Coryphorus aquilus Peters

Molineri, Carlos, Grillet, Maria-Eugenia, Nieto, Carolina, Dominguez, Eduardo & Guerrero, Edmundo, 2011, New species and records for the mayfly families Caenidae, Leptohyphidae and Coryphoridae (Ephemeroptera, Pannota) from Venezuelan Guayana’s Uplands, Zootaxa 2750, pp. 39-50 : 43

Coryphorus aquilus Peters

( Figs. 10–13 )

Coryphorus aquilus Peters 1981: 211 ; Molineri et al. 2002: 120.

Material. Venezuela, Estado Bolívar: 2 3 imagos (slide 511) from Tarotá, N 5° 49' 15" – W 61° 25' 4", 1324 m, 27/ VI/2007, EG, AMO, CA and MEG cols.; and 1 Ƥ imago (slide 512) from Mareman-Parú, N 5° 44' 49" - W 61° 24' 6", 1308 m, 28/VI/2007, EG, AMO, CA and MEG cols. One ɗ and 1 Ƥ deposited in MLBV; 1 3 in IML.

Discussion. In spite of some differences in size and coloration between the Venezuelan material and that previously known from Colombia and Brazil ( Peters 1981, Molineri et al. 2002), we consider all specimens as the same species, Coryphorus aquilus Peters. The specimens from these different populations are not morphologically distant, and we cannot find distinct features defining them. A short comparison of the new material with the previously known specimens is provided below.

Male imago ( Fig. 10 , at right). Length (mm): body, 7.0; forewings, 7.5–7.7; cerci, 11.0; terminal filament, 8.0. Much larger than previous known material (with a wing length of 5.1–5.3 mm, Fig. 10 at left). Color pattern ( Fig. 13 ) more extended and marked than in males from other populations (Leticia, Colombia and Presidente Figueiredo, Brazil). Fore wings ( Fig. 12 ) with more numerous cross veins (110–123 versus 75–100).

Female subimago ( Fig. 11 ). Length (mm): body, 6.0; forewings, 8.1–8.2; cerci, 4.0; terminal filament, broken off and lost. As discussed in male, this female from Venezuela show a general coloration strongly marked, and a large size if compared with the previously known female from Colombia. Also, the wings present 93–99 cross veins (versus 75 in the Colombian material), and are much less pigmented with black (only in the basal third of C and Sc cells, versus the entire wing base in Colombian female). Abdominal sternum 9 (arrow in Fig. 11 ) projected and medially cleft (originally described as not projected and broad, but the previously known female is somewhat dry and shrunken, so this structure was not well seen by Molineri et al. (2002).

Ecology. Imagos were collected along the stream margins at night, during the rainy season (June 2007). Streams flow through the savanna area (1308–1325 m) and they were bed-rock, uncovered small to medium size streams (12–30 m wide; 2nd–3rd order), with very shallow (~ 30 cm) and acidic (pH = 5) waters ( Fig. 25 ).

Figures

FIGURES 10 – 13. Coryphorus aquilus: 10, male imago from Leticia (Colombia) at left and from Venezuela at right; 11, female subimago; 12, male fore wing; 13, male abdomen, d. v.

FIGURES 23 – 26. Study sites: 23, Kaku Parú; 24, Kavanayén; 25, Mareman Parú; 26, Aponwao.