Code QE029999

Baetid nymphs are small (under 10mm when fully grown), slender, and streamlined, and the gills single not bifid. The first abdominal gill is plate-like and covers the other gills. The antennae are longer than the head (cf. Siphlonuridae). The head is hypognathous (downward-directed) except in Platybaetis , in which it is prognathous (forward-directed). The caudal filaments are usually fringed with setae, the terminal filament has a setal fringe on both lateral margins and the cerci are fringed only on the inner margin.

Baetids are widespread and abundant mayflies of all waters. Although most common in clear, cold streams, Cloeon and Centroptilum are found in depositional areas, macrophyte beds and still waters in rivers and wetlands. All other genera are associated with riffle habitats.

The genus Baetis , widely used for Australian baetids, is not actually present. Taxa allocated to this genus in the past belong to a number of presently un-named genera (Suter, 1996).

Reference:

Suter, P.J. (1996) Baetidae. pp. 13-28. In: Dean, J.C. and Suter, P.J. Mayfly Nymphs of Australia. A guide to Genera. Cooperative Research Centre for Freshwater Ecology, Identification Guide No. 7., Albury, NSW.