Small Starfish

[wds21921]

I've seen a few postings about a nuisance(?) starfish that is very light brown in color that many have said to remove from the tank. The only problem I can see from these things is that they populate fairly quickly. There legs never seem to grow out evenly and they are about 1/2"-3/4" fully grown.

Does anyone have any experience with these things? They're similar to your yellow tiny stars Ken, the legs are different and the color.

As far as I can tell they're only consuming detrius and or algae so I don't see where they're that much of a nuisance?

Thoughts or comments?

 

[nanoreef16g]

They're Asterina sp. starfish. The only coral I've ever seen them pick at is dying coral. I think the "nuisance" comes from the epidemic proportions they can reach in a home aquarium. Since my tanks are small, I remove them when I see them. I don't see a problem in larger systems unless the population gets to insane levels. At that point I think they'd be easy to cull out.

 

[kaptken]

No chicken fat YELLOW stars here! i do have some of those little stubby ones that seem to divide, but they do no harm. some have claimed they eat SPS, but no way!!

 

[wds21921]

Seriously? I've not even seen them go near any of my polyps or corals. They seem to hang in areas where there is a dense growth of dark rich green algae.
Ocassionally they'll take a jaunt up the glass too but again it's in algae covered areas.
I'll keep an eye on the population. I added a large green brittle star Saturday so that should put me at about 8-12 assorted stars now.

 

[wds21921]

I checked out some pics of the species and yes that's it. I didn't know there were so many variations though lol.

 

[MadTownMax]

tons of variations - maybe due to what they're eating in different tanks.... or the photographer

I've got tons of 'em and never remove them, unless someone wants a few

I see them being the same as the stomatella snails - yes they reproduce quickly, but never harm a thing, and do not approach populations such as flatworms.

 

[Gordonious]

I love them and I'm very happy my population is coming back. It seems almost be an old wise tail that they are harmful and most really knowledgeable sources state so. I have in the past asked my friends at the LFS to bring some home to me any time they saw them.(but of course there tanks had tons of them and the lazy bums never brought me one )

Jon

 

[wds21921]

Mine seem to reproduce pretty quick Jon, I'd be happy to donate a few if you'd like some?
Give me time to catch a couple though ok? My rock is pretty dense at the moment.

 

[MadTownMax]

same here - I've actually seen a few lately that have grown to almost 3/4" - for these little guys that's the biggest I've seen.

any other micro inverts you might be interested in also - stomatella's, mysis, or copepods (or amphipods - whichever is larger ) - I've got plenty to spare :thumbsup:

 

[Gordonious]

Awsome MadTownMax, I will PM you in a second. I have a decent amount of the stars now though thank you wds.

I just started culturing copepods and wanted to do something like mysis shrimp.

 

[wds21921]

Hmm they reprouce apparently by division.
I've found a few that where halves of each other and are moving about.

 

[Gordonious]

Yep. It is odd sometimes I go several weeks with out seeing any then all of a sudden there are two. I have always wondered if they hid themselves or buried themselves while they are dividing to protect themselves. I'm pretty sure this is what they do, but I haven't really studied these guys hard core. You will also read that the reason they never seem to have the same length legs is because they divide faster then the lost legs can catch up. If the legs are close to all being the same size then it's past time that it is capable of dividing.

Jon

 

[wds21921]

Hmm if they keep multiplying/dividing at this rate I shold be able to have my own kung fu weapons supply in no time.

 

[kaptken]

Sure-Ya-Can!!

 

[wds21921]

For anyone that has any of the medium to large green brittle stars, do they always remain pretty much nocturnal?

 

[Gordonious]

I have had three brittle stars. One was red, two where black and white and all of them were nocturnal. I have a feeling brittle stars as a hole are that way. Ever want to see them during the day offer them some food, or place a finger or feeding stick near by and keep it still till they wrap around it and slightly gently pull it back. I had mine trying to pull my finger into his rock 20 minutes ago, lol.

Long time ago when I had first set up my tank I bought two cleaner shrimp. After a long acclimation I let them go and one landed on the leg of what was I guess a very hungry brittle star. I went in to try and save it, but I there was no way anything was staying alive. Probably one of the most expensive snacks a non green brittle has ever had. (You know the greens often eat small slower fish right? ) Funny thing is the other cleaner shrimp out of the pair lived in there a long time with out any harm.

Jon

 

[wds21921]

Good to know Gordonius. Most of my fish are actually pretty darn fast so I don't think that's an issue. The smallest one that could possibly be considered slow is my Lawnmower Blenny who's about 5" long and pretty powerful.
He (the brittlestar) doesn't seem to be very interested (yet) in any of my shrimps. After I acclimated him he found one spot in the middle of the tank and doesn't seem to stray too far from it even at night when I've flashlighted him to see where he goes and what he does.
They're definitely good at sensing light too lol.

 

[Gordonious]

Yeah... that would be something to read about. I didn't think they have eyes yet hate light... All three of the brittles I have owned have stayed under one particular rock for months at a time. I think it in well fed tank they may never move there whole lives.

 

[wds21921]

I know the tentacles on the Medusa worm are loaded with small eyes or photo sensitive sensors of some sort. After watching it closely for a while I thought it was merely touch sensory but it like the brittle star it reacts to light.

 

[wds21921]

Right after I posted about him staying in one area of the tank he completely proved me wrong today.
This morning I found him all the way on the left side in the back much closer to a lighted area but still under some rocks. I'm guessing he depleted his food source in the middle of the tank and moved on to more cuisine oriented substrate?