By Dan Underwood
WHAT IS IT?
Weak snick is a condition where a seahorse has difficulty sucking or is unable to suck food into its snout. It is a relatively common complaint seen on message boards and one that we often get on calls to our help desk. In mild cases, the seahorse is still able to eat; it just has some difficulty getting the food in. Left untreated, this condition will continue to get worse until the seahorse reaches a point where it can no longer take in food, causing it to starve. This ailment won’t fix itself and requires intervention. Early recognition and intervention has a very good prognosis. Even at late stages where a seahorse has stopped eating entirely, that seahorse can potentially be saved, if the hobbyist has correctly diagnosed and aggressively treated its cause of weak snick.
Seahorses, unlike most fish, have a fixed jaw. Instead of opening their mouth using a hinged jaw motion to take in food, they have a tubular snout that relies on suction to draw food in. There has been a lot of study into exactly what takes place during this highly coordinated activity. In short, the seahorse tilts its head and a number of muscles go into action, expanding the oral (buccal) cavity and creating negative pressure; this, in turn, draws water in, all within a fraction of a second. The suction effect, much like a slurp gun, is very powerful. Prey (food) is drawn in during this process—sometimes even larger than the diameter of the snout! As the prey is drawn in, it is macerated, as evidenced by what appears to be smoke coming out the back of the seahorse’s head. This “smoke” is actually food particles that are ejected with water during the ingestion process (one of the reasons why seahorses put such a large organic load on a tank).
If you watch closely while seahorses feed, they have amazing accuracy and skill in snicking (sucking) their food. They will normally snick shrimp from the tail first. This prevents them from being injured by the rostrum of certain species of shrimp. Seahorses can also take in what they want of the shrimp’s body and spit its head back out. In cases where they are determined to eat prey too large for their snout, they may snick that prey multiple times until it’s broken up enough to be ingested.
WHAT CAUSES WEAK SNICK
Anything that affects the seahorse’s head, surrounding musculature, oral cavity, and/or snout can impact that seahorse’s ability to snick. Causes of Weak Snick range from parasites to mechanical injury to bacterial infection to dietary deficiencies.
Parasitic issues are by far, the most common cause we see in the hobby. In tanks that are too small, overstocked, under filtered, or where flow is too low, old food is lying about, or there is a general lack of maintenance, organics can build up. As these organics begin to accumulate, so does the microbial population of bacteria and protozoans that feed on them. Protozoans can be ingested into the seahorse’s oral cavity during normal respirations or feeding. If the population of protozoans grows within the seahorse’s oral cavity, this infection can create irritation and inflammation. If this imbalance of protozoans negatively affects any of the muscles, nerves, cartilage or bones of the seahorse that are used during the snicking process, the strength of the snick will weaken.
Mechanical injury can occur when a seahorse inadvertently snicks a foreign object such as a piece of crushed coral or gravel, or a bristle worm or the seahorse’s snout area experiences some form of physical trauma.
Bacterial infections can be the primary cause or the secondary cause of Weak Snick. Most commonly, we see it as a secondary cause following either injury or parasite infestation.
Dietary Deficiencies are difficult to diagnose for the average hobbyist. These should be suspected based upon the specific seahorse’s health and behavior history and/or the hobbyist ruling out the previously listed causes. A lack of Vitamin E, Selenium, and potentially other nutrients, can cause Nutritional Myopathy (disease of muscle tissue).
As I write this, it occurs to me, that I can’t recall Seahorse Source ever having to deal with Weak Snick with our seahorses, and we’ve been raising seahorses since 2003. Most of our brood stock reaches between five to ten years of age, and we often have hundreds of seahorses on hand. We’ve dealt with Weak Snick with acquisitions, but never in the seahorses we have bred, raised, and maintained ourselves.
The key to prevention of parasitic and bacterial issues requires adhering to the following:
- maintaining the proper setup with the appropriate sized tank and filtration scheme;
- maintaining proper stocking densities for the setup to prevent the buildup of organics; and
- preventing food from lying around on the bottom of the tank and decaying.
We have noticed since changing our advice on stocking density of seahorses to 1 pair per 25 to 30 gallons, the number of customers who encounter this ailment has decreased.
Stray food items left lying about the tank will quickly become colonized with both bacteria and protozoans to break it down. For this reason, we train our seahorses to eat out of the water column. Uneaten food is siphoned out twice a day and we adjust how much we feed the next feeding. A feeding dish can be deployed and seahorses can be trained to eat from it. The dish should be cleaned regularly. A good cleanup crew can also be very helpful in cleaning up stray food items.
Additional research needs to be performed to properly identify nutritional deficiencies in the captive environment. We’ve seen many hobbyists who have only fed frozen mysis to their seahorses for several years and those seahorses have never developed an issue. Still, it makes sense to vary a captive seahorse’s diet by periodically adding some live food for its overall health and longevity. We achieve this variety by using adult artemia and gut loading it with enrichments. Amphipods and live mysids also make great additions to the captive seahorse’s diet.
