in 1975, until some years after John Wamsley had created Warrawong Sanctuary (see below) in the 1980s, setting a platypus breeding program there, and it had subsequently closed. In 2017 there were some unconfirmed sightings downstream, outside the sanctuary, and in October 2020 a nesting platypus was filmed inside the recently reopened sanctuary. There is a population on Kangaroo Island introduced in the 1920s, which was said to stand at 150 individuals in the Rocky River region of Flinders Chase National Park before the 2019–20 Australian bushfire season, in which large portions of the island burnt, decimating all wildlife. However, with the SA Department for Environment and Water recovery teams working hard to reinstate their habitat, there had been a number of sightings reported by April 2020.
The platypus is no longer found in the main part of the Murray-Darling Basin, possibly due to the declining water quality brought about by extensive land clearing and irrigation schemes. Along the coastal river systems, its distribution is unpredictable; it appears to be absent from some relatively healthy rivers, and yet maintains a presence in others, for example, the lower Maribyrnong, that are quite degraded.
In captivity, platypuses have survived to 17 years of age, and wild specimens have been recaptured when 11 years old. Mortality rates for adults in the wild appear to be low. Natural predators include snakes, water rats, goannas, hawks, owls, and eagles. Low platypus numbers in northern Australia are possibly due to predation by crocodiles. The introduction of red foxes in 1845 for hunting may have had some impact on its numbers on the mainland. The platypus is generally regarded as nocturnal and crepuscular, but individuals are also active during the day, particularly when the sky is overcast. Its habitat bridges rivers and the riparian zone for both a food supply of prey species, and banks where it can dig resting and nesting burrows. It may have a range of up to 7 km (4.3 mi), with a male's home range overlapping those of three or four females.
The platypus is an excellent swimmer and spends much of its time in the water foraging for food. It has a very characteristic swimming style and no external ears. Uniquely among mammals, it propels itself when swimming by an alternate rowing motion of the front feet; although all four feet of the platypus are webbed, the hind feet (which are held against the body) do not assist in propulsion, but are used for steering in combination with the tail. The species is endothermic, maintaining its body temperature at about 32 °C (90 °F), lower than most mammals, even while foraging for hours in water below 5 °C (41 °F).
Dives normally last around 30 seconds, but can last longer, although few exceed the estimated aerobic limit of 40 seconds. Recovery at the surface between dives commonly takes from 10 to 20 seconds.
When not in the water, the platypus retires to a short, straight resting burrow of oval cross-section, nearly always in the riverbank not far above water level, and often hidden under a protective tangle of roots.
The average sleep time of a platypus is said to be as long as 14 hours per day, possibly because it eats crustaceans, which provide a high level of calories.


The platypus is a carnivore: it feeds on annelid worms, insect larvae, freshwater shrimp, and freshwater yabby (crayfish) that it digs out of the riverbed with its snout or catches while swimming. It uses cheek-pouches to carry prey to the surface, where it is eaten. The platypus needs to eat about 20% of its own weight each day, which requires it to spend an average of 12 hours daily looking for food.


