<a href=showthread.php?s=&postid=5142689#post5142689 target=_blank>Originally posted</a> by uberfugu
I suspect that transit stress is a major factor in the demise of frogfish. Lefty, I agree with Cherie that these guys are so easy to catch; cyanide isn't needed. They certainly show symptoms though, delayed death, respiratory issues, sudden death.
On another forum site, there have been a lot of discussions about this problem in frogfishes. They seem to follow two patterns, death within two weeks from acquisition and a mid-term captivity death from say 6 months to a year. This excludes death from accidents, gross husbandry issues, or tankmate issues.
In the case of early deaths there seem to be two patterns, massive bacterial/parasitic infections and unexplained, 'overnight' deaths. While the former could be from our new frogfish not having natural antibodies or resistance to pathogens in their new system (per LisaD, this has been found in seahorse populations), I think it would be more logical to assume that transit stress (high ammonia levels, temp fluctuations, varying water parameters, and physical abuse including air embolis) would weaken the fish to the point that it would be susceptable to disease. The later deaths would seem to be gill burn from metabolite excesses in transit. These symptoms are similar to cyanide poisoning.
As to frogfish deaths in cases of an established fish in a mature system, there was an account by Dr Bruce Carlson when he was at the Waikiki Aquarium of established, long-term commerson anglers succumbing to either a bacterial or fungal disease. I believe the aquarium used a flow-though system of fresh ocean water and the commersons is endemic to Hawaii so it would seem that water quality is not the issue. Most likely the problem is dietary in nature. Several years ago, I spoke with Dr. McCosker at the california Academy of Science and he felt that dietary problems were the probable cause of early frogfish deaths in captivity. I haven't cut open any deceased frogfish, wouldn't know the difference between a sick one and a healthy one but I have been trying to avoid the one-food syndrome (a diet too high in Doritos is not good)
Sorry for being wordy