The first step is for the hobbyist to make a complete assessment to try to determine the possible cause of the weak snick. Sometimes this cause is obvious, but many times it isn’t. Assessment includes evaluating history as well as performing a complete visual examination of the seahorse. In the history, the hobbyist will want to review the tank setup and the filtration scheme. The hobbyist should also assess the water quality, and feeding methods and habits including any changes to the food. Finally, with regard to the seahorse’s behavior, the hobbyist should compare and contrast how well the seahorse used to snick to how it snicks currently, as well as its recent color changes, any possible injuries, etc. Look for clues. In the visual examination, look at the seahorse’s respiration rate, obvious white patches as well as small patches that may have developed anywhere on its body. Look the entire animal over, not just around its head. As always be sure to look for signs of injuries.
If the assessment doesn’t reveal any potential clues, I like to do a Freshwater (FW) Dip (Instruction can be found here Hyperlink). The FW Dip works as both a therapeutic treatment and a diagnostic tool. If the seahorse reacts to the dip as explained in the above referenced FW Dip article, there is a high probability that at least part of the Weak Snick cause is from a buildup of protozoans in the Oral Cavity. In minor cases where this is caught early, the FW Dip may be all that is needed. Most cases, however, will require additional treatment. It is also worth noting, if one seahorse is found to have parasitic issues within the oral cavity, others that share the tank likely do as well, even if they are not symptomatic. If the seahorse does not react to the FW Dip, then its Weak Snick probably isn’t caused by protozoans, and we should consider either mechanical injury, bacterial infection, or nutritional deficiencies.
Supportive Care During Treatment
Supportive care revolves around nutritional support until the seahorse can resume consuming food normally. Seahorses can lose weight quickly when not getting enough nutrition. If the seahorse is able to snick some food, but is just having a difficult time doing so, then consider offering smaller or softer foods.
Different brands of frozen mysis have different sized pieces and/or consistency of shrimp. Another possibility is to chop or shave some frozen mysis into smaller pieces.
Adult Artemia (Brine Shrimp) is generally very soft and easy for a seahorse to snick. Sometimes though, during weak snick, the seahorse loses its enthusiasm in chasing down food because of its difficulty in sucking the food in. Some cases the adult Artemia works, and in some, it doesn’t.
Tube feeding is a last resort. Tube feeding gets some nutrition into the seahorse. The idea is keep the seahorse going until it can resume feeding on its own. Tube feeding can be stressful for both the seahorse keeper as well as the seahorse. Done properly, with a little patience and practice, it becomes easier for both. This form of feeding should only be done once a day. The amount given during tube feeding will not be enough to fatten up the seahorse, but will be enough for the seahorse to survive.
After the FW Dip, seahorse keepers have a choice of placing the seahorse back in the display tank or a hospital tank for additional treatment. When the weak snick is believed to be caused by parasites, I like to place the seahorse in a hospital tank and treat with a Long Term Formalin Immersion. This is performed by adding one (1) ml of 37% Formalin per 10 gallons of water (25 ppm) every other day for three (3) treatments. If the hospital tank doesn’t have a biological filter, water changes will be needed and the medication adjusted. In this case, we start off by adding one (1) ml of 37% Formalin per 10 gallons and each day thereafter do a 50% change and add ½ the dose back in (0.5 ml 37% Formalin per 10 gallons) for the six days.
In severe cases, where the seahorse is completely unable to snick the food, and continues to be unable to do so even after the FW dip and a couple of days of Formalin, a Short Term higher dose Formalin Bath may be indicated. I don’t like doing repeated back-to-back FW Dips. The Formalin Bath is done by adding 1 ml of 37% Formalin per gallon (250 ppm) of water for 45 minutes. It is important that this mix of Formalin and water is aerated well as Formalin displaces oxygen. After the Formalin Bath, the seahorse is placed back in the hospital tank. The seahorse is re-evaluated after 24 hours.
In most cases, especially when caught early, the FW Dip and Formalin treatment take care of the issue when Weak Snick is caused by protozoans. In really stubborn cases, the seahorse keeper may have to go a step further as there are two other likely possibilities which require additional treatment measures. First a secondary bacterial infection may have set in, in which case, antibiotics would be indicated. Secondly, some protozoans such as Uronema can become resistant to Formalin. If the above treatment hasn’t alleviated the Weak Snick, consider treating with Metronidazole. First, do a 100% water change on the hospital tank, and then follow the dosing instructions on the product being used. I would consider treating for at least six (6) days and then re-evaluate.
Mechanical Injury Treatment
There isn’t much that can be done with mechanical injury other than supportive care and careful observation in case a secondary infection sets in. If so, then antibiotic treatment would be indicated.
Nutritional Deficiencies Treatment
Again there isn’t much a hobbyist can do short term to fix thisl Maintain supportive care and make adjustments to the diet. It would take a fair amount of time for a nutritional deficiency to be corrected which could mean a long time of tube feeding.
We try to remain available to our customers and other hobbyist if they have questions, need help diagnosing, calculating dosages or deciding what to do next. We are not veterinarians, but we do have a tremendous amount of experience in helping folks with these issues.