SOme kind of starfish-Good or Bad?

Its amazing the little things you find in your tank in the AM when the lights go on!! Never seen this star in my tank assuming its an asterina species maybe??

 

Yep, Asterina. Should be harmless. While there are species that feed on Zoas, they're normally found on Zoa colonies, not algae or Coralline covered rocks.

 

Thanks I dont even have any zoas at the time being. I did read that they eat coralline but I dont see any coralline patches with lines going through them they are all perfectly circular and spreading

 

I believe there is only one zoa eating species. The ones that eat coralline seem to be bluish in color.

 

Mine seems white/pink/tannish (sorry colorblind) so I guess its jsut an algae grazer??

 

they will eat the coralline algae, you may not notice when they are in small numbers. Over time they can take over, and your coralline will slowly disappear. I had a outbreak of them so bad in my old 75 there was no purple left.... Solution was a harlequin shrimp (there were hundreds)

 

I can personally attest to the fact that they do eat coralline! Off the rock, walls and everywhere else. Leaving behind small white spots. Looks like they suck the color right out of the algae.

 

This is an excellent article on Asterina. There are multitude of different types. As previously mentioned some do indeed eat Coralline. Other types may be opportunistic and begin to eat corals. Some types just eat corals as the primary food source.

I have had them eat Zoanthids, seen a few well documented thread regarding Asterina feeding on SPS.

As with most things available food source dictates population numbers.

Reefkeeping Magazine - Reefkeeping 101

 

they eat zoas and palys and coriline and are potential an major problem when the numbers get up i had a bad outbreak also... i never want that again if i ever see one i pluck it out. not only do they eat corals the irritate other corals to the point of frogspawns shrinkin up and never showing their heads again....... Garf's has a good acticle on them

 

I have some of those. They come and go and when there is excess food in the bottom they will multiply. What I don't like is that they never have five points like a normal star..