Snapping sounds in my tank

[Toolman]

I just added about 80 lbs of live rock to my tank and now once in a while I hear snapping sounds comming from my tank. They seem to come in fast groups of 3 , I had a mantis shrimp hitch hiker from some other rock but I got rid of it. I have a fidler crab, could he be making the noises. I have lost 3 fish since I put in the new rock. I have a very small crab which I believe is a gorrila crab living in one of the rocks, but it seems to small to be killing my fish. Any body know what makes a loud sharp snapping sound ???

[blueyota]

I think you might have another mantis in there somwhere

[no_bs]

or pistol shrimp

[blueyota]

Just the missing fish leads me to think mantis....not sure but i dont think pistolshrimp will kill fish

[Toolman]

the other mantis didn't make any sounds like I hear now, could either of the crabs be doing it ? I heard that gorrila crabs are bad ???

[Toolman]

The snapping is rapid fire if that means anything ??

[untamed]

The snapping is rapid fire if that means anything ??

I don't think you can tell the difference between a pistol or a mantis just by the snap noise. I wouldn't worry about it either way.

[Toolman]

I am pretty sure the fish are worried about it

[Canadian]

There are a number of things it could be. Mantis and pistol shrimps get blamed most of the time. But I've heard similar noises from clown fish that will making a snapping sound with their jaws from time to time. Additionally, I discovered earlier this year that blue leg hermit crabs can make similar sounds as they attempt to violate each other for their shells. I was sitting by my tank and heard that dreaded clicking sound and jumped up to see what it was. I discovered it was a hermit crab violently tugging on another crab trying to evict it from its home and hitting the shell on the glass of my bare bottom tank.

[Eyford01]

maybe check out some cheap diy mantis and crab traps just in case, leaning a glass jar with bait on the bottom against a rock for the night might catch the gorilla before it causes any (more?) damage, also i had a HH pistol shrimp, he would snap sometimes several times (up to 5 or 6) about a second apart but never caused any problems, only ever saw it twice just heard it lots

[Toolman]

The three fish I lost were all smaller, I also have an large anenome crab as well that I just added. Could he be the culprit ?? Maybe I will throw him in the sump and see what happens ??

[Toolman]

I found the carcass of the crab with one very LARGE claw and the snapping has seemed to stop, I don't know if it was the large anenome crab that got him but if he was the culprit then good riddance...........