Karyotypic diversity in a population of Bryconamericus aff. iheringii (Characidae).

In vivo genotoxicity of the pyrethroid pesticide beta-cyfluthrin using the comet assay in the fish Bryconamericus iheringii.

Environmental pollution by pesticide residues is a major environmental concern due to the extensive use of these substances in agriculture. The insecticide beta-cyfluthrin is a synthetic pyrethroid widely used in agricultural and other domestic activities. The aim of the present study was to assess the genotoxic effects of a sublethal exposure of the fish Bryconamericus iheringii (Characidae) t...

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

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 aimed to analyze the karyotype diversity in Astyanax species from different watersheds by conventional G...

Cytogenetic divergence in two sympatric fish species of the genus Astyanax Baird and Girard, 1854 (Characiformes, Characidae) from northeastern Brazil

The fish genus Astyanax is widespread throughout the Neotropical region and is one of the most species-rich genera of the Characiformes. Cytogenetic studies of Astyanax have revealed marked intra- and interspecific diversity, with the identification of various species complexes. In this report, we describe the karyotypic structure of two sympatric species of Astyanax (Astyanax sp. and Astyanax ...

Diversity of Nematodes of Red-tail-lambari Astyanax Aff. Paranae (teleostei: Characidae) from Polluted Sites of a Tropical River System Diversidad De Los Nematodos De Tetra Cola Roja Astyanax Aff. Paranae (teleostei: Characidae) De Sitios Contaminados De Un Sistema De Río Tropical

Daily feeding activity of Bryconamericus microcephalus (Characiformes, Characidae) from Córrego Andorinha, Ilha Grande - RJ.

The present study was conducted at the Córrego Andorinha on the eastern slope of Ilha Grande and aimed to determine the alimentary daily rhythm of Bryconamericus microcephalus. Fishes were sampled at a 4 hours interval over a 24 hours period during winter 2002 and summer 2003. Gut fullness was determined according to a numerical scale ranging from 0 (empty gut) to 3 (full gut). No differences w...