Microglanis

Abstract: A new species of Microglanis is described from the upper rio Tocantins basin, Barro Alto, Goias 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.

Abstract: The gross morphology of the gas bladder is described and compared for representatives of all valid genera of Pseudopimelodidae (Siluriformes). Cephalosilurus albomarginatus and species of Batrochoglanis, and Microglanis have the most basic form: a large, cordiform gas bladder with a simple internal T-shaped septum. Cephalosilurus apurensis, C. fowleri, and C. nigricauda also have a large, cordiform gas bladder, but they have well-developed trabeculae associated with the internal T-shaped septum, and a pair of well-developed constrictor muscles inserted on the external wall; the latter feature is present in most species of Pimelodidae, but absent in all other catfishes. The monotypic Lophiosilurus alexandri also has well-developed constrictor muscles, and its gas bladder is moderately sized. The species of Pseudopimelodus and Cruciglanis have a diminutive gas bladder partially divided into two lateral sacs without internal communication, and lack constrictor muscles. The parapophysis of the fourth vertebra is a wide and long shelf connected to the dorsal surface of the gas bladder in most pseudopimelodid genera. However, in the species of Pseudopimelodus and Cruciglanis the parapophysis of the fourth vertebra is shorter and has its anterior ramus folded back, partially covering the gas bladder anteroventrally; and the tympanic opening is smaller than in species of the other genera. Five phylogenetic characters are proposed based on the morphology of the gas bladder and associated structures in species of Pseudopimelodidae, and the evolution of those characters in the family is discussed. J. Morphol., 2011. © 2011 Wiley-Liss, Inc.

Abstract: A new pseudopimelodid catfish of the genus Microglanis, collected in small rivers at the lower and middle Peruipe, middle Jucurucu and Cahy basins, in the southeastern coast of the Bahia state, is described. The new species has a comparatively high number of anal fin proximal radials, 12, shaped as thin tubes, the last one bearing a laminar extension; a pectoral fin spine with a bony point and with a smaller number of serrations on its posterior border; seven pleural ribs and a narrow head width. We provide information on the external morphology and also on some osteological features for the new species. A key to species is presented for the coastal drainages between Rio de Janeiro and Bahia states. E descrito um novo pseudopimelodideo do genero Microglanis, coletado em riachos tributarios das bacias do baixo e medio rio Peruipe, medio rio Jucurucu e rio Cahy, na costa sudeste do estado da Bahia. A nova especie tem comparativamente um maior numero de radiais proximais da nadadeira anal, 12, em formato de finos tubos, sendo que o ultimo elemento possui uma extensao laminar; nadadeira peitoral com extremidade ossea e com pequeno numero de serrilhas no bordo posterior; sete costelas pleurais e cabeca estreita. Sao fornecidas informacoes sobre a morfologia externa bem como sobre alguns aspectos da osteologia da nova especie. E apresentada uma chave para as especies nas drenagens costeiras entre os estados do Rio de Janeiro e Bahia.

Abstract: Microglanis garavelloi, new species, collected in tributaries of rio Paranapanema and rio Tiete, is the first species of the genus described from upper rio Parana basin. The new species can be distinguished from other species of Microglanis on morphometric characters, color pattern, caudal-fin shape, pectoral-spine morphology and lateral line development. Characters used specifically to distinguish M. garavelloi from M. cottoides (laguna dos Patos and rio Uruguay basins) and M. parahybae (rio Paraiba do Sul basin) include morphometrics, color pattern and pectoral-spine serration. Microglanis garavelloi, especie nova, coletado em tributarios do rio Paranapanema e rio Tiete, e a primeira especie do genero descrita da bacia do alto rio Parana. A nova especie pode ser distinguida das outras especies de Microglanis com base em caracteres morfometricos, padrao de colorido, forma da nadadeira caudal, morfologia do espinho da nadadeira peitoral e desenvolvimento da linha lateral. Caracteres utilizados para distinguir M. garavelloi de M. cottoides (bacias da laguna dos Patos e rio Uruguai) e M. parahybae (bacia do rio Paraiba do Sul) incluem a morfometria, o padrao de colorido e as serras do espinho da nadadeira peitoral.