Live feeds are often essential for larval fish. Live feeds are proven to be essential first-feed for many larval fish, essentially all those that hatch from small eggs with limited yolk reserves and often immature feeding and digestive functions. Live feeds provide larval fish with essential nutrients that are naturally ‘microencapsulated’ in bite-sized packages. They include a high proportion of easily-assimilated free amino acids and free fatty acids, as well as digestive enzymes and beneficial bacterial microfloras in the gut contents of the prey. The swimming activity of live prey also stimulates feeding responses in larval fish, a vital concern because small larvae with very limited metabolic reserves can quickly starve if they do not promptly begin feeding actively.