[rjs5134]

Shortly after adding Chaeto to my sump/refugium I noticed these snail like inverts on my Monti. caps. They don't appear to be harming the corals, but always seem to be sitting on top of the Monti. caps.

Any idea what they may be? Are they harmful or beneficial?

Thank you

[scubadude]

Not 100% but they appear to be a chiton. You might want to do an image search on google for "chiton" and compare to what you are seeing and see if the match is close. If they are truely chitons then I dont think you have anything to worry about.....But you say they are ontop of the montiporas? Can you take some pics of them in action? Do they seem to favor the montis more than anywhere else in the tank?

[rjs5134]

Thanks Rocky, They sit(like in the left photo) right on top of the flat M. cap, several of them at once. I don't see any tissue damage, yet, but it has been a few weeks. I haven't noticed them anywhere else, except in the QT, but that may be because they are so obvious sitting in the middle of a purple or orange field. I QT'd my Chaeto for a few weeks and now I have dozens of these guys in the QT.

[scubadude]

Hmmm....is there a patch of algae maybe where they have been all congregating ontop of the M. Cap? They primarily are algae grazers

[rjs5134]

Rocky, I was told on another forum to look up "limpets" and found some pictures that are similar, but not exact, mostly in size. There is no algae on the M. caps, but they are always sitting right on top. Right now I'm going to go with limpets until I find something closer, or see damage, then they're outta there.

Thanks

[zhenya]

Hi Rob,

It is hard to be precise with the images that you provided.., however, if you see eight shells on the back of this snails then they are indeed the Chitons.
I couldn't quite make out in your second picture if there are any shells(or plates on the back of the snail), but looking at the first image makes me think that it is a different snail of some sort. Can you tell what size these snails are, or perhaps describe their physical attributes a bit more detailed?
Chitons belong to the class Polyplacophora if you want to do a scholar search.

On a side note, if you would like to take a better image of one, take it out of the tank into the shallow dish with tank water and take a shot of it from the top. Then take if out of the dish and if it has an aperture wait until animal withdraws completely into the shell and take a picture of the aperture. Chitons do not have an outside shell that they can withdraw into, so it should be an abvious feature that could tell if it is a Chiton or a regular snail.

[zhenya]

Originally Posted by rjs5134

Rocky, I was told on another forum to look up "limpets" and found some pictures that are similar, but not exact, mostly in size. There is no algae on the M. caps, but they are always sitting right on top. Right now I'm going to go with limpets until I find something closer, or see damage, then they're outta there.

Thanks

They do remind me of limpets(and some of them do eat corals) but what species exactly they belong to is hard to tell from the images.

[scubadude]

im sorry you guys are right....limpets...was my fault....FWIW I was thinking limpets :P

[rjs5134]

Rocky I had a suspicion that's what you meant. Thanks for the ID guys, I feel better. Funny, now they've moved from the M. caps and I haven't seen them in a few days. I guess it was a good spot for a couple of weeks but it was time to move on.

Rob