What do penguins eat?
Depending on where they live, penguins eat a variety of fish including anchovies, sardines, mullet, opal fish, lanternfish, blue cod, red cod, squid, cuttlefish, octopus, and krill (a small shrimp like creature with an entire biomass of 500 million tons, about twice that of all humans). Antarctic penguins eat a lot of krill. Krill is considered a keystone species, near the bottom of the food chain, because it feeds mostly on phytoplankton and zooplankton to convert those small drifting organisms into a major food source form many sea creatures. Penguins eat while swimming. Some species of penguin hunt surface-schooling fish while others are mid-water or bottom feeders. Penguins have rear pointing, tooth-like barbs on the tongue and roof of the mouth which assist them in holding and swallowing their slippery prey. They do not eat on land and will subsist entirely on a layer of fat underneath their skin.
