Hypostomus chrysostiktos, a new species of armored catfish (Siluriformes: Loricariidae) from rio Paraguaçu, Bahia State, Brazil

Abstract

Hypostomus chrysostiktos, a new species of armored catfish of the family Loricariidae, is described. The most remarkable characteristic of the new species, which allows its prompt diagnosis from congeners, is the high number of branched rays in the dorsal fin (10-11). In addition, the new species can be diagnosed from the remaining Loricariidae by the combination of the following characters: slightly evertible cheek plates, four branched anal-fin rays, naked abdomen, and snout almost completely plated. The characters states shared by H. chrysostiktos and the tribe Hypostomini, which indicates it as belonging to that group, are: a hatched-shaped opercle, the anterior process of the pterotic-supracleitrum passing halfway the orbit, a pointed post-cleithral process, and slightly evertible cheek plates. The description of this armored catfish provides more evidence for the high level of endemism in the ichthyofauna of rio Paraguaçu basin, a coastal river of northeastern Brazil.Uma nova espécie de cascudo da família Loricariidae, Hypostomus chrysostiktos, é descrita. A característica mais marcante da nova espécie, que permite diagnosticá-la das congêneres, é o grande número de raios ramificados da nadadeira dorsal (10-11). A nova espécie pode ser ainda diagnosticada dos demais Loricariidae pela combinação dos seguintes caracteres: placas laterais da cabeça levemente eversíveis, quatro raios ramificados na nadadeira anal, abdômen nu, e focinho quase completamente coberto por placas. Os estados de caracteres compartilhados entre H. chrysostiktos e a tribo Hypostomini, os quais indicam que a nova espécie pertence ao grupo, são: opérculo em forma de machado, processo anterior do pterótico-supracleitro passando metade da órbita, processo pós-cleitral afilado, e placas laterais da cabeça levemente eversíveis. A descrição deste cascudo é outro exemplo que evidencia o alto grau de endemismo da ictiofauna da bacia do rio Paraguaçu, uma drenagem costeira do nordeste brasileiro.

Astyanax vermilion and Astyanax burgerai: new characid fishes (Ostariophysi: Characiformes) from Northeastern Bahia, Brazil

“…Coastal northeastern Brazilian rivers are recognized by its high degree of endemism together with the increasing description of new species in the last decade (Lima & Gerhard, 2001;Malabarba et al, 2004;Zanata & Akama, 2004;Britto et al, 2005;Sarmento-Soares et al, 2005;Benine et al, 2007;Birindelli et al, 2007;Zanata & Camelier, 2008). This assertion fits precisely for rivers crossing the area around Ilhéus on Bahia State, as rio Almada, rio Cachoeira and rio do Braço, which holds various putatively endemic species.…”

A new species of the armored catfish genus Pareiorhaphis Miranda Ribeiro (Siluriformes: Loricariidae) from the rio Paraguaçu, Bahia State, northeastern Brazil

“…This fact can be exemplified by discoveries of two new species of Hypostomus describe recently (Birindelli et al, 2007;Zanata et al, 2013) and a new species of Pareiorhaphis described herein.…”

A new dark-dotted species of Hypostomus Lacépède (Siluriformes: Loricariidae) from rio Paraguaçu, Bahia State, Brazil

“…Although a study of relationships was not performed, we suggest that the closest relatives of H. jaguar are possibly congeners from outside the rio Paraguaçu basin. The endemic nature of the rio Paraguaçu ichthyofauna has been previously highlighted (e.g., Lima & Gerhard, 2001;Santos & Zanata, 2006;Birindelli et al, 2007;Santos & Caramaschi, 2007) and a total of 16 described species are now known to be endemic to the basin. Hypostomus jaguar represents the tenth siluriform species that is apparently endemic to the Paraguaçu basin.…”

“…Ten species of Hypostomus are reported from Brazilian northeastern coastal drainages and eight are known to occur in the rio São Francisco basin, the largest drainage in the region. Four species of the former group were described in the State of Bahia: Hypostomus brevicauda (Günther, 1864) and H. wuchereri (Günther, 1864), both with the vague type locality stated as "Bahia", Hypostomus unae (Steindachner, 1878) from rio Una, and the recently described H. chrysostiktos Birindelli, Lima & Zanata, 2007, endemic to the rio Paraguaçu basin. The first three of those species were described from material sent to the Natural History Museum, London, by Otto Wucherer, who most likely collected the specimens in coastal river basins south of Salvador (the Capital of the State of Bahia), as suggested by the type localities of reptiles also collected by him in the cities of Canavieiras, Nazaré, and Ilhéus (Günther, 1861(Günther, , 1863Wucherer, 1861aWucherer, , 1861bWucherer, , 1863aWucherer, , 1863b.…”