I wanted to update everybody on my unsuccessful battle against the bug that hit my seahorse tank. I have lost 13 of 18 seahorses, all farm-raised reidi. The survivors are a different, unknown species and include a mother and her three young that I successfully raised (dad died from internal gas bubble disease). I have one reidi hanging on sick after the bug hit 2 1/2 weeks ago, but I doubt he will survive. This experience has really reinforced the idea Wolfesbane expressed above about the danger of mixing batches of ponies together.
I converted the Eclipse 12 cheato nursery into a hospital tank, and first tried Formalin as an external anti-protozoan agent. I had read that this helps in raising fry. Two days later I added Kanomycin (anti-bacterial) to this. I also de-wormed everybody that was eating with Pipzine-soaked mysis. After 2 more days, I ran lots of carbon for several hours to remove everything, then added Metronidazole (Flagyl) external and internal anti-protozoan (Heximita). All through this I kept adding seahorses as they sickened. Nothing worked, only the mother lived through every treatment (she kept eating but slowly). Everything was quiet for about a week, and then the few remaining starting slowing down and dieing again.
Autopies with my nice microscope were inconclusive. One pony had a surprising amount of bacteria on the gills, especially for coming out of a Kanomycin-laden tank. Nothing visible in the gut track like worms, Heximita, etc... though. Another pony didn't have any bacteria on the gills, but had a green lesion on the liver that was just a mass of clean tissue, no pathogen visible (simple cancer?). I froze a few dead ones and will look later for the liver lesions, perhaps these are from the powerful medications I tried?
I have a theory from this and my poor success in raising fry: Hobbyist probably cannot raise fry due to unknown parasites, they keep scratching with their tails despite medication (Formalin). Only those few that develop resistance survive, and that is rare. Reidi seahorse farms such as in Sri Lanka have found a way to raise them in pretty much sterile environments, and can produce saleable sized teenagers for the market. However, these have never been exposed to any pathogens, and are susceptible once in hobbyists tanks, even living a year or so until exposed. Doesn't matter, they were sold and the farms will keep producing (sorta like cut flowers).
There must be some way to know if the seahorses we buy were somehow one of the lucky ones that survived a normal dieoff during the first few days of life. Those are the ones that have developed some resistance and will persist in our tanks. Otherwise we are just buying "bubble boys" doomed to die. The 3 teenagers I have successfully raised were from a batch of 44 fry(and 4 more subsequent unsuccessful batches), so are very special. They are happy as can be with everybody else dieing around them.
Hang in THERE! I'm sufferring almost the same thing as you, except with my maroon clownfishes.
