Please tell me this is not a asterina...

[WalkerLoves_TheOcean]

I have a lot of these little stars around my tank, and if they are asterinas then... Well I don't know what I will do.

 

[ISpeakForTheSeas]

That's definitely an Aquilonastra star (known in the hobby as Asterina).

Some people consider them just a part of the CUC.

 

[JGT]

It’s not asterina… but it is…sorry.

 

[WalkerLoves_TheOcean]

That's definitely an Aquilonastra star (known in the hobby as Asterina).

Some people consider them just a part of the CUC.

Don't they eat corals though?

 

[Pistondog]

If the tank is 50 g or larger, wait until there are dozens or a hundred then get a harlequin shrimp. Cool little guy, only eats starfish.
Youll have to rehome when they are eaten, 3 or 4 months.
Def asterina

 

[WalkerLoves_TheOcean]

If the tank is 50 g or larger, wait until there are dozens or a hundred then get a harlequin shrimp. Cool little guy, only eats starfish.
Youll have to rehome when they are eaten, 3 or 4 months.
Def asterina

I have a 15g tank, so I don't think that will work for me though...

 

[ISpeakForTheSeas]

Don't they eat corals though?

It's disputed:

Personally, I like them, but they do tend to reproduce very quickly.

I've heard some species eat corals and others don't - I've seen convincing evidence for one species (a very darkly colored one), and one piece of somewhat convincing evidence for one different species, but the vast majority of these guys seem to be at least mostly safe.

With regards to whether or not the average "Asterina" (technically Aquilonastra - Asterina is a separate genus within the Asterinidae family) eat corals, it might be a species specific thing, it might be a you have way too many starfish so they're out of other food options thing, it might be they're eating the slime coat/mucus on the coral rather than the coral itself (see below), or they might just opportunistically eat unhealthy corals. Based on how starfish eat, it seems plausible to me that it may also be coincidental (i.e. the star goes to eat something off the coral and the coral just happens to be one that is able to be negatively effected by the star's everted stomach). Regardless, Zoas are just about the only coral I've heard about regular "Asterina" stars potentially going after with any sort of frequency.

A quote I like to refer to for this:

Timfish said:
It's an Aquilonastra spp. starfish and is a great scavenger. I see them with anywhere from 4 to 12 legs. The whole discusion around them seems to me excellent examples of misidentification, mistaken behaviour and assumed causality based just on heresay without looking at the research. Asterina spp starfish are preditary but only reproduce sexually and are shortlived so while it's possible some might get into a tank even if it did happen it's not going to be around long. Aquilonastra are one of the uncommon species that reproduce fissiparous or by splitting so are easy to identify by the different sized legs regrown after splitting. They perform an important function not only feeding off algae films but also feeding off microbial films including those on corals (at least ones that don't sting). FYI the mucus coating on corals ages and corals have to periodicely shed it to renew it and maintian healthy microbial processes (Ref 1, Ref 2). If Aquilonastra are feeding on zoas or softies I'll argue they are either benign or even beneficial as they may be reducing the unhealthy older mucus which can be full of unhealthy microbes which the animal is trying to get rid of and are far more likely to be the actual problem.

Here's an example, this Toadstool is doing one of it's periodic sheddings. The Aquilonastra have been in this system for years but only climb onto the Toadstool when it's shedding. In the first picture you can see the old mucus film, Aquilonastra starfish and areas they have cleaned off. The second picture shows the Toadstool a week later.

 

[Pistondog]

I have a 15g tank, so I don't think that will work for me though...

Manual control then.

 

[vetteguy53081]

I have a lot of these little stars around my tank, and if they are asterinas then... Well I don't know what I will do.

It is and I consider them a pest. They multiply like mice and end up in sumps, intakes, eat zoas and just a nuisance. While they eat some algae, they reproduce faster than algae accumulates.
Some love their presence while others are haunted by their presence. On My behalf, they have caused lots of problems especially a pair I caught (below) that attained the size of a nickel and took down a colony of BamBam zoa. I recently acquired colonies of acro and once again- Asterina
As before, I have manually removed them as I seen them and do know they are thinning out. Ironically most were found amongst my zoa once again.

I removed these who were eating my zoas

 

[WalkerLoves_TheOcean]

You have multiple threads asking the same stuff over and over again. Nothing but trolling now.

If you read my reply to your comment before, these are different. I am a beginner, who doesn't know much about the hobby. I just got live rock, and I am seeing something new almost everytime I look at the tank. I am just asking if I should remove them and looking for a ID. I am not trying to troll.

