Fallceon grandis, González-Lazo & Salles, 2007

González-Lazo, D. & Salles, F. F., 2007, Description of a new species of Fallceon from Cuba, and redescription of the larva of F. longifolius (Ephemeroptera, Baetidae), Zootaxa 1583 (1), pp. 51-57 : 52-54

Fallceon grandis sp. n.

( Figs. 1 – 12 )

Larva. Body lenght, 7.5–8.0 mm, cerci 6.5–6.8 mm, paracercus 3.0– 3.2 mm.

Head. Coloration of vertex pale brown, genae dark brown. Antennae pale yellow to pale brown, scape and pedicel pale brown, flagellum pale yellow. Frontal keel absent. Labrum ( Fig. 1 ) rounded distally, with median emargination; one submedial and three submarginal simple setae present on each side; simple setae scattered dorsally on midposterior region; long, fine, simple setae on anterior margin, and long, fine, branched setae on anterolateral margin. Right mandible ( Fig. 2 ) with eight denticles; tuft of simple setae between prostheca and molar present; base of incisors with 7–8 simple setae, distal end of molar with 2 long, simple setae. Left mandible ( Fig. 3 ) with seven denticles, almost inconspicuous tuft of simple setae present between prostheca and molar; blunt triangular process present at base of molar; short, stout simple setae at base of triangular process and molar; distal end of molar with 1 long, simple seta. Maxillae ( Fig. 4 ) short, robust, maxillary palps subequal to galea-laciniae; segment 1 0.7x length of segment 2, segments 1 and 2 with scattered fine, simple setae; 1+4-5 long, simple setae at base of galea-laciniae. Labium ( Fig. 5 ) with palp segment 1 0.9x length of segments 2 and 3 combined, segment 2 with 5–7 simple setae dorsally, segment 3 apically rounded, with many spurs and fine setae of various lengths on surface; glossae 0.9x length of paraglossae, with 11-12 simple setae in inner margin and 6-8 simple setae ventrally, outer margin with 6 simple setae. Paraglossae basally broad, tapering distally, with 2 apical rows of simple setae. Hypopharynx as in Fig. 6 .

Thorax. Nota pale brown to dark brown. Pronotum with medial pale markings, sterna pale yellow. Legs robust, pale yellow, proximal and distal end of femora, tibia and tarsi dark brown. Femora ( Fig. 7 ) dorsally with 41 long, robust spurs (more abundant basally, 25 spurs), ventrally with 8 short spurs and medial pale brown macula on anterior face. Tibiae ( Fig. 7 ) with 13–15 short, stout spurs and fine simple setae ventrally; dorsal margin with 3–4 long, stout spurs and fine, long simple setae. Tarsi ( Fig. 7 ) with 9 stout spurs ventrally, those on distal end longer and more robust; dorsal margin with two rows of fine, long simple setae. Tarsal claws ( Fig. 8 ) with 9–10 denticles, one subapical seta present.

Abdomen. Color pale yellow to dark brown. Terga 1–3 and 5–7 dark brown, terga 4 and 8–10 pale yellow, terga 8 and 9 anteriorly pale brown, terga 2–8 with two submedian dark spots. Sterna pale yellow. Tergal surface ( Figure 9 ) with abundant angulate scale bases and scattered, fine simple setae, posterior margin with sharp triangular spines. Gills ( Fig. 10 ) broad and richly tracheated, margins serrated, with fine simple setae between serrations ( Fig. 11 ). Paraprocts ( Fig. 12 ) with scattered small angulate scale bases, 13–14 irregular spines in posterior margin. Caudal filaments pale brown.

Male and female adults: Unknown

Material examined: Holotype. 1 mature larva: Cuba, río Yara , Granma, 06.1999, P. López col. , - Paratype. 2 larvae, same data as holotype .

Distribution. Río Yara, Granma, Eastern Region of Cuba.

Etymology. The epithet of the species is in allusion to its large body size.

Discussion. F. grandis can be easily distinguished from all other species of Fallceon by the following combination of characters: (1) frontal keel absent; (2) maxillary palp subequal to galea-laciniae ( Fig. 4 ); (3) dorsal margin of femora with greater number of setae ( Fig. 7 ); (4) tarsal claws with one subapical seta ( Fig. 8 ); (5) gills broad and richly tracheated ( Fig. 10 ); (6) tergal surface with abundant angulate scales bases and posterior margin with sharp triangular spines ( Fig. 9 ); (7) paraprocts with 13–14 irregular spines in posterior margin ( Fig. 12 ).

The absence of frontal keel, and specially, the tarsal claws with a subapical setae, indicate that F. grandis is similar to two other species of Fallceon , both of which were described as Caribaetis by Kluge (1992a), F. alcarrazae and F. planifrons . Despite these similarities, F. grandis can be differentiated from F. planifrons because of its larger body size, the greater number of setae along the dorsal margin of femora, and richly tracheated gills. F. grandis and F. alcarrazae can be differentiated based on abdominal coloration, number and size of tergal scale and angulated scale bases (both of which are smaller and less abundant in F. alcarrazae than in F. grandis ), and tracheation of gills.

Apparently F. grandis is a rare species, since only three larvae were collected in the Río Yara, in spite of the numerous samplings in this river.

Figures

FIGURES 1–12. Fallceon grandis sp.n. Larva: 1, labrum, d.v.; 2, right mandible v.v.; 3, left mandible v.v.; 4, maxillae v.v.; 5, labium, left v.v., right d.v.; 6, hypopharynx v.v.; 7, fore leg; 8, fore tarsal claw; 9, posterior margin of tergum IV; 10, gills I–VII; 11, gill IV (detail of margin); 12, paraproct.