So what's the TRUTH on Asterina Stars

[Stray32]

I have heard they are beneficial scavengers and that I should keep them in my tank.

And I just read about a guy that put a Harlequin in his tank to get rid of them.

So what's the deal? Are they good or bad?

FYI, I have about 20 or 30 in my DT.

 

[chrisstie]

Harlequins almost exclusively eat starfish bits. By "getting rid of them" I think he meant to feed his shrimp.

They are harmless little guys that cruise the glass. Suppoesdly they eat corraline algae and given enoughw ill multiply into many. I consider them good. Others may not like little tiny stars all over the place, though.

 

[SeaSpza]

I have never had any problems with them but I have read that some species will eat coral.The ones i have seen in pictures that were supposedly bad looked kind of light greenish.All the ones i have had were always all white or white with grey/brown on the backside.

 

[jhildebrand]

Agreed. Most species benign and harmless unless you have a population explosion. For the most part it's like bristleworms - they tend to get blamed for all kinds of stuff. There are a bunch of species though and just like all stars certain species can have different food preferences. we really don't see these species though and i'm pretty sure most reports are passing blame on them unfairly. 99.9% of the little white guys are fine in small numbers. After spending thousands on my system I still have people come over that think the damn little deformed starfish are the coolest thing in the tank. ~sigh~

 

[mastou]

I am also in doubt whether these small stars are good or bad, because it seems to me like they are a bit tough on some or my polyps (I tried to take a picture showing it):

They sometimes crawl on top of the polyps and sit there preventing the polyps from opening - but I don't know whether the damage is from the star eating the polyp or simply from preventing it from opening. However, it doesn't look like just a coincidence since I never see the stars sitting on the base of the polyps only on "head".

/Magnus

 

[neo1013]

think about 75 of them in a 125 is too many. they multiply like bunnies

 

[geofloors]

The tiny little blue/grey guys are definitely problematic. The larger brownish stars not so much. IME


George

 

[Freed]

I have thousands in my 180 gallon tank. You can see they only eat algae

 

[LeslieH]

I copied this from a reply I made to an earlier inquiry...

"There's 26 genera and many more species in the family Asterinidae. Even the genera require a specialist to tell them apart so you can imagine how hard it is to distinguish the various species of small asexually reproductive stars. Just on gross differences in appearance there seems to be several species showing up in tanks. The vast majority of animals are mild mannered grazers but there are a few that do feed on corals. Awhile ago I looked at a year's worth of posts/pics here on RC & elsewhere to see if there's a consistent difference. In general the very small white or cream colored ones are harmless. Coral & zoa eaters tend to be larger & have different colored mottling (orange, red, black, brown, gray, blue, green). Not every colored asterinid is dangerous mind you, but those are the ones to keep an eye on."

 

[madadi]

i seen one eat a polyp with my own eyes. the starfish had red speckles. in my tank i have a few colored ones. bluish, reddish, white and gray. the reason i noticed is because i had a new paly that had just 3 polyps and i was looking at it a lot. i dont know if other polyps have been eaten. the colony is too big now too notice.