11becca20

The first time I bought green chromis, I had four. Two of them fell ill and died. One went missing mysteriously, and was never seen again. The last one lived and is still in my tank. Recently I bought three more chromis in order to return the number to the origional of four. Withing three days, two of the new chromis had dispeared. I have a brown sally lightfoot crab in my tank and I have seen it try to catch both the small and large fish. The fish always get away in the nick of time, but I was wondering if this crab could be the culpret of the mysterious disapearing fish. Could it be catching and eating the chromis, the smallest of my fish?

mastercave

how big is the crab compared to the fish? during feeding time, i see the sallys kinda lunge in the direction of close-by chromis' but it's usually for bits of food and the fish is too fast. also, i don't think a sally can eat a chromis in 1 night so have you checked all the nooks and crannies of the rocks?

in the beginning, i had lost a chromis and it turned out it swam into a hole and couldn't back out, so it died in there.

Tumbleweed

Chromis are often referd to as schooling fish, and to a point they are. But they are also part of the Damisel family. In the wild they school in families of hundreds or thousands, and have rum to move. In your tank the area is much smaller, and the school size also decreases. Fish will start to show more dominant or submissive traits then. Every chromis I have kept showed these traits. You start out with 4-6 chromis and within a couple of weeks/months you are down to 2-3 if you are lucky. This is normal as usually 1 chromis will become the dominant fish of the group and will boss the others around. You might even see 2 seperate groups form.
So to answer your question, they are probably beating each other up. Just keep an eye on them and make sure they are all eating when you feed them. If 1 or 2 of them are not. They stay hiding or just don't go near the food because the others are there, you might want to consider moveing them to anther tank, or returning them to the store.

Salvatore

I also had the disappearing chromis happening in my tank. Could not figure out where the were going and never saw any remainder of them. Then one day I did a water change and turned off the filter. I have a wet dry, when I turned it back on I notices that the force of the water pushed something through the plumbing and onto the pad of my wet dry. There they were. The poor little fishes were a bit too small for my tank and were somehow getting sucked up into the filter. I even put a filter pad along the top of the tank where I thought they were going into but then I found another one. I guess maybe my tank is not meant for some guys that small!! Not sure how your set up is but it may be something that you want to take a look at!! Next time I go to the store I will be looking for larger chromis!!