What specific habitat requirement distinguishes Brychius hungerfordi from many common pond dwellers?
Requiring flowing riffle zones often associated with clean, coarse substrates.
The Hurd's Crawling Water Beetle, *Brychius hungerfordi*, is highlighted as an organism exhibiting extreme habitat specificity. Its survival is critically dependent on lotic systems, specifically the riffle zones of rivers where water is actively flowing and maintaining a consistent current. Furthermore, the required bottom composition is defined as a mix of sand and gravel that must be relatively clean, meaning it cannot be choked with excessive fine sediment or siltation. This requirement contrasts sharply with the preferences of many generalist species that thrive in still, silty environments or those abundant with vegetation found in lentic systems. The beetle's location is thus defined not just by the presence of a river, but by precise hydrologic and geologic conditions within that river.
