copepoda

Century Dictionary and Cyclopedia

1. An order of minute entomostracous fresh-water and marine Crustacea: so named because their five pairs of feet are mostly used for Swimming. The body is divided into several rings, the cuirass or carapace covers the head and thorax, and themouth is furnished with foot-jaws. The females carry their eggs, when they are expelled from the ovarium, in two bags at the base of the tail. The young present a form differing greatly from that of the parents. The limits of the order vary with different authors to some extent, the Epizoa (siphonostomous and lernæoid parasitic crustaceans) being, in part or as a whole, often included, and then distinguished as Parasita or Siphonostomata from the Gnathostomata or Eucopepoda, or copepods proper; in this case the Copepoda may be defined as entomostracous crustaceans with elongated and usually well-segmented body, without shell-forming reduplicature of the skin or abdominal appendages, and with biramous swimming-feet (Claus). The order is commonly known as that of the oar-footed crustaceans. Some forms, as Notodelphys, are commensal in the branchial sac of ascidians. A species, Cetochilus septentrionalis, forms much of the food of whales. Also Copopoda.

GNU Webster's 1913

1. n. (Zoöl.) An order of Entomostraca, including many minute Crustacea, both fresh-water and marine.

WordNet 3.0

1. n. minute planktonic or parasitic crustaceans