Copepod

Natural history

The copepod may be the most abundant single species of animal on Earth. Kope is Greek, meaning “oar” or “paddle;” pod is Greek for “foot.” A copepod has antennae and appendages that are used like paddles for movement. Some species swim in a jerky fashion, while others move more smoothly.

They have a somewhat cylindrical, segmented body, one simple eye, two antennae and an exoskeleton. Most are pale gray or brown, but some are brightly colored red, orange, pink, purple, green, blue, or black.

Copepods inhabit a huge range of waters, from fresh to hyper salty; from subterranean caves to high altitude lakes; from polar ice-water to hydrothermal vents.

Conservation

The open ocean is the world’s “plankton pasture,” home to the tiny drifting plants and animals that power enormous food webs. The copepod represents the single most important group of animal plankton. Small fishes feed on them and are in turn eaten by bigger fishes, seabirds, seals and whales. We, too, depend on fishes nourished by ocean plankton.

Cool facts

• A single copepod may eat from 11,000 to 373,000 diatoms in 24 hours!
• Copepods are fast swimmers. Some can travel distances of 295 feet (90 m) in an hour—the human equivalent of swimming 50 miles per hour (81 km/h).