What's this?

[Dave-T]

This came off when I dipped some new Coral in KCl

 

[tbrown]

Chiton I believe.

 

[Dave-T]

I thought chitons had shells?

 

[tbrown]

Maybe. It looks like an isopod of some sort which chitons are isopods I believe.
@ISpeakForTheSeas ?

 

[ISpeakForTheSeas]

Going from the pic, it's either a chiton (segmented shell like a rolypoly on top, snail foot underneath), or an isopod (rolypoly's and relatives; segmented shell on top, little legs underneath).

Chitons are a kind of mollusk (like clams, snails, nudibranchs, octopuses, etc.) while isopods are arthropod crustaceans (like crabs, shrimp, copepods, lobsters, etc.).

There's a small chance it could be a limpet or similar (one-piece, non-segmented shell on top, snail foot underneath), but the elongated shape would be quite unusual for that, so I doubt it.

 

[Dave-T]

Thanks! In any case, it's not anything I have to worry about it eating my corals.

 

[ISpeakForTheSeas]

Thanks! In any case, it's not anything I have to worry about it eating my corals.

Chitons are harmless/beneficial; most isopods are too, but a handful of kinds are problematic (fish and inverts parasites and/or "micro-predators").