Caenis cuniana Froehlich, 1969

Lima, Lucas R. C. & Boldrini, Rafael, 2017, New distributional records and life stage description of Caenis species (Ephemeroptera: Caenidae) from Brazil, Zootaxa 4276 (2), pp. 285-292 : 286

Caenis cuniana Froehlich, 1969

( Figs. 1 , 4–5 )

Caenis sp. Demoulin 1955: 4 (nymph)

Caenis cuniana Froehlich, 1969: 104 (female imago, nymph); Hubbard, 1982a: 261; Da-Silva, 1993: 413 (male imago); Salles et al., 2010: 304 (nymph); Shimano et al., 2011: 245 (nymph); Lima et al., 2015: 3 (nymph). Caenis ? cuniana Malzacher, 1986: 94 (nymph).

Egg. Length: 94–126 µm; width: 77–91 µm. Coloration light yellow. Oval shaped with length 1.2–1.4 maximum width. Chorion surface smooth with polygonal imprints of follicle cells as in Fig. 4 . One coiled polar cap with about ten terminal knobs ( Fig. 5 ), and positioned around the main axis. Micropyle funnel-shaped, very short, with a small sperm guide ( Fig. 4 ).

Distribution. Brazil: States of Espírito Santo, Mato Grosso, Pará, Rio de Janeiro and São Paulo. New record: Roraima State.

Material examined. Eight imagos (five females and three males), Brazil, Roraima State, Boa Vista county , Rio Cauamé , Campus Cauamé da Universidade Federal de Roraima, 2°51’46 N/ 60°42’53” W, 09.vii.2016; Boldrini, R. coll. One female imago (reared) and two nymphs, Brazil, Roraima State, Cantá county , Serra Grande II, 2°32’N / 60°46’W; Boldrini, R. and Salles, F.F. cols.

Comments. Caenis cuniana has been described from imagos of both sexes, nymphs and eggs ( Froehlich 1969; Da-Silva 1993) and is characterized by the male genitalia with strong, sclerotized, and apically pointed forceps, and nymphs with large denticles on fore and middle tarsal claws. In the original description, the eggs were only superficially described by Froehlich (1969) without pictures or SEM images. Froehlich (1969) reported polar cap either at one or at both poles. However, in our material we observe only single-capped eggs ( Fig. 4 ). This mix of single- and double-capped eggs also exist in the North American species C. anceps Traver, 1935 and C. hilaris (Say, 1839) . This record of C. cuniana is the second from the Amazon River Basin (Northern Brazil) with the first by Malzacher (1986).

Figures

FIGURES 1 – 3. Caenis spp., male (dorsal view). 1, C. cuniana. 2, C. elidioi. 3, C. teipunensis.

FIGURES 4 – 7. Caenis spp., eggs. 4 - 5, C. cuniana: 4, detail of surface (c = chorion; mc = micropylar canal; pc = polar cap); 5, detail of polar cap. 6 - 7, C. reissi: 6, detail of surface (c; chorion; mc = micropylar canal; pc = polar cap); 7, detail of micropyle.