Please help me ID, thanks

[TNT]

 

[user 26995]

Looks like a dorid nudibranch

 

[tike]

Definitely a nudibranch ....maybe Chromodoris rubrocornuta. Most are sponge eaters but not real sure on this one. There are just sooooooo many of them! I think it looks REALLY cool!

 

[TNT]

Sponge eaters ...Ok I have a Aussie spider sponge in my tank, no wonder he was next to it...Really appreciated the help. I not gonna put him back...

 

[returnofsid]

Moving to Leslie's Invert Forum, for Leslie's input.

 

[Boomer]

That looks like a Sidegill slug to me, a non-nudy. I see no external gill. Really need a better pic.

 

[user 26995]

They come in many different colors, but doesnt it look like this?
DSCF9209.JPG | Flickr - Photo Sharing!

 

[Boomer]

That is a Dorid nudibranch, this is a Sidegill Slug.

 

[Boomer]

Or does it look more like this

Chromodoris sp. Nudibranch

 

[Boomer]

Here are the groups for ID

 

[LeslieH]

IPisces & Boomer are right, it's a dorid nudibranch.

Definitely not Chromodoris rubrocornuta, color & papillation on the back are way different - The Sea Slug Forum - Chromodoris rubrocornuta

Not a Chromodoris at all. The members of that genus usually have long bodies and smooth dorsums (backs).

One thing that EXTREMELY useful to know before trying to identify something is where did it come from. There can be similar-looking animals from very different localities, such as the Rostanga pulchra that IPisces linked which comes from the US west coast and other species of Rostanga from the Caribbean & Indo-Pacific. Without knowing the area of origin, I'd be happy to leave it as probably a species of Rostanga, dorids with obvious papillated backs. They are sponge eaters and the individual species are very particular about which sponges they will eat. Usually the animal's color matches the color of the food sponge so they are very well camouflaged. Even the color of the eggs will match the food sponge.

Some other species of Rostanga just for comparison & another dorid showing the back --
The Sea Slug Forum - Rostanga bifurcata
The Sea Slug Forum - Doriopsis granulosa
The Sea Slug Forum - Rostanga rubra

 

[Boomer]

Me not correct I thought it was more like a sidegill but this Rostanga rubra is more like it I missed page 62 of my "nuke" book where there is a

Rostanga muscula that looks like his.

and Rostanga_elandsia is similar

 

[user 26995]

this one is soo cute!

That is a Dorid nudibranch, this is a Sidegill Slug.

[/img]