Pin Cushion Urchin

[jackinfobo]

So my LFS has a really cool looking black and orange pin cushion urchin right now. How much algae do they typically eat compared to coraline algae?
Thanks!

[katarina]

I have a small one, maybe two inches across. It eats the algae in it's path. It seems to have a track that it sticks to for the most part and in that path it eats everything. As for the coraline, it eats what it can reach. It seems to have a hard time getting into nooks and crannies.