Camelobaetidius spinosus, Boldrini & Pes & Francischetti & Salles, 2012

Boldrini, R., Pes, A. M. O., Francischetti, C. N. & Salles, F. F., 2012, New species and new records of Camelobaetidius Demoulin, 1966 (Ephemeroptera: Baetidae) from Southeastern Brazil, Zootaxa 3526, pp. 17-30 : 24-28

Camelobaetidius spinosus sp. nov. Boldrini & Salles

(Figs. 12; 23–32)

Diagnoses. Nymphs: 1) Segment II of labial palp with distomedial projection triangular with apex pointed (Fig. 28); 2) thoracic gill absent at the base of forecoxa; 3) tarsal claws with 20 – 24 denticles (Fig. 29); 4) posterior margin of terga with pointed spines (Fig. 30); 5) paraproct with six pointed spines (Fig. 32); 6) terminal filament as long as cerci.

FIGUES 19–22. Camelobaetidius juparana sp. nov., nymph. 19a, foreleg. 19b, detail tarsal claw. 20, posterior margin of terga IV. 21a, gill IV. 21b, detail of margin of the gill IV. 22, paraproct.

FIGUES 23–28. Camelobaetidius spinosus sp. nov., nymph. 23, labrum (left v.v., right d.v.). 24, left mandible. 25, right mandible. 26, hypopharynx. 27, maxilla. 28, Labium (left v.v., right d.v.).

FIGUES 29–32. Camelobaetidius spinosus sp. nov., nymph. 29, foreleg. 30, posterior margin of terga IV. 31a, gill IV. 31b, detail of margin of the gill IV. 32, paraproct.

Comments. Camelobaetidius spinosus sp. nov. is possibly closely related to C. cayumba , both species present the unique combination of characteristics such as the terminal filament as long as cerci, segment II of labial palp with distomedial projection triangular with apex pointed, and thoracic gill absent at base of forecoxa. This species is easily distinguished from C. cayumba by the presence of pointed spines on posterior margin of terga.

Description

Nymph. Length of body: 3.4–4.0 mm; length of antennae: 1.6–1.7 mm; length of cerci: 2.2 mm; length of terminal filament: 2.2 mm; tibia I and II: 0.8 mm; tibia III: 0.7 mm.

Head (Fig. 12). Light brown. Antennae light brown, scape and pedicel subcilindrical. Lateral branch of epicranial suture straight.

Labrum (Fig. 23). Narrowly rounded anteriorly, base wider than apex, broader than long. Length about 0.6× maximum width; lateral margin with long, fine, simple setae; anterolateral margin with long, fine, pectinate setae; medially with short, robust, apically pectinate setae. Dorsally with four short, fine, simple setae scattered over basal area; dorsolateral arc of setae with a row 1 + 8 long, fine, apically pointed setae. Ventrally with two short, spinelike setae on anterolateral margin.

Left mandible (Fig. 24). Prostheca robust, apically denticulate. Margin between prostheca and mola straight, without a row of spine-like setae; subtriangular process narrow and produced; tuft of setae at apex of mola absent. Basal half bare.

Right mandible (Fig. 25). Prostheca robust, shorter than left mandible, apically denticulate; margin between prostheca and mola almost straight, with a row of spine-like setae; tuft of spine-like setae at base of mola present; tuft of setae at apex of mola present. Basal half bare.

Hypopharynx (Fig. 26). Lingua subequal in length to superlingua; apex rounded, with tuft of short, fine, simple setae. Superlingua not expanded with fine, simple setae scattered over lateral and distal margin.

Maxilla (Fig. 27). Crown of galea-lacinia with four denticles. Inner dorsal row of setae with two pectinate denti-setae. Medial protuberance of galea with 1 + 3 long, fine and simple setae. Maxillary palp 1.4× in length of galea-lacinia. Palp segment II 0.6× in length of segment I. Fine and simple setae scattered over maxillary palp.

Labium (Fig. 28). Glossa narrow and shorter than paraglossa; inner margin with ten spine-like setae increasing in length distally; apex with two long, spine-like setae; outer margin with four long, spine-like setae; ventral surface with six short, fine, simple setae on anteromedian area; dorsal surface bare. Paraglossa sub-rectangular, curved inward; apex with two rows of long, fine, simple setae; ventral surface bare; dorsal surface with three fine, spine-like setae near to apex. Labial palp with segment I subequal in length of segments II and III combined; segment II with distomedial projection triangular with apex pointed; dorsally with a row of three fine, spine-like setae; segment III rounded, length 0.6× width, scattered with simple setae, and spine-like setae.

Thorax (Fig. 12). Light brown; metanotum brown. Hind wing pad present. Thoracic gill absent at the base of forecoxa. Femur, tibia and tarsi light brown; apex of femur brown. Tibia I and II 0.8× in length of the respective femur; tibia III 0.9× in length of femur III; tarsi I, II and III about 0.4× in length of the respective femur.

Forefemur (Fig. 29). Length about 3.6× maximum width; dorsally with row of c.a. 65 long, spine-like setae; length of setae 0.2× maximum width of femur; ventrally with seven short, spine-like setae. Foretibia (Fig. 29). Ventrally with row of six short, spine-like setae; anterior surface with a row of long, fine, simple setae; tibiopatelar suture less than half the length of tibia. Foretarsi (Fig. 29). Ventrally with a row of five spine-like setae increasing in length toward apex. Tarsal claws with 20–24 denticles.

Abdomen (Fig. 12). Light brown. Terga IV with surface creased (Fig. 30); posterior margin with pointed spines. Gills IV (Fig. 31a). Light brown; margins with narrow spine intercalating short, fine, simple setae (Fig. 31b); tracheae pigmented, extended from main trunk. Gills oval. Gill I 0.9× length of segment II; gill IV 1.7× length of segment V. Gill VII 0.7× length of segment VIII.

Paraproct (Fig. 32). with six spines near inner margin; surface with fine, simple setae, without shagreened area; postero-lateral extension with minute marginal spines. Cerci light brown and terminal filament whitish, distal 3/4 with a brown mark; outer and inner margin of the terminal filament and inner margin of the cerci with tufts of long, simple setae.

Etymology: From the Latin word spin, due to the spines on the posterior margin of the terga of the nymph.

Distribution. BRAZIL: Minas Gerais.

Material examined. Holotype: One nymph, BRAZIL, Minas Gerais, Bom Jesus do Galho , 19º43’669’’S/ 42º28’200’’W, 23.vii.2005, Francischetti, C.N. leg ( CZNC) . Paratypes: One imature nymph, same data holotype ( INPA) . One nymph, BRAZIL, Minas Gerais, Bom Jesus do Galho , 19º43’669’’S/ 42º28’200’’W, 29.x.2005, Francischetti, C.N. and Salles, F.F. leg, without mouth parts ( CZNC) . Same as preceeding except one nymph mounted on slides, 23.iv.2005, Francischetti, C.N. ( CZNC) . One nymph mounted on slides, Minas Gerais, Pingo D´Agua, Rio Sacramento , 19º49’S / 42º18’W, 29.x.2005, Francischetti, C.N. & Salles, F.F. leg ( INPA) .