A new species of Hemiancistrus from the rio Araguaia basin, Goiás state, Brazil (Siluriformes: Loricariidae)

Abstract

Hemiancistrus cerrado is described from the tributaries of rio Araguaia, rio Tocantins basin. Hemiancistrus cerrado has external similarities with H. megalopteryx and H. punctulatus from coastal streams of southern Brazil, and can be distinguished by having a larger internarial width, 15.9-21.1% of head length (vs. 11.2-14.0% in H. megalopteryx and 11.2-13.9% in H. punctulatus) and, with little overlap, by the larger adipose-fin spine length, 9.4-13.6% of standard length (vs. 7.1-8.7% in H. megalopteryx and 7.4-10.0% in H. punctulatus). Hemiancistrus cerrado further differs from H. megalopteryx by having the pectoral-fin spine reaching maximally to the middle of the pelvic-fin spine when adpressed in adult males (vs. reaching tip). Hemiancistrus cerrado differs from other members of Hemiancistrus by color and numerous morphometric and meristic data.Hemiancistrus cerrado é descrito de tributários da margem esquerda do rio Araguaia, bacia do rio Tocantins. Hemiancistrus cerrado possui similaridades externas com H. megalopteryx e H. punctulatus de drenagens costeiras do sul do Brasil, e pode ser separado das duas espécies pela maior distância entre as narinas, 15.9-21.1% do comprimento da cabeça (vs. 11.2-14.0% em H. megalopteryx e 11.2-13.9% em H. punctulatus), e, com alguma sobreposição, pela maior nadadeira adiposa, 9.4-13.6% do comprimento padrão (vs. 7.1-8.7% em H. megalopteryx e 7.4-10.0% em H. punctulatus); de H. megalopteryx ainda difere por espinho da nadadeira peitoral de machos adultos se estendendo até o meio do espinho da nadadeira pélvica quando adpressa (vs. se estendendo até a ponta do espinho). Hemiancistrus cerrado difere de outros congêneres pela coloração e diversos dados merísticos e morfométricos.

The species of Hemiancistrus (Siluriformes: Loricariidae) from Ecuador

“…Since then, several species from different regions of South America have been included in this genus. The species come from the Guyana Shield, the Caribbean Sea Basin (Lake Maracaibo, Magdalena, Atrato), the Pacific slope of Panama, Colombia and Ecuador, the basins of the Uruguay River, the Tocantins River and other watersheds in southeastern Brazil (Kner 1854;Günther 1867;Regan 1904Regan , 1913Eigenmann 1916Eigenmann , 1918Schultz 1944;Cardoso & Malabarba 1999;Cardoso & Lucinda 2003;Cardoso 2004;Cardoso & Pezzi 2004;Werneke et al 2005a, b;de Souza et al 2008). Four species described from Ecuador, original or subsequently were placed in this genus, the four species were collected on the Pacific slope.…”

“…Hemiancistrus hammarlundi is considered synonymous with H. landoni (Armbruster et al 2015) and, Hemiancistrus fugleri Ovchynnyk 1971, described from the Bogota River, Cadondelet, Santiago river system, Esmeraldas, considered synonymous of H. annectens (Armbruster et al 2015). Since 1999, there has been a remarkable increase in the number of species, mostly from Brazil and Venezuela (Cardoso & Malabarba 1999;Cardoso & Lucinda 2003;Cardoso 2004;Cardoso & Pezzi 2004;Werneke et al 2005a, b;Lujan & Chamon 2008;de Souza et al 2008). Hypotheses of phylogenetic relationships inside the subfamily Hypostominae (Armbruster 2004(Armbruster , 2008Lujan et al 2015) point out that some of the species in the genus Hemiancistrus show close relationships with species of the genera Hypostomus, Pterygoplichthys, Pseudancistrus, Baryancistrus, Hypancistrus, and Peckoltia.…”