i am thinking it’s a snail of some sort, about 3/4 inch. i can almost see 2 thin antennae type things coming out of the hole at the bottom. lights are on.
Vermitid maybe? Is it stuck to the rock?
Not the typical type, but a larger type. They often come out of the Caribbean. Filter feeder. Harmless.
thanks. odd vermetid if that’s what it is, b/c i can’t locate any pics on google images that look similar. kinda nice anyway.
Semi similar images:
http://www.melevsreef.com/id/vermetid.html
http://www.reefs.org/hhfaq/worms/vermetid1.jpg
Best test you could do:
Mix up some frozen food and don’t rinse it, add a little bit of the raw juice to that aquarium.(and use the feed timer to kill the main circulation pumps for 5 minutes) If it puts out a net to collect food, but is stationary and doesn’t move then it is a stationary snail which I would refer to as a vermetid snail. It may technically be something part of another genus, but I don’t think it is doing any harm. Larger species like that and ones with dark color typically do not reproduce quickly at all and I wouldn’t call them a pest. Some people call the smaller species pests, but they only reproduce in large numbers when nutrients are high.