When the platypus was first encountered by European naturalists, they were divided over whether the female lays eggs. This was finally confirmed by William Hay Caldwell's team in 1884.
The species exhibits a single breeding season; mating occurs between June and October, with some local variation taking place between different populations across its range. Historical observation, mark-and-recapture studies, and preliminary investigations of population genetics indicate the possibility of both resident and transient members of populations, and suggest a polygynous mating system. Females are thought likely to become sexually mature in their second year, with breeding confirmed still to take place in animals over nine years old.
Outside the mating season, the platypus lives in a simple ground burrow, the entrance of which is about 30 cm (12 in) above the water level. After mating, the female constructs a deeper, more elaborate burrow up to 20 m (65 ft) long and blocked at intervals with plugs (which may act as a safeguard against rising waters or predators, or as a method of regulating humidity and temperature). The male takes no part in caring for his young, and retreats to his year-long burrow. The female softens the ground in the burrow with dead, folded, wet leaves, and she fills the nest at the end of the tunnel with fallen leaves and reeds for bedding material. This material is dragged to the nest by tucking it underneath her curled tail.
The female platypus has a pair of ovaries, but only the left one is functional. The platypus's genes are a possible evolutionary link between the mammalian XY and bird/reptile ZW sex-determination systems because one of the platypus's five X chromosomes contains the DMRT1 gene, which birds possess on their Z chromosome. It lays one to three (usually two) small, leathery eggs (similar to those of reptiles), about 11 mm (7⁄16 in) in diameter and slightly rounder than bird eggs. The eggs develop in utero for about 28 days, with only about 10 days of external incubation (in contrast to a chicken egg, which spends about one day in tract and 21 days externally). After laying her eggs, the female curls around them. The incubation period is divided into three phases. In the first phase, the embryo has no functional organs and relies on the yolk sac for sustenance. The yolk is absorbed by the developing young. During the second phase, the digits develop, and in the last phase, the egg tooth appears.
Most mammal zygotes go through holoblastic cleavage, meaning that, following fertilization, the ovum is split due to cell divisions into multiple, divisible daughter cells. This is in comparison to the more ancestral process of meroblastic cleavage, present in monotremes like the platypus and in non-mammals like reptiles and birds. In meroblastic cleavage, the ovum does not split completely. This causes the cells at the edge of the yolk to be cytoplasmically continuous with the egg's cytoplasm. This allows the yolk, which contains the embryo, to exchange waste and nutrients with the cytoplasm.
There is no official term for platypus young, but the term "platypup" sees unofficial use, as does "puggle". Newly hatched platypuses are vulnerable, blind, and hairless, and are fed by the mother's milk. Although possessing mammary glands, the platypus lacks teats. Instead, milk is released through pores in the skin. The milk pools in grooves on her abdomen, allowing the young to lap it up. After they hatch, the offspring are suckled for three to four months. During incubation and weaning, the mother initially leaves the burrow only for short periods, to forage. When doing so, she creates a number of thin soil plugs along the length of the burrow, possibly to protect the young from predators; pushing past these on her return forces water from her fur and allows the burrow to remain dry. After about five weeks, the mother begins to spend more time away from her young, and at around four months, the young emerge from the burrow. A platypus is born with teeth, but these drop out at a very early age, leaving the horny plates it uses to grind food.


Adults range from 2 to 3 years in age. Banded killifish are schooling fish, usually traveling in groups of 3–6 individuals, while the juveniles travel in groups of 8–12.  The fish are most often found in the shallow and quiet areas of clear lakes, ponds, rivers, and estuaries with sandy gravel or muddy bottoms and with abundant aquatic vegetation. The sand and gravel provides hatchlings and juveniles with places to hide when threatened by predatory fish such as the largemouth bass Micropterus salmoides, northern pike Esox lucius, bluegill Lepomis macrochirus, and trout.  Because the banded killifish is small, it generally does not venture into deeper waters, where it would be vulnerable to predation as well as unable to swim in the fast currents.  However, adult banded killifish have been observed to travel into deep bodies of water to feed. Banded killifish often congregate near aquatic vegetation, as it provides protection as well as breeding habitat.
Banded killifish are euryhaline, but they usually inhabit freshwater streams and lakes.  The largest adult recorded, observed in Indian Bay, Canada, was 12.8 cm (5.0 in).  People have used banded killifish as fish bait. Most people do not favor them as pets because they require a high level of maintenance and therefore do not survive well in an aquarium setting.  They are important to aquatic ecosystems because they are a food source for larger fish such as largemouth bass, northern pike, and trout.  They are also a food source for birds such as belted kingfisher (Megaceryle alcyon), common merganser (Mergus merganser), and herons.
In January 2005 the banded killifish was listed as a vulnerable species under the Newfoundland Labrador Endangered Species Act and the Canada Species at Risk Act (SARA).  This species is facing habitat degradation due to industrial development, motorized watercraft activities, and removal of aquatic vegetations.


The banded killifish (Fundulus diaphanus) is a North American species of temperate freshwater killifish belonging to the genus Fundulus of the family Fundulidae.  Its natural geographic range extends from Newfoundland to South Carolina, and west to Minnesota, including the Great Lakes drainages. This species is the only freshwater killifish found in the northeastern United States. While it is primarily a freshwater species, it can occasionally be found in brackish water.


