From Bob Fenner
Brittle/Serpent and Basket Stars.
The Brittle or Serpent Stars are grouped as the Class Ophiuroidea, characterized by having highly mobile arms that can be used to assist in (relatively) rapid motion. These starfish-like echinoderms are decidedly quicker and more delicate than asteroids. Their common name is derived from their sinuous, snake-like movements, and the fact that they're truly brittle and break away easily if they come under attack. The podia in this class are generally used as sensory organs, rather than for active feeding as with their kin, the asteroids. There are more than 2,000 described species worldwide, and they're found congregating throughout shallow reef environments, hiding under rocks and within and between other living organisms.
Seemingly on the other end of the machismo scale are the Brittle or Serpent Stars, which are so retiring and nocturnal that you may never see them in your system. In the world's reefs, they are everywhere.
One species in common use warrants a statutory warning. This is the Green Brittle Star of the genus Ophiarachna. This animal is a predatory fish eater, that does indeed do a spiffy janitorial job when small... but grows quickly, and under darkness of night can/does learn to eat aquarium fishes. This species has been documented to arch up in "sleeping caves" of captive fishes and drop down on unsuspecting meals. If you use this species, keep an eye on it, and a count on your piscine livestock.
Thanks for all of the information everyone! My reason behind asking is...that I have had 1 serpent for many months in my 92g without any worries but recently purchased a red show serpent and it seems to be doing well but has eatten at least 1 of my sally lightfoot crabs. The other is missing, but I assume it met the same fate. So far, he hasn't attacked any other crabs but I have been worried and watching him closely. The reason I know it was him was I found him over the remains of one of them and he was serious mis-shapen. It was horrible. This happened within 48 hours of his arrival and the crabs had been doing well, I assume they hadn't died before that.
I hadn't heard of this and just wondered what everyone elses experiences were...
Originally Posted by Mr_X http:///forum/post/2724532
green serpents or green brittles?
brittles sorry, there really is no biological distiction between them but I did mean to say green brittles, the ones with the spikes perpendicular to the arms.