 New fish dying
I have a 92 gallon bow front corner tank. We have fish, live rock, hermit crabs, peppermint and cleaner shrimp, and zoanthis polyps. The water quality seems good, O ammonia, O nitrite and 20 nitrate. The tank was second hand and came with most of the rock, a blue tang, a yellow tang, a yellowtail damsel, a yellow watchmen, 2 nemo clown fish, one very large peppermint shrimp, one zebra hermit crab and one snail. We have added lots of hermit crabs (some blue legged, some red legged, some zebra, and one orange legged), 5 peppermint shrimp and one cleaner shrimp, and some snails, and a red starfish, these were all added over time. We added one 4 stripe damsel, and a domino damsel. The 4 stripe was injured on the drive home (got caught in the corner of the bag) and ended up with an infection, so she died. The domino damsel went missing for a couple of days then I found him stuck in a hole half eaten by bristleworms and a hermit crab. Yesterday we got 5 tiny blue green Chromis and this morning 3 of them are gone. I saw one way in the back being eaten by a peppermint shrimp, but I assumed he died first then the shrimp ate him. I don't think we have a mantis shrimp but there is a crab of unknown identity, he seems so small, always hiding, and slow though. He does have hairy legs which I have heard is a bad thing. He is very small, between the size of a dime and a quarter. I have only ever seen him in one of 2 rocks, he usually stays in a hole right by some zoanthid polyps and his little pinchers come out at feeding times.
Could this little crab be the problem with our new fish? What else could be killing them? The new fish seemed fine and were mostly schooling well when they were released. They were acclimated slowly. Could we have other bad inverts and not know it? I have never seen anything else. The new fish were all very small, could they be injured or killed by hermit crabs or the shrimp. Our hermit crabs are all quite small. Most are very small, and 6 are a bit bigger, but still about the size of a quarter or smaller (not including the shell). The shrimp are all medium except the one that came with the tank, he is pretty big, and also very bright red (but still striped like the other peppermints).
The temp is 77-79 F (can't read the thermometer accurately but it is stable) and the specific gravity is 1.024.
There are also quite a few bristlewroms, they are pretty big, but not huge. the biggest I have seen is 4-5 inches, and lots of tiny starfish like things (brittlestars?) None of these seem dangerous.
Maybe the fish hide in the rocks at night and something eats them? If it is the crab, how do we get it out?
Thanks,
Marcie  |