Apobaetis fiuzai Salles & Lugo-Ortiz 2002

Cruz, Paulo Vilela, 2020, Redescription of three species of Apobaetis Day, 1955 (Ephemeroptera: Baetidae), Zootaxa 4808 (2), pp. 317-330 : 322-323

Apobaetis fiuzai Salles & Lugo-Ortiz 2002

Diagnosis. Male imago (according to Cruz et al. 2011). 1) posterior margin of styliger plate triangular, area between unistyligers with a deep V emargination (Figs 10a and 10b in Cruz et al. 2011).

Larva. 1) labrum rectangular, distal margin without shallow medial emargination, dorsal surface with three to four elongate and blunt setae medially near distal margin ( Fig. 4A ); 2) lingua subquadrangular, with one medial protuberance ( Fig. 4D ); 3) maxillary palp long, 1.5× length of galea-lacinia, segment II apex without constriction ( Fig. 4E ); 4) labial palp segment II with distomedial projection pointed and laterally directed, segment III rectangular, distal margin almost straight ( Fig. 4F ); 5) tarsal claws 0.6× length of tarsus, without row of denticles ( Fig. 5A ); 6) posterior margin of terga IV with triangular, pointed spines ( Fig. 5B ); 7) abdominal terga II, III, V, VI and IX darker.

Redescription. Larva. Head: antenna with minute spines and fine, simple setae on apex of each segment. Frons with two keels. Labrum ( Fig. 4A ): rectangular, broader than long; length about 0.5× maximum width; distal margin without shallow medial emargination; ventral surface with robust spine-like setae on distolateral and distal margins; dorsal surface with three to four elongate and blunt setae medially near distal margin; dorsal surface medially, near distal margin, with one row of long and thin setae. Right mandible ( Fig. 4B ): incisors deeply cleft in two sets; outer and inner set of incisors each with 3 denticles; prostheca slender, bifurcated at apex; margin between prostheca and mola concave; tuft of spine-like setae at base of mola absent; denticles of mola not constricted; lateral margin convex. Left mandible ( Fig. 4C ): incisors deeply clefted in two sets; outer and inner set of incisors with 5 and 3 denticles, respectively; prostheca robust, bifid at middle, inner lobe slender, outer lobe robust; margin between prostheca and mola concave; tuft of spine-like setae at base of mola absent; subtriangular process wide; denticles of mola not constricted; lateral margin convex. Hypopharynx ( Fig. 4D ): lingua subquadrangular, with one medial protuberance, and apical tuft of setae, subequal than superlingua; superlingua not expanded, with short, fine, simple setae scattered over distal margin. Maxilla ( Fig. 4E ): maxillary palp long, 1.5× length of galea-lacinia; segment II apex without constriction; maxillary palp with fine and simple setae scattered over surface. Labium ( Fig. 4F ): glossa basally broad, narrowing slightly apically, subequal in length than paraglossa; inner margin with one row of blunt setae; apex with three short spine-like setae; outer margin with six spine-like setae; ventral surface covered with thin setae. Paraglossa curved inward; apex with two spine-like setae; outer margin with one row of ten robust spine-like setae; dorsal surface with one longitudinal row of five robust spine-like setae near inner margin; ventral surface with one longitudinal row of five robust spine-like setae at middle. Labial palp with segment I 0.8× length of segments II and III combined; segment I covered with micropores (not illustrated); segment II with distomedial projection pointed and laterally directed, apex of distomedial projection almost straight, outer margin and distomedial projection covered with fine, long and simple setae; inner margin bare; segment III rectangular, length 0.6× width, covered with fine, long and simple setae on outer margin, ventral surface with three robust spine-like setae near distal margin, dorsal surface with one row of five robust spine-like setae, distal margin almost straight. Thorax. Foreleg. Femur ( Fig. 5A ): dorsally with row of 11 short concave and blunt setae; apex with two concave and blunt setae; ventrally with row of 11 elongated spine-like setae. Tibia: dorsally bare; ventrally with one row of nine short spine-like setae. Patella-tibial suture present, apparently restricted to ventral margin. Tarsus: dorsally bare; ventrally with one row of 12 spine-like setae. Tarsal claws 0.6× length of tarsus, row of denticles absent. Abdomen. Terga II, III, V, VI and IX darker. Terga surface covered by scale-like triangular spines, micropores and short, fine and simple setae; posterior margin with triangular, pointed spines ( Fig. 5B ). Gills as in Figure 15 in Salles et al. (2002). Paraproct ( Fig. 5C ) with marginal spines, posterolateral extension with spines. Cerci with small lateral spines on all segments, paracercus without spines.

Material examined: Holotype, larva, Brazil, Minas Gerais state, Córrego Danta, Fazenda Prata, Rio da Prata , 19°45.29’ S, 46° 5.53’ W, small stones near river margin, slow current, shallow, 9/viii/2001, C. R. Lugo-Ortiz and F. F. Salles, UFES . Paratypes, two larvae, same data as holotype.

Figures

FIGURE 4. Apobaetis fiuzai. A. labrum (left d.v., right v.v.); B. right mandible; C. left mandible; D. hypopharynx; E. maxilla; F. labium (left d.v., right v.v.).

FIGURE 5. Apobaetis fiuzai. A. foreleg; B. posterior margin of tergum IV; C. paraproct.