Besides frozen brineshrimp, bloodworms, daphnia & mysis shrimp, you can feed frozen but defrosted prawn, fish, squid and other marine foods. Just buy a pack of frozen prawn (raw or cooked) and keep it in the freezer. Take one out and defrost it. Remove the shell and head and pull the gut out. Then use a pr of scissors to cut it into little pieces and offer a few bits at a time to the fish.
Live brineshrimp, adults and newly hatched, can be fed and are easy to culture at home in a bucket of salt water.
If you have roses in the garden, get a plastic icecream bucket and put it under the rose buds, then tap the aphids off the roses into the bucket.
Small flies, moths & mosquitoes can be fed as long as they are free of chemicals and pesticides.
Weevil larvae can be cultured in buckets of flour, rice or any grain.
Mozzie larvae are regularly found in buckets of water with leaves in, sitting outside under a tree. They should be scooped out with a fine mesh net and rinsed then fed to the fish so they don't turn into adult mozzies and spread disease.
Bloodworm (Chiromonid midge larvae) are often found in the same containers of water as mozzie larvae. The bloodworms live on the bottom and are red, whereas the mozzie larvae are black and sit under the surface of the water.
You can culture daphnia and rotifers in containers of green water. Green water is simply single celled algae that has multiplied until the water looks like green soup.
Microworms, grindal/ grindle worms, white worms & earthworms can be fed to fish. Earthworms are probably too big for your fish but the other types can be fed.
Fish eggs and baby fish are regularly eaten by other fish but probably not what you want to hear.
Baby shrimp are readily taken by fish too. Glass shrimp are tough and live in most aquariums, and if you have a group they will breed and the young can be eaten by the fish.