Evidence of (some) "asterina" / aquilonastra stars eating (some) zoanthids

[vetteguy53081]

Ive had this more than once and caught them red handed and often blamed my fish. Some after eating colonies got to large as a nickel. Some eat algae but are bad news

 

[twentyleagues]

I have had the white and grey ones do it also. I pulled one off a zoa polyp and there was a clear to the naked eye hole where the star was. I have posted this elsewhere and was poo-pooed. Once I got a harly and the star population disintegrated my zoas grew fine. I now do not trust the stars of any of the colors.

 

[Minifoot77]

Looks like a harlequin shrimp is in my near future

 

[mwil79]

I have come to terms that I don't believe the Asterinas are actively seeking to eat zoas as I've had an overloaded tank with them. I believe, however I may be wrong, that they are attempting to eat detritus or even algae that is covering or starting to grow on your zoa frags. Starfish eat by extruding their stomach which then wraps around whatever its trying to eat which starts the digestion process. This would account for zoas and hole forming in frags and colonies. If they were really after zoas and that's what they are seeking and accept for food I would only assume that a colony would be covered in them but even with 100s in my frag tank at a point I had never witnessed anything close to that.

Edit: Also the frag tank that was overloaded was 100% zoas from racks and colonies on plates. They never congregated to zoas specifically, only randomly throughout the tank.

 

[twentyleagues]

Looks like a harlequin shrimp is in my near future

Mine (2) wiped out the population in my system in about 6-9months. 125g, 120g and the extensive sump system. I was getting more stars from reefers in the area, then buying them from lfs for 5 cents each then buying chocolate chip stars once a month then I eventually sold them to another reefer. as far as I know they moved houses about 3 times before I lost track of them. Cool little critters, Horrifying what they do to cc stars.

 

[Marlyreef]

You'll never convince me that they don't eat zoas. I've caught mine in the act too many times. It's taken weeks, but I believe I've got the stars out. Manual removal with a vengeance. Pulled every rock out and inspected. Dipped what I could. Did all this during a gradual tank transfer. I've not spotted a single star now in over a week but I'm still actively looking. Mine were the darker ones and yes, they had splotches of red in them.

 

[ISpeakForTheSeas]

For observations sake (and to hopefully get some clarity on which of these species are safe and which aren't):

Would everyone who has some kind of Aquilonastra star in their tank post pics of them like taricha's quoted pics below (preferably with pics of the star's underside too) and list if they've been observed eating corals (with harm), eating corals/coral mucus (without harm), or not observed on corals at all?

I'd love to see if we can't figure out some species ID's to start figuring out which are reef-safe and which may eat zoas (the color is a useful starting point for ID, but isn't the only characteristic needed):

 

[taricha]

Edit: I also wonder if we could figure out a way to tell why they're showing a preference for/going for certain colonies but not others.

This one doesn't feel that mysterious to me. Every animal that sometimes munches coral shows clear preferences. An aiptasia eating filefish I had at one point absolutely thought attractive zoas were tasty, and left me only the ugliest zoas and some palys.
With fish like that, you might wonder if appearance has something to do with it - but with the stars, color/appearance can't be relevant. It has to be chemical. These corals are known for brewing up strong chemical compounds and I'd definitely bet anything that munches one would be able to tell the difference from one colony to the next by taste.

Having learned how important it is for coral to shed thier mucus coatings and seen corals benefit from aquilonastra my takaway is to avoid the ones with red flecks on their dorsal side

That's where I am as well. And that was Dong Zou's advice in the linked video - toss the ones with red flecks and keep the others.

Unfortunately some will use this as justification to remove all aquilonastra even though the majority are providing and essential service for corals helping them remove old biofilms that need to be rejuveniated.

True. People can go overboard and get hyper-aggressive about nuisances - often doing stuff that would be worse than just letting it ride.
You make a good point and it's worth stating how narrow the evidence is:
Of many types of aquilonastra stars, one type is a likely coral muncher. But that one type leaves almost every type of hobby coral alone - except zoanthids. And within zoanthids, only some of those seem to ever show effects from being munched on. And most people only observe those effects when the star population gets huge (100s of stars).

