Mantis Shrimp?!?!

[codenaruto]

Ok so yesterday something weird happened....

last night i was looking at my fish tank (20 gal saltwater aquarium) and my big black damsel fish was hanging at the bottom of the tank (just like normal swimming) under a cave like formation of the live rock.

Now, for the longest time, there has always been a buildup of something directly under this rock..... I have just been thinking its just a dead spot of debris that the filter hasnt gotten...

but then this morning something weird happened... my biggest fish went missing without a trace.

and the closer i look now, i see a hole in the bottom of the live rock, right above where this fish was swimming last night... like the debris below was actually a mantis burrowing deeper!!!

did my fish get eaten by a mantis shrimp?!!! i dont hear any clicking, but then again i am normally pretty far away from my aquarium at night

PLEASE HELP ME!!

 

[little_fish]

Hello and Welcome!

That is a pretty good sign you have a predatory animal in there, but it could also be a crab, mantis shrimp arent the only bad guys out there.

Do spend some time trying to figure out what you have because crabs are a whole lot easier to get rid of than mantis shrimp. Mantis are very, very smart and if you fail to catch them the first time they will remember that method and cant be caught that way again.

 

[codenaruto]

Hey so it turns out you were right! i think its called a gorilla crab? Anyway its a big hairy looking thing thats burrowing into my rocks. Any chance that if i keep it well fed (cooked shrimp) I could leave it in there? I only have a 20 gal tank so i have no sump to out it in or anything

 

[little_fish]

Not really, they are opportunistic predators so given the chance they will go after a fish even if they have been fed. You can decrease the chance the but not get rid of it totally