Pest or Sea Hare

[Horsham Mark]

Hi

can somebody help identify these for, have noticed several feeding side of aquarium after dark, have siphoned them off as I’m concerned they are done type of pest. Fast moving critters.

corals all seem fine

thanks in advance for any help/assistance/guidance

 

[Dennis Cartier]

Hard to tell from the pics, but does it have a fingernail sized shell on it's back? If so they are the good guys, a Stomatella snail would be my guess.

Welcome to Reef 2 Reef as well!

Dennis

 

[JGT]

Stomatella, herbivore, good guy.