Crayfish are known to feed on whatever material lands at the bottom of rivers and streams, or is washed downstream by fast currents. They consume algae that grows on rocks or debris found within their environment as well as decayed plant or animal matter that gets washed downstream; some aquarium owners have even reported sightings of crayfish eating small fish from their aquarium tanks!
Home owners can feed crayfish a wide range of foods, including fresh vegetables such as romaine lettuce and mashed peas, as well as frozen fish food pellets, bloodworms, brine shrimp and daphnia. While protein may not be essential, adding some will help the animal build its exoskeleton which then sheds as they grow and is then reabsorbed back into their bodies.
Crayfish tend to be nocturnal creatures that do not like being handled, so feedings should take place only at night and they should have ample opportunity to rest during the day in their aquarium. Be careful when handling crayfish - their heads contain vital nerves which should never be touched! Hold them by their claws instead and wear thick gloves when handling one.
Crayfish tend not to consume fish kept in an aquarium, however this could happen if it's an extremely slow moving species such as an anemone or shrimp. This depends on several factors including tank size and number of inhabitants as well as species kept.
