First ever footage of smalleye stingray (Dasyatis microps).
My postdoc was spent looking at hybridization between humpback (Gila cypha, above) and roundtail (G. robusta) chub in the Colorado river system (see here for a publication that stemmed from that – perhaps sometime I’ll post on that work). My fieldwork was at the confluence of the Colorado and Little Colorado rivers where we’d capture, measure, tag & photo the fish. Thus, I’m happy to report the following:
The humpback chub, a closely watched indicator of the Grand Canyon’s ecological health, has grown steadily in number since 2001 as changing conditions on the Colorado River have created a more hospitable habitat.
The population of the endangered fish grew by 50 percent over the past eight years, the U.S. Geological Survey reported Monday. By the end of last year, there were an estimated 7,650 adult chub, fish at least 4 years old, near the confluence of the Colorado and Little Colorado rivers. That’s up from about 4,000 fish as recently as 2000.
Back in October, Afarensis introduced us to the Douc langur (Pygathrix nemaeus), and noted that the species was comprised of three subspecies, one of which was the grey-shanked douc langur (P. n. cinerea). That subspecies is one of the 25 rarest primates in the world and fewer that 1000 individuals were believed to exist in Vietnam. Encouragingly, AFP is reporting that a new population of at least 116 individuals (and perhaps 180) has been discovered in Quang Nam province. Scientists believe that any more individuals may live in the surrounding un-surveyed forest.
My post-doctoral research was in hybridization among endangered desert fishes here in the American Southwest, so it has made me happy to read that a new population of the endangered Desert pupfish (Cyprinodon macularius, above) has mysteriously appeared in man-made research ponds in Salton Sea, California. Many of the over 1000 specimens are juveniles, which has lead scientists to infer that substantial breeding is going on in the ponds.
The old story goes that JBS Haldane felt that God had an inordinate fondness for beetles. It also seems he likes catfish. CJ Ferraris has produced a checklist of fossil and living catfishes and estimated that there are 3093 valid species in 478 genera (and 36 families). Of these 72 species are known solely from fossils. No one who knows catfishes will be surprised that the largest family is the Loricariidae (716 species in 96 genera), but interestingly, three genera of living catfishes could not be assigned to existing families: Conorhynchos and Phreatobius from South America, and Horabagrus from Asia.
Update: Fixed dumb homonym mistake. Sheech!
There has been some blogospheric notice of the Conservation International survey in Surimane which has found 24 new species. Other good news is that the previously thought to be extinct dwarf suckermouth catfish (Harttiella crassicauda, above) has been re-discovered. The species – which reaches a size of about five centimeters – had last been spotted over fifty years ago.
AP is reporting:
Female sharks can fertilize their own eggs and give birth without sperm from males, according to a new study of the asexual reproduction of a hammerhead in a U.S. zoo.
The joint Northern Ireland-U.S. research, being published Wednesday in the Royal Society’s peer-reviewed Biology Letter journal, analyzed the DNA of a shark born in 2001 in the Henry Doorly Zoo in Omaha, Neb. The shark was born in a tank with three potential mothers, none of whom had contact with a male hammerhead for at least three years.
The baby was killed within hours of its birth by a stingray in the same tank. Analysis of its DNA found no trace of any chromosomal contribution from a male partner.
Shark experts said this was the first confirmed case in a shark of parthenogenesis, which is derived from Greek and means “virgin birth.”
So I noticed that visits to the blog ramped up after 2100 EST tonight with traffic increasing ten-fold. And the reason? Grey’s Anatomy mentioned this little blighter.
Over at Fark.com they are discussing this photo of a Goliath tigerfish (Hydrocynus goliath) which occurs in the Congo River basin, the Lualaba River, Lake Upemba and Lake Tanganyika.
Four new species of Loricariid catfish have been described from the upper Río Orinoco of southern Venezuela: (A) Hypancistrus inspector, (B) H.
lunaorum, (C) H. furunculus, and (D) H.
debilittera, Full details are in Armbruster et al. (2007) “Four New Hypancistrus (Siluriformes: Loricariidae) from Amazonas, Venezuela” Copeia 2006(1): 62-79 (link).
Experts at Planet Catfish claim that the species have been sold under the following L-numbers: L201 (H. contradens); L129 (H. debilittera); L199 (H. furunculus) and L339 (H. lunaorum).
This little beauty is a new species of Pemelodus catfish. P. tetramerus was described from the Rio Tapajos and Rio Tocatins in Brazil. It is related to the Pictus catfish that are available in many fish stores.
O. batmani is a new species of loricariid catfish native to the Rio Pure in Colombia and two creeks draining into the Rio Amazonas near Iquitos in Peru. The specific name (“batmani”) is in honor of Batman and is due to the bat-like black markings in the tail (source).
Ref: Lehmann, PA (2006) “Otocinclus batmani, a new species of hypoptopomatine catfish (Siluriformes: Loricariidae) from Colombia and Peru” Neotropical Ichthyology 4(4): 379-383.
Regular readers may remember that I have a softspot for catfish and earlier this year purchased a lace catfish (Synodontis nigrita), a species native to many African countries. The genus Synodontis (Cuvier 1816) is interesting for a number
of reasons. For example, S. multipunctatus (the gorgeous fish pictured above) is the only fish known to practice brood parasitism: it manages to mix it eggs with those of mouthbrooding cichlids in Lake Tanganyika, its larvae grow faster than those of the host and feed on them.
Lake Tanganyika is, of course, famous for the cichlids which have been studied as an example of a rapid, recent radiation which was caused by environmental change (in this case, fluctuations in water level). It is also home to to other endemic fauna, including ten species of Synodontis. A recent study has used mitochondrial DNA to study the history of the genus in the region.