Banded killifish have been observed to feed at all levels of the water column.  The adults feed on a variety of items such as insects, nymphs, mollusks, turbellarians, and other small crustaceans. Mosquito larvae are also a popular food source.  In contrast, the smaller individuals are limited to fewer items such as chironomid larvae, cladocerans, copepods, and midge larvae. Both young and adult banded killifish have been observed to feed mostly in the afternoon.


The banded killifish has a narrow, elongate bluish-gray or olive-colored body with a darker dorsal surface and white or yellowish underparts extending to the anal fin. Spawning males develop yellow pectoral and pelvic fins, a bright blue patch on the anal fin, and brilliant blue iridescence on the lower portion of the body including the area around the anal fin. There are 12–20 vertical bands along the sides. In females the bands usually appear as thin and distinct black bands that often do not span the full width of the body. In males, the bands are silvery in color, are less distinct, and are closer together. The number of bands are useful in sexing an individual; male banded killifish have a greater (approximately >9) number of bands anterior to the dorsal fin. Fins rounded, base of first dorsal ray slightly ahead of or directly over first anal ray. Snout is blunt, with small superior mouth and projecting lower jaw. Lateral line is missing; 39–43 scales in the lateral series. 10–13 dorsal fin rays, 9–11 anal fin rays, 6 pelvic fin rays. Max length 13 cm (5.1 in) TL, average length 6.3 cm (2.5 in) TL.
The eastern subspecies, F. d. diaphanus, can be differentiated from the western subspecies, F. d. menona, by the presence of a further anterior dorsal fin position, increased number of anterior bars in the males of the subspecies (9-15 compared to 5-0 for F. d. menona) with more intense bars along the side that stay intact along the anterior back, a higher number of scale rows (40-44 F. d. menona, 45-49 F. d. diaphanus), and a combined number of dorsal and anal fin rays totaling 24-26, compared to 23-24 for F. d. menona. Larger maximum sizes have been reported for F. d. diaphanus than F. d. menona.
The banded killifish is similar in habitat preference and appearance to the mummichog, Fundulus heteroclitus, and the two species have been known to interbreed where their habitat overlaps. The banded killifish, while euryhaline, is more commonly found in freshwater, whereas the mummichog primarily inhabits brackish and coastal waters. The two species can be visually identified by the difference in bands; the banded killifish has thin dark bars, while the mummichog has thin light bars. The species can also be differentiated by the thicker caudal peduncle in the mummichog and brachiostegal rays often numbering 6,6 for the banded killifish (5,5 in the mummichog). Banded killifish have larger and more numerous gill rakers compared to mummichogs (8-12 vs. 4-7, respectively).
The Waccamaw killifish, Fundulus waccamensis, is a closely related species to the banded killifish that is endemic to Lake Waccamaw, North Carolina, and its tributaries. the Waccamaw killifish differs by its slimmer profile; the ranges of the two species do not overlap.


The ornate wrasse occurs in on rocky areas where there are growths of algae and Posidonia sea grass beds, it is found from 0 to 50 metres (0 to 164 ft). It can also be found living in anthropogenic structures including shipwrecks, piers and jetties. The females and the juvenile normally live in small groups while the adult males are solitary. In the breeding season the males become territorial and guard a harem. Its diet consists of small molluscs and crustaceans and the juveniles will act as cleaner fish, feeding on the ectoparasites taken off the skin of other fishes. As it hunts for this prey it swims with quick jerky movements. They bury into sandy areas at night by vigorously shaking their tail, spending the night on their sides in the sand.
The ornate wrasse is a protogynous hermaphrodite and females may transform into males which is signified by a change of colour. This means that the population is dominated by a large number of young, fertile females which can produce a large number of eggs. The older and larger solitary males are fewer in numbers as they suffer from a greater predation pressure. Spawning occurs in the spring and the eggs are pelagic.


The ornate wrasse, Thalassoma pavo, is a species of wrasse native to the rocky coasts of the eastern Atlantic Ocean and the Mediterranean Sea. This species is of minor importance to local commercial fisheries, is also popular as a game fish, and can be found in the aquarium trade.


