(class Insecta, order Coleoptera)
Family of tiny, pubescent, black to reddish beetles, less than 5 mm long. The antennae are very short and thick, with six or more segments forming a pectinate club. They live in or near water, crawling on aquatic vegetation. Larvae often have tufts of external gills at the end of the abdomen, or a mobile operculum, and are found under stones in streams or in permanently waterlogged fields. There are 250 species.
Subjects: Zoology and Animal Sciences.