Cnesterodon brevirostratus Rosa & Costa, 1993

Lucinda, Paulo H. F., 2005, Systematics of the genus Cnesterodon Garman, 1895 (Cyprinodontiformes: Poeciliidae: Poeciliinae), Neotropical Ichthyology 3 (2), pp. 259-270 : 266

Cnesterodon brevirostratus Rosa & Costa, 1993

( Fig. 9 )

Cnesterodon brevirostratus Rosa & Costa, 1993: 705 , fig. 17. Type -locality: Brazil, Rio Grande do Sul, Cambará do Sul, Parque Nacional dos Aparados da Serra, Arroio Camisa, tributary to Rio das Antas.

Diagnosis. Cnesterodon brevirostratus is diagnosed by the following autapomorphies: (1) snout blunt; (2) presence of small scales covering lateral and ventral region of body below pectoral fin in adult females; (3) bony style of ray 3 of gonopodium of fully developed mature males large and sinuous, covered with few membranous tissue ( Rosa & Costa, 1993; fig. 11). Furthermore, C. brevirostratus is readily distinguished from C. omorgmatos and C. raddai by dark brown blotches along body sides (forming bars vs. circular or irregular, respectively). Cnesterodon brevirostratus is distinguished from C. carnegiei , C. hypselurus , and C. septentrionalis by dark bars on sides of body, mostly confined to midline, covering less than three scales in a transverse row, never extending to dorsal and ventral profiles (vs. dark bars of body very elongate reaching dorsal and ventral profiles, covering more than four scales in a transverse row). The absence of a longitudinal dark brown band along flank differentiates C. brevirostratus from C. hypselurus .

Distribution. Cnesterodon brevirostratus inhabits the upper portion of the rio Pelotas and rio Canoas of the rio Uruguay drainage, the rio Jacuí, the headwaters of the rio Maquiné in the Tramandaí system, and the headwaters of rio Itajaí - Açu drainage.

Remarks. The color pattern of C. brevirostratus is quite variable. It can be a typical Cnesterodon pattern with vertical bars along flanks, a pattern of bars irregularly set and shaped, or even dotted.

Figures

Fig. 9. Cnesterodon brevirostratus. MCP 26050, São José dosAusentes, Rio Grande do Sul, Brazil:(a) male, 25.2 mm SL; (b)female,33.7 mmSL.