Apobaetis kethepiali, Cruz, Paulo Vilela & De-Souza, Marcia Regina, 2014

Cruz, Paulo Vilela & De-Souza, Marcia Regina, 2014, Two new species of Apobaetis Day, 1955 (Ephemeroptera: Baetidae) from Brazil, Zootaxa 3866 (4), pp. 591-599 : 592-595

Apobaetis kethepiali sp. nov.

( Figures 1 ; 3–14)

Diagnosis. Mature nymph. 1) distal margin of labrum medially with spatulate setae; 2) maxillary palp 1.80× length of galea-lacinia ( Fig. 7 ); 3) segment II of maxillary palp without apical constriction ( Fig. 7 ); 4) apical margin of lingua straight ( Fig. 8 ); 5) segment II of labial palp with distomedial projection rounded and with anterior margin straight ( Fig. 9 ); 6) segment III rectangular, length 0.71× width ( Fig. 9 ); 7) tarsal claw 1.25× length of tarsus ( Fig. 10 a); 8) posterior margin of abdominal terga without spines ( Fig. 11 ); 9) paraproct with four marginal spines ( Fig. 12 ).

Description. Mature male nymph. Length of body: 3.00 mm; cerci, terminal filament and antenna broken.

Body coloration ( Fig. 1 ). Head. Coloration: light yellow. Antenna light yellow. Turbinate portion of compound eyes light brown. Thorax. Light yellow with medial spot on mesothorax. Foreleg ( Fig. 10 ). Femur, tibia and tarsus light yellow. Abdomen. Terga IV with postero-medial brown mark, V with one medio-medial black mark, IX black, all terga with medioanterior sigilla strong pigmented ( Fig. 1 ).

Body morphology. Head. Antenna with minute spines and fine, simple setae at apex of each segment ( Fig. 3 ). Frons with two keels. Labrum ( Fig. 4 ). Subrectangular, broader than long, with anterolateral margins rounded; length about 0.61× maximum width; distal margin without medial emargination; ventral surface with robust spinelike setae on anterolateral and distal margins; dorsal surface with four to five short and spatulate setae medially near distal margin; dorsal surface covered by long and thin setae near distal margin. Right mandible ( Fig. 5 ). Incisors deeply cleft in two sets; outer and inner set of incisors respectively with 3 and 2 denticles; prostheca slender, bifurcated at middle, both lobes pectinated; margin between prostheca and mola concave; tuft of spine-like setae at base of mola present; denticles of mola not constricted; apex of mola with two simple setae; lateral margin convex. Left mandible ( Fig. 6 ). Incisors deeply cleft in two sets; outer and inner set of incisors respectively with 4 and 3 denticles; prostheca robust, bifid, inner lobe slender and outer blunt and strongly pectinate at base; margin between prostheca and mola concave; tuft of spine-like setae at base of mola present; subtriangular process wide; denticles of mola not constricted; lateral margin convex. Hypopharynx ( Fig. 8 ). Lingua subquadrangular without apical lobe, slightly longer than superlingua; superlingua not expanded; short and thin setae scattered over distal margin of lingua and superlingua. Maxilla ( Fig. 7 ). Maxillary palp long, 1.80× length of galea-lacinia; segment II 1.09× length of segment I, apex without constriction; maxillary palp with fine and simple setae scattered over surface. Labium ( Fig. 9 ). Glossa basally broad, apically rounded and slightly longer than paraglossa; inner margin bare; outer margin with seven spine-like setae; apical margin with small spine-like setae; ventral surface covered with thin and long setae. Paraglossa curved inward; apex subtriangular; outer margin with one row of 13 robust spine-like setae; dorsal surface with one longitudinal row of four robust spine-like setae near inner margin; ventral surface with one longitudinal row of seven robust spine-like setae at middle. Labial palp with segment I 0.67× length of segments II and III combined; segment I covered with micropores; segment II with distomedial projection rounded and with anterior margin straight, outer margin and distomedial projection covered with fine, long and simple setae; segment III rectangular, length 0.71× width, covered with fine, long and simple setae on outer margin, ventral surface with robust spine-like setae near outer margin, distal margin with one row of robust spinelike setae. Thorax. Foreleg ( Fig. 10 a). Ratio 2.0:1:1.2:1.5. Forefemur. Length about 6.50× maximum width; dorsally with row of 10 short concave and apically straight setae ( Fig. 10 b); apex bare; ventrally with row of 18 spine-like setae. Tibia. Dorsally bare; ventrally with one row of ten short spine-like setae. Tibio-patelar suture present. Tarsus. Dorsally bare; ventrally with one row of 13 short spine-like setae. Tarsal claws 1.25× length of tarsus, without row of denticles. Abdomen. Terga surface covered by scale-like triangular spines, micropores and short, fine and simple setae; posterior margin without spines ( Fig. 11 ). Gills lost. Paraproct with four marginal spines, posterolateral extension broken and lost ( Fig. 12 ). Cerci with small lateral spines on all segments ( Fig. 13 ), terminal filament without spines ( Fig. 14 ).

Etymology. Kethepiáli means fishing-bait in Baniwa, a language and indigenous tribe that inhabit the area where the species was collected. This word often is used to refer to mayflies, in general, by them.

Material examined. Holotype: nymph on slide, BRAZIL, state of Amazonas, São Gabriel da Cachoeira, small stream parallel to BR307, 13km, 26.viii.2011, S00º04’44.6’’ / W067º00’15.9’’, Cruz P.V., Fernandes A. S. and Reis E. (colls.).

Figures

FIGURES 1 – 2. Dorsal habitus of nymphs. (1) Apobaetis kethepiali sp. nov.; (2) Apobaetis pucupi sp. nov.

FIGURES 3 – 9. Apobaetis kethepiali sp. nov. (3) antenna; (4) labrum (left d. v., right v. v.); (5) right mandible; (6) left mandible; (7) maxilla; (8) hypopharynx (left d. v., right v. v.); (9) labium (palp were separated to facilitate visualization of structures).

FIGURES 10 – 14. Apobaetis kethepiali sp. nov. (10 a) foreleg; (10 b) detail of dorsal margin setae of forefemur; (11) posterior margin of abdominal terga IV; (12) paraproct; (13) detail of cerci; (14) detail of terminal filament.