Saw this in my tank

Tobes

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What is this guys? A star? It is about a pinky nail size, moves around but how come 2 legs are thick and the other 4 thin and short?

DSC00407.gif
 

jacquesb

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Hello Tobes! Yes - it is a star-fish - BUT A VERY BAD KIND! It is known to prey on soft-corals.... I would remove this star-fish immediately from your tank. I cannot remember the name - BUT I know that this is a bad kind of star....

Rather take it out and either place it in the sump (it would most likely die), or (preferably) take it to your LFS....
 
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Hi Jacquesb, would appreciate any more info that you may have on that starfish - they are extremely common on the breakwaters at Durban harbour and I have been trying to find out more about them. Thought for a while that they were just juveniles that were somehow deformed until it became apparent how common they are there. Thanks
 

Mike

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Hello Tobes! Yes - it is a star-fish - BUT A VERY BAD KIND! It is known to prey on soft-corals.... I would remove this star-fish immediately from your tank. I cannot remember the name - BUT I know that this is a bad kind of star....

Rather take it out and either place it in the sump (it would most likely die), or (preferably) take it to your LFS....
Hi Jacquesb, would appreciate any more info that you may have on that starfish - they are extremely common on the breakwaters at Durban harbour and I have been trying to find out more about them. Thought for a while that they were just juveniles that were somehow deformed until it became apparent how common they are there. Thanks

Easy boys, that is a very innocent little Asterina star fish, a detrivore, totally harmless, could possibly breed a bit much but other than that, about as dangerous as aneutered mouse
 

Kanga

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Easy boys, that is a very innocent little Asterina star fish, a detrivore, totally harmless, could possibly breed a bit much but other than that, about as dangerous as aneutered mouse
I would have to agree with my learned Muppet like friend here, saw them in a John dorys(PMB) tank with some great soft corals in
 
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i hade those where fine with my softies maybe it will eat a coral if it is sick i dont know just a thought though
 

Kanga

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i hade those where fine with my softies maybe it will eat a coral if it is sick i dont know just a thought though
Actually you are quite correct, they will eat dead or dying polyps as the are detrivores.

They actually reproduce by "losing" legs and the leg grows, thats why you will see 3 legged, 4 legged, 5 legged and 6 legged ones;)
 

Kanga

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MarLIN - The Marine Life Information Network

Also check out WWM about these.

In all fairness some guys think they do in fact eat polyps, however it seems they just got a raw deal because they do eat dead polyps, I speak under correction but I think Alan has a few in his tank
 
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Think that your link refers to a different species Kanga. I have asked a friend of mine to ID the animal for me and will post the identification. Life history is probably pretty much the same though from what I have seen the animals do.
 

jacquesb

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OK - I must apoloigize - I could have been too hasty. BUT, even though I am quite positive that you do indeed get a predatory species of star-fish that looks EXACTLY like the one in the picture. Asterina too looks like the one in the pics - I just remember the one "leg" being longer than the other 4, on the predatory species. I will research some more and post my findings.

Ok found the following:
GARF predatory starfish 11/25/01

Here's a pic:
starfish444385.jpg
 
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wow they look the same
 

Kanga

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Here we go from Wet Web Media AsterinaFAQs

from "http://www.wetwebmedia.com/asterinafaqs.htm said:
Asterina eating a polyp 12/20/06
Hello Crew,
<Hey Nick, JustinN with you today>
Thanks for the awesome website!
<Thanks for the kind words!>
I was wondering if you could help me with a couple questions I couldn't find an answer to.
<I can certainly try, can't I? *grin*>
I have numerous little white starfish which I believe to be Asterina.
<Likely so, very common>
I have had them for well over a year with no problems. A few days ago I noticed that some of the polyps on one of my Zoanthid colonies were not looking very good, shriveled and discolored. Last night I looked at the colony and noticed one of the Asterina engulfing one of the polyps.
<Scavenging, as they do...>
Do you believe that this starfish was only eating the polyp because it was dead or dying? -or-
Do you think it just attacked the polyp because it was hungry. (although I've never seen this happen for over a year since I've had the starfish population)
<I think you answered your own question here *grin* You witnessed the degrading of the polyps before the incident happened, and as you stated, you are well over a year incident free. I personally believe these intriguing (and invariably free!) reef denizens have gained a bad rap in the Zoanthid fanatic circles. I've not seen anything beyond circumstantial at best information on this behavior from Asterina stars.>
Worried, I peeled the starfish off and removed him from the tank. But now I wonder what would have happened if I had left him.... Do you think he just would have beneficially eaten the decaying part of the colony or would he have eaten the health polyps as well.
<My thought is the former, not the latter.>
So if I see this again should I just let the starfish do his work?
<Yes, if you witness this again, I would just let it happen, is part of the biota balance.>
One other quick question, I am giving some Chaetomorpha macroalgae to my brother for his refugium. I have a population of flatworms in my tank that I don't mind, but my brother might. I was curious if it would be ok to freshwater dip this algae to remove the worms.... I could just swish it in saltwater, but I'm afraid that it might not remove them all.
<Why not just take the safety route and use both methods? Rinse in some saltwater first, then do a short freshwater dip before rerinsing in saltwater and bagging for your brother.>
Thank you so much in advance for your help. Everyone have a happy Holiday!
-Nick
<Happy holidays to you and yours as well, Nick. Hope this helps you! -JustinN>

Asterina Starfish compatibility 11/24/06
Hello,
<Hello and a happy Thanksgiving to you, Rosemary! JustinN with you today.>
I very much enjoyed reading the information you had posted on your web sight about Star Fishes. I am looking for information about a specific breed I did not see mentioned on your web sight. I was told it is called "Asterina Mini Star" I will email you the listing off eBay so you might see what they look like.
<Mmm, not necessary, am very familiar with this species>
I am interested in learning anything you know about this species. I especially wanted to know if they are coral safe? I currently have a pair of Erectus sea horses and a bluestriped pipe fish in a 15 gallon tank. I wanted to make sure this is a peaceful type. According to the sellers listing this type is suppose to remain small so I thought it might be perfect for my tank. I would greatly appreciate to learn what you know about them. I would be extremely grateful for any help you could give me!
Thank you so much for your time!
Best Wishes
Rosemary
<While some people like to point fingers and blame Asterina stars for such things as polyps not extending, and of consuming Zoanthids, myself and many other reefers in my area have many of these in our tanks and have never seen any deleterious effects. These starfish have little to no affect on the overall bioload, and are excellent detritivores. The main reason that they seem to get accused of as much ill as they do, is because they do reproduce like weeds. If your tank is nutrient rich enough, they can grow to plague proportions, although it is typically easy to keep in check with manual extraction. Do you have any live rock in your aquarium? If so, you may already have some Asterina stars and not know it yet! Have a browse through our existing Asterina starfish FAQ's and decide for yourself if they sound right for you: http://www.wetwebmedia.com/asterinafaqs.htm Hope this helps you! -JustinN>
 

Tobes

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Howzit guys, back from JHB. Thanks for all the info - quite an interesting read. I saw him ate some white stuff underneath the live rock the other day, didn't see him on my polyps yet.
 

Tobes

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Will do, hasn't seen him for the last couple days - maybe something ate him....:p
 

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