krill

Any of several Antarctic crustaceans, the most common species being Euphausia superba. Similar to a shrimp, it is up to 5 cm/2 in long, with two antennae, five pairs of legs, seven pairs of light organs along the body, and is coloured orange above and green beneath. It is the most abundant animal, numbering perhaps 600 trillion (million million). (Order Euphausiacea.)

Moving in enormous swarms, krill constitute the chief food of the baleen whales, and have been used to produce a protein concentrate for human consumption, and meal for animal feed.