Cobblestone long-toed water beetle

Cobblestone long-toed water beetle (Dryops viennensis) is a small aquatic beetle in the family Dryopidae, native to riverine and coastal habitats in Europe, from central Europe eastward, with occasional records in North America. Dryopid beetles are characterised by long, clawed tarsi adapted for gripping substrates in fast-flowing water; adults are aquatic or semi-aquatic, often found clinging to stones and gravel in swift streams and river riffles. The genus Dryops contains numerous species distributed across the northern hemisphere. Cobblestone long-toed water beetle inhabits clean, well-oxygenated rivers and streams with stony or gravelly substrates, particularly riffle zones. Adults and larvae feed on algae, periphyton, and fine organic matter adhering to submerged surfaces. Like many specialised freshwater invertebrates, this species is sensitive to water quality degradation, siltation, and riparian habitat loss. Its IUCN conservation status is Not Evaluated. Freshwater beetle communities, including Dryopidae, are used as bioindicators of water quality in European river assessment programmes. The conservation of cobblestone habitats in montane and foothill rivers is important for the persistence of this and related species.