Cnesterodon iguape, Lucinda, 2005

Lucinda, Paulo H. F., 2005, Systematics of the genus Cnesterodon Garman, 1895 (Cyprinodontiformes: Poeciliidae: Poeciliinae), Neotropical Ichthyology 3 (2), pp. 259-270 : 263-264

Cnesterodon iguape , new species

( Fig. 5 and 6 , Table 2 )

Holotype. MZUSP 79672 , male, Brazil. São Paulo. Apiaí, creek on headwaters of rio Iporanga , inside Mineradora Oxical , 24º24’42"S 48º39’25", W. Buck et al., 4 Apr 1999. Paratypes. MZUSP 54978 , 12 / 2*, collected with the holotype.

Diagnosis. Cnesterodon iguape is diagnosed by the following autapomorphy: a large post -gonopodium blotch on the ventral profile in adult males.

Furthermore, C. iguape is distinguished from its congeners by distal portion of anal-fin proximal radials 2 and 3 in adult males fused [72-1]. Cnesterodon iguape is readily distinguished from C. omorgmatos and C. raddai by dark brown blotches along body sides (forming bars vs. circular or irregular, respectively). It is distinguished from C. brevirostratus by the pointed snout and by the absence of minute scales covering lateral and ventral regions of body below pectoral fin in adult females. The absence of a very prominent dark brown longitudinal band along body sides (longitudinal band along body lacking or faint) distinguishes it from C. hypselurus . Cnesterodon iguape is distinguished from C. carnegiei , C. septentrionalis , and C. hypselurus by the presence of dark bars on sides of body vertically short, mostly confined to midline, covering less than three scales in a transverse row, never extending to dorsal and ventral profiles. Cnesterodon iguape is distinguished from C. decemmaculatus by the configuration of the bony style at gonopodium tip in adult males (relatively long and slightly arched, and bearing a membrane progressively narrowing towards tip forming a distal filament vs. relatively short and very arched. Membrane on bony style never forming a distal filament in C. decemmaculatus ) ( Fig. 6 ).

Description. Morphometric data in Table 2 . Range of SL: 18.5 to 24.9 mm (females); 18.5 to 22.4 mm (males). Body compressed, width in predorsal region uniform, about half body depth. Post -dorsal region compressed towards caudal peduncle. Predorsal profile convex. Dorsal -fin base convex. Postdorsal profile slightly concave. Pre -anal profile very convex. Anal -fin base oblique. Post -anal profile concave in females, and almost straight in males. Dorsal fin with semicircular border, located posteriorly to mid-body. Origin of dorsal fin in females on vertical passing through base of third anal - fin ray; in males, origin of dorsal fin posterior to vertical passing through origin of anal fin. Pectoral fin with high insertion in horizontal passing through orbital center. Longest ray reaching about seventh scale in longitudinal series. Pelvic fin small, pointed and not reaching origin of gonopodium in adult males; not reaching origin of anal fin in females. Anal fin of females with straight border. Origin of anal fin of females closer to caudal peduncle than to snout tip. Origin of anal fin of males closer to snout tip than to caudal peduncle. Mouth superior, almost aligned with upper border of pupil.

Dorsal -fin rays: 7 [1], 8* [9], 9 [1]. Pectoral -fin rays: 10* [2], 11 [7], 12 [2]. Pelvic -fin rays: 4* (males), 5 (females).Anal - fin rays (females): 10 [4]; Gonopodial rays: 8 [5]. Caudal -fin rays: 26 [1], 27 [5], 28* [6]. Pre -dorsal scales: 12 [4], 13* [2], 14 [3]. Longitudinal series scales: 27 [1], 28 [6], 29* [2], 30 [1], 33 [1]. Scales around caudal peduncle: 16* [13]. Scales in transverse row: 10 [9], 11 [2], 12* [2]. Pleural ribs: 15 [2]. Epipleural ribs: 8 [2]. Vertebrae: 32 [1], 33 [1].

Gonopodial complex composed of 10 gonactinosts. Functional gonapophyses absent. Gonactinosts 2, 3, 4 fused. Gonactinost 4 with wing -like expansions. Ligastyle absent. Gonopodium symmetrical. Eight gonopodial rays. Rays 1 and 2 unbranched and short. Ray 1 with 5-7 segments. Ray 2 with 7 or 8 segments. Ray 3 with 23 or 24 segments. At tip, long slender bony style bearing narrow membrane produced in terminal filament. Four or five paired retrorse spines on distal segments of ray 4p. Ray 5a with subdistal and discrete dorsal curvature and terminated by retrorse claw. Dorsal convexity located between segments 11 to 19 of ray 5p. Rays 6, 7 and 8 branched. Distal segments of rays 6 and 7 partially ankylosed.

Color in alcohol. Eye black with greenish brown pupil. Background color cream yellow. Scale borders and subjacent skin replete with brown chromatophores, conferring reticulate pattern to body sides. Dorsum darker than ventral region. Head dorsum dark brown. Median dark brown line along predorsal surface. Median dark brown line along preanal surface (inconspicuous in large females). Fins hyaline. Fin rays with two rows of brown chromatophores on each side, along entire ray. Seven to nine dark brown vertical bars along body sides, mostly confined to midline. Large blotch on each side of ventral portion of body near gonopodium, meeting midventral post -anal line.

Distribution. Known only from the type-locality in the upper rio Iporanga ( Fig. 1 ).

Etymology. Cnesterodon iguape is named after the rio Ribeira de Iguape, in whose headwaters is the type-locality.

Figures

Fig. 5. Cnesterodoniguape: (a) holotype, male, MZUSP 79672, Apiaí, São Paulo, Brazil, 22.3 mm SL; (b) paratype, female, MZUSP 54978, 24.8 mm SL, collected with the holotype.

Fig. 6. Gonopodium tip of Cnesterodon iguape, MZUSP 54978. Bar 1 mm. DE = dorsal expansion. R3, R4a, R4p, R5a, R5p = gonopodial rays.

Fig. 1. Collection localities of Cnesterodon species: C. septentrionalis (eight-pointed stars, 1), C. hypselurus (triangles, 2), C. iguape (five-pointed stars, 3), C. omorgmatus (cross, 4), C. carnegiei (lozenges, 5), C. raddai (pentagons), C. brevirostratus (circles, 6), and C. decemmaculatus (squares, 7). Some symbols represent more than one lot or locality. Numbers represent type localities.