Gastón Aguilera

Jenynsia luxata, a new species from Northwestern Argentina, with additional observations of J. maculata Regan and phylogeny of the genus (Cyprinodontiformes: Anablepidae)

Jenynsia luxata, a new species from northwestern Argentina, is described. This species is diagnosable from all other Jenynsia by the medial processes of left and right pelvic bones relatively reduced and separated from each other. The new species resembles J. multidentata, but it is further distinguished from this species by the absence of a swelling between the urogenital opening and the anterior base of the anal fin in females and details of coloration. Phylogenetic analyses, both under implied and equal weighting, recover the subgenera Plesiojenynsia and Jenynsia as monophyletic units. New information on previously missing characters of Jenynsia maculata is added. These data and phylogenetic characters coded for the new species herein described contribute to a better resolution of the phylogenetic relationships within the subgenus Jenynsia, which is herein supported by additional synapomorphies relative to previous phylogenies.

Living in the waterfalls: A new species of Trichomycterus (Siluriformes: Trichomycteridae) from Tabay stream, Misiones, Argentina

A new species assigned to the genus Trichomycterus from the area of the waterfalls of Tabay stream, Paraná River basin, Misiones, Argentina, is described. Trichomycterus ytororo sp. nov. is distinguished from all other species in the genus by the presence of 31–35 dorsal procurrent caudal-fin rays and the combination of some external characters such as: coloration, number of pectoral–fin rays and pores of the laterosensory canals. The new taxon belongs to a presumably monophyletic group of species composed of T. crassicaudatus, T. igobi, and T. stawiarski based on the presence of 24 or more thickly ossified and rigid procurrent caudal-fin rays with a slender distal tip extending along the tips of at least ten neural spines.

First record of Astyanax puka Mirande, Aguilera & Azpelicueta, 2007 (Teleostei: Characidae) in Juramento River basin, Salta, Argentina

Astyanax puka was described from the endorheic Rio Sali basin, Argentina, and it was not previously recorded elsewhere, being considered until now as endemic from that basin. Herein we record for the first time this species in the Rio Juramento basin, Rio de La Plata system.

First record of Hypostomus boulengeri (Siluriformes: 1 Loricariidae) from Río Bermejo basin.

Hypostomus boulengeri (Eigenmann y Kennedy 1903) es una especie poco conocida registrada de las cuencas de los Rios Paraguay Parana. En este trabajo reportamos por primera vez la presencia de esta especie en la cuenca del Rio Bermejo representado una ampliacion en la distribucion de mas de 600km.

First record of the banjo catfish Bunocephalus doriae Boulenger 1902 (Siluriformes: Aspredinidae) in the Bermejo River basin, Salta, Argentina

Intense sampling in the upper Bermejo River basin revealed the presence of specimens of the aspredinid genus Bunocephalus . After detailed morphological and morphometric analyses specimens were identified as Bunocephalus doriae . This is the first record of any member of the Aspredinidae in the upper Bermejo River basin.

Range extension of Hypostomus cochliodon Kner, 1854 (Siluriformes: Loricariidae) in Bermejo River, Salta, Argentina

Hypostomus cochliodon Kner, 1854 had been recorded from Paraguay and Parana rivers in Argentina. We recorded for the first time specimens of H. cochliodon to the Bermejo River basin. It is also the first record of this species to Salta province, Argentina.

A new species of Heptapterus Bleeker 1858 (Siluriformes, Heptapteridae) from the Río Salí basin, north-western Argentina

A revision of fish specimens previously identified as Heptapterus mustelinus from the endorheic Río Salí Basin, Tucumán, Argentina, reveals that they present several morphological differences from that species. This paper describes Heptapterus qenqo sp. nov. from the Río Salí Basin. The new species is diagnosed by a combination of the following characters: presence of small serrae on the anterior proximal margin of the first pectoral-fin ray; anal-fin rays iv-v, 11-13 (15-17 total anal-fin rays); adipose-fin base 40·9-47·4% standard length; small eyes (7·4-14·2% head length); adipose-fin confluent to caudal fin and maxillary barbel not reaching pectoral-fin base in adults, and reaching or scarcely surpassing the first pectoral-fin ray in small juveniles.