been seeing this little critter around my tank. I haven't seen it harming coral in any way. just wondering if anyone knows what kind of starfish it is and whether it's beneficial or a pest.
asternia starfish, generally safe. there are a lot of different types, most eat algae but some can eat your zoanthids. never had this happen to me personally
Asterina Starfish. As long as they don't reach plague proportions from uneaten food and poor husbandry, they are not terrible to have. I used to have a lot. Hitchhiked on live rock. They do eat Coralline algae. So if you see your purple on your rock with white spots here and there, they are the ones eating it. I don't mind it, but if you love Coralline algae, definitely remove them. If you put them into the sump, some can make it back into the display. I have had that happen before I know as crazy as it sounds. Harlequin shrimp can eat them but will go hungry once all the starfish are gone. If you don't like them, you can always give them to me!