Starfish ID

[WhitePanther93]

Spotted one of these little guys hitching a ride on one of my nassarius snails a while back. Wasn’t able to get my lense filter in time to get a good pic. (I swear that thing disappears whenever I need it)

I’ve been seeing thes guys a little more often recently. Should I be worried? I haven’t seen any of my corals particularly ticked off by them so I’m not worried yet.

 

[ManWithAClam]

aquilonastra starfish

 

[WhitePanther93]

aquilonastra starfish

Judging by your lack of urgency I’m guessing they’re fine?

 

[IKD]

I would have guess asterina starfish. Middd reviews on coral safeness. If he’s hanging on/around your zoanthids, I would remove out of caution

 

[ISpeakForTheSeas]

As mentioned, mixed reviews on their reef-safeness. Most of them probably don't eat corals (the corals that are purportedly eaten most often are zoas), but some of them may.

For the long answer, see the quotes below:

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.

 

[WhitePanther93]

As mentioned, mixed reviews on their reef-safeness. Most of them probably don't eat corals (the corals that are purportedly eaten most often are zoas), but some of them may.

For the long answer, see the quotes below:

All I see is a possible excuse to get a harlequin shimp

 

[ISpeakForTheSeas]

All I see is a possible excuse to get a harlequin shimp

That's fair. Just be aware that harlequins tend to clear these stars out pretty quickly, and they will need fed other starfish once the Aquilonastras are all gone.

 

[WhitePanther93]

That's fair. Just be aware that harlequins tend to clear these stars out pretty quickly, and they will need fed other starfish once the Aquilonastras are all gone.

Maybe I’ll try to propagate them.

 

[ISpeakForTheSeas]

Maybe I’ll try to propagate them.

If you do, I'd love to know how many Aquilonastra stars it takes daily to feed a harlequin shrimp.

 

[EeyoreIsMySpiritAnimal]

Maybe I’ll try to propagate them.

Doesn't work that way, a shrimp will outpace any propagation attempt.

 

[ISpeakForTheSeas]

Yeah, you would need a pretty intensive farming setup with these guys to get enough to feed them (which is part of why I commented that I'd love to know how many you'd need each day to feed one). So, you'd likely need to have a several hundred gallons worth of space outside the harlequin tank to grow enough stars for the shrimp.

 

[WhitePanther93]

Yeah, you would need a pretty intensive farming setup with these guys to get enough to feed them (which is part of why I commented that I'd love to know how many you'd need each day to feed one). So, you'd likely need to have a several hundred gallons worth of space outside the harlequin tank to grow enough stars for the shrimp.

Holy crap really?

 

[ISpeakForTheSeas]

Holy crap really?

Yeah, I've seen people on here use just a pair of harlequins to clear several hundred Aquilonastra stars out of large tanks in a matter of months (I think the biggest tanks I've seen cleaned out were ~300 gallons, but I don't recall for sure).

Edit: just to add, if you were to try and farm them, I'd probably try a lot of long, wide, and shallow tanks to maximize space for them, since they wouldn't need a water column to swim in.

 

[EeyoreIsMySpiritAnimal]

You can also feed them chocolate chip starfish, but that gets expensive... I had a large harlequin that ate 2-3 chocolate chips per month... Ended up passing it on to another reefer with an asterina problem.