Foods for Saltwater Fish and Invertebrates By Stan & Debbie Hauter Stan & Debbie Hauter Stan and Debbie Hauter are aquatic experts and writers with three decades of professional experience in the field of saltwater fish aquariums and pet fish. They have worked in many aspects of the aquarium pet fish industry, including owning a fish collecting business. Learn more about The Spruce Pets' Editorial Process Updated on 07/29/25 Credit: Moto "Club4AG" Miwa/Flickr/CC BY 2.0 Saltwater aquarists use a variety of fish foods to ensure their selection of fish and invertebrates receives proper nutrition. While some find basic flake or pellet fish foods sufficient, others prefer mixing various foods to provide a more balanced, vitamin-rich diet. The following food sources are excellent choices for feeding captive fish and perfect for do-it-yourself food recipes. 01 of 07 Brine Shrimp Available in freeze-dried flakes, time-release blocks, and cubes, and as eggs you can hatch for fresh live fish food. Brine shrimp are a natural marine fish food that provides a healthy amount of protein for nearly any creature's diet. 02 of 07 Krill Krill are small marine crustaceans commonly found in cold Arctic waters. This high-protein fish food is considered "rich" and should be fed sparingly. Available in freeze-dried flakes and pellets, it's used to supplement a well-balanced diet. Krill is rich in astaxanthin, which enhances fish's natural pink to orange-red colors. 03 of 07 Marine Flakes and Pellets Most "Marine Flake" fish foods and Marine Pellets are designed by manufacturers to be a complete balanced diet for marine fish, containing essential proteins, carbohydrates, vitamins, and minerals. Many saltwater aquarists use basic "Marine Flakes" as primary fish food and supplement them with other foods for additional nutrients. 04 of 07 Mysis Shrimp High in protein and amino acids, Mysis Shrimp are excellent for both fish and invertebrates. They are the preferred food for seahorses in aquariums. Available in frozen cubes and freeze-dried flakes, frozen Mysis contains between 4.7% and 10.5% protein, depending on the manufacturer and shrimp size. Mysis fish food flakes contain about 46% protein. Continue to 5 of 7 below 05 of 07 Phytoplankton Most phytoplankton are sold as a blend of fish foods that contain essential amino and fatty acids, fiber and high levels of carotenoids. Most phytoplankton produced for the aquarium trade are aquacultured and naturally occurring and are of the 5- to 25-micron size, providing a broad range for filter-feeding marine invertebrates. They are also used to supplement and fortify live foods. 06 of 07 Plankton Used as a fish food supplement, freeze-dried plankton is rich in proteins and lipids as well as beta-carotene, which helps to bring out the vibrant colors of marine animals. Ideal as a treat or supplement for all medium to large marine fish and invertebrates. 07 of 07 Seaweed Seaweed is an all-natural fish food for your herbivorous fish to add to a balanced and varied diet. Allows fish to "graze" as they do in the wild within their new habitats. Available as "nori" in the oriental food section of many stores, seaweed is a popular natural fish food for most tangs. Explore more: Fish & Aquariums Saltwater Fish & Aquariums Saltwater Fish Breeds