Camelobaetidius francischettii Salles, Andrade and Da-Silva 2005

Boldrini, R., Salles, F. F. & Pes, A. M. O., 2012, Review of the genus Camelobaetidius Demoulin (Ephemeroptera: Baetidae) with reduced terminal filament, Journal of Natural History 46 (33 - 34), pp. 2033-2073 : 2047-2052

Camelobaetidius francischettii Salles, Andrade and Da-Silva 2005

( Figures 5B ; 6B ; 7B; 8; 9; 10A)

Salles, Andrade and Da-Silva 2005: 48; Salles, Serrão and Pereira 2005: 74; Salles and Serrão 2005: 269; Domínguez et al. 2006: 645; Boldrini and Salles 2009: 10; Salles et al. 2010: 302; Lima et al. 2010: 729.

Diagnosis

Camelobaetidius francischettii differs from the other described species of the genus with the terminal filament reduced based on the following combination of characteristics in nymphs: (1) segment II of labial palp with distomedial projection strongly produced ( Figure 8F ); (2) forefemur with prominent protuberance on inner margin ( Figure 9A ); (3) foretibia with indentation at apex; (4) small thoracic gill present at the base of forecoxa; (5) prosternum with a single, medial protuberance ( Figure 10A ); (6) tarsal claws with 34–39 denticles; (7) paraprocts with 18–23 small marginal spines ( Figure 9D ).

Redescription – nymph

Length of body: 5.3–6.7 mm; antennae: 1.9–2.4 mm; cerci: 4.8–6.1 mm; terminal filament: 0.6 mm; tibia I: 1.4 mm; tibia II and III: 1.8 mm.

Head ( Figure 6B ). Brown, vertex with irregular light brown marks. Turbinate portion of male compound eyes reddish brown. Antennae with scape and pedicel subcylindrical, with short, fine, simple setae on apex of each segment. Lateral branch of epicranial suture sinuous. Labrum ( Figure 8A ). Rectangular, broader than long; dorsal surface flat. Length about 0.4 × maximum width; distal margin with shallow medial emargination with asymmetrical margins; lateral margin with long, fine, simple setae; anterolateral margin with long, fine, pectinate setae; medially with short, robust, pectinate setae. Dorsally with many short, fine, simple setae scattered over basal area; dorsolateral arc of setae not defined. Ventrally with short, spine-like setae on lateral and anterolateral margin. Left mandible ( Figure 8B ). Inner and outer incisors fused, respectively with 3 + 2 denticles; prostheca robust, greatly enlarged, apically denticulate; margin between prostheca and mola straight, with a row of spine-like setae; subtriangular process narrow; tuft of setae at apex of mola absent; basal half with short, fine, simple setae scattered over dorsal area. Rigth mandible ( Figure 8C ). Inner and outer incisors fused, respectively with 3 + 2 denticles; prostheca robust, shorter than left prostheca, 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 with short, fine, simple setae scattered over dorsal area. Hypopharynx ( Figure 8D ). Lingua subequal in length to superlingua; apex rounded, with tuft of short, fine, simple setae. Superlinguae slightly expanded laterally, with fine, simple setae scattered over lateral and distal margin. Maxilla ( Figure 8E ). Crown of galea-lacinia with inner dorsal row of setae with three pectinate denti-setae. Medial protuberance of galea with 1 + 3 long, fine and simple setae. Maxillary palp subequal in length to galea-lacinia. Palp segment II subequal in length of segment I; maxillary palp with fine, simple setae scattered over surface. Labium ( Figure 8F ). Glossa narrow and subequal in length to paraglossa; inner margin with 10 spine-like setae increasing in length distally; apex with two long, spine-like setae; outer margin with six long, spine-like setae; ventral surface with five short, fine, simple setae on anteromedian area; dorsal surface bare. Paraglossa 1.2 × length of glossa, sub-rectangular, curved inward; apex with two rows of long, fine, pectinate setae; ventral surface with two fine, simple setae near base; dorsal surface with two robust, simple setae near apex. Labial palp with segment I 0.9 × length of segments II and III combined; segment I scattered with micropores, inner and outer margins with short, simple setae; segment II with distomedial protuberance strongly produced, with long, simple setae; dorsally with a row of five fine, spine-like setae; segment III rounded, length 0.6 × width, scattered with simple setae and fine, simple, spine-like setae.

Thorax ( Figure 5B ). Pronotum and mesonotum light brown with brown marks, metanotum dark brown. Hind wing pad present. Small thoracic gill present at the base of forecoxa. Prosternum with a single, medial protuberance ( Figure 10A ). Foreleg ( Figure 9A ) light brown with brown marks. Tibia I 1.0 × length of femur I; tarsi I 0.4 × length of femur I. Forefemur with prominent protuberance on inner margin; length about 2.5 × maximum width; dorsally with row of c.80 long, spine-like setae; length of setae 0.09 × maximum width of femur; ventrally with many short, spine-like setae scattered over surface; anterior and posterior surface with many short, spine-like setae on inner margin. Tibia. Dorsally with a row of short, fine, simple setae; ventrally with many short, spine-like setae; anterior surface with long, fine, simple setae; posterior surface with many short, spine-like setae near inner margin; tibiopatellar suture more than half length of tibia, located at apex of tibia; foretibia with indentation at apex. Tarsus. Dorsally with short, fine, simple setae; ventrally with 11 spine-like setae, increasing in length toward apex. Tarsal claws with 34–39 denticles. Mid and hind femora without prominent protuberance on inner margin, and mid and hind

tibia without indentation at apex. Tibia II and III 1.0 × length of femur II and III, respectively; tarsi II and III 0.3 × length of femur II and III, respectively.