The ornate wrasse shows sexual dichromatism. the females are greenish-brown with a dark bar on each scale and five bluish vertical stripes. Males have red heads with blue markings. Situated immediately to the rear of the pectoral fin they have a vertical blue stripe with red margins. The caudal fin in both sexes is turquoise. The juveniles are green overall and have a black spot halfway along the back, positioned immediately below the dorsal fin. The body is elongated and laterally compressed with a sharp, oval head. The snout is short with a small, terminal mouth and thick lips. In younger fish the  caudal fin and as the fish matures it becomes concave with elongated outer rays forming filaments. It can reach 25 cm (9.8 in) in length, though most do not exceed 20 cm (7.9 in).  The dorsal fin has eight spines and 12-13 soft rays while the anal fin has three spines and 10-12 soft rays.


The black drum is usually found in or near brackish waters.  Larger, older fish are more commonly found in the saltier areas of an estuary (closer to the ocean) near oyster beds or other plentiful food sources.  Juvenile fish have four to five bold vertical black bars on a light background and can be mistaken for sheepshead at first glance, but are distinguished on closer inspection because sheepshead have teeth and black drum have chin barbels.  These stripes usually fade to dull gray as the fish grow from 12 to 24 inches (30 to 61 cm) in length.  Juvenile fish are more commonly found in less salty areas and relate more strongly to structure and cover.  In the western Atlantic, black drum are found from Nova Scotia to Florida, the Gulf of Mexico, the Antilles (uncommon), and the southern Caribbean coast; also from the Orinoco delta to Argentina. They are common between the Delaware Bay and Florida coasts, and most abundant along the Texas coast. After reaching maturity by the end of their second year, black drum spawn in and around estuarine waters.  In Texas, most spawning takes place in February and March.


Black drum larvae eat mostly zooplankton, and young black drum (less than 20 cm long) eat worms and small fish. Black drum are mostly bottom feeders, with adults eating mostly mollusks and crabs. In shallow water, they have been reported to feed with their heads down so that their tails show above the water surface.  Their sensitive chin barbels help locate food, and strong pharyngeal teeth crush the shells of these preferred foods.  It has been reported that, in captivity, large drum were able to eat more than two commercial-sized oysters per kilogram of body weight each day. This translates into the potential for a 20 kg drum (about 45 lb) to eat 40 oysters a day.  Fishing advice for black drum along the east and southeast coasts of the United States often includes the suggestion to locate an oyster bed.  However, this preference has also caused black drum to be a nuisance for those who raise oysters commercially. A group of black drum can do great damage to an oyster bed in a single day.


Black drum are edible, with a moderate flavor and are not oily. Some restaurants in the southern US serve smaller black drum.  Big drum can be challenging to clean; removing the large scales is a challenge.  Many fishermen prefer to fillet with an electric knife, first removing the fillet from along the backbone, and then using the electric knife to cut the fillet from the skin and scales.  Fish over 15 pounds (6.8 kg) can become tough and have a consistency comparable with chicken, rather than the flakey texture of many species of fish.  Younger fish are often indistinguishable in flavor from red drum.


The European green toad (Bufotes viridis) is a species of toad found in steppes, mountainous areas, semi-deserts, urban areas and other habitats in mainland Europe, ranging from far eastern France and Denmark to the Balkans and Western Russia. As historically defined, the species ranged east through the Middle East and Central Asia to western China, Mongolia and northwestern India, and south through Italy and the Mediterranean islands to North Africa. Following genetic and morphological reviews, 14 population (all largely or entirely Asian, except for the African and Balearic green toads) are now regarded as separate species. These species and the European green toad are placed in their own genus Bufotes, but they were included in Bufo.


The spots on the back vary from green to dark brown and sometimes red spots appear, too. The underside is white or very lightly coloured. The European green toad will change colour in response to heat and light changes. Females are larger than males and can lay 9,000 to 15,000 eggs at a time.
It can reach a maximum size (head and body length) of 10 centimetres (3.9 in), but growth to this size is rare.


