Hydromastodon sallesi Polegatto and Batista, 2007

Polegatto, C. M. & Batista, J. D., 2007, Hydromastodon sallesi, new genus and new species of Atalophlebiinae (Insecta: Ephemeroptera: Leptophlebiidae) from West and North of Brazil, and notes on systematics of Hermanella group, Zootaxa 1619 (1), pp. 53-60 : 55

Hydromastodon sallesi Polegatto and Batista , new species ( Fig. 1 -21)

Mature nymph, male. In alcohol. Body length: ca. 6.7mm, without caudal filaments; head ca. 1.4mm.

Head (Fig. 2). Color pattern: head of male nymph light brown, upper portion of eyes orange-brown, lower portion black; in male, lower portion of eyes about 1/5 width of upper portion. Antennae 1,6 length of head. Labrum ( Fig. 13 ): dorsal surface with fourteen to fifteen long setae; ventral surface with long setae in a oblique row decreasing posteriorly, and short setae on posterior area; posterior and lateral margin with short and relatively long setae respectively. Hypopharynx: as in Fig. 18. Left mandible (Fig. 21): incisors with three denticles, one prominent denticle and two smaller; prostheca with numerous long and fine setae, and two hard setae; mola with a prominent and hard posterior area. Right mandible (Fig. 19-20). Anterior incisor with three denticles, one of them prominent, posterior incisor with two subequal denticles; prostheca more slender than right, with long and fine setae. Maxillae (Fig. 16-17). Setae on crown of galeolaciniae numerous, and with setae on the base of tooth; setae on medial galealacinial margin fine and long in a single row, except on anterior region with two rows; all setae as in Fig. 13 ; third segment of maxillary palpi with long and fine setae in six parallel rows; apex of third segment bare and soft (Fig. 17). Labium (Fig. 14-15). Glossae and paraglossae with setae as in Fig. 14; labial palp: segment two with nine long dorsal setae, segment three with long setae concentrated ventrally, third segment with fifteen-sixteen short spine-like setae on inner margin (Fig. 15).

Thorax. Color pattern: thorax brown, legs light brown. Pronotum with weak anterolateral angle, with two setae. Legs (Fig. 7-10). Femora with long, strong and fine setae on posterior margin, and short setae on anterior margin; tibiae with long fine setae on anterior margin, scarce on third tibiae; long setae on all femora and on third tibiae, clavate apically (Fig. 10); short setae on median margin of tibiae and tarsi as in Figs. 7-9; tarsal claws ( Fig. 6 ) with subequal denticles, three apical and five at middle point, in two separate rows.

Abdomen (Fig. 4). Color pattern: segments 1 to 5 pigmented of black, segments 6 to 10, with color pattern as in Fig. 4. Segments 6 to 9 with posterolateral spines. Gills (Fig. 11) with a minute fine apical projection.

Mature nymph, female. In alcohol. Color pattern: Head and abdomen of female nymph with pattern as in Figs. 3, 5; thorax with color similar to male; segments 1 to 5 pigmented of black as in male, but with small areas lighter; segments 6 to 10 similar of in males, as in Fig. 5.

Diagnosis: This species can be distinguished from Hydromastodon mikei (Thomas & Boutonnet, 2004) , by the the following combination of characters: presence of posterolateral spines on abdominal segment 6 to 9; absence of spots in tibiae and tarsi; more numerous dorsal setae on labrum; prominent and hard posterior area of left mola; and color pattern of abdomen.

Adults: unknown.

Etymology: The name of species is in honour to my friend Frederico Falcão Salles, a great specialist in Ephemeroptera in Brazil.

Material examined: Holotype: mature nymph male, North of Brazil State of Roraima, Bem Querer Stream , 18-X-2004., Frederico F. Salles . Paratypes: 1 mature nymph female, same of holotype, 1 imature nymph male, West of Brazil, State of Mato Grosso, near to Nova Xavantina , Pindaíba Stream ; II-2003; Joana D. Batista & Helena S. R. Cabette .

The holotype and 1 paratype are deposited in the National Research Institute of Amazon, and 1 paratype is deposited in the Museum of Zoology of the University of São Paulo ( MZSP) , São Paulo.

Figures

FIGURES 1 TO 5. Hydromastodon sallesi: 1, nymph of male. 2, male head. 3, female head. 4, male abdomen, dorsal view. 5, female abdomen, dorsal view.

FIGURES 6 TO 12. Hydromastodon sallesi: 6, tarsal claws. 7, leg I, right, dorsal view. 8, leg II, right, dorsal view. 9, leg III, left, dorsal view. 10, detail of clavate setae on femur I. 11, gill 4. 12, male abdomen, ventral view.

FIGURES 13 TO 21. Hydromastodon sallesi: 13, labrum, left: ventral view, right: dorsal view. 14, labium, left: dorsal view, right: ventral view. 15, labial palp, detail of third segment. 16, maxilla, right, dorsal view. 17, maxillary palp, third segment, right, dorsal view. 18, Hypopharynx, ventral view. 19, mandible, right, ventral view. 20, detail of incisors, prostheca and mola of right mandible, ventral view. 21, same of left mandible, ventral view.