Provide proper nutrition to fish-eating marine species. Silversides are a preferred alternative to conventional freshwater feeder fish that lack the nutrition marine carnivores require. Since these small, elongated fishes are from the ocean, they're an excellent source of marine protein and oils for predatory aquarium carnivores. Nutritious Ocean Nutrition Silverside is also a good frozen food item for anemones, shrimp, crabs, and other carnivorous invertebrates.