There comes a time in most Aquarist's life when they start thinking of changing the fishes diet and possibly adding some live foods. Live foods often have an advantage over processed foods like flakes and pellets, in that they will encourage the fish to use their hunting instincts which is most often fascinating to observe. Along with this, live foods are sometimes required to stimulate fish to breed, also live foods can provide fish with vitamins and minerals that they normally wouldn't get with processed foods.
Due to many different fish sizes, the choices of live foods can vary, from anything from brineshrimp to even Goldfish. Although most fish will eat brineshrimp, they are far to small for many larger fish to consider a meal. Below I have created a rough guide on what live foods can be fed to certain types of fish.
Small tetras, guppies, gouramies, rasboras- brineshrimp, mosquito larvae, whiteworms.
Medium sized fish eg Firemouths, Convicts- guppies, other fish fry, blackworms.
Large fish (Oscars, Jack Dempsy's, Arrowana's, Saratoga)- guppies, other fish babies, goldfish.
Newly hatched babies will often require live food as their first foods, after they have exhausted their supplies of egg yolk. Depending on the size of the fry, newly hatched brineshrimp will do, along with with this finely crushed fish flakes can be used for fry raising. One important thing to take into consideration when feeding live fish is the possibility of infection being spread to your fish from the feeder fish. For this reason, the best thing to do is to produce your own feeders in a controlled disease free tank or purchase your feeders from a very reputable source.