Unrevealing the Karyotypic Evolution and Cytotaxonomy of Armored Catfishes (Loricariinae) with Emphasis in , , , , , and .

This study provides new insight into the chromosomal diversification in Loricariinae. We analyzed nine species from different Brazilian hydrographic basins, using conventional and molecular cytogenetic methods, aiming to understand the karyotypic diversification, and contribute with cytotaxonomic markers in this group considered one of the most diverse of Loricariidae. Our results evidenced a high karyotypic variability in diploid number (2) ranging from 2 = 54 ( and ), 2 = 60 ( and ), 2 = 62 (), 2 = 64 ( complex species), 2 66 (), and 2 = 68 ().

Cytogenetic Trends in Two Families of the Neotropical Catfishes: Heptapteridae and Pseudopimelodidae (Siluriformes).

Several neotropical Siluriformes groups suffered important taxonomic revisions based on the evaluation of morphological and molecular characteristics that allow the construction of new phylogenetic hypothesis. In the present study were cytogenetically analyzed six species belonging to Heptapteridae (Cetopsorhamdia iheringi, Phenacorhamdia tenebrosa, Rhamdella eriarcha, Pimelodella meeki, Pimelodella australis, Heptapterus mustelinus) and two to Pseudopimelodidae families (Microglanis cottoides and Microglanis cibelae) by means of differential staining techniques to describe more precisely cytogenetic similarities and differences. The diploid number of R.

Hidden Diversity in the Populations of the Armored Catfish Kner, 1854 (Loricariidae, Hypostominae) from the Paraná River Basin Revealed by Molecular and Cytogenetic Data.

Only one species of armored catfish, Valenciennes 1836, has been historically described in the basin of the Paraná River, from Misiones (Argentina). However, the ample variation found in the morphology and coloration of the populations sampled in the tributaries of the Brazilian state of Paraná makes it difficult to establish the real taxonomic status and evolutionary history of the specimens, suggesting that is not the only species found in this basin. By combining data on mitochondrial DNA (COI gene) and chromosomal markers from different populations, totaling 144 specimens, in the tributaries of the Paraná, and specimens from Misiones (type-locality of ), we detected five distinct evolutionary lineages.

Cytogenetic studies in the redtail catfish, (Bloch & Schneider, 1801) (Siluriformes, Pimelodidae) a giant fish from Amazon basin.

The objective of this study was to cytogenetically analyze comparing the findings with other data to infer relationships among Pimelodidae species. The results revealed a diploid number of 2n = 56 and the karyotype composed of 16 metacentric, 20 submetacentric, 6 subtelocentric and 14 acrocentric chromosomes (FN = 98). The Ag-NORs, 18S rDNA and CMA signals were coincident in location occupying the short arm of an acrocentric chromosome pair (23), in a secondary constriction.