Hermit Crabs being picked off at Night

[VKernus]

Every morning when I go to feed the fish, I notice another small Hermit Crab fatality.  Not sure who is responsible. All that is left are the legs and head.

 

Tank inhabitants:

 

Sm Hippo Tang

Fox Face

Lyretail Anthias

Chromis

Purple Fire Fish

Watchman Gobi

Brittle Star

Peppermint Shrimp

Blood Red Fire Shrimp

Tiger Pistol Shrimp

Tuxedo Urchin

 

Any thoughts on who may be the culprit?

 

[PupChow]

I wonder if your small hermits were molting?

[VKernus]

Never thought of that.  The other crabs seem to be eating the remains.  There are a number of empty shells.  I did not keep track of whether the crabs perhaps took up a new home.

[Matt LeBaron]

In my experience, the Pistol Shrimp is your likely culprit. Before mine passed away I had to buy more small hermits every 4-6 months because he slowly killed off my population. I always found the poor guys dead outside one of his holes, I believe that they got to close and he didn't appreciate their presence. Every morning is a bit extreme but maybe you have a very angry shrimp.

[VKernus]

Thanks for the response Matt. 

 

My pistol has built himself quite the under sand condo system.  Extends across nearly half the 90 gallon tank.  He has multiple openings.  Plenty of food in the tank, perhaps it is a combination of molting and the pistol.

[Matt LeBaron]

My tank is a 90G too and my shrimp and gobies would pop up all over the tank from one side to the other.

[VKernus]

Shrimp did not invite Goby into the cave.  The goby does stand watch for him though

[Matt LeBaron]

I got my two gobies and the shrimp as a Divers Den combo years ago so they all hung out together. Sometimes I wouldn't see them for days if they were all hanging out in the tunnel system the pistol shrimp dug. While I was sad when the shrimp passed away, I do see my gobies a lot more often now.