Haliplidae
| Crawling water beetles | |
|---|---|
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| Haliplus ruficollis, Haliplus flavicollis and Peltodytes caesus (not to scale) | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Coleoptera |
| Suborder: | Adephaga |
| Superfamily: |
Haliploidea Aubé, 1836 |
| Family: |
Haliplidae Aubé, 1836 |
| Genera | |
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The Haliplidae are a family of water beetles who swim using an alternating motion of the legs. They are therefore clumsy in water (compared e.g. with the Dytiscidae or Hydrophilidae), and prefer to get around by crawling. The family consists of about 200 species in 5 genera, distributed wherever there is freshwater habitat; it is the only extant member of superfamily Haliploidea. They are also known as crawling water beetles or haliplids.
The imagines of these beetles are generally oval in shape, with a very convex upperside, and are generally 1.5–5.0 mm (0.059–0.197 in) long. They are generally yellowish to light brown in color, frequently with light and dark patterns dotted with 10 or more rows of punctures on the elytra. The family's most distinctive characteristic is the large coxal plates of the hindlegs, which are immobile (though not fused in the centerline) and extend back along the underside to cover most of the abdomen base and the hindleg trochanters and femora. They are used as air storage supplementing the air carried under the elytra.
The compound eyes are markedly protruding from a smallish head, which bears antennae with 11 segments set upon an antennophore with a conspicuously short base (scapus). The extension of the prosternum is broad, with a truncated tip, ending adjacent to the metasternal process. The metasternum has a complete transverse ridge. The slender legs have long swimming hairs on tibiae and tarsi, but are not flattened into "flippers". The foreleg tibiae lack the apparatus for antenna cleaning present in many other beetles. Unlike in other Adephaga, the hindwings are not folded under the elytra, but rolled together apically.
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Wikipedia