Electrolocation-communication discharges of the fish Gymnotus carapo L. (Gymnotidae: Gymnotiformes) during behavioral sleep.

Are NORs Always Located on Homeologous Chromosomes? A FISH Investigation with rDNA and Whole Chromosome Probes in Gymnotus Fishes (Gymnotiformes)

Gymnotus (Gymnotiformes, Gymnotidae) is the most diverse known Neotropical electric knife fish genus. Cytogenetic studies in Gymnotus demonstrate a huge karyotypic diversity for this genus, with diploid numbers ranging from 34 to 54. The NOR are also variable in this genus, with both single and multiple NORs described. A common interpretation is that the single NOR pair is a primitive trait whi...

Karyotypic diversity in four species of the genus Gymnotus Linnaeus, 1758 (Teleostei, Gymnotiformes, Gymnotidae): physical mapping of ribosomal genes and telomeric sequences

Conventional (Giemsa, C-Banding, Ag-NORs, CMA3) and molecular (5S rDNA, 18S rDNA, telomeric sequences) cytogenetic studies were carried out in specimens of ten distinct fish populations of the genus Gymnotus (Gymnotus sylvius Albert and Fernandes-Matioli, 1999, Gymnotus inaequilabiatus Valenciennes, 1839, Gymnotus pantherinus Steindachner, 1908, and G. cf. carapo Linnaeus, 1758) from different ...

Nesting and Paternal Care in the Weakly Electric Fish Gymnotus (Gymnotiformes: Gymnotidae) with Descriptions of Larval and Adult Electric Organ Discharges of Two Species

Parasitism of Cichlasoma paranaense Kullander, 1983 and Gymnotus carapo Linnaeus, 1814 by Clinostomum complanatum (Rudolphi, 1814) metacercariae in the Taquari river.

The infection, known as yellow spot disease, produced by metacercariae of Clinostomum spp. was studied in fishes of the Taquari river, located in Jataizinho, Paraná State, Brazil. A total of 1,582 specimens, belonging to 36 species, were collected between March 1999 and April 2001. Yellow spot disease was observed only in Gymnotus carapo Linnaeus, 1814 (Gymnotiformes, Gymnotidae) and Cichlasoma...

Species diversity and geographic distribution of Gymnotus (Pisces: Gymnotiformes) by nuclear (GGAC)n microsatellite analysis

Patterns of amplified DNA fragments flanked by (GGAC)n microsatellites, obtained by single primer amplification reaction (SPAR), from 198 Gymnotus specimens (Pisces: Gymnotiformes) sampled from 8 southeastern Brazilian river basins were analyzed. The species studied were Gymnotus carapo, G. pantherinus, G. inaequilabiatus, and G. sylvius. The indirectly obtained patterns reflected the distribut...