Crab and Snail???

[Fishdude]

Hi,

I need some help on identifying some crabs and snails. I have these two crabs about the size of a fingertip that have red and white striped legs. There also seem to be these red and white bands around the edge of the shell too. They hide in rock crevices during the daytime and only come out a little ways at night. If you shine a light on them, they recede back into their holes. I've noticed these guys for a while with no visible signs of any damage to anything. Just wondering if anyone knows what they are.

I also have some small snails that have 1 thick proboscis that come out at night. I think one killed another small grazer snail I had. The grazer got stuck against the glass and one day I noticed one of the other snails on it. When I looked, the grazer was nothing but an empty shell. Are these guys predators and should I get rid of them???

Thanks.

 

[Wormy]

Don't know about your crabs, but I think I have the same kind of snail in my tank. The only ID's I've seen on it are of the "some kind of whelk" variety. These guys seem to eat snails that are much smaller then they are. I've got a lot of breeding snails in my tank, so I haven't had problems yet. I've got at least 3 of these whelks, one of which is getting quite large (about an inch long now, and growing fast). I figure I'll eventually have to pull them out, but for now they aren't destroying my grazing snail population (the snails are still out populating their predators), and are pretty neat to watch. If your snails aren't breeding, or you notice a decrease in your snail population, I'd remove these predators.