Taxonomy of Ixinandria Isbrücker & Nijssen (Loricariidae: Loricariinae) based on morphological and molecular data

Abstract

The genus Ixinandria was described in 1979 to include I. steinbachi from the upper río Juramento in northern Argentina and I. montebelloi from the upper río Bermejo in southern Bolivia. We used a multivariate morphometric analysis (Principal Components Analysis) and a molecular comparison of the Cytochrome Oxidase I gene to investigate variation among distinct populations from the known distribution range of both species. We conclude that the populations are not significantly distinct and do not deserve separate species recognition, and we place I. montebelloi in the synonymy of I. steinbachi.O gênero Ixinandria foi descrito em 1979 para incluir I. steinbachi do alto rio Juramento no norte da Argentina e I. montebelloi do alto rio Bermejo no sul da Bolívia. Utilizamos análise morfométrica multivarida (Análise de Componentes Principais) e uma comparação molecular do gene Citocromo Oxidase I para investigar a variação entre populações distintas da área de distribuição de ambas as espécies. Concluímos que as populações não são significativamente distintas e não merecem reconhecimento como espécies separadas, e colocamos Ixinandria montebelloi na sinonímia de I. steinbachi.

Using Different Methods to Access the Difficult Task of Delimiting Species in a Complex Neotropical Hyperdiverse Group

“…langei , probably because these species did not reach the reciprocal monophyletic. A similar situation was found in the genus Ixinandria by Rodriguez et al [ 4 ], who tried to define the boundaries between I . steinbachi and I .…”

“…montebelloi using morphological and genetic characters and discovered that this species was not reciprocally monophyletic. The difference in our results is that, in Rodriguez et al [ 4 ], they considered the morphologic distinction insufficient to validate the two species and opted for synonymy, while we are of the opinion that the morphological differences between R . kronei and R .…”

“…With the implementation of the Barcoding of Life project, the gene COI has been used for some time as a tool for identification of fish species. [ 1 ] This gene has been an efficient tool for delimiting species of particular taxonomic groups and providing evidence of independent evolutionary units or operational taxonomy units (OTUs) with the recognition of genetic patterns within groups that support the traditional taxonomic studies [ 2 – 4 ].…”

Intergeneric phylogenetic relationships in catfishes of the Loricariinae (Siluriformes: Loricariidae), with the description of Fonchiiloricaria nanodon: a new genus and species from Peru

“…Morphometric variables were measured with a digital calliper (to 0·1 mm). Measurements and counts follow Rodriguez et al (2008), except for the premaxillary ramus length (due to difficulty of measurement), and the orbital diameter excluding the notch. These two measurements were excluded.…”

“…Within the Loricariidae, members of the subfamily Loricariinae are united by a long and depressed caudal peduncle and by the absence of an adipose fin, but they exhibit substantial variation in body shape, lip morphology and dentition. There are currently 220 valid species of Loricariinae, distributed in 30 genera (Covain & Fisch‐Muller, 2007; Fichberg & Chamon, 2008; Ghazzi, 2008; Ingenito et al , 2008; Rapp Py‐Daniel & Fichberg, 2008; Rodriguez & Miquelarena, 2008; Rodriguez & Reis, 2008; Rodriguez et al , 2008; Thomas & Rapp Py‐Daniel, 2008; de Carvalho Paixão & Toledo‐Piza, 2009; Thomas & Sabaj Pérez, 2010).…”