Caenidae
Guides
Brachycercus
squaregilled mayflies
Brachycercus is a genus of small mayflies in the family Caenidae, commonly known as squaregilled mayflies. The genus is characterized by its distinctive square-shaped gills and is distributed primarily in the Palaearctic and Nearctic realms. At least six species have been described, including B. harrisella, which is the type species described by Curtis in 1835.
Brachycercus nitidus
Brachycercus nitidus is a species of small squaregill mayfly in the family Caenidae, first described by Traver in 1932. The genus Brachycercus is part of the superfamily Caenoidea, a group characterized by reduced wing venation and other adaptations to lentic (still-water) habitats. As a member of the Caenidae, this species likely exhibits the family's typical traits including small body size, short antennae, and forewings with few crossveins. The specific epithet "nitidus" (Latin for "shiny" or "polished") may refer to a characteristic sheen of the cuticle, though this interpretation is speculative without direct examination of type material.
Caenis
Common Square-gills
Caenis is a genus of small mayflies in the family Caenidae, commonly known as "square-gilled mayflies." Adults are among the smallest mayflies, with some species measuring only 3–4 mm in body length. The genus is globally distributed across multiple continents and serves as an indicator taxon for aquatic ecosystem health. Nymphs inhabit various freshwater environments, and adults emerge in synchronized events.
Caenis hilaris
Caenis hilaris is a species of small square-gilled mayfly in the family Caenidae. It is found in North America. As a member of the order Ephemeroptera, it shares the characteristic life history of mayflies, with aquatic nymphal stages and short-lived winged adults.