Otothyropsis polyodon Calegari, Lehmann A., Reis, 2013

Fig. 27

Body elongated; greatest depth contained 6.8 to 8.1 times in SL; head length 2.6 to 3.0, pectoral-fin length 3.7 to 4.7 and pelvic-fin length 4.9 to 6.9 in SL; snout length 1.9 to 2.1, horizontal orbital diameter 6.1 to 7.5 and least interorbital width 2.6 to 3.1 in HL. Mouth inferior; premaxilla and dentary with 14-21 teeth. Longitudinal series with 24 or 25 plates. Dorsal fin with I,7, rarely 8, pectoral fin with I,6, pelvic fin with 6 and anal fin with 6 rays (Calegari et al., 2013). Ground color brown; dark-brown longitudinal stripe from snout to caudal fin. Hyaline fins, with dark-brown spots; upper caudal-fin lobe with dark-brown spot close to its tip; lower caudal-fin lobe dark, with hyaline portion on its lower portion, frequently with small dark-brown spots.

Maximum standard length. 37.9 mm.

Biological data. Males of O. polyodon have a conical urogenital papilla immediately posterior to the anus opening, longer pelvic-fin spine, shorter internarial distance, and shorter prenasal length (Calegari et al., 2013).

Distribution. Rio Ocoí, tributaries of the rio Verde and the rio Iguatemi drainage, right bank of the upper rio Paraná.

Remarks. Otothyropsis polyodon was identified as Hisonotus sp. by Graça, Pavanelli (2007). Besides, it has been captured in the rio Iguatemi drainage, tributary of the right bank of the upper rio Paraná, since 2008 by V. F. B. Silva and collaborators, with its first cytogenetic record provided by Fernandes et al. (2016).