As with a large geographical distribution, this species also lives in a wide range of flowing water habitats. Waterways such as rivers, streams, floodwater streams and drainages, lakes, ponds, potholes, hot springs, sinkholes, and seasonal melt water or spring fed ponds are all viable brook stickleback territories.  Though the species can thrive in these habitats, primary spawning, breeding, and rearing grounds are located in shallow (< 1.5m) near shore environments with high vegetation cover and low velocity water. The species has a wide elevation range with specimens identified from sea level to ~ 2,400m.


Culaea inconstans, commonly known as the brook stickleback, is a small fish (<87 mm) that occurs throughout the southern half of Canada and the northern part of the eastern United States. It is one of the smallest fishes in the region. Brackish water populations are uncommon but certainly exist. It extends down to the southern reaches of the Mississippi River – Great Lakes drainage basins. Populations also exist in Colorado and Nebraska to the west, and in Alberta, Manitoba, and Northwest Territory to the north. Though these are typically the native ranges of the brook stickleback, the species has been introduced to Alabama, Kentucky, Tennessee, northwestern Colorado, northeastern Utah and California, and even in parts of South Dakota and Washington State. Certain geographical distribution studies have found that certain populations may have been native in New Mexico and still exist today. Nebraska does have brook stickleback populations, but they are generally found in small streams in the northern portion of the state. The fish have been found in Nebraska since the early part of the nineteen hundreds. River drainages that sustain brook stickleback populations are the Loup, Middle Platt, Niobrara, and smaller distributions in the Lower Platte, Missouri River tributaries, North Platte, and South Platte. Though the species appears to have an abundant distribution across North America, the Nature Conservancy has declared the species to be a S3 (vulnerable) level. Reasons for the level of vulnerability could be due to increased dam construction, especially in the eastern United States. This can lead to a destruction of habitat, increase in silted waterways, alteration of stream nutrient transport, and damaged breeding grounds. Alteration of stream dynamics could also lead to a change in predator frequency, thus exposing the brook stickleback to unforeseen predators.


The brook stickleback is an omnivore, with primary feeding tendencies toward aquatic insect larvae, adult terrestrial insects, crustaceans, fish eggs and larvae, snails, oligochaetes, nematodes, rotifers, and mites. However, brook stickleback feed on vascular plant material, as well as algae. Newly hatched stickleback larvae and planktonic crustaceans from both streams and ponds. Juveniles eat small organisms due to mouth size restrictions, and adults eat both large and small organisms.


Certain large invertebrates, birds, mammals, and fish all prey on the brook stickleback. With its small size, this species of stickleback has evolved piercing spines and protective plates to hinder predators. With this protection, as well as advanced anti-predator behavior, the brook stickleback is only a minor prey item. In a lab study, adult water bugs (Lethocerus americanus) and dragonfly nymphs (Aeschna spp.) both successfully preyed on the stickleback, but only in a night setting. Fish have been observed to be the most successful predator of the brook stickleback. Examples of these fish predators include: yellow perch (Perca flavescens), rock bass (Ambloplites rupestris), creek chub (Semotilus atromaculatus), burbot (Lota lota), central mudminnow (Umbra limi), smallmouth bass (Micropterus dolomieu), largemouth bass (Micropterus salmoides), northern pike (Esox lucius), brook trout (Salvelinus fontinalis), rainbow trout (Oncorhynchus mykiss) and round goby (Neogobius melanostomus). Brook stickleback eggs can be cannibalized, as well as consumed by rainbow trout (Oncorhynchus mykiss). Competition among the ninespine stickleback exists. However, ninespine stickleback habitat exists in the pelagic zone, while the brook stickleback occupies the littoral zone. In the presence of fathead minnows (Pimephales promelas), the brook stickleback has a more diverse diet since the fathead is a more generalist feeder.


The brook stickleback has a tapered body with a slim caudal peduncle and a fan-shaped tail. It very much resembles the ninespine stickleback but only has five, or occasionally six, dorsal spines. It also lacks lateral bony plates. Most of the year the colouring is grayish or olive green with a varying amount of indistinct mottling, but during the spawning season, males are nearly black and females have darker and lighter patches. This species grows to a maximum length of 3 to 5 cm (1.2 to 2.0 in).


