Brown Slug

[gregk]

:help: I noticed a brown slug in my reef tank that only comes out at night. It has a small black shell on its back that resembles an oyster.
Does anybody know what this is? Is it harmful? Please advise.
Thank you...........Greg

 

[fender]

Limpet, it's cool.

 

[gregk]

Thanks Fender

 

[bonebrake]

Doesn't sound like a limpet.
My bet is on a snail from the genus Stomatella.

:joy:

 

[krull001]

remove it from the tank.. they like to attack corals from time to time

 

[fender]

Don't you love it. lots of answers.
Bonebrake is probably right but the black color and oyster shaped shell led me to a limpet. Some of them (keyhole limpets and a couple others) might be harmful but Stomatellas are fine and people even spend money from some places to get them. Watch them and take a pic for better identification if needed. Truth is there is alot of stuff in the ocean and we get a best guess on things (especially without a pic) and just because one person has good fortune doesn't mean another will. Keep an eye on them and remove if you have problems.
p.s. Stometellas often "stand" on a rock and "spawn" - you can see the eggs and sperm being dispersed in the water column. Doesn't harm anything and will provide food for you filter feeders. (and maybe babies later).