Hermit Crab Homicide

[rinker]

My 55 gallon is 6 weeks old and has completed a cycle. SOmething is killing my hermit crabs (as in eating them). They look like something went throught the shell. My only fish is a clown and a fire shrimp.
I did notice 2 small chocolate chip star fish (I think). They were hitch hikers in a live rock. They're about 1/8 inch. Could they be the killers. I say killers because only the legs of the red legged crabs were left behind

 

[jdragunas]

it's most likely the choc. star. These are carnivores and are very well known for eating hermits, snails, and other such critters. If you want to have any inverts at all in your tank, i'd say remove them, and see if you can trade them into your LFS for store credit, or try to find a home for them. Sorry about the bad luck.

 

[ophiura]

If they were hitch hikers they are more likely Asterina stars which are small (maybe the size of a nickel), with 6-8 arms, usually uneven. They will not get larger, nor ar they the culprits here....IMO very very few are predators and none, that I know of, would take a hermit crab. If you look in the hitchhiker ID thread at the top of this forum, you'll see pictures.
If something "went through the shell" then my first thought is a mantis shrimp. Do you here "clicking" at any time in the tank?
Now, are you positive these are not molts as well? You are definitely seeing that the shells of the hermits are broken?

 

[rinker]

These were definetly hitchhikers and they do look like the CC starfish although at 1/8 very hard to be sure. Any idea how they would take down a hermit

 

[ophiura]

Sure they don't look like any of these?
https://www.saltwaterfish.com/vb/showthread.php?t=163871
I've never heard of anyone getting chocolate chip stars as hitch hikers. A picture would help. I've never seen any that small.
But they would not break the shell, nor, IMO would a star that small eat that many...in fact for a star that small the hermits are a threat. If the shell is broken, that is something like a mantis.
Where is your rock from...eg Florida, Fiji?

 

[rinker]

It does look like the picture of the Brown color asterina. I need to investigate a mantis shrimp. Could that be a hitch Hiker

 

[ophiura]

A mantis absolutely could be a hitch hiker.

 

[jdragunas]

actually, mantis are more often than not hichikers... i don't know anyone who would willingly put a mantis in their tank (unless the tank was designed to specifically hold a mantis...)

 

[rinker]

Any tips on finding a mantis if it's in there? I heard of using soda bottle?? :notsure: