Snail ID

[sultros]

Hey there Dr. Ron. A few nights ago I noticed something sticking out like a pyramid from under a piece of live rock. I thought it was an inflated tunicate or something and passed it off as just the same unusual stuff I see. This morning I noticed it again...this time in a different spot so I turned the rock over. Low and behold it turned out to be a snail...and one ive never before encountered

My picture of its bottom isnt the best but I'll compare it to a stomatella/abalone. It doesnt have the ability to "retract" into its shell like most other common smails. It has the same grazing set up as a astrea with a scraping radula and two "feelers". After placing it on the glass, it immediately joined the rest of my clean up crew grazing on algae.

My favorite part of this hobby is finding creatures like this. Amazingly, this snail is almost 1inch and Im amazed ive never noticed it before. Makes me wonder what else is lurking in the depths

http://reefcentral.com/gallery/showphoto.php?photo=45430

http://reefcentral.com/gallery/data/500/54577snail_top.JPG

http://reefcentral.com/gallery/data/500/54577snail_bottom.JPG

[rshimek]

Hi,

It is a keyhole limpet, they are common hitchhikers.

Keyhole limpets are gastropods with a conical shell with an aperture near the apex. The aperture may be round or slit shaped and may be either on the aperture or displaced somewhat forward of the apex. This aperture is an excurrent aperture for breathing water. The gills lie just behind the head, on the body under the shell and the breathing water is brought in from the front and exits through the hole in the top of the shell. As with true limpet snails, the shell here is coiled but all evidence of this is lost early in development.

As with the true limpets, these animals make their living by rasping food off of rocks. Unlike true limpets, keyhole limpets also tend to graze on sessile animals such as sponges, soft corals and hydroids. I know of none that have been implicated in grazing on corals, but I think it is likely that some species may do so. Shallow-water keyhole limpets appear to be largely omnivorous, eating both plant and animal materials. Deeper water forms seem to be wholly carnivorous.

As with the true limpets, some of them have very strong radular teeth and may scratch or groove acrylic tanks.

They require reef normal conditions to do well, and of course require a steady diet. The latter is generally not a problem, as a number of them appear to be able to eat just about anything. They typically are oval in cross-section, often with raised ribs radiating from the apical opening. The ones seen in aquaria are generally less than two centimeters in length, but there are larger species.

[sultros]

Thanks a ton for the help.

It looks like I have one of the larger species. This one is about an inch.

Hopefully it will do well in combating my algae.