Frank Raynner V. Ribeiro

A new species of Pimelodus LaCépède, 1803 (Siluriformes: Pimelodidae) from the rio São Francisco drainage, Brazil

Pimelodus pohli, new species, is described from the rio Sao Francisco drainage. It differs from congeners by the following characters in combination: adults with dark spots on anterodorsal region of body and young specimens (up to 100 mm SL) with three rows of dark spots laterally on body; comparatively long adipose fin, more than one third of the distance between posterior end of dorsal fin base and the vertical through posterior end of anal-fin base (21.8-26.2% SL); lips poorly developed; 20-25 gill rakers; and maxillary barbels slightly surpassing the caudal-fin base. A key to the species of Pimelodus of the rio Sao Francisco drainage is presented.

Ichthyofaunal survey of stretches of the Guariba and Rooselvelt Rivers, in Guariba State Park and Guariba Extractive Reserve, Madeira River basin, Amazonas, Brazil

The fishes presented herein were collected in small streams, in channel of lagoons and in the main channel of the Guariba River, as well as in one tributary of the right bank of the Roosevelt River, both clear-water tributaries of Aripuana River, Madeira River basin. Field work was carried out in November 2008, during the low water season. Sampling resulted in 3924 specimens belonging to 160 species distributed in 34 families, and seven orders. Eight species are recognized as new, two of which were recently described. This study represents the first fish survey for the region and will certainly provide valuable information for future studies and maintenance of the poorly known fish diversity of these two conservation areas.

Ageneiosus uranophthalmus, a new species of auchenipterid catfish (Osteichthyes: Siluriformes) from river channels of the central Amazon basin, Brazil

Ageneiosus uranophthalmus is described from river channels of the central Amazon basin, Brazil. The new species is widely distributed in the Amazon and is distinguished from its congeners by the V-shape snout and eye laterally placed and dorsally oriented, more visible in dorsal view than in ventral view. Ageneiosus uranophthalmus shows a range of variation on color pattern when compared with its congeners. This and other differences are described and discussed herein.

Pimelodus microstoma Steindachner, 1877, a valid species of pimelodid catfish (Siluriformes: Pimelodidae) from the upper rio Paraná drainage

Pimelodus microstoma, which has been treated as a junior synonym of P. fur, is resurrected and its type locality restricted to Irisanga (=Orissanga), Sao Paulo State, in the upper rio Parana. An identification key is provided for Pimelodus species from the upper portions of the Parana drainage.

Bryconops munduruku (Characiformes: Characidae), a new species of fish from the lower Tapajós River basin, Brazil.

A new species of Bryconops is described from a right tributary of the lower Tapajós River, State of Pará, Brazil. Bryconops munduruku, sp. nov., differs from its congeners, except B. inpai and B. piracolina, by having a black adipose fin (vs. adipose fin hyaline in alcohol) and, except B. inpai, by possessing two humeral blotches (vs. lack of humeral blotch or only one humeral blotch). Bryconops munduruku differs from B. inpai by having a uniform color pattern on the posterior portion of the side of the body (vs. a dark stripe extending posteriorly from the half of the anal-fin base onto the base of the middle caudal-fin rays). It differs further from B. inpai and B. piracolina by the presence of a black adipose fin that is hyaline along its base (vs. entirely black adipose fin in B. inpai and B. piracolina). The new species is allocated in the subgenus Creatochanes by having a maxillary bone with one to three teeth on both sides, and its posterior extension reaching the junction of second and third infraorbital bones.

Stream ichthyofauna of the Tapajós National Forest, Pará, Brazil

Abstract The fish fauna of freshwater streams in the Tapajos National Forest was surveyed and a list of species is presented. The sampling was conducted from 2012 to 2013 during the dry season. Fish were collected with dip nets and seine nets in 22 streams of 1st to 3rd order. Sampling resulted in 3035 specimens belonging to 117 species, 27 families and six orders. The most abundant species were Bryconops aff. melanurus, Hemigrammus belottii, and Hemigrammus analis. Four undescribed species were recognized, one of which is known only from the area of this study. A significant dissimilarity was observed in fish species composition among drainage systems. This is the first survey of the stream ichthyofauna in the Tapajós National Forest, and it presents relevant information for future studies and decision-making in the management and conservation of fish fauna in this conservation unit.

A new species of Pimelodus La Cépède, 1803 (Siluriformes: Pimelodidae) from rio Ribeira de Iguape basin, Brazil

Pimelodus multicratifer, a new species, is described from the rio Ribeira de Iguape basin. The new species differs from the other Pimelodus species by the following features: 26 to 30 gill rakers on the first branchial arch; a combination of three to six rows of dark spots regularly or irregularly scattered on the flanks and several small dark spots irregularly scattered on the dorsal surface of head, supraoccipital process, and sometimes on the dorsal and caudal fins; striated lips; maxillary barbels reaching between posterior tip of the pelvic-fin rays and posterior tip of the middle caudal-fin rays.

Pimelodus heraldoi Azpelicueta, 2001, a junior synonym of Pimelodus microstoma Steindachner, 1877 (Siluriformes: Pimelodidae)

The examination of the holotype and 61 of the 64 paratypes of Pimelodus heraldoi, syntypes of P. microstoma and additional specimens from the upper rio Parana showed that the former species is a junior synonym of the latter. Both species were originally described from the rio Mogi-Guacu, upper rio Parana.

Three new Pimelodus species (Siluriformes: Pimelodidae) from the rio Tocantins drainage, Brazil

Three new species of Siluriformes from the rio Tocantins drainage of Brazil are placed in the genus Pimelodus, P. stewarti, P. joannis, and P. halisodous. Pimelodus halisodous differs from the sympatric P. joannis and P. stewarti by the number of premaxillary tooth rows (13-16 vs. 5-9). Pimelodus joannis differs from P. stewarti by the presence of two dark blotches on the base of the caudal fin. The three new species differ from all other species of Pimelodus by the possession of a uniform gray coloration along flanks; the relatively short distance between the posterior nostril and the anterior orbital border; a short maxillary barbel, that only slightly surpasses the caudal-fin base.