Integrative taxonomy of Imparfinis (Siluriformes, Heptapteridae) from the Upper Paraná River basin, Brazil, with description of a new species.

The Neotropical family Heptapteridae comprises 228 valid species widely distributed in South America. Imparfinis is one of the most diverse genera of this family, with 25 valid species widely distributed, inhabiting streams from Costa Rica to Argentina. Old descriptions coupled with lack of recent systematic studies of the species of Imparfinis from the Upper Paraná river basin have led to a taxonomic impediment and hindered the advancement of studies in other areas, such as ecology, cytogenetic, phylogenetic, and evolution.

Moenkhausia andrica (Characiformes: Characidae): a new species from the rio Tapajós basin, Brazil, with minute fin hooklets in females.

In this study, a new species of Moenkhausia is described from the upper rio Juruena, rio Tapajós basin, Brazil. It is distinguished from all congeners by the presence of minute bony hooks in all fins of both mature females and males and combination of a prepelvic region flattened, dorsal portion of the humeral blotch extending two scales horizontally and vertically, lateral line with 28-32 scales, five scale series above and below lateral line; circumpeduncular scales 13-14, anal-fin rays 16-19 and dorsal portion of eyes blue in live specimens. The new species is also supported by high divergence in the mitochondrial gene cytochrome c oxidase subunit I (COI).

Taxonomy of Moenkhausia australis Eigenmann, 1908 (Characiformes, Characidae) with a discussion on its phylogenetic relationships.

The species Moenkhausia australis was described based on two specimens from arroyos Trementina and Chagalalina, Rio Paraguai basin, Paraguay. Its taxonomic history is complex and for many years the species was considered a synonym of Moenkhausia sanctaefilomenae. Moenkhausia australis shares a reticulated color pattern with the Moenkhausia oligolepis/M.

A new species of Hemigrammus Gill 1858 (Characiformes: Characidae) from the upper Rio Negro, Amazon basin, Brazil.

A new species of Hemigrammus is described from the upper Rio Negro, Amazon basin, Brazil. The new species is distinguished from all congeners by its unique color pattern consisting of a single humeral blotch clearly spaced from a conspicuous midlateral dark stripe, which extends from fifth or sixth anteriormost vertical scale row to the basis of the middle caudal-fin rays. Comments on its putative relationships are provided.

New species of Neoplecostomus (Neoplecostomini: Loricariidae) lacking adipose fin from upper Rio Paraná basin, central Brazil.

In the present study, we describe a new species of Neoplecostomus from central Brazil. The new species is known from Córrego Cachoeira a right tributary of the upper Rio Paraná basin. It can be distinguished from all congeners by absence of adipose fin or azygous plates on the dorsum surface of the caudal peduncle.