Guanacos inhabit the steppes, scrublands and mountainous regions of South America. They are found in the  altiplano of Peru, Bolivia and Chile, and in Patagonia, with a small population in Paraguay. In Argentina they are more numerous in Patagonian regions, as well as in places such as Isla Grande de Tierra del Fuego. In these areas, they have more robust populations, since grazing competition from livestock is limited. Guanaco responded to forage availability, occupying zones with low to intermediate food availability in the breeding season, and those with the highest availability in the non-breeding season.
Estimates, as of 2016, place their numbers around 1.5 to 2 million animals 1,225,000-1,890,000 in Argentina, 270,000-299,000 in Chile, 3,000 in Peru, 150-200 in Bolivia and 20-100 in Paraguay. This is only 3-7 % of the Guanaco population before the arrival of the Spanish conquistadors in South America.  A small population introduced by John Hamilton exists on Staats Island in the Falkland Islands (Malvinas), with a population of around 400 as of 2003. In Torres del Paine National Park, the numbers of Guanacos increased from 175 in 1975 to 3,000 in 1993.
Guanacos live in herds composed of females, their young, and a dominant male. Bachelor males form separate herds. While reproductive groups tend to remain small, often containing no more than 10 adults, bachelor herds may contain as many as 50 males. When they feel threatened, guanacos alert the herd to flee with a high-pitched, bleating call. The male usually runs behind the herd to defend them. They can run at 56 km (35 mi) per hour, often over steep and rocky terrain. They are also excellent swimmers. A guanaco's typical lifespan is 20 to 25 years.
In Bolivia, the habitat of Guanacos is found to be threatened by woody plant encroachment.


Like all camels, Guanacos are herbivores, they graze on grasses, shrubs, herbs, lichens, fungi, cacti and flowers. The food is swallowed with little chewing and first enters the forestomach to be  digested finally after rumination. This process is similar to that of ruminants - to which camels are not zoologically classified. The camels' digestive system is likely to have developed independently of ruminants, which is shown by the fact that the forestomachs are equipped with glands.


The guanaco is a diurnal animal. It lives in small herds consisting of one male and several females with their young. When the male detects danger, he warns the group by bleating. The guanaco can run up to 64 km/h. This speed is important for the survival of guanacos because they cannot easily hide in the open grasslands of the Altiplano.
Natural predators of the guanaco include pumas and the culpeo or Andean fox. Fox predation was unknown until 2007 when predators began to be observed in the Karukinka Reserve in Tierra del Fuego. Scientists attribute the reason for the alleged new predation to the unfavourable climatic conditions on the island, which are causing food to become scarce, weakening the animals. The absence of pumas on Tierra del Fuego is also believed to be a factor that allows the fox to occupy its ecological niche. Finally, it is believed that this behaviour is not new, as the fox is nocturnal, which allows it to capture most of its prey, but makes it challenging to observe. Faced with the threat of the red fox, guanacos resort to cooperative strategies to protect their young with a shield formation, a circle around the vulnerable. If they are successful, they chase the fox away, which would be impossible with a puma.
When threatened, the guanaco alerts the rest of the herd with a high-pitched bleating sound, which sounds similar to a short, sharp laugh. Though typically mild-mannered, guanacos often spit when threatened, and can do so up to a distance of six feet.


The guanaco (/ɡwɑːˈnɑːkoʊ/; Lama guanicoe) is a camelid native to South America, closely related to the llama. Guanacos are one of two wild South American camelids, the other being the vicuña, which lives at higher elevations.


Mating season occurs between November and February, during which males often fight violently to establish dominance and breeding rights. Eleven-and-a-half months later, a single chulengo is born. Chulengos are able to walk immediately after birth.  Male chulengos are chased off from the herd by the dominant male around one year of age.


The great barracuda is present in tropical to warm temperate waters, in subtropical parts of the Indian, Pacific and Atlantic oceans, from mangrove areas to deep reef, with a lower depth limit of 110 meters. They are reported to be declining in Florida, and the Florida fish and wildlife conservation commission are considering imposing catch limits.


Sphyraena barracuda, commonly known as the great barracuda, is a species of barracuda: large, predatory ray-finned fish found in subtropical oceans around the world.


