Brittle stars are great detrivores for any aquarium, but some individuals may develop a taste for fresh fish. Brittle stars can get very large, reaching a foot or more from the tip of one leg to another. Their central disk can also get quite large, and large invertebrates require a lot of food. If you keep the star fed, it may not bother your fish. But if you fail to spot feed it, the star will take matters into its own hands.