Two new species of Microglanis (Siluriformes: Pseudopimelodidae) from the upper-middle rio Araguaia basin, Central Brazil

Abstract

Two new species of Microglanis are described from tributaries of upper-middle rio Araguaia, States of Mato Grosso and Goiás, Brazil. Microglanis oliveirai differs from its congeners by the short supraoccipital process not reaching the small anterior nuchal plate, and reduced number of gill rakers, lateral line pores, ribs, vertebrae, and caudal-fin rays. Microglanis xylographicus differs from its congeners by the presence of melanophores surrounding the neuromasts of the superficial lines, snout length 11.4-12.9% SL and body color pattern consisting of horizontal brown stripes similar to a wooden bark pattern. An identification key of Microglanis species from the Amazon basin is presented.Duas espécies novas de Microglanis são descritas de tributários do alto-médio rio Araguaia, estados do Mato Grosso e Goiás, Brasil. Microglanis oliveirai difere de seus congêneres pelo processo supraoccipital curto não atingindo a pequena placa nucal anterior, e número reduzido de rastros branquiais, poros da linha lateral, costelas, vértebras e raios da nadadeira caudal. Microglanis xylographicus difere de seus congêneres pela presença de melanóforos ao redor dos neuromastos alinhados superficialmente, comprimento do focinho 11,4-12,9% CP e padrão de colorido do corpo, formado por listras horizontais castanhas como marcas de casca de madeira. Uma chave de identificação de espécies de Microglanis da bacia Amazônica é apresentada.

Gross morphology of the brain of Pseudopimelodus bufonius (Valenciennes, 1840) (Siluriformes: Pseudopimelodidae)

“…1) is the type species of the genus, which in turn is the type genus of the family (Shibatta, 2003a). Pseudopimelodidae includes five additional genera and about 32 valid species, among of them are four species of Pseudopimelodus (Shibatta, 2003b;Ruiz & Shibatta, 2011). The group is widely distributed throughout the Neotropical region, from the río Atrato in Colombia to the río de la Plata in Argentina (Lundberg et al, 1991).…”

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

“…The latter condition is usually present in adults of some species, as seen in M. poecilus Eigenmann, 1912, M. iheringi Gomes, 1946(Mees, 1974, M. pellopterygius Mees, 1978(Mees, 1978, M. robustus Ruiz & Shibatta, 2010(Ruiz & Shibatta, 2010, M. xylographicus Ruiz & Shibatta, 2011, M. oliveirai Ruiz & Shibatta, 2011(Ruiz & Shibatta, 2011, M. lundbergi (Jarduli & Shibatta, 2013), and M. leniceae. As noted in juvenile of M. maculatus Shibatta, 2014(Shibatta, 2014, the hooks of the anterior margin of the pectoral fin spine are retrorse in the beginning with addition of antrorses hooks throughout the development.…”

“…The shortest lateral line in Microglanis can be observed in M. oliveirai, in which the canal not reaches the vertical through the first branched ray of dorsal fin (Ruiz & Shibatta, 2011). The longest lateral line in the genus occurs in M. iheringi, in which the canal reaches the vertical through beginning of adipose fin (Mees, 1974).…”

Development and characterization of microsatellite loci of Microglanis cottoides (Siluriformes: Pseudopimelodidae) and cross-species amplification

“…With 21 valid species described to date (Ruiz & Shibatta, 2011), the genus Microglanis is also characterized by its wide mouth (gape width same as head width), short maxillary barbel (occasionally reaching pectoral-fin origin) and small eye without free orbital margin, among other particular characters (Shibatta, 2003a(Shibatta, , 2003b. These small catfishes are widely distributed across South America, occurring from Guyana to the Rio de La Plata basin in Argentina (Shibatta & Benine, 2005;Sarmento-Soares et al, 2006).…”

“…Although our knowledge of the number of Microglanis species has increased in the last decade (Shibatta, 2003a(Shibatta, , 2003bBertaco & Cardoso, 2005;Shibatta & Benine, 2005;Sarmento-Soares et al, 2006;Alcaraz et al, 2008;Ottoni et al, 2010;Shibatta & Ruiz, 2010;Shibatta & Ruiz, 2011), the biology of Microglanis still remains poorly known (Shibatta, 2003a). Recently, it has been shown that some species can occur in small populations patchily distributed along the river basins where they are found (Esguícero & Arcifa, 2010).…”