Four legged starfish

[Reefer_Marc]

Hello everyone!

Yesterday for the first time i found this 4 legged starfish, never seen it before and its the only one i have seen.

Can anyone id him? Is he reef safe or should i try to get him out?

Thanks everyone for your help!

 

[Gtinnel]

Looks like an asterina starfish to me.

They are generally considered a pest. Some people claim they eat certain corals and other claim the won't. I have never had any in my tanks so i have no first hand experience.

Even if they dont eat any of your corals they can still grow into a large population quickly.

 

[BristleWormHater]

Asterina starfish, although that refers to many different species that are all nearly or entirely indistinguishable without a microscope, a species complex.
Some of these species may eat coral but it seems like that is pretty rare. I welcome them in my tanks, never had any isssues, although I do not keep zoanthids, which is what many people claim they eat.

 

[Reefer_Marc]

Thank you for your answers both!
I will do some more research on them before i decide if i get it out or not.

I so have one frag of zoas, so definitely wanna look out for that.
So far i only saw one and only on the glass, but i will keep monitoring it

 

[SaltyMomma]

We had them—and are still trying to get rid of them. They rapidly multiply and do in fact eat corals. Annoying lol

 

[Turkey head]

I like them. Never had them eat corals. I have two tanks. One did have a problem with them multiplying to an excessive amount. The other tank has something that are them I assume since the population remained small. I dont know if they serve any purpose but they havent hurt anything either

 

[Mr. Mojo Rising]

I take them all out. They eat coraline for sure, I really suspect they eat zoa's, and I've seen them often on my seahorses, I don't know what they are doing on seahorses but it freaks me out. Check your tank early in the morning while its still a bit dark, thats when they are all out on the glass. That one will turn into hundreds or thousands within a few months.

 

[BonnieB]

And to add to this, you’ll know they are multiplying bc they “drop” their legs (probably why you only see 4) and that is how they propagate.

 

[Sisterlimonpot]

These wouldn't be so bad if they didn't multiply in plague like proportions.

You see one today, and hundreds/thousands covering everything in 6 months.

 

[Reefer_Marc]

After reading all of the feedback here, i decided to get it out.
Even though he looks cool, seems hes not worth the risk of getting plagued by them :)

 

[ReefNutsThailand]

Hello everyone!

Yesterday for the first time i found this 4 legged starfish, never seen it before and its the only one i have seen.

Can anyone id him? Is he reef safe or should i try to get him out?

Thanks everyone for your help!

I saw sometimes in my tank , then disappear in a few days.

 

[mcarroll]

After reading all of the feedback here, i decided to get it out.
Even though he looks cool, seems hes not worth the risk of getting plagued by them :)

Keep in mind when you hear of folks with critters (or anything) "blooming" out of control – there is almost always something out of balance in that system. Too many variables to predict what it is in "all tanks" but it's always something.

If that wasn't the case, we'd ALL be having the issue with Asterinas...not just the few folks who report it.

You would have no posts in your thread like post #3, #6 and people like me saying they are great and harmless. Zero.

If they really ate coralline algae, I wouldn't have some of the scars I have from scraping that coralline out of deep tank corners!!! If they eat it, they cannot eat a significant amount. (Otherwise large amounts of coralline in the tank would cause them to bloom. Never happens.)

Same if they really ate corals. We'd ALL have that problem, not just the few that report it. I have ****-loads of them, always 5-10 on the glass, some as large as a nickel. Never had an issue with them eating coral, and this system has been running since the mid 2000's....20'ish years.

They eat bio-film.

The confusion/misunderstanding is not really a mystery though...

Bio-film is on everything in a fish tank, including corals and coralline algae.

They will never bother healthy coral in a healthy tank.

Last, any coral eater isn't going to make a good hitchhiker. They hitchhike in on live rock, etc, because they are bio-film eaters....plentiful even on spray-cleaned live rock. (Coral eaters aren't going to be good hitchhikers. No corals around for most of the journey!)

FYI...

Being starfish, they do not have teeth so they can't bite things like coraline or coral tissue.

They eat by ejecting their stomach and digest things outside themselves and then suck it back in. Yum! (Be glad you aren't a coral or starfish....1 hole for in and out!!)

The overlooked reality is that there aren't very many things that will breed in tanks AND be helpful.

Asterinas are one of the critters that will create procreate....bristleworms are another (and they're even planktonic!). Free AND a valuable sub-members of your CUC.

But online in the land of hand waving and hair fires, folks are often afraid of both of them – similarly how some folks tend to be afraid of live rock.....as if reefs aren't made from it!!!!

Be kind(er) to your Good Guy hitchhikers – it gives you a better reef, and makes you a better reef keeper.

 

[Sisterlimonpot]

The intent of my post is to stress the fact that if you don't nip it in the bud now, you may regret it later on when its too late.

There's nothing wrong with having them in your tank (if you choose) but I think it needs to be an informed decision and not one stemmed from discovering what an asterina is based on, "look at the tiny starfish I found in my tank". That sentiment is usually based in naivety.

I personally don't subscribe to the notion that they eat coral, at least I've never had any and conclude that the ones people attest to eating coral are simply the asterina feeding on algae on exposed already dying coral skeleton.

I think the best approach for someone who discovered asterina stars is to remove them as they see them and when they get more experience they can truly make an informed decision. It's not like this opportunity is rare, they are in abundance throughout the community.

Aside from the whole, "truly a wonder of nature, this asterina starfish..." they are a source of frustration, and I rank them right up there with aiptasia. Which BTW are also "one of the critters that will create procreate..." that's not reason enough to allow them to live in my ecosystem.

 

[mcarroll]

Aside from the whole, "truly a wonder of nature[Ed:.........what???

Maybe ham radio or video games would be better than reefing for all those "no wonder of nature" types out there? (What on earth are they even doing in this hobby!! LOL)

This hobby really has changed...back in the day this was the WHOLE REASON to set up a reef tank, the corals were just gravy and came with the package.

Now folks want FCWLR tanks.

Fish and Coral WITHOUT Live Rock.

A funny and paradoxical goal.