Bottom of Goni colony

[joefishtank]

I bought a Goni colony and it has a lot of critters under it. I’m going to frag it and wonder if I should try to save some for my micro tank. There are more starfishes on a different coral I bought I think they are the same kind.

 

[blaxsun]

 

[joefishtank]

I kept 4 stars and 2 mussel shells 1 starfish I put in my main tank so if it is bad plz lmk. I also fragged and did my new coral procedure.

 

[A Young Reefer]

what kind of starfish? if asterina I would avoid adding them they can explode in numbers and certain species of them are said to eat corals.

 

[joefishtank]

what kind of starfish? if asterina I would avoid adding them they can explode in numbers and certain species of them are said to eat corals.

 

[A Young Reefer]

yep those are asterina remove them, bad for the most part.

 

[joefishtank]

If it's still where I saw it last I'll put it in my micro tank lol if not I don't mind watching it for a while in my nano tank.

 

[ISpeakForTheSeas]

Yeah, some people hate these starfish and believe they eat corals, and some people like them/think they’re good CUC.

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.

 

[reefsUP2]

I bought a Goni colony and it has a lot of critters under it. I’m going to frag it and wonder if I should try to save some for my micro tank. There are more starfishes on a different coral I bought I think they are the same kind.

I always use a tooth brush to clean of most when in doubt.better safe than sorry later.

 

[vetteguy53081]

I bought a Goni colony and it has a lot of critters under it. I’m going to frag it and wonder if I should try to save some for my micro tank. There are more starfishes on a different coral I bought I think they are the same kind.

One vermetid and various sponges - most everything that desires darker low flow areas
Bottoms of many plugs often have secret tenants
Asterinas will take down coral mainly zoa in time. These guys took down a bamBam colony of mine

 

[joefishtank]

I think they are Aquilonastra asterina based on the fact that some of the legs are shorter than others. In my tank they are probably as dangerous as shrimp, but they might explode in population since I over feed and I'm trying to grow micro algae in my tank as part of the ecosytem like a refugium. I think if they did explode in population I would get a harlequin shrimp and hope it balances their numbers and I don't have to source extra starfish for it.