predator star????

[gregarlington]

I have a couple of small red stars and a larger brittle star(kind of brown and hairy looking). Ever since I got this brittle star, it seems that some of my crabs have dissapeared and now this morning two of my firefish have seem to vanished into thin air. Is it possible that this starfish is really a fierce predator or should i be blaming someone else?

 

[katara]

Do you:
See any empty shells anywhere?They could be getting knocked off by other hermits that need bigger shells..i
Have you heard any loud clicking?Could be the predator Mantis shrimp?Just some ideas to maybe start with.Good Luck!

 

[banshee]

It's possible that your brittle star may be the culprit. I had a rather large green brittle star that would prey on small fish. It took me months to figure that one out. Or, it could even be something that you haven't seen, yet....like a mantis. It's kinda hard to tell unless you catch the killer in the act. Good luck!

 

[lesa]

My brittle star done the same thing and he took a trip the the lfs

 

[ophiura]

Anything is possible, but don't overlook other possibilities. Can you give tank specs, including water chem values, age of the tank, etc?
Do you feed the brittlestar anything? Also keep in mind that brittlestar are put in the tank to scavenge, and will eat dead, dying or weak animals.
2 firefish would be any awefully large meal for a brittlestar at once, especially to hunt and kill and eat. The disk of the brittlestar would be incredibly inflated and bloated. How long have they been missing? Often they can hide for a time. Have you looked on the floor, in the sump or overflow? How many firefish do you have? How long have you had them?
What kind of crabs? Hermits? Emeralds? If hermits, yes, they might be picked off by other hermits, or perhaps normal die off. How long have you had them. I doubt a brittlestar would get an emerald or sally, for example, which are more commonly predators of the star. Since they are sharp, I would also anticipate some damage to the disk of the brittlestar if it ate a sally, for example.

 

[jferrier]

I really doubt its your bristle star doing this. I have always observed mine and friends stars as very timid. Mine has roughly 6" long arms and he scurries away from a little sally light foot. Like the other guy said bristles are scavengers , not hunters. Did you actually find the stars dead or are tehy just missing?

 

[jferrier]

OOPs I meant are the firefish just missing? How many firefish do you have? I have ahd problems w/ my firefish fighting fiercely w/ each other.

 

[ophiura]

Some stars, most notable the green brittlestar Ophiarachna incrassata are indeed predatory, as noted in the scientific literature based on observations of wild animals. And when locked up in an all you can eat buffet like our tanks, which are often relatively underfed considering the number of scavengers and such we put in, they eat stuff. They aren't doing anything wrong though, which people often forget. It is a risk of the hobby.
And since they don't even have a brain, well, this is really quite impressive Hard to think about if they are eating your $$, but phenomenal for me
I have found my green recently clearly engaging in predatory behavior. But such is life. He was chowing down on the arm of another brittlestar though, and I had to put an end to that.
Other people have reported issues with other species of brittlestar, including Ophiocomid brittlestars, which you likely have. Dr. Ron Shimek comes to mind as one who has reported predatory behavior with them (though this has not been reported in the wild, yet...donations for studying these tropical brittlestars in their natural pristine tropical habitat, such as the Bahamas, are always welcome ).
Keeping them spot fed is important, but not a guarantee. However, not feeding them, and not having many large fish which are fed a lot, can be a potential factor. These animals will not allow themselves to starve, if it can be avoided. And growing large and being able to reproduce is instinctive...so eating whatever is available is a good idea.
All in all, it comes down to the personality of the star, and the tank situation it finds itself in. However, it is important to clarify about the crabs and firefish, because I think a lot of people are quick to blame the star. Is this a young tank, mature tank, large tank??