Antarctic krill
The members of the Euphausiacea are commonly called krill and are all marine shrimp-like species whose pleopods (abdominal appendages) function as swimmerets. They swarm and mostly feed on plankton. This group is composed of only 90 species, some of which are the most abundant species on the planet; in fact, it is estimated that the biomass of the Antarctic krill "Euphausia superba"' is 500 million tons.