Callibaetis (Abaetetuba) cochlea Cruz, Salles & Hamada, 2017, sp. nov.
Creators: name: Cruz, Paulo Vilela
name: Salles, Frederico Falcão
name: Hamada, Neusa
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Ephemeroptera
Baetidae
Callibaetis
Callibaetis cochlea

description: Callibaetis (Abaetetuba) cochlea sp. nov.
(Figs 1–4 and 21 B)
Callibaetis sp. A: Cruz et al. 2016
Known stage: nymph
Diagnosis. Mature nymph: 1) distal margin of labrum with row of apically bifid setae medially (Fig. 2 B); 2) maxillary palp 1.8× length of galea-lacinia (Fig. 2 E); 3) two rows of setae on basal part of inner-dorsal row of maxilla (Fig. 21 B and similar to Fig. 21 A); 4) paraglossa subrectangular and arched, with truncated apex (Fig. 2 G); 5) paraglossa with three tufts of thin setae (Fig. 2 H); 6) inner margin of labial palp segment III tapering towards the base (Fig. 2 G); 7) segment III of labial palp trapezoid; 8) posterior margin of metanotum without spines; 9) anterior surface of fore tarsus without stout setae (Fig. 3 A); 10) hind claw with minute denticles (Fig. 3 F).
Description. Mature nymph. Length: body, 10.1–12.4 mm; cerci, 4.3–5.3 mm (n=2). Head light brownishyellow (Figs 1 A–1C). Antenna with spines and thin setae on flagellum (Fig. 2 A). Labrum (Fig. 2 B) maximum length about 1.3× minimum length; anterolateral margins with long and simple stout setae; distal margin with apically bifid stout setae medially; dorsal surface with numerous long and thin setae, near distal margin with two pairs of robust and long setae; distal margin with one row of stout setae ventrally; ventral surface with short stout setae near lateral margin. Right mandible (Fig. 2 C) with 4+3 denticles; margin between prostheca and mola convex; basal half with short, thin setae and pores scattered over dorsal surface. Left mandible (Fig. 2 D) with 6+4 denticles; margin between prostheca and mola straight; basal half with short and thin setae, and pores scattered over dorsal surface. Lingua of hypopharynx (Fig. 2 F) covered with small simple setae; short and thin setae scattered over inner margin of superlingua. Maxilla (Fig. 2 E) with two rows of setae on basal part of inner-dorsal row (Figs 21 B and similar to 21A); medially, on inner margin, with 1+4 stout setae. Maxillary palp 1.8× length of galea-lacinia; palp segment II 0.8× length of segment I; outer margin of segment I covered with long and thin setae; inner margin of segment II with stout setae. Labium (Figs 2 G–2H) with glossae shorter than paraglossae; inner margin of glossae with 16 stout setae; apex with 3–5 long and stout setae; outer margin with one row of long and stout setae; dorsal surface with one oblique tuft of long and stout setae. Paraglossae subrectangular and arched, with truncated apex, and with one row of stout setae and three tufts of simple setae at apex; dorsal surface with one longitudinal row of long and stout setae near outer margin and one tuft of long and stout setae on basal half near inner margin; outer margin with one row of long and stout setae. Labial palp with segment I 1.1× length of segments II and III combined; inner margin of segment II with six short and stout setae, and few thin and short setae; dorsal surface of segment II with row of 12 short and stout setae; inner margin of labial palp segment III tapering towards the base; whole margin, on dorsal surface, of segment III with one row of long and stout setae; segment III trapezoid, dorsal surface concave. Thorax brownish yellow. Metanotum without spines. Foreleg ratio (Fig. 3 A) 1.5:(1.4 mm):0.7:0.5. Forefemur length about 7.3× maximum width; dorsal margin with row of short and stout setae; length of setae on dorsal margin about 0.07× maximum width of femur; ventral margin with one row of short and stout setae; anterior surface, near ventral margin, with one row of bifid and trifid stout setae; near dorsal margin with one row of short and blunt setae. Ventral margin of tibia with one row of short and stout setae; anterior surface with one row of short and stout setae. Ventral margin of tarsus with one row of stout setae and one row of short, trifid and stout setae (Fig. 3 G). Claw 0.6× length of tarsus. Mid and hind leg similar to foreleg except anterior surface of femur, tibia and tarsus covered with robust and strong pectinate stout setae; claw with minute denticles (Fig. 3 F). Abdomen brownish yellow. Posterior margin of terga with regular spines (Fig. 4 A); terga III, V, VII and IX with lateral brown marks. Surface of sterna covered with thin setae; female mature nymphs with two pairs of reddish marks near anterior margin on sterna II–VII, sterna VIII and IV with pair of longitudinal reddish marks. Gill I subequal to length of segment II, with three folds. Gill IV equal to length of segments V and VI combined, with two folds. Gill VII equal to length of segment VIII and half of segment IX combined, with one fold. Paraproct (Fig. 4 B) with ca. 36 marginal spines. Paracercus and cerci with long spines on all segments (Figs 4 C and 4D).
Comments. The nymph of C. (Ab.) cochlea sp. nov. is similar to the nymph of C. (Ab.) capixaba Cruz, Salles & Hamada, and can be distinguished by the trapezoid segment III of labial palp in C. (Ab.) cochlea sp. nov. while in C. (Ab.) capixaba the labial palp segment III is subrectangular.
Etymology. cochlea, in Latin, meaning spoon, in reference to the concavity of the third segment of labial palp.
Material examined. Holotype: mature nymph, BRAZIL, Minas Gerais, Juiz de Fora, Reserva Biológica Municipal Poço D’anta, 27.x.2011, 21°44’33.1”S / 043°18’56.4” W, P.V. Cruz coll., INPA. Paratypes: Two nymphs, same data.
Distribution. Brazil: Minas Gerais.
description: Published as part of Cruz, Paulo Vilela, Salles, Frederico Falcão & Hamada, Neusa, 2017, Four new species of Callibaetis Eaton (Ephemeroptera: Baetidae), nymphal description of Callibaetis (Abaetetuba) fasciatus (Pictet) and keys for South American species of Callibaetis, pp. 229-261 in Zootaxa 4250 (3) on pages 230-235, DOI: 10.11646/zootaxa.4250.3.3, http://zenodo.org/record/495027