Baby brittle star hitchhiker found. Now what?

[Chineseghoststory]

When gazing at my tank today I saw a baby brittle star nimbly moving across the LR and then vanishing from view into any one of the nooks and crannies of his choosing. I have had my tank for just over a month and have never even so much as suspected he was in there to begin with, and it may be just as long before I see him again. This is no panic situation since he is small, and by that I mean real small.......from arm tip to arm tip he might have stretched across my thumbnail. I have medium sized hands if that means anything.

 

I know nothing about these guys. Before you flame me, I have indeed looked at this web site's list of nano-negative critters, and of course predatory starfish are not suggested. In other news, the sky is blue. No info is given about the habits of brittle stars though. Other web sites offer a lot of scientific names unaccompanied by "regular" names of these species, and at least no pictures of brittle stars, though that doesn't mean a lot.

 

Is he predatory? How and when would it be best to remove him if I have to? Just how long will this guy take to get big enough to pose a threat to any fish or shrimp? Is there any chance he'll get eaten by an adult cleaner shrimp, which is what I was going to put in there when cycling is over with? Is there anything else which may do me the necessary favor of eating him such as a snail? And just what has he been eating up to now?

 

Thanks,

 

Jeff

[Kalanianaole]

The same scenario happened to me a few weeks ago, only there around 5 that I've seen in my tank. I couldn't find any info on them when I randomly saw a post accompanied by a pic on another reef board. My "baby" brittles are the size you stated and completely white, as I assume yours are too.

 

It should be something along the lines of Amphipholis squamata, a minature brittle star. It won't get any bigger than what it already is and is benifical for your tank, or so said the board. It is a member of your clean up crew, eating detrius and such. I've not seen my peppermint shrimp, pygmy angel or any snails prey on any of my squats, so predation's not been an issue yet.

 

That's all I know. For more info do a Google search of Amphipholis squamata. See if the pics match up.

 

Oh, if it is Amphipholis squamata then you may like to know that they're supposedly phosphourescent. When they feel like it.

[Guest AbSoluTc]

Here is some info that was given to me by ophiuroid on reefcentral. She really know her stars

 

HI Kris,

No worries about a camera, I know what they are! There are quite a few posts on them. Not to worry, you have plenty of what many people try to buy! They are common in detritovore packages. This tiny guy (assuming they have five arms and no bands on the arms which are white) is Amphipholis squamata. Dr. Ron and I seem to be at odds over this specific ID, however, this is a very very common brittlestar (perhaps the most common on earth). A colleague of mine recently concluded after some genetic research (for his dissertation), that there is only this one species (link below). They are full grown at the size you are reporting, about .1" in disk diameter.

 

Now for the cool bits. They are not predatory, but are great additions to the tank. They are true detritovores, and also good sand bed fauna. You have so many because they are self fertilizing hermaphrodites that brood their young! Yes, even tinier brittles are growing inside those tiny guys. Sometimes quite a few of them! There is a report of one individual having 25 embryos inside! This is more typical of temperate animals (these guys live from tropical to polar regions and from the intertidal to the deep sea [4,363 ft is the deepest record}). In our tanks, they breed year round but have fewer offspring at one time. Still, you can see how, given favorable conditions, they will reproduce very rapidly! Since our tanks are relatively 'dirty' because of the amount of food in them, conditions are typically favorable. If you get one (typically on LR), they will reproduce pretty rapidly.

 

Interestingly, they are also bioluminescent, which in their case is a defensive tactic. There are some cool videos of these guys. A crab may grab and arm, which breaks off, and starts flashing. The crab looks really perplexed with this strange meal, and the rest of the brittlestar escapes to live another day (and regrow the arm).

 

The guy who studies these is Samuel DuPont. Here is a picture from his page and his site (http://www.biol.ucl.ac.be/fyga/californie/index.htm)

 

[JPF]

I have many of these small brittle stars. They arrived on the live rock. The biggest after a year has a diameter of about 41/2 inches. Most are much smaller. They are offwhite with black bands. They stick their arms out of the live rock, especially at feeding time and always at night. I never catch them in the open unless I move a piece of rock. Very cool animal.

[jdiver]

I have had a recent "explosion" of mini-brittle stars. I had two for quite some time that I have been able to see their arms sticking out of holes. In the past week or so, the population has increased dramtically and I would say there are at least 20-25 of them in my tank. There are usually 3-5 completely out in the open crawling around, and practically any piece of coral substrate I flip up has a star under it. I will soon be taking some out (by scooping up a bit of substrate) and sharing them with my friend and dad for their tanks. Very cool little creatures.

[BCOrchidGuy]

Depends on what colour it is in my opinion, although I don't have any experience with other brittles I did have a green brittle and it was very aggressive and VERY predatory. In the morning when the lights would come on it would fly (and I mean move like it got a shock from a cattle prod) and grab a fish that was still sleepy and it would have it in its mouth in no time. I had to take the tank apart to get it out of there.

[ajroahkni]

JPF - Yours sounds like mine... Do they have five or do they have six arms? Mine are all six-armed little guys.

[ricknbecky]

I am stuck with a battery of all sorts of tiny brittle stars and serpant stars. I have Green, Red and Black stars that have the bristly legs, and many og the withe one with the black banded arms. I also have meor of the little beighe to white dime sized guys some have six and other have five legs. In so far I have guessed that I have over 40 of so hitchhiker stars in at least 5 vireaty. I am also mor ehtan willing to share if any one in the tampa area is interested.

[JPF]

ajroahkni mine have five or six arms. I never actually counted. They rarely appear completely exposed. I put three in my sons tank a few months back and now there are probably several dozen. Fun without being invasive.