Slug ID please

[barbra]

At least I think it is a slug. I have several scutus running around my tank. I found this guy last night. He is similar to the standard black variety I am used to, but different in a couple of ways:

*His mantle (or whatever you call it) does not cover the shell on his back - ever. The shell is larger and has what seems to be a brown pattern on it, but it could be algae growth and not a pattern at all.

*He is not black, but a dark grayish brown color.

*He is thicker than the black kind. His "bumper" that runs around the outside is not as elegant as the black ones and seems to have a lot more to it.

I watched him for quite a while and he appears to be eating algae only. Anyone have any ideas?

 

[GerritM]

Yes, it´s an Scutus unguis, they are variable.
http://www.poppe-images.com/?t=11&family=FISSURELLIDAE&fullspecies=Scutus unguis&catid=10

 

[barbra]

Thank you @GerritM, that's a great link :thumbsup:

 

[pagojoe]

As Gerrit says, it's a Scutus. Opinions differ as to how many species of Scutus may be lumped under the name S. unguis, but most of the researchers figure there at at least a couple. The species was named from the dead shell, which leaves the question unanswered as to which species was actually named Scutus unguis, assuming there are more than one species with essentially identical shells. I believe there are researchers currently working on the problem at the molecular level, so some of the questions may be answered fairly soon. It still might be difficult to say which species should properly be called S. unguis, though.

Cheers,



Don