Hygrobia

All species occur in lowland areas and are mainly found in stagnant water. They live in the mud, silt, and detritus of ponds. Both adults and larvae are predators, specialized on oligochaete worms. The adults feed for as long as 30 min, coming to the surface very briefly to renew the air-supply. Adults are able to stridulate, producing an audible sound, which is why they are called squeak or screech beetles. == Morphology ==

The body length ranges from 8.0 to 11.0 mm. Compound eyes are present, not divided into ventral and dorsal portions, strongly protruding. Labrum is short and transverse. The antennae are filiform, almost glabrous, with 11 segments. == Phylogeny and evolution ==

The monophyly of the family is not in doubt. Regarding the relationships among the species of Hygrobia, a recent phylogenetic analysis suggested a sister group relationship between H. hermanni and a clade formed by the Australian species, with H. nigra sister to H. australasiae. Hygrobiidae probably diverged from other Hydradephagan clades around the time of the initial breakup of Pangea. The split between today's Palearctic and Australian clades occurred later, possibly in the middle Mesozoic, by dispersal events. == Species diversity and distribution ==

Hygrobia australasiae (Clark, 1862) - Australia Hygrobia davidi Bedel, 1883 - Jiangxi, southeastern China Hygrobia hermanni (Fabricius, 1775) - Europe, northern Africa (Morocco, Algeria and Tunisia), and Israel Hygrobia maculata Britton, 1981 - Australia Hygrobia nigra (Clark, 1862) - Australia Hygrobia wattsi Hendrich, 2001 - Australia == Family name ==

There has been a controversy associated with deciding which is the valid family name of squeak beetles: Hygrobiidae or Paelobiidae. ==References==