I also have the black brittle star and he is a great scavenger. When I feed the BTA it's weekly bit of shrimp I make sure that I break off a piece and find the brittle star which is usually hidden in the rocks with its legs searching for the shrimp that it smells. Then I just dangle the shrimp in front of him. It's funny to see the leg come out searching. Then I place the piece of shrimp on the leg and it curls the shrimp up in its leg and makes it disappear into it's hiding spot in the rocks. I don't believe you have to spot feed them but this is my preference. I have never had a problem with my black brittle star. When I first started reefing I got a green brittle star, which is a known fish eater, but I never had a problem with him either because I did the same feeding - when I decided to keep some smaller fish I traded him in and he was huge.