Nassarius Snails vs Hermits

[bbl_nk]

Strange one for you all and wondering if anyone else experienced this. I have read all over people warning about hermits taking out your snail population and have seen it the other way around in my tank.

After a month of cycling my 75g I thought it was time to bring in a clean up crew to take care of some algae on the live rock. Well I found one hermit body one morning and no shell. I thought maybe it was a hermit vs. hermit thing over a shell.

Well one night I peeked in on the tank and in an archway of my live rock over the substrate I noticed a small hermit (shell about 3/8 of an inch long) stuck in a spot in the aragonite substrate. It was "after hours" and was peeking in with a dim flashlight when I noticed one of my snails out.

To me it appeared as if the snail was stuck in a glob of sand and snail secretion with the crab struggling to free itself as the snail approached. The snail slowly crawled to the shell and began to climb over it. With no place to go, the hermit crab left its shell and tried to take refuge out of the snails grasp.

THen one morning I swear there was a conga line of about 6 hermits looking to save their compadre from a snail enveloping the shell. Needles to say another snail moved in to help and now I have one empty shell in my substrate.

I have more on it on my blog at http://oceanathome.blogspot.com/2008/06/reverse-predation-nassarius-snail-vs.html and have a video I'll look to post tomorrow.

[rroselavy]

I have some Zebra hermits that are frequently looking to upgrade their shells, and have pestered various snails in the course of hermit events. The latest run was after I added six Cerith snails to the tank. Despite having extra shells in the tank, the hermits went for the ceriths. It is pretty ridiculous for the hermit to wear a elongated shell that runs perpendicular to their path. Makes movement across the LR fairly awkward and tenuous. Perhaps it is a fashion statement?

Two Ceriths fell victim to the hermit onslaught, and a third was on the way. When I discovered the hermit who had left his shell to occupy the now vacant Cerith, it was just in time to see a speeding Nassarius bearing down on the defenseless hermit. I tried twice to dissuade the Nassarius, but he remained determined to strike back on behalf of his brethren. I relented, and watched as the Nass wrapped his foot around the hermit, as if to constrict or smother the poor sod.

Just another form of competition dynamic in the tank.

[CarmieJo]

My tank never has things like this happen!

[PhotoJohn]

thats amazing!