Hikari Bio-Pure Frozen Mysis Shrimp is an especially good diet for Seahorses and Pipefish. Mysis Shrimp have been the primary food source of reef aquariums for years. The small shrimp like crustacean is much like brine shrimp but contains much higher nutrient levels while still being an enticing food source for marine fish. Mysis Shrimp are a staple, primary food source for marine and freshwater fish alike.