Thursday, May 24, 2018

[Ichthyology • 2018] Corydoras benattii From the Inside Out: A New Species of Armoured Catfish Corydoras (Siluriformes, Callichthyidae) with the Description of Poorly‐explored Character Sources


Corydoras benattii  Espindola, Tencatt, Pupo, Villa-Verde & Britto, 2018

Photo by  Hans Evers

Abstract  
A new species of the armoured catfish genus Corydoras is described from the Xingu–Tapajos ecoregion, Brazilian Amazon. The new species can be distinguished from its congeners by having the following combination of features: short mesethmoid, with anterior tip poorly developed, smaller than 50% of bone length; posterior margin of pectoral spine with serrations directed towards spine tip or perpendicularly oriented; infraorbital 2 only in contact with sphenotic; ventral laminar expansion of infraorbital 1 poorly or moderately developed; flank midline covered by small dark brown or black saddles with similar size to remaining markings on body; relatively larger, scarcer and more sparsely distributed dark brown or black spots on body; absence of stripe on flank midline; caudal fin with conspicuous dark brown or black spots along its entire surface; slender body; and strongly narrow frontals. A more comprehensive description of poorly‐explored internal character sources, such as the gross morphology of the brain, Weberian apparatus and swimbladder capsule elements is presented.

Keywords: Brazilian Amazon, Corydoradinae, Corydoras sp. C22, gross brain morphology, taxonomy, Xingu–Tapajos ecoregion




Figure 1: Corydoras benattii sp. nov. in (a) aquarium and (b) natural habitat, uncatalogued specimens, both near Altamira, lower Rio Xingu Basin. 

Figure 2: Corydoras benattii sp. nov., MZUSP 121671, holotype, 25·4 mm standard length, Brazil, Mato Grosso, Canarana–Gaúcha do Norte, Rio Culuene, tributary to Rio Xingu Basin.

Corydoras benattii, sp. nov.

Corydoras sp. 4. Castilhos & Buckup, 2011: 241 (species list).
Corydoras sp. C22. Evers, 1994: 755, Fig. 2 (species catalogue). Glaser et al., 1996: 92 (photos, species catalogue). Evers & Schäfer, 2004: 11, 12 (photos, species catalogue). Füller & Evers, 2005: 281, 285, 294 (species catalogue).
Corydoras sp. aff. C22. Glaser et al., 1996: 90 (photos, species catalogue).

Geographical distribution: Corydoras benattii occurs in both the Rio Xingu and Rio Tapajós basins, Brazilian Amazon (Fig. 10). In the Rio Xingu basin, it is known in Mato Grosso State from tributaries to the Rio Culuene, a clearwater tributary of the upper Rio Xingu (type locality) and in Pará State from the Rio Fresco sub drainage (Rio Trairão and Igarapé Manguari), middle Rio Xingu and from the lower Rio Xingu basin near Altamira. In the Rio Tapajós basin, it occurs in the Rio Peixoto de Azevedo, a tributary to the Rio Teles Pires, Mato Grosso and from Rio Cururu, a tributary to the Rio São Manuel, Pará.

Habitat notes: Specimens of Corydoras benattii were found in lotic habitats in the Rio Culuene, Rio Xingu basin and Rio Braço Norte, tributary to Rio Peixoto de Azevedo, Rio Tapajós basin (Fig. 11). Both localities have muddy‐brown water with clay and sandy substrata. Most specimens were captured in the small forest streams of black or clearwater, or in marginal ponds.

Etymology: The specific name, benattii, honours the late Laert Benatti for his humanitarian work, providing fresh water from artesian wells to poor communities in Brazil. Case is genitive.



V. C. Espíndola, L. F. C. Tencatt, F. M. Pupo, L. Villa‐Verde and M. R. Britto. 2018. From the Inside Out: A New Species of Armoured Catfish Corydoras with the Description of Poorly‐explored Character Sources (Teleostei, Siluriformes, Callichthyidae). Journal of Fish Biology.   DOI: 10.1111/jfb.13602

    

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