What is it?

[down and outman]

Sorry I don't have a pic. It moved as soon as I hit it with a light. It appears to be a large flat slug like creature about 2 inches long and an inch wide, oval shaped. Relatively flat with wavy edges, a couple of antenae and black with a thin white stripe in the middle. He was crawling on the glass of my overflow. I could see it thru the cave opening. I'm hoping it is some kind of glass cleaner type of critter. At least point me in the general direction to ID this critter. I always love finding new creatures in my tank.

 

[ReeferChick85]

Sounds like Stomatella . Google it and check to see if it is. If it is,they are beneficial to our reef tanks.

 

[down and outman]

Think I found it. Elephant slug. Check out the link:

http://www.seaslugforum.net/factsheet.cfm?base=scutus

It is a sponge and algal grazer, Cool Beans.

 

[noahm]

Sounds like it could be a polyclad flatworm from the speed of it. Some are good, some not.

Here are some good pics of diff species.

http://www.rzuser.uni-heidelberg.de/~bu6/Introduction07.html

 

[Shablin]

Sounds like a limpet to me. The white stripe is a shell under the skin; they are nocturnal; some can be harmful; i have several black limpets and never had a problem with them. They are about the size you describe, much larger than the stomatella I have.

here's a pic of one in my gallery

http://reefcentral.com/gallery/data/500/4675slug1.jpg

 

[down and outman]

Elephant slug, Shield Slug, and Ducksbill Limpet. That's what it is. He's off cleaning something. Lot's of hiding places in my tank.
Thanks!

 

[Elysia]

Yea, your description was spot on for Scutus. And great job finding the best info out there on the web for them. Scutus are a type of limpet, but they aren't carnivores. They are awesome snails.