A new subterranean species of Phreatobius Goeldi, 1905 (Siluriformes, Incertae sedis) from the Southwestern Amazon basin

A new species of the previously monotypic catfish genus Phreatobius is described from an artificial well in the village of Rio Pardo, located 90 km south of the city of Porto Velho, State of Rondônia, Brazil, in the drainage area of the Rio Branco (Rio Madeira system, Amazon basin). Phreatobius dracunculus n. sp. differs from its only congener, P. cisternarum, by the absence of eyes (vs. present), the lack of dark integumentary pigmentation (vs. faint dark pigment always present), the presence of five pectoral-fin rays (vs. four), ventral procurrent rays 11-13 (vs. 22 to 26), dorsal procurrent rays 29-31 (vs. 42 to 50), fewer vertebrae (52 or 53 vs. 59 to 64) and the larger pseudotympanus. The new species shows all diagnostic characters so far proposed for Phreatobius, including an unusual red coloration in life. The localities of the two species of Phreatobius are approximately 1900 km apart. That, in association with their peculiar and mostly inaccessible habitats, indicates that the genus may be widely distributed in the Amazon basin.Uma nova espécie do gênero previamente monotípico Phreatobius é descrita de um poço artificial no Povoado de Rio Pardo, localizado 90 km ao sul da cidade de Porto Velho, Estado de Rondônia, Brasil, na área de drenagem do rio Branco (sistema do Rio Madeira, bacia Amazônica). Phreatobius dracunculus sp. n. difere da única espécie congênere, P. cisternarum, pela ausência de olhos (vs. presente), ausência de pigmentação na pele (vs. algum pigmento escuro sempre presente), presença de cinco raios na nadadeira peitoral (vs. 4), menor número de raios procorrentes ventrais 11-13 (vs. 22 a 26), e menor número de raios procorrentes dorsais 29-31 (vs. 42 a 50), menor número de vértebras (52 ou 53 vs. 59 a 64) e pseudotímpano maior. A nova espécie apresenta todos os caracteres diagnósticos propostos para Phreatobius, incluindo a conspícua coloração vermelha em vida. As localidades das duas espécies de Phreatobius estão aproximadamente a 1900 km de distância. A presença desta espécie em região tão distante da ocorrência de P. cisternarum em associação com o ambiente freático peculiar, evidenciam que o grupo pode estar amplamente distribuído na bacia amazônica

Gross brain morphology of Rhamdia quelen (Quoy & Gaimard 1824) (Ostariophysi: Siluriformes: Heptapteridae)

The brain gross morphology of Rhamdia quelen is described and compared with seven species of six genera of Heptapteridae. Interspecific variation in shape, size, and position of brain subdivisions was observed in all examined species. The posterior position of the hypophysis on the hypothalamus and presence of a lateral subdivision on the lobus facialis are shared by all examined heptapterids. Rhamdia quelen and Pimelodella gracilis, currently considered closely related within the family Heptapteridae, exhibit the anterior and posterior area of the telencephalon with equivalent widths, and the lateral line lobe reaching the anterior area of the lobus vagi. Members of the so called Nemuroglanis sub-clade (Cetopsorhamdia iheringi, Heptapterus mustelinus, Imparfinis mirini, and Phenacorhamdia tenebrosa) share the lobus vagi proportional smaller than the lobus facialis; the lateral line lobe reaching the half length of the lobus facialis; the tectum mesencephali in contact with the telencephalon, and thinner anterior area of the telencephalon. The results reveal several features that are phylogenetically informative among the heptapterids examined, and corroborate previous hypotheses based on other non-neural anatomical characters

A new species of Microglanis(Siluriformes: Pseudopimelodidae) from the upper rio Tocantins basin, Goiás State, Central Brazil

A new species of Microglanis is described from the upper rio Tocantins basin, Barro Alto, Goiás State, Brazil. This species is distinguished from the others by presenting a unique color pattern, consisting of round spots in the flank between the larger dark brown blotches. Moreover, it can be distinguished by the combination of the following features: caudal fin emarginate, the upper lobe slightly larger than the lower, lateral line relatively long, reaching vertical through posterior margin of the pelvic fin, and light stripe on supra-occipital region absent or very narrow and with irregular shape

A new species of bumblebee catfish of the genus Microglanis (Siluriformes: Pseudopimelodidae) from the upper rio Paraguay basin, Brazil

ABSTRACT A new species of Microglanis from upper rio Paraguay basin is described. The species differs from congeners by the following combination of characters: deeply forked caudal fin with pointed lobes, bifurcated hook between antrorse and retrorse hooks on anterior margin of pectoral-fin spine, lateral line relatively long, surpassing the vertical through end of dorsal fin but not reaching adipose fin, color pattern of dorsal region of head dark brown with a restrict thin light area between anterior nostril and eye, broad light stripe on supraoccipital region