Abdomen ( Figure 5B ). Brown. Segments IV–V light brown with anterior region brown; segments VI–IX with light brown band along midline. Terga IV creased ( Figure 9B ); posterior margin with truncate spines. Gills [ Figure 9C (a)] whitish with margins light brown; margins with narrow, spine-like setae intercalating short, fine, simple setae [ Figure 9C (b)]; trachea unpigmented, with one main trunk. Gills oval. Gill I 1.8 × length of segment II; gill IV 1.9 × length of segment V; gill VII 1.2 × length of segment VIII. Paraproct ( Figure 9D ) with 18–23 marginal spines on inner margin; surface shagreened with short, fine, simple setae; postero-lateral extension with marginal spines. Terminal filament 0.09 × length of cerci. Cerci light brown; outer margin with tufts of long, simple setae.

Comments

This species was described based on nymphs from Brazil, from the states of Alagoas and Rio de Janeiro ( Salles, Andrade and Da-Silva 2005). Later, Boldrini and Salles (2009) recorded this species from the state of Espírito Santo. Boldrini et al. (2010) described the imagos based on reared nymphs, and Lima et al. (2010) recorded this species from the state of Bahia. The nymphs are found more often in areas with moderate to fast currents. Adults were not observed in light traps in places where the nymphs were found. We examined two specimens of C. cf. francischettii , from the states of Goiás and Tocantins, with small differences in the number of setae on labrum. These specimens possess the dorso-lateral arc of setae forming one main row, unlike the original description of C. francischettii .

Camelobaetidius francischettii is possibly closely related to other species in which the forefemur has a prominent protuberance on inner margin, namely C. leentvaari , C. mantis and C. ipaye . It is differentiated from the last two species by the presence of a medial protuberance on prosternum, and from C. leentvaari by number of denticles on tarsal claw, 17–23 versus 34–39 in C. francischettii .

Distribution

BRAZIL: Alagoas, Bahia, Espírito Santo, Rio de Janeiro; new records : Tocantins, Goiás, Minas Gerais.

Material examined

Paratype. One nymph mounted on slide, BRAZIL, Alagoas, Murici, Cachoeira na Fazenda da Pedra Branca , 450 m, 09 ◦ 11 ′ 11.4 ′′ S, 35 ◦ 55 ′ 62.7 ′′ W, 16 March 2004, Francischettii, C.N. leg ( PPGBT) . One nymph mounted on slides, BRAZIL, Tocantins, Aurora, corredeira do Rio Palmas , Balneário Dourados , 12 ◦ 48 ′ 12.2 ′′ S, 46 ◦ 22 ′ 06.5 ′′ W, 06 August 2003, Hamada, N and Salles, F.F. leg ( PPGBT) . Two nymphs, BRAZIL, Bahia, Camacã, Rio Panelão , 15 ◦ 24 ′ 24.9 ′′ S, 39 ◦ 32 ′ 01.8 ′′ W, 2 August 2010, Boldrini, R and Hamada, N. leg ( PPGBT) . Three nymphs, BRAZIL, Bahia, Itacaré, Cachoeira do Tremembé , 14 ◦ 09 ′ 00.6 ′′ S, 39 ◦ 05 ′ 32.8 ′′ W, 31 July 2010, Boldrini, R. and Hamada, N. leg ( PPGBT) . One nymph mounted on slide, BRAZIL, Goiás, Montividiu, Rio Ponte de Pedra , 671 m, 17 ◦ 10 ′ 24.3 ′′ S, 50 ◦ 50 ′ 48.8 ′′ W, 21 May 2006, Hamada, N. leg ( PPGBT) . Four nymphs, BRAZIL, Espírito Santo, Alfredo Chaves, Nova Mantova , Fazendo Nego Boldrini , 20 ◦ 39 ′ 22.6 ′′ S, 40 ◦ 50 ′ 12.9 ′′ W, 20 November 2009, Boldrini, R. leg ( INPA) . Seven nymphs, same data above, except, 28 May 2007 ( PPGBT) . Two nymphs, one mounted on slide, same data above, except, 13 July 2007 ( INPA) . One nymph mounted on slide, BRAZIL, Minas Gerais, Bom Jesus do Galho , 19 ◦ 49 ′ S, 42 ◦ 18 ′ W, 16 October 2005, Francischetti, C.N. leg ( PPGBT) .

Figures

Figure 5. Camelobaetidius spp., nymphs (d.v.). (A) C. billi; (B) C. francischettii; (C) C. ipaye; (D) C. leentvaari; (E) C. maranhensis; (F) C. rufiventris.

Figure 6. Camelobaetidius spp., nymphs. (A) C. billi (head, f.v.); (B) C. francischettii (head, f.v.); (C) C. ipaye (head, f.v.); (D) C. maranhensis (head, f.v.); (E) C. rufiventris (head, f.v.); (F) C. billi (v.v); (G) C. billi (detail of thoracic gill).

Figure 8. Camelobaetidius francischettii, nymph. (A) Labrum (left v.v., right d.v.); (B) left mandible; (C) right mandible; (D) hypopharynx; (F) maxilla; (G) labium (left v.v., right d.v.).

Figure 9. Camelobaetidius francischettii, nymph. (A) Foreleg. (B) posterior margin of terga IV; (C(a)) gill IV; (C(b)), detail of the margin of Gill IV; (D) Paraproct.

Figure 10. (A) Camelobaetidius francischettii (detail of prosternum, ventro-lateral v.); (B) Camelobaetidius maranhensis (detail of pronotum, dorso-lateral v.).