 

[ChrisPPolys]

I recently saw them at a LFS being sold for 25$ a starfish….I could not believe my eyes. thought the debate was finally over and Went to double check online where the debate continues to rage on. I’ve had them in my reef tank for years and never had a problem with them. That being said I do not have Zoa’s in my tank. Supposedly there are multiple types of Asterina and some are believed to be good, some are bad.
I only have a 32 gallon nano. If anything with a 15 gallon tank you can manually remove them.

When your lights are off at night they will be more active. As stated a harlequin is a cool addition to a tank and will completely wipe out any starfish. That being said you will need to get rid of the harlequin once it eradicates the population. (Which will take no time at all for a 15 gallon) They only eat starfish and will starve to death if you leave it in the tank.

 

[ISpeakForTheSeas]

Supposedly there are multiple types of Asterina and some are believed to be good, some are bad.

Yeah, there are currently 32 accepted species of Aquilonastra stars, so lots of different species out there.

WoRMS - World Register of Marine Species - Aquilonastra O'Loughlin in O'Loughlin & Waters, 2004

www.marinespecies.org

 

[WalkerLoves_TheOcean]

I recently saw them at a LFS being sold for 25$ a starfish….I could not believe my eyes. thought the debate was finally over and Went to double check online where the debate continues to rage on. I’ve had them in my reef tank for years and never had a problem with them. That being said I do not have Zoa’s in my tank. Supposedly there are multiple types of Asterina and some are believed to be good, some are bad.
I only have a 32 gallon nano. If anything with a 15 gallon tank you can manually remove them.

When your lights are off at night they will be more active. As stated a harlequin is a cool addition to a tank and will completely wipe out any starfish. That being said you will need to get rid of the harlequin once it eradicates the population. (Which will take no time at all for a 15 gallon) They only eat starfish and will starve to death if you leave it in the tank.

No way! 25 dollars for what some people consider a pest?? That's crazy! If they become a problem, I will start removing them, but for now they are kind of cool, so I think I may leave them. If I start seeing them reproduce, then I am taking all visible ones out, but like everyone else said, 15g is easy to maintain what is in it.

 

[ChrisPPolys]

Yeah, there are currently 32 accepted species of Aquilonastra stars, so lots of different species out there.

WoRMS - World Register of Marine Species - Aquilonastra O'Loughlin in O'Loughlin & Waters, 2004

www.marinespecies.org

Agreed. It’s interesting to note the one I saw for sale at the LFS was pretty big for an Asterina. It looked about the size of a dime. Mine really do not get big.

I’ve always been told if in doubt, take them out. Mine seem to be the good ones, free CUC!

 

[EeyoreIsMySpiritAnimal]

No way! 25 dollars for what some people consider a pest?? That's crazy! If they become a problem, I will start removing them, but for now they are kind of cool, so I think I may leave them. If I start seeing them reproduce, then I am taking all visible ones out, but like everyone else said, 15g is easy to maintain what is in it.

It also depends on what type of coral you have... IF they are a coral eating variety, they may prefer only one type of coral. I'm familiar with some that eat zoas but leave everything else alone.

 

[WalkerLoves_TheOcean]

It also depends on what type of coral you have... IF they are a coral eating variety, they may prefer only one type of coral. I'm familiar with some that eat zoas but leave everything else alone.

That's what I heard, most coral eating variety go after zoas, which to be honest I was not planning to put in the tank.

 

[EeyoreIsMySpiritAnimal]

That's what I heard, most coral eating variety go after zoas, which to be honest I was not planning to put in the tank.

I have some and they don't bother anything. In my 90, I let them get pretty numerous because I wanted a harlequin shrimp, but once it ate them all I had to get more from other hobbyists that wanted to give them away (once or twice I paid for some). Maybe there's someone in your area with a harlequin that would love to take some of yours if you get more than you want.

 

[Doctorgori]

I’ve had no problems with them in some tanks, pest in others…
I have 4 reef tanks: one is infested, one has a few, two tanks have none…no clue why
…if it were me, I would relentlessly remove every last one I see for the foreseeable future,…better safe than sorry

does the OP mind if I respectfully ask approx age/experience ?

 

[ChrisPPolys]

I have some and they don't bother anything. In my 90, I let them get pretty numerous because I wanted a harlequin shrimp, but once it ate them all I had to get more from other hobbyists that wanted to give them away (once or twice I paid for some). Maybe there's someone in your area with a harlequin that would love to take some of yours if you get more than you want.

If you have a 90 gallon just buy your harlequin a chocolate chip starfish lol

 

[WalkerLoves_TheOcean]

I’ve had no problems with them in some tanks, pest in others…
I have 4 reef tanks: one is infested, one has a few, two tanks have none…no clue why
…if it were me, I would relentlessly remove every last one I see for the foreseeable future,…better safe than sorry

does the OP mind if I respectfully ask approx age/experience ?

I am new to the hobby, and have had my tank cycling for 3 1/2 weeks now.