Just want to throw this out there. If you ever have a fish die, and you don't know what caused it, a necropsy can be extremely helpful in determining cause of death. I routinely perform necropsies on any fish I lose, especially if I'm not able to determine cause of death by appearance alone.
My new moorish idol decided to crash and burn yesterday, going from brightly colored, swimming normally and eating well, to barely able to balance in the water and no longer eating. By this morning, it couldn't even swim, and was being blown around by the current from the HOB filter on the quarantine. I decided to euthanize the fish, and took it to the veterinary clinic I work at to perform a necropsy.
First, I performed a skin scraping and gill clipping to look for signs of parasites, such as ich, velvet, and especially flukes. The fish was negative for those issues. Gill color was also good and the tissue was in good shape, i.e no signs of ammonia burn and the fish was not anemic.
Next, the thorax and abdominal cavity were opened via an incision starting at the vent and going up across the sternum to expose the internal organs. The heart, liver, and intestines looked completely normal. The stomach was nice and plump, still full of the nori and mysis shrimp that the fish had been consuming up until yesterday.
What was most interesting, and the key finding of the necropsy, was that both kidneys were basically gone. They had atrophied and rotted away to a black sludge material. This, along with the fact that the coloration of the fish did not fade post mortem, are indicative of cyanide being used to collect the fish for the aquarium trade. These fish often appear in good health, brightly colored, and relatively alert. Some eat well, some will never eat in captivity. But as a general rule, almost all of them collected with cyanide die within 30 days. Usually the fish do relatively well for the first week or so, then begin to crash.
Purchasing fish from areas of the world like Kenya, the Maldives, Australia, Fiji, Tonga, Japan, Mexico, or the Caribbean can help avoid these issues since these places ban the use of cyanide collection. In the case of fish with a wide distribution, like the moorish idol in this case, according to the online retailer, it was imported from Africa, where cyanide is not normally used. However, based on the results of the necropsy, the current availability of fish from the same vendor out of the Philippines and Indonesia, where cyanide use is still prevalent, and the fact that fish I received from this particular vendor have repeatedly been in poor shape and quickly passed away, or been DOA, it would lead me to believe the fish was falsely advertised as coming from an area where cyanide is not used, as a way to increase sales.
Work with your LFS to support better collection and care practices of the fish we keep as pets. Support stores that work with wholesalers that take the time to bring in healthy livestock from areas of the world that actually care about their reefs and the animals that live there, and their survival after importation for the aquarium hobby. Many wholesalers, like Quality Marine, have MAC certified fish available, or have clear locales listed for where the fish are collected from. This allows you to order fish from sustainable fisheries, and support the health of the wild reefs, and improves your chances of success with the fish in your aquarium long term.
I will keep a moorish idol again, but this time I will acquire the fish through a LFS where I can see the fish in person before purchasing, and make sure it was acquired from a reputable, sustainable wholesaler.
My new moorish idol decided to crash and burn yesterday, going from brightly colored, swimming normally and eating well, to barely able to balance in the water and no longer eating. By this morning, it couldn't even swim, and was being blown around by the current from the HOB filter on the quarantine. I decided to euthanize the fish, and took it to the veterinary clinic I work at to perform a necropsy.
First, I performed a skin scraping and gill clipping to look for signs of parasites, such as ich, velvet, and especially flukes. The fish was negative for those issues. Gill color was also good and the tissue was in good shape, i.e no signs of ammonia burn and the fish was not anemic.
Next, the thorax and abdominal cavity were opened via an incision starting at the vent and going up across the sternum to expose the internal organs. The heart, liver, and intestines looked completely normal. The stomach was nice and plump, still full of the nori and mysis shrimp that the fish had been consuming up until yesterday.
What was most interesting, and the key finding of the necropsy, was that both kidneys were basically gone. They had atrophied and rotted away to a black sludge material. This, along with the fact that the coloration of the fish did not fade post mortem, are indicative of cyanide being used to collect the fish for the aquarium trade. These fish often appear in good health, brightly colored, and relatively alert. Some eat well, some will never eat in captivity. But as a general rule, almost all of them collected with cyanide die within 30 days. Usually the fish do relatively well for the first week or so, then begin to crash.
Purchasing fish from areas of the world like Kenya, the Maldives, Australia, Fiji, Tonga, Japan, Mexico, or the Caribbean can help avoid these issues since these places ban the use of cyanide collection. In the case of fish with a wide distribution, like the moorish idol in this case, according to the online retailer, it was imported from Africa, where cyanide is not normally used. However, based on the results of the necropsy, the current availability of fish from the same vendor out of the Philippines and Indonesia, where cyanide use is still prevalent, and the fact that fish I received from this particular vendor have repeatedly been in poor shape and quickly passed away, or been DOA, it would lead me to believe the fish was falsely advertised as coming from an area where cyanide is not used, as a way to increase sales.
Work with your LFS to support better collection and care practices of the fish we keep as pets. Support stores that work with wholesalers that take the time to bring in healthy livestock from areas of the world that actually care about their reefs and the animals that live there, and their survival after importation for the aquarium hobby. Many wholesalers, like Quality Marine, have MAC certified fish available, or have clear locales listed for where the fish are collected from. This allows you to order fish from sustainable fisheries, and support the health of the wild reefs, and improves your chances of success with the fish in your aquarium long term.
I will keep a moorish idol again, but this time I will acquire the fish through a LFS where I can see the fish in person before purchasing, and make sure it was acquired from a reputable, sustainable wholesaler.
