[医] 挠足亚纲

[ noun ]
minute planktonic or parasitic crustaceans
<noun.animal>

Copepoda \Co*pep"o*da\, n. pl. [NL., from Gr. ? an oar + -poda.]
(Zo["o]l.)
An order of Entomostraca, including many minute Crustacea,
both fresh-water and marine.

Note: They have a distinct carapace. The eggs are carried in
a pair of external pouches. Some are parasites of
fishes.