HELP! Is this Asterina Starfish?

[maximinireef]

Hi, I am aware that asterina starfish are kind of controversial in the hobby because some swear they eat their zoas/corals. I noticed this starfish hitch hike with my coral. It doesn’t move during the day time and seems more active at night. I would probably keep it if it’s an asterina starfish, however, I do understand that there’s a lot of starfish species that resemble each other. Can someone double check if this is an asterina starfish? 
 

I noticed it earlier today. I do not think it is harming any of my corals. I took the picture at night when everything else was close

[patback]

Yes. Asterina. 

[Tired]

It might start chewing corals out of sheer desperation, if all your rock is that white. There's nothing in there for it to eat. That's what causes a lot of the bad reports against them, I'd wager; they hitchhike into newer tanks, get hungry, and eat anything they can.

 

Also, you're likely going to run into some issues with lighting, putting all those corals up together. SPS want different lighting than ricordea and zoas do.

[maximinireef]

On 4/5/2023 at 10:13 PM, Tired said:

It might start chewing corals out of sheer desperation, if all your rock is that white. There's nothing in there for it to eat. That's what causes a lot of the bad reports against them, I'd wager; they hitchhike into newer tanks, get hungry, and eat anything they can.

 

Also, you're likely going to run into some issues with lighting, putting all those corals up together. SPS want different lighting than ricordea and zoas do.

Thanks for the reply. I got the sps this week so I am light acclimating that frag (that’s why it’s placed with my zoas and ricordia). Unfortunately, my LEDs do not have acclimation or dimming capabilities so ill just move it up more week by week. Thanks for the reply tho

[mcarroll]

On 4/5/2023 at 8:09 PM, maximinireef said:

Hi, I am aware that asterina starfish are kind of controversial in the hobby because some swear they eat their zoas/corals.

They have been with the hobby "forever" but have only become "controversial" in the last few years....as folks become less and less familiar with live rock and what part it (and all its "hitchhikers") play in the stability of a healthy reef.

 

IMO the core discrepancy is that lots of folks (newbs especially) have trouble differentiating between predator that kills and scavenger that cleans up.  

 

Lots of Asterinas have been sighted on dead/dying corals, especially by newbs.  This leads naturally to lots of mistaken accusations.   (Similar fate has befallen the lowly Bristleworm.)

 

While there are surely exceptions in the wild (eg Crown of Thorns sea star), the Asterina sea stars that make it into our tanks historically are algae-eating scavengers (ie cleaning up diatoms, etc that live on algae and other hard surfaces), not predators.  

 

 

[Tired]

Agreed. I mean, I wouldn't be surprised if someone somewhere has found a strain of asterina-like starfish that will eat reasonably healthy corals if they get the chance, but I do strongly suspect that just about every coral nibbling case which isn't a dead/dying coral is because the tank is bleach-sterile and the asterinas are starving. Basically anything will eat coral if you starve it enough. 

[mcarroll]

19 minutes ago, Tired said:

Basically anything will eat coral if you starve it enough. 

I like the pronouns.....makes it work both ways, which is true.

 

Starve a coral enough and it'll start dying....then just about anything can eat the sloughing mucus and tissue.

 

Starve X critter enough and it's behavior will deviate from its normal diet however it can in order to survive.

 

Corals are pretty resistant to being eaten though, generally speaking.

 

 

Check this out for a nice summary of what eats corals and some interesting details on the topic:

Rotjan RD, Lewis SM (2008) Impact of coral predators on tropical reefs. Mar Ecol Prog Ser 367:73-91. https://doi.org/10.3354/meps07531   

 

(There's a PDF out there if you hit Google Scholar with the title.)