Slug or Snail ID

[kewwlkat123]

I noticed a slug like creature today on my rocks. I took a few pictures and then attempted to remove him by grabbing him with tweezers. That didn't work as the last photo shows. He was attached to the rock and I was unable to get him and he split. The head portion was able to escape and move into the rocks. The last picture shows the remaining piece on the rock and this piece continued to move and wiggle as if nothing happened to the snail. After a half hour or so I looked for that piece and it had disappeared. Here's a few photos...any ideas what it could be and if it's good or bad so I can remove him if I come across him again if needed.

 

[twelvejewelz]

Stomatella snail? http://www.reefcorner.com/SpecimenSheets/stomatella_varia.htm

 

[kewwlkat123]

Thanks for the ID. It does seem to a Stomatella or something very similar. If someone objects please advice here.

http://reefkeeping.com/issues/2004-05/rs/index.php

"Their shell shape precludes their retraction into the shell, but evolution has given them a rather neat way to escape many predators. The rear portion of their foot can break off, much like some lizards' tails, when they are threatened by a predator. The detached portion then writhes, and twists and otherwise distracts the predator while the snail, presumably, makes good its escape. "

This is what the one in my tank did.

Thanks twelvejewelz!

 

[pagojoe]

Yep, it's a Stomatella (probably Stomatella varia). The ability to autotomize the rear portion of the foot isn't all that common in the molluscan world, but Stomatella snails will do it readily if harassed or threatened. Harp Shells (Harpa species) and their relatives may also do this, and I've seen one species of cowry do it (Cypraea caurica). Some Discodoris species of nudibranchs will also drop the outer ring of the mantle in an attempt to escape predation.

Cheers,




Don

 

[xurifle06]

I found something similar on my rocks this morning. I believe it is the same snail. From what ive read they are very good cleaners and rapidly reproduce.

Rich