Need some suggetions/help

[Squiddy]

My 90G reef has been doing quite well lately. The corals are looking great and fish seemed to be doing fine. All of a sudden just before Christmas, my chromis, six line wrasse and coral beauty disappeared, leaving my percula clown. Later that day or the next day, I was able to spot the crabs eating what looked like a fish body in the back of the tank. I was also able to see the coral beauty hiding right in the back and using a flashlight was able to see that she looked healthy but just looked a bit scared. A day or so after that, the coral beauty was out in the open in the tank and looked totally fine. I fed the clown and the angel and all seemed fine except for the missing six line and chromis. The next day I looked for the coral beauty but she was no where to be seen. She has not shown up since and this was about 2 weeks ago now. The clown is doing just fine and shows no sign of anything ever happening.

I am looking for suggestions as to what could have happened. Nothing in the tank has changed during this period and I checked all of the parameters after noticing the fish were gone, and everything is fine.

We were thinking that it could have been something that was on my hand when I put it in the tank but that doesn't explain why the clown and the corals look better than ever. I am also pretty careful with washing my hands before and after entering the tank.

One possibility is a hairy hitchiker crab that I noticed a few months back. I haven't been able to get a good picture of him but he only comes out at night and seems to hang around one of my zoo rocks. We watched him for quite a while one night to make sure he wasn't eating the zoos. He was actually carefully eating the macro algae growing around them but not harming any of the polyps. I haven't had a problem with him with regard to the fish or corals as of yet but he was the first thing I thought of when these fish went missing.

Is it possible that this crab could have made an attack during the night? The clown hosts in my anenome and is pretty well protected every night. The other fish used to go into the back where they each had their own hiding spots.

I know which rock the crab is in and could fresh water dip the rock to get him out probably but I would like to hear some suggestions first. I'm stuck and don't really know how to figure this one out.

[GMGQ]

I dont think those ugly, black, hairy crabs are much of a threat to fish? They're slow, and they seem to just pick on algae all the time...

[Der_Iron_Chef]

Maybe a mantis shrimp came in on some live rock? A serpent star lurking about, feeding at night? :idea:

I read a thread on RC about someone's clown fish that was dragging other fish into the host anemone. Crazy, but true.

Maybe try getting rid of the crab and seeing what happens. Eliminate each possibility one by one.

[Jim Barry]

I have had problems with healthy fish going missing in the night. I have probably lost 5 fish in the past year. I have 3 big hairy crabs in my tank that I can't catch. My guess it is the crabs....fish are pretty slow when they are sleeping

[Der_Iron_Chef]

Try ye ol' inverted bottle trick?

[justinl]

there's too many possible explanations for the case given in which there is too little evidence (except for the lack of fish of course). My suggestion is to just observe. CHeck every nook and cranny with a light and see if you can see anything, do it during the day and night. At night, have a stakeout. just sit and watch with the lights off. Maybe then you'll get an idea of what might be the culprit. Has your water quality dropped of late? If it hasnt then the fish probably aren't decomposing in a crack somewhere and have been comsumed by whatever. Check your equipment too. sometimes weak/old/dying fish get sucked into intakes or pipes.

good luck and good hunting!