Who’s this little guy?

[TristanBara1273!!]

I went into my room to check on my clownfish and i see this little guy. should i be concerned?

 

[ying yang]

Asterina starfish.
Some say totally reef safe and some say some kinds may eat corals.
So depends who you ask of reef safe or not ^_^

Edit: also fwiw I see most call them asterina starfish bit just lately see quite a few call them something different but can't remember name lol

 

[Jedi1199]

I went into my room to check on my clownfish and i see this little guy. should i be concerned?

Sweet little Asterina starfish. I hope you like him.. he invited 10,000 of his friends to the party....

Totally safe for the tank... no worries there.

 

[TristanBara1273!!]

Sweet little Asterina starfish. I hope you like him.. he invited 10,000 of his friends to the party....

what?!!?

 

[ying yang]

what?!!?

He saying they reproduce quickly,they detach a limb and then you got another and so on

 

[Jedi1199]

what?!!?

Haha!! These little guys are prolific multipliers. That one will be hundreds in short order.

 

[ISpeakForTheSeas]

Asterina starfish.
Some say totally reef safe and some say some kinds may eat corals.
So depends who you ask of reef safe or not ^_^

Edit: also fwiw I see most call them asterina starfish bit just lately see quite a few call them something different but can't remember name lol

They’re technically Aquilonastra starfish, but they’re known in the hobby as Asterinas (which are actually an entirely different genus of predatory starfish).

Yeah, they’re generally considered reef safe, but some people think they eat corals - as mentioned it might be a species thing, or a number of starfish thing, or just a big misunderstanding (there’s some evidence to suggest they may actually be beneficial to the corals, but it’s not for sure).

Either way, they do reproduce fast enough to cause most people to want to get rid of them.

 

[Goaway]

They’re technically Aquilonastra starfish, but they’re known in the hobby as Asterinas (which are actually an entirely different genus of predatory starfish).

Yeah, they’re generally considered reef safe, but some people think they eat corals - as mentioned it might be a species thing, or a number of starfish thing, or just a big misunderstanding (there’s some evidence to suggest they may actually be beneficial to the corals, but it’s not for sure).

Either way, they do reproduce fast enough to cause most people to want to get rid of them.

From web search.
Aquilonastra is a genus of small sea stars within the family Asterinidae. It has over 20 described species. I don't see any issues with calling them asterina. I guess asterini would be better.

 

[Tamberav]

I have them, I like them. They eat algae off my glass/rocks. They mostly come out at night and during water changes I do cull the numbers by sucking them off the glass.

 

[ISpeakForTheSeas]

From web search.
Aquilonastra is a genus of small sea stars within the family Asterinidae. It has over 20 described species. I don't see any issues with calling them asterina. I guess asterini would be better.

There’s not a problem, it’s just a technicality, and they’re widely known as Asterinas to the hobby, so there’s little confusion about which species are meant when it’s brought up - I was just explaining what and why they’re sometimes called by other names on the board here.

Aquilonastra and Asterina are both from the same family (Asterinidae), but they’re different genuses, and they typically have different diets and methods of reproduction (fissiparous vs oviparous). Asterini may be more accurate for specimens of the family than Asterina, but, again, as it’s used in the hobby, I don’t see an issue with Asterina.

 

[Goaway]

There’s not a problem, it’s just a technicality, and they’re widely known as Asterinas to the hobby, so there’s little confusion about which species are meant when it’s brought up - I was just explaining what and why they’re sometimes called by other names on the board here.

Aquilonastra and Asterina are both from the same family (Asterinidae), but they’re different genuses, and they typically have different diets and methods of reproduction (fissiparous vs oviparous). Asterini may be more accurate for specimens of the family than Asterina, but, again, as it’s used in the hobby, I don’t see an issue with Asterina.

There's the big issue. Knowing who is who. Some eat soft coral.. So, I have heard.

I have these little guys in my sump for 2 years. Never multiplied into plague portions as others I have kept.

 

[aurora.k]

I call them asterinas and don’t have an opinion on whether that is right, BUT I like them too. I’ve never seen one on a coral, just on the live rock or glass. Not plague populations for me either. Also people who always visit don’t care about my $x hundred coral but are like “oh my god, look at this cute little starfish”

 

[ISpeakForTheSeas]

There's the big issue. Knowing who is who. Some eat soft coral.. So, I have heard.

I have these little guys in my sump for 2 years. Never multiplied into plague portions as others I have kept.

Yeah, in the OP’s case here, the six legs and different length of legs is typical of fissiparous reproduction, so I’d feel quite confident it’s an Aquilonastra.

Again though, I don’t see anything wrong with calling them Asterinas - and I actually like them too; I plan on keeping pretty well as many species of them as I can find.

With regards to whether or not they eat corals, Timfish has some great posts about that, including this one here:

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.

 

[Lavey29]

Haha!! These little guys are prolific multipliers. That one will be hundreds in short order.

Surprisingly that did not occur with me for some reason. I wonder if wrasses eat the small ones? I saw a few on the glass many months back but nine now.

 

[Goaway]

Yeah, in the OP’s case here, the six legs and different length of legs is typical of fissiparous reproduction, so I’d feel quite confident it’s an Aquilonastra.

Again though, I don’t see anything wrong with calling them Asterinas - and I actually like them too; I plan on keeping pretty well as many species of them as I can find.

With regards to whether or not they eat corals, Timfish has some great posts about that, including this one here:

Very good read. As I never had any eat my coral. Makes sense about them cleaning up coral mucus. Since softies often can shed.

 

[Goaway]

Surprisingly that did not occur with me for some reason. I wonder if wrasses eat the small ones? I saw a few on the glass many months back but nine now.

I wonder about that. I like the tiny starfish. My wrasse eats everything. I can't keep hermits in my dt either. Melanurus is a monster.

 

[Jedi1199]

Surprisingly that did not occur with me for some reason. I wonder if wrasses eat the small ones? I saw a few on the glass many months back but nine now.

Check out the tank after lights out.. They are nocturnal and in my own tank, I see them mostly after dark. I see one here and there in daylight hours, but when the lights go out, they cover my glass.