Should I be concerned?

These guys hitched in with my latest macro shipment. Either they grow really fast, or this is the first time I've seen the big guy. There's these three (that I know of) in the sump, and one made it into my DT yesterday. Can anyone tell me what they are and if I should worry?

 

They look like some sort of flat worm or nudibranch.. Will be tagging along to see if someone knows. Im curious now

 

Make that five in the sump now.
I was thinking nudibranch too, but I've seen pics and read on other forums that it could be a harmless slug.
Anyone? Anyone? Buler? Buler?........

 

well, I am curious.. So here is a bump8)

 

try oxynoe viridis and see if it looks anything like one of the many variations. My guess is that this guy feeds on the macroalgae he came with.

 

Yep, it's an Oxynoe species, an algae eater. It's probably either a variant of O. viridis as SAY says, or if it's from the Atlantic/Caribbean, O. antillarum.

Cheers,



Don

 

SAY, you appear to be correct! Thank you very much!