" 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. A Green Brittle Star, Ophiarachna in captivity. This animal is often becomes a fish predator with growth/size.
Brittle stars have the same good/bad choices amongst them. My strong advice is to seek out smaller individuals of species that stay small. Brittle stars are nocturnal and require a dark space to hide during the light of day; they are active scavengers at night, and are not opposed to ingesting sleeping fishes they can get their legs on."
from the pages of Wetwebmedia
From what they say they can become fish eaters as they get larger.........