Barracudas appear in open seas. They are voracious predators and hunt by ambush. They rely on surprise and short bursts of speed up to 27 mph (43 km/h) to overrun their prey, sacrificing maneuverability. Barracudas are more or less solitary in their habits. Young and half-grown fish frequently congregate in shoals.
Barracudas can reach at least 14 years of age. The spawning season lasts from April to October. Females can release about 5,000 to 30,000 eggs. The diets of these top predators of reefs are composed almost totally of fish, cephalopods, and occasionally shrimp. Large barracudas, when gorged, may attempt to herd a school of prey fish in shallow water where they guard over them until they are ready for another hunt.


Barracudas are scavengers, and may mistake snorkelers for large predators, following them in hopes of eating the remains of their prey. Swimmers have been reported being bitten by barracuda, but such incidents are rare and possibly caused by poor visibility. Barracudas may mistake objects that glint and shine for prey.
Barracuda attacks on humans are rare, although bites can result in lacerations and the loss of some tissue. They are a popular target for recreational fishing, due to the strong fight they put up when hooked. However they are also known for the pungent odor they release upon being caught, and their meat has a chance of causing Ciguatera fish poisoning when eaten.


Great barracudas are large fish, and one of the largest of the Barracudas. Mature specimens are usually around 60–100 cm (24–39 in) in length and weigh 2.5–9.0 kg (5.5–19.8 lb). Exceptionally large specimens can exceed 1.5 m (4.9 ft) and weigh over 23 kg (51 lb). The record-sized specimen caught on rod-and-reel weighed 46.72 kg (103.0 lb) and measured 1.7 m (5.6 ft), while an even longer example measured 2 m (6.6 ft). The largest great barracuda was said to have measured 3 m (9.8 ft).
The Great barracuda is blue-gray above, fading to silvery and chalky-white below. Sometimes, a row of darker cross-bars occurs on its upper side, with black blotches on each lower side. The second dorsal fin and the anal and caudal fins range from dark violet to black with white tips.
In general, barracudas are elongated fish with powerful jaws. The lower jaw of the large mouth juts out beyond the upper. Barracudas possess strong, fang-like teeth that are unequal in size and set in sockets in the jaws and on the roof of the mouth. The head is quite large and is pointed and pike-like in appearance. The gill covers do not have spines and are covered with small scales. The two dorsal fins are widely separated, with the first having five spines and the second having one spine and 9 soft rays. The second dorsal fin equals the anal fin in size and is situated more or less above it. The lateral line is prominent and extends straight from head to tail. The spinous dorsal fin is situated above the pelvis. The hind end of the caudal fin is forked or concave, and it is set at the end of a stout peduncle. The pectoral fins are placed low down on the sides. The barracuda has a large swim bladder.


Eastern mosquitofish are native to the southeastern United States. They have been introduced worldwide and have become an invasive species in many places including Australia and Europe.
Eastern mosquitofish are found in shallow, standing to slow-flowing water, mostly in vegetated ponds, lakes, and sloughs. This species thrives in water between 31 °C (88 °F) and 35 °C (95 °F), and seems to be able to acclimate to temperatures above and below this. G. holbrooki has been shown to survive in water with pH and chemical levels known to kill other fish species, and prefers to live in areas where the water flows at a slow pace, is clear and without free-floating plant life, and seeks shelter in rooted plants. No decrease in this species due to human activities has been noted. The Eastern mosquitofish is easily maintained and has never been considered an endangered or threatened species due to its ability to thrive in its native habitat. Due to releases in new areas, G. holbrooki has actually increased its range. It tolerates chemical and thermal changes quite easily.


The eastern mosquitofish (Gambusia holbrooki) is a species of freshwater fish, closely related to the western mosquitofish, Gambusia affinis. It is a member of the family Poeciliidae of order Cyprinodontiformes. The eastern mosquitofish is native to the eastern and southern United States from Florida to Pennsylvania and inland to Alabama and Tennessee, while the western mosquitofish has a larger distribution throughout the United States.


