Karyoevolution of the toadfish Thalassophryne nattereri (Batrachoidiformes: Batrachoididae)

Abstract

ABSTRACT. The Batrachoididae includes some venomous brackish and marine fish found in the Atlantic, Indian and Pacific oceans. This family is composed of 69 species, distributed among 19 genera. Species of the genus Thalassophryne have been reported along the coast of Rio Grande do Norte (Brazil); T. nattereri has been responsible for a large number of human injuries. Little is known about the cytogenetic features of this family. We made a karyotypic characterization of T. nattereri collected from the estuary of the Apodi/Mossoró River, using conventional Giemsa staining, C-banding and silver nitrate-nucleolar organizer region technique. There was a modal diploid value of 2n = 46 chromosomes (8m + 8sm + 24st + 6a; fundamental number = 86). Single ribosomal sites were detected in the terminal region on short arms of a subtelocentric pair (19th). Heterochromatin segments were preferentially located over centromeric regions in some chromosome pairs. Pericentric inversions and Robertsonian rearrangements seem to have played a major role in karyotype evolution within this genus of toadfish.

Chromosomal differentiation and speciation in sister-species of Grammatidae (Perciformes) from the Western Atlantic

“…While 4 m-sm and 38a occur in G. loreto, 6 m-sm and 36a occur in G. brasiliensis, likely as a result of pericentric inversