Elminae

Curtis, 1830

riffle beetles

Genus Guides

Ancyronyx(spider water beetles)
Elmini(riffle beetles)
Macronychini(riffle beetles)

Elminae is a of riffle beetles ( Elmidae) comprising at least 120 and over 1,300 described . Members are primarily aquatic, inhabiting running water across all major biogeographic regions. The subfamily exhibits considerable morphological diversity, with some genera showing pronounced secondary and miniaturization traits.

Hexacylloepus ferrugineus by (c) Justin Williams, some rights reserved (CC BY), uploaded by Justin Williams. Used under a CC-BY license.

Macrelmis texana by (c) Justin Williams, some rights reserved (CC BY), uploaded by Justin Williams. Used under a CC-BY license.

Microcylloepus formicoideus by (c) Trevor Van Loon, some rights reserved (CC BY), uploaded by Trevor Van Loon. Used under a CC-BY license.

Pronunciation

How to pronounce Elminae: //ˈɛl.mɪ.neɪ//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Habitat

Running water systems including streams and rivers; specific microhabitats include riffles, sandy stream bottoms, and areas with moderate current. Some inhabit small sandy streams (2–3 m width) with clear water in tropical rainforest settings with dense cover.

Distribution

distribution spanning Afrotropical, Neotropical, and other major biogeographic regions. Documented from French Guiana, Suriname, Peru, Venezuela, Brazil (Rio de Janeiro, Minas Gerais, São Paulo states), and various Afrotropical localities.

Life Cycle

Larvae aquatic, found in sandy substrates of streams; also aquatic. Specific developmental details vary by and .

Ecological Role

Members have been observed in pristine forest streams and are generally considered indicators of good water quality in freshwater systems.

More Details

Taxonomic diversity

The contains at least 120 with considerable variability in several genera; revisionary work is recommended to assess monophyly of variable .

Miniaturization

Some Elminae exhibit extreme miniaturization (ca. 1.0–1.2 mm), with associated traits including reduced tarsal formula and feathery wings with reduced venation.

Secondary sexual dimorphism

Pronounced secondary has been documented in some , with males possessing modified protarsal and mesotarsal claws, spines on the , and ventrally directed processes on the metaventrite.