 

[VintageReefer]

Mine were small, white, with red markings on the top. These are the best pics I have. They only showed interest in exospheres. My harlequin took care of them all

This is a 2x2 frag tile

 

[VintageReefer]

Nobody can bluntly say “they do eat coral” or “they don’t eat coral”.

I have misspoken before. “Some can eat coral” is more correct.

From my own research there are at least 15 species of these starfish and some look very similar. And a few are known to eat coral. More research is needed. Don’t tell me none of them do. Some can and some will

 

[taricha]

I have seen the ones with red flecking but they're not common.

Likely true, but it seems the red fleck type is quite common among people who report zoa polyps being eaten.

@VintageReefer I love that you already did the same breeder box exclusion intervention that I stumbled across here and saw the same rebound in the zoa population.

Update : I snatch up any asterina star I see and remove from tank.

I moved the colony into an isolation box.

The zoa losses have stopped, the survivors have gotten larger, and I have new baby zoa growing at the base

Success

 

[taricha]

For observations sake (and to hopefully get some clarity on which of these species are safe and which aren't):

Would everyone who has some kind of Aquilonastra star in their tank post pics of them like taricha's quoted pics below (preferably with pics of the star's underside too) and list if they've been observed eating corals (with harm), eating corals/coral mucus (without harm), or not observed on corals at all?

Agreed. This seems like a worthwhile direction to expend some effort.

 

[ISpeakForTheSeas]

It has to be chemical. These corals are known for brewing up strong chemical compounds and I'd definitely bet anything that munches one would be able to tell the difference from one colony to the next by taste.

Yeah, I'm wondering if we could figure out which specific chemicals and why they're found in one colony of the same morph but not another (like with the experience I quoted in my first post, two colonies of the same morph, one is bothered but one is left alone; I'm wondering if we could figure out what specifically is causing that preference on that level) - is it something the coral itself is producing, is it just proximity to the coral colony, or is it something we can't see like a biofilm that is colonizing one coral and not the other?

I don't know a way to test that at the moment (especially not at the hobbyist level), but it would interesting to see.

 

[VintageReefer]

Likely true, but it seems the red fleck type is quite common among people who report zoa polyps being eaten.

@VintageReefer I love that you already did the same breeder box exclusion intervention that I stumbled across here and saw the same rebound in the zoa population.

I needed to be sure before buying a harlequin

 

[VintageReefer]

I dig these pics up. They are sequential

Original colony. Closed and open

Started noticing some random ones appeared missing and others not opening
Colony was degrading

Closeups of the starfish

Nearly ate the whole colony

Moved colony into protective box and in a day or two the remaining polyps started opening.

After a few weeks I had new polyps growing

Moved them out of the box when the starfish population was destroyed. Colony continues to grow to this day and never had an issue again

 

[VintageReefer]

Colony today

I dipped this once when I started losing polyps. It was no help and I continued to lose them.

Then the only changes I made:
Put in the box
Observed remaining polyps open
Observed new polyps growing
Added harlequin
When asterina population was gone, removed from box and put back in original spot
Over the next 2-3 months we have a nearly full recovery

You can say what you want but I am absolutely sure it was those starfish. I am also sure there are ones that don’t touch zoa. They all look extremely similar and are beyond my skills to distinguish. If you don’t experience them eating zoa, then you have a good strain/s

But I fully believe there are predator varieties also. And I do believe that they have some sort of attraction to certain zoa.

