Mackerel icefish are an important part of Antarctic ecosystems. They primarily consume krill, mysids, and hyperiids (small crustaceans), very occasionally eating small fish. In turn, they are eaten by several species of fish. Also, Ade´ lie and chinstrap penguins feed on them at a low rate. Occasionally, arctic fur seals or gentoo penguins will eat mackerel icefish as well. Lastly, humans fish and consume C. gunnari as well. (Kock 2005b)