Camelobaetidius sallesi sp. nov. Boldrini

(Figs. 5; 38–47)

Diagnose. Nymphs: 1) Labrum narrowly rounded anteriorly (Fig. 38); 2) segment II of labial palp with distomedial projection triangular with apex pointed (Fig. 43); 3) thoracic gill absent at the base of coxae; 4) tarsal claws with 48–51 denticles (Fig. 44 a); 5) posterior margin of terga with pointed spines (Fig. 45).

Description. Nymph. Length of body: 5.2–6.9 mm; length of antennae: 1.3 mm; length of cerci: 2.0 mm; length of terminal filament: 1.8 mm; tibia I: 0.6 mm; tibia II: 0.75 mm; tibia III: 0.8 mm.

Head (Fig. 5). Light brown. Antennae light brown. Lateral branch of epicranial suture straight.

Labrum (Fig. 38). Narrowly rounded anteriorly, broader than long. Length about 0.7× maximum width; lateral margin with long, fine and bifid setae; anterolateral and anterior margin with long, fine, bifid and pectinate setae. Dorsally with eight short, fine, simple setae scattered over basal area; dorsolateral arc of setae with 1 + 7 long, fine and apically pointed setae. Ventrally with three fine, short, spine-like setae on anterolateral margin.

Left mandible (Fig. 39). Prostheca robust, apically denticulate. Margin between prostheca and mola with one spine-like setae; subtriangular process narrow. Basal half with four simple setae.

Right mandible (Fig. 40). Prostheca slender, apically with longitudinal row of denticles; margin between prostheca and mola straight, with three spine-like setae; setae at apex of mola present. Basal half with two simple setae.

Hypopharynx (Fig. 41). Lingua shorter than superlingua; apex rounded, with tuft of short, fine, simple setae. Superlingua not expanded, with fine, simple setae scattered over lateral and distal margin; apex obliquely truncated.

Maxilla (Fig. 42). Inner dorsal row of setae with two pectinate denti-setae, apical denti-seta opposed to canines. Medial protuberance of galea with 1 + 2 long, fine, simple setae. Maxillary palp little shorter than galealacinia.

Labium (Fig. 43). Glossa shorter than paraglossa; inner margin with seven spine-like setae increasing in length distally; apex with two long, spine-like setae; outer margin with five long, spine-like setae; ventral surface with five short, fine, simple setae. Paraglossa sub-rectangular, curved inward; apex with two rows of long, fine, simple setae; ventral surface bare; dorsal surface with five robust, simple setae near apex. Labial palp segment II with distomedial projection triangular with apex pointed; dorsally with a row of four fine, spine-like setae; segment III rounded, length 0.5× width, scattered with fine, simple setae, and fine, spine-like setae.

Thorax (Fig. 5). Light brown. Hind wing pad present. Thoracic gill absent at base of coxae. Femur light brown. Tibia I 0.8× length of femur I; tarsi I 0.5× length of femur. Tibia II 0.9× length of femur II; tarsi II 0.5× length of femur II. Tibia III subequal to femur III; tarsi III about 0.6× length of femur III.

Forefemur (Fig. 44). Length about 2.7× maximum width; dorsally with row of c.a. 40 long, spine-like setae; ventrally with two short, spine-like setae. Foretibia. Ventrally with few, short, spine-like setae; anterior surface with seven short, fine spine-like setae near ventral margin, posterior surface with a row of short, fine simple setae near dorsal margin; patella-tibial suture present, 0.6× in length of tibia. Foretarsi. Ventrally with five spine-like setae, and one long, fine, simple setae near apex. Tarsal claws (Fig. 44 a) with 48–51 denticles. Mid femur. Length about 2.9× maximum width; dorsally with row of c.a. 48 long, spine-like setae. Hind femur. Length about 2.8× maximum width; dorsally with row of c.a. 48 long, spine-like setae.

Abdomen (Fig. 5). Light brown, except for anterolateral brown oblique stripe on segments III to VI. Terga with creased surface, posterior margin of tergum IV with pointed spines (Fig. 45). Gills oval. Gills IV (Fig. 46) white washed with brown; margins with narrow spines intercalating short, fine, simple setae; tracheae pigmented. Gill I 0.8× length of segment II; gill IV 1.6× length of segment V; gill VII 0.8× length of segment VIII. Paraproct (Fig. 47). With two spines near inner margin; surface without shagreened area; postero-lateral extension with spines. Cerci light brown; outer and inner margin of terminal filament and inner margin of the cerci with tufts of long, simple setae.

Etymology: The name of the species is in honor of Dr. Frederico Falcão Salles, for his significant contributions to the knowledge of Ephemeroptera .

Distribution. BRAZIL: Goiás.

Comments. The nymphs of Camelobaetidius sallesi sp. nov. is possibly related to C. spinosus Boldrini & Salles, 2012b, both species present the unique combination of characteristics such as segment II of labial palp with distomedial projection triangular with apex pointed (Fig. 43), thoracic gill absent at the base of forecoxa, terminal filament as long as cerci, and presence of pointed spines on posterior margin of terga (Fig. 45). The new species is easily distinguished from C. spinosus by the number of denticles on tarsal claws (48–51 denticles in C. sallesi sp. nov., 20–24 denticles in C. spinosus).

Material examined. Holotype: Nymph, BRAZIL, Goiás, Rio Verde, bellow the bridge in the BR 0 60, 14. vii. 2004, 17°32’33.5’’S / 50°33’25.7’’W, Hamada, N. leg (INPA). Paratypes: Three nymphs, BRAZIL, Goiás, Pirenópolis, Córrego Barriguda, 15°50'46.1"S / 48°55'17.1"W, 26.vi.2003, Hamada, N. leg (CZNC); Two nymphs (mounted on slides, medium Euparal), same data as paratype (UFRR).