Description of the nymph of Caenis teipunensis Molineri, Grillet, Nieto, Domínguez & Guerrero, 2011 (Ephemeroptera: Caenidae) and key to the nymphs of Caenis from South America

Caenis teipunensis Molineri, Grillet, Nieto, Domínguez & Guerrero, 2011 was described based on male imago from the Venezuelan Amazon. In this study, we describe the nymph, with association to the male imago through the rearing process. The nymphal stage of Caenis teipunensis can be differentiated from others of the genus by the following combination of characters: pronotum with rounded anterolateral margins not projected laterally, fore tarsal claws with six denticles increasing in size toward the apex with the last two denticles 2/3 longer in relation to the first, operculate gills with elongated and apically fringed microtrichia ventrally along a submarginal row, and a smooth dorsal surface with long simple setae only. Additionally, we present an updated key to species of South American Caenis with known nymphs.