Coral Skeleton Eating? - Starfish Hitchhiker id (with photos, doesn't look like asterina)

[ClutchCityReefer]

As the subject indicates, can anyone help ID the photos of the attached hitchhiker? I've seen it the last two mornings crawling around a euphilia base/skeleton (hammer yesterday and octospawn today, both still look fine).

This doesn't look like an asterina to me and I've read about starfish that eat LPS skeletons. That said, I am somewhat new to things so please let me know what you guys think. Should I try to procure a harelequin shrimp to wipe these out before my euphilia gets devoured?

 

[Cell]

Asterina starfish

 

[Brit’s Fish]

Looks like an asterina to me as well. I wouldn’t get a Harlequin shrimp unless you have a TON of these guys and you’re prepared to keep feeding it starfish after it hunts all the asterinas down. Otherwise, they’re pretty easy to keep pulling out of the tank. Wait until after lights out and you’ll find a lot of them.

 

[ClutchCityReefer]

Awesome thanks guys, I will leave them be they aren't a huge problem for me. This guy seemed so "regular" compared to the other asterina I have so I was worried it may be something different. I suppose for now I will just continue to monitor, thanks!

 

[Mr. Mojo Rising]

I have lots of the white asterina's, but no brown one's. I always understood that the brown one's were bad. Hope someone can confirm?

 

[ClutchCityReefer]

interesting thanks @LordofCinder, I guess its time to wait and see what others think...any more thoughts?

 

[ISpeakForTheSeas]

As the subject indicates, can anyone help ID the photos of the attached hitchhiker? I've seen it the last two mornings crawling around a euphilia base/skeleton (hammer yesterday and octospawn today, both still look fine).

This doesn't look like an asterina to me and I've read about starfish that eat LPS skeletons. That said, I am somewhat new to things so please let me know what you guys think. Should I try to procure a harelequin shrimp to wipe these out before my euphilia gets devoured?

Yeah, "Asterina" star (technically Aquilonastra) - it was probably crawling around to eat biofilm off the coral's skeleton rather than to eat the coral itself.

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 a possible exception for zoanthids).

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 (there are a handful of anecdotes of them going after other corals, but this seems to happen about as frequently as instances of tangs or clownfish going after corals).

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.

 

[ClutchCityReefer]

Thanks so much @ISpeakForTheSeas .... you've summed up a lot of what I have also read succinctly and given that I haven't seen my coral experience any negative consequences as a result of the stars I think it is best to just sit back - they definitely arent too much of a nuisance. I have too many different kinds of "pests" that I fear that totally eradicating one will just screw up the balance and let another take over (I have collonista snails, asterina stars, ghost/clear flatworms, etc.)

 

[ClutchCityReefer]

What's the communities take on asterinas in a sump? I have the little guy I photographed in the jar still. Can I put it in the sump to take care of some detritus in between the shop-vac sessions or is that just inviting disaster?

 

[ISpeakForTheSeas]

What's the communities take on asterinas in a sump? I have the little guy I photographed in the jar still. Can I put it in the sump to take care of some detritus in between the shop-vac sessions or is that just inviting disaster?

I honestly don't know if I've heard of someone keeping them intentionally in a sump, but I imagine it'd be fine (particularly if they can't access the DT from the sump).

 

[EeyoreIsMySpiritAnimal]

What's the communities take on asterinas in a sump? I have the little guy I photographed in the jar still. Can I put it in the sump to take care of some detritus in between the shop-vac sessions or is that just inviting disaster?

Not sure what "disaster" they would cause... As long as they have enough food, you can put them wherever.