G. holbrooki is considered a planktivorous species which consumes algae and detritus. Feeding habits seem to change based on maturity and mating season. Gambusia holbrooki will, if need arises, switch food sources to survive. With an increase of competition, this species will switch from a diet rich in plankton, algae, and detritus to one consisting of zooplankton, other invertebrates, the larvae of many species, and plant-associated animals. The main source of competition for G. holbrooki seems to be an increase of its own species and other planktivorous species. The main problem with this is, as mentioned before, it will change its diet; this is common even among the juveniles and both sexes of its own species. The females tend to not specialize on one prey, and consume all evenly, whereas the males and juveniles specialize on one prey type. However. males, females, and juveniles all consume detritus at the same rate.


Little research has been done to determine all G. holbrooki predators, due to its own predatory nature in the areas where it has been introduced. In the introduced areas, it has been known to cause top-down trophic effects due to its eating the larvae of some top predators, which include frogs and other fish. Visual exposure to its predator, largemouth bass (Micropterus salmoides) is known to affect its reproduction.


The Eastern mosquitofish is a small, light-colored fish with semitransparent fins. The females usually have a black stripe near their eye area and light spots can be seen on the caudal and dorsal fins of both sexes. Due to its similar size, shape, and reproductive habits, it can easily be mistaken for a guppy.  Generally, males reach 1.5 in (3.8 cm) and females 2.5 in (6.4 cm). These fish are a livebearer species, and as such, the females are larger and more rounded than the males. Pregnant females are also easily recognizable by their gravid spot; a darker area on their bellies where they hold the fry.
Mosquitofish may have a melanistic color pattern with black spots, resembling a dalmatian. This could result in its being misidentified as another species.


The western red-backed salamander (Plethodon vehiculum) is a species of salamander in the family Plethodontidae. The species is  found in extreme southwestern Canada and the northwestern United States. The western red-backed salamander is found in temperate rainforests of the Pacific Northwest. It is considered widespread in the region and is not strictly associated with a specific habitat type.


The western red-backed salamander is found from southwestern Oregon to southwestern British Columbia. Within that geographic range, the salamander is found from the western slopes of the Cascade Mountains to the Pacific Coast. The western red-backed salamander has been found on Vancouver Island. A variety of habitats are inhabited by the salamander, including temperate forests, rocky talus slopes, and riparian areas.


The western red-backed salamander has a slender build with relatively short limbs. Adults average 1.5 to 2 in (3.8 to 5.1 cm) in snout-to-vent length (SVL), and 3 to 4.5 in (7.6 to 11.4 cm) in total length (including tail). The western red-backed salamander has a colored stripe on its back, which extends from the anterior of the head to the end of the tail. The coloration of the stripe is highly variable, ranging from the typical reddish orange to bright yellow, with melanism also being documented in the species.


The least weasel feeds predominantly on mouse-like rodents, including mice, hamsters, gerbils and others. It usually does not attack adult hamsters and rats. Frogs, fish, small birds and bird eggs are rarely eaten. It can deal with adult pikas and gerbils, but usually cannot overcome brown rats and sousliks. Exceptional cases are known of least weasels killing prey far larger than themselves, such as capercaillie, hazel hen and hares. In England, a favoured prey item is the field vole (Microtus agrestis). These have fluctuations in population size, and in years of abundance may form up to 54% of the weasel's diet. In years of scarcity, birds form a greater proportion of the diet and female least weasels may fail to breed.
Despite its small size, the least weasel is a fierce hunter, capable of killing a rabbit five to 10 times its own weight. Although they are commonly taken, the rabbits are usually young specimens, and become an important food source during the spring, when small rodents are scarce and rabbit kits are plentiful. Male least weasels take a higher proportion of rabbits than females, as well as an overall greater variety of prey. This is linked to the fact that being larger, and having vaster territorial ranges than females, males have more opportunities to hunt a greater diversity of prey.
The least weasel forages undercover, to avoid being seen by foxes and birds of prey. It is adapted for pursuing its prey down tunnels, though it may also bolt prey from a burrow and kill it in the open. The least weasel kills small prey, such as voles, with a bite to the occipital region of the skull or the neck, dislocating the cervical vertebrae. Large prey typically dies of blood loss or circulatory shock. When food is abundant, only a small portion of the prey is eaten, usually the brain. The average daily food intake is 35 g (1 oz), which is equivalent to 30–35% of the animal's body weight.