| Is the brittle star green? They have been known to turn on smaller fish from time to time. I also had a pair of CBS that used to try to catch my chromis, and even tried to take on my coral beauty. The brittle star, depending on it's size, may eat a chromis, but I seriously doubt it would take on a coral beauty. The shrimp would try to eat anything, but were never successful in catching any fish. The shrimp and star are both gone from my reef now for those very reasons.
While I wouldn't necessarily expect either of those to catch and consume fish regularly, I'm not surprised you didn't find any remains, as both are excellent scavengers. | 
