HEMIPSILICHTHYS PAPILLATUS PEREIRA, OLIVEIRA & OYAKAWA (FIG. 6)

Hemipsilichthys papillatus Pereira, Oliveira & Oyakawa, 2000: 378: fig. 1 [type locality: Ribeirão Santana, tributary of Rio Preto, at Rio Preto ( approximately 22°02′S 43°47′W) Rio Paraíba do Sul drainage, Minas Gerais, Brazil].

Specimens examined: Brazil: Minas Gerais: Holotype: MZUSP 53085 (91.8 mm SL), male, Ribeirão Santana, tributary of Rio Preto, at Rio Preto, Rio Paraíba do Sul drainage (approximately 22°02′S 43°47′W), 22 July 1997 . Paratypes: all collected with the holotype: MCP 21423 (2 + 1 c&s, 70.6–77.2 mm SL), MZUSP 53086 (1, 60.0 mm SL), UFJF 0378 (5 + 1 c&s, 26.1–85.9 mm SL), UFJF 0379 (3, 65.2–75.3 mm SL) and USNM 352350 (1, 60.4 mm SL) . Other specimens: MCP 27982 (2, 26.8–36.7 mm SL), Ribeirão Santa Rita, tributary of Ribeirão Santana, itself a tributary of Rio Preto, Rio Preto, 29 July 1997 . MCP 27983 (6, 26.3–45.3 mm SL), Ribeirão Santana, tributary of Rio Preto, Rio Preto, 27 September 1996 .

Diagnosis: Hemipsilichthys papillatus is diagnosed by an autapomorphic mesial bend of the ventral portion of both preopercle and quadrate, forming a concave fossa where strong facial odontodes are implanted (Fig. 7), and by the absence of a dorsal-fin spinelet. It can also be distinguished from H. gobio and H. nimius by having no plates in the dorsal series between the dorsal-fin origin and the end of the adipose fin (vs. dorsal series of plates complete but plates not reaching the mid-dorsal line). H. papillatus can be further distinguished from its congeners by its smaller orbital diameter (8.6–11.8% HL vs. 12.0–14.7% in H. gobio and 15.3–16.9% in H. nimius).

Description: This species was recently described and illustrated by Pereira et al. (2000) and the description will not be repeated here. Morphometric data, however, are presented in Table 1 for comparative purposes.

Distribution: Hemipsilichthys papillatus is known only from two localities in a tributary of the Rio Preto, Rio Paraíba do Sul basin, Minas Gerais, Brazil (Fig. 5).

Ecology: The type specimens were collected in a small, shallow river, with clear water, moderate to strong current, and a substrate of rocks, loose stones, and gravel.