Yeah shrimp too. You can make a blender mush. Basicly you throw bunch of seafood from the supermarket into a blender and blend to a semi- fine mush. Scallops, shrimp, clam meat, mussels, nori, crab, oysters, garlic, cod, squid. Pretty much anything that comes from the sea high in nutrition. You want fresh seafood tho, no canned stuff as it contains preservatives and generally higher phosphate.
Blend it and freeze it into flat sheets or cubes and thaw a piece before feeding. Extremely nutritious And much cheaper than buying frozen fish food. The amount you can make and the ability to pick and choose ingredients makes it well worth it.
I need to make some more soon.