Results: 15

A new miniature species of Priocharax (Characiformes: Characidae) from the upper rio Ipixuna, Purus drainage, Brazil

Neotrop. ichthyol; 19 (2), 2021
A new species of miniature fish of the characid genus Priocharax is described from a small lake near the rio Ipixuna, rio Purus drainage, Amazonas State, Brazil. It is distinguished from all congeners except P. pygmaeus by the lower number of teeth on the maxilla and dentary. It differs from P. pygmaeus ...

Seminal characteristics and sensitivity of Astyanax lacustris (Characiformes: Characidae) sperm to cryoprotective solutions based on dimethylsufoxide and methylglicol

Neotrop. ichthyol; 18 (3), 2020
This study aimed to determine the semen characteristics of Astyanax lacustris after hormonal induction and to evaluate the sensitivity of the species sperm to cryoprotective solutions based on the cryoprotectants dimethyl sulfoxide and methyl glycol. Volume, color, sperm concentration, total motility and...

Zygoparity in Characidae - the first case of internal fertilization in the teleost cohort Otomorpha

Neotrop. ichthyol; 18 (1), 2020
Most teleosts are externally fertilizing, with internal fertilization occurring as a relatively rare event. Until now, Euteleosteomorpha is the only teleost cohort known to undergo internal fertilization. In the teleost cohort Otomorpha, it has been recorded the presence of sperm in the ovaries of some s...

Cytogenetic markers as tools in delimiting species of the highly diverse Neotropical fish Bryconamericus (Characiformes: Characidae)

Neotrop. ichthyol; 17 (3), 2019
Bryconamericus is a highly diverse group of characid fishes, being cytogenetic a valuable tool for the delimitation of species. Bryconamericus aff. iheringii (Upper Uruguay/Lower Paraná), B. coeruleus (Upper Paraná), B. cf. ecai e B. cf. eigenmanni (Upper Uruguay) were studied cytogenetically, and pres...

Redescription of Hyphessobrycon itaparicensis, a senior synonym of H. sergipanus (Characiformes: Characidae)

Neotrop. ichthyol; 16 (1), 2018
Hyphessobrycon itaparicensis was originally described from a small stream in the Itaparica coastal island, Bahia State, Brazil, and has been sampled in several coastal rivers draining Bahia and Sergipe States. Broad examination of type material and recently collected specimens resulted in the redescripti...

Comparative cytogenetics of Astyanax (Teleostei: Characidae) from the upper Paraguay basin

Neotrop. ichthyol; 16 (1), 2018
Astyanax is one of the most abundant and diverse taxa of fishes in the Neotropical region. In order to increase the amount of cytogenetic information for Astyanax as well as to exhibit data to subsidize future taxonomic studies, this work analyzed three species of Astyanax: two species are cryptic, and a...

Molecular phylogeny and biogeographic history of the Neotropical tribe Glandulocaudini (Characiformes: Characidae: Stevardiinae)

Neotrop. ichthyol; 16 (1), 2018
Although former studies on systematics and biogeography represent a progress on the knowledge of the tribe Glandulocaudini, none was grounded on molecular evidence. Thus, the first hypothesis of relationships for the tribe based on a multilocus analysis is presented, including all genera and most of the ...

Conserved number of U2 snDNA sites in Piabina argentea, Piabarchus stramineus and two Bryconamericus species (Characidae, Stevardiinae)

Neotrop. ichthyol; 16 (1), 2018
The chromosomal location of 5S rRNA and U2 snRNA genes of Piabina argentea, Piabarchus stramineus and two Bryconamericus species from two different Brazilian river basins were investigated, in order to contribute to the understanding of evolutionary characteristics of these repetitive DNAs in the subfami...

Description of a new species of Moenkhausia (Characiformes: Characidae) from the upper Paraguay basin, Central Brazil, with comments on its phylogenetic relationships

Neotrop. ichthyol; 16 (2), 2018
A new species of Moenkhausia is described from tributaries of the upper rio Sepotuba, Paraguay basin, Brazil. The new species is distinguished from its congeners by a combination of characters, including an inconspicuous oval-shaped vertically elongated humeral blotch, extending horizontally from third t...

Karyotypic diversity among three species of the genus Astyanax (Characiformes: Characidae)

Braz. j. biol; 76 (2), 2016
Abstract The group Incertae sedis within the Characidae family currently includes 88 genera, previously included in the subfamily Tetragonopterinae. Among them is the genus Astyanax comprising a group of species with similar morphology and widely distributed in the Neotropics. Thus, the present study aim...