 

[VintageReefer]

If anyone wants a link to my box I ordered from here and requested it to be made custom to the 4x4x4 version the seller mentions is available. It was 43$ with tax and is great as an isolation box or frag box to reduce flow, stop fish biting, and to protect delicate corals. I opted for the taller version so I could also house some Goni frags and give them room to open

Small Magnetic Frag Box With Cover - Etsy

This Aquariums & Tank Decor item by Printed3dParts has 19 favorites from Etsy shoppers. Ships from Houston, TX. Listed on Jun 15, 2024

www.etsy.com

 

[Doctorgori]

I now do not trust the stars of any of the colors.

regardless they overpopulate, then become unsightly

Looks like a harlequin shrimp is in my near future

John Maloney of Reef Cleaners will hook you up, I got a pair ($80) arriving today as a matter of fact…timely thread

buying chocolate chip stars once a month then I eventually sold them to another reefer. as far as I know they moved houses about 3 times before I lost track of them. Cool little critters, Horrifying what they do to cc stars.

Was wondering how much food a pair of harlequins require: As above, pair arriving today, I have three tanks with these pesky stars, my thinking was house the harlequins in the sump and net off the stars from all three tanks… I am told you can collect starfish, no clue where to find them

Would everyone who has some kind of Aquilonastra star in their tank post pics of them like taricha's quoted pics below

Every animal that sometimes munches coral shows clear preferences

true and anything that overpopulates will get less picky. My plan is remove em all, let the harlequin shrimp sort them out…
Again, timely thread…thank you… and following

 

[VintageReefer]

regardless they overpopulate, then become unsightly

John Maloney of Reef Cleaners will hook you up, I got a pair ($80) arriving today as a matter of fact…timely thread

Was wondering how much food a pair of harlequins require: As above, pair arriving today, I have three tanks with these pesky stars, my thinking was house the harlequins in the sump and net off the stars from all three tanks… I am told you can collect starfish, no clue where to find them



true and anything that overpopulates will get less picky. My plan is remove em all, let the harlequin shrimp sort them out…
Again, timely thread…thank you… and following

I just went through this. One harlequin cleared hundred from my tank in a month. They won’t eat the super tiny baby asterina starfish. I bought chocolate chip star and cut one arm off at a time and gave to the harlequin. This lasts 1-2 days and then he’s out in the open wanting more. They almost constantly eat. When it gets down to 2 arms and a center disk I wold give the remains as a whole. This lasts 2-3 days. I found on average one medium chocolate chip lasts a week.

You could give the whole star at once but you will go through them quicker.

I did not enjoy this process or path I set myself on.

The harlequin starve quickly. Unfortunately he was out wanting more. I had two chocolate chip starfish in my sump. But I was going out and didn’t have time. Figured I would feed when I’m home. Later on he wasn’t out. I figured he found some of the asterina to munch on. And…I never saw him again. He had no predators. I don’t know how long he was looking for food before he came out that day. But if they are out, they are hungry. And I kept him well fed. It couldn’t have been more than 1 day without food before he was out. And I missed feeding that day. So I am assuming they can’t go more than roughly 2 days without eating

 

[Doctorgori]

I just went through this. One harlequin cleared hundred from my tank in a month. They won’t eat the super tiny baby asterina starfish. I bought chocolate chip star and cut one arm off at a time and gave to the harlequin. This lasts 1-2 days and then he’s out in the open wanting more. They almost constantly eat. When it gets down to 2 arms and a center disk I wold give the remains as a whole. This lasts 2-3 days. I found on average one medium chocolate chip lasts a week.

You could give the whole star at once but you will go through them quicker.

I did not enjoy this process or path I set myself on.

The harlequin starve quickly. Unfortunately he was out wanting more. I had two chocolate chip starfish in my sump. But I was going out and didn’t have time. Figured I would feed when I’m home. Later on he wasn’t out. I figured he found some of the asterina to munch on. And…I never saw him again. He had no predators. I don’t know how long he was looking for food before he came out that day. But if they are out, they are hungry. And I kept him well fed. It couldn’t have been more than 1 day without food before he was out. And I missed feeding that day. So I am assuming they can’t go more than roughly 2 days without eating

I had NO CLUE, but figured a few dozen stars would feed a shrimp…guess I was wrong..

added: that’s what I get for inadequate research before purchase

I can’t afford $20/week to feed a pair of shrimp, looks like I need to find a tide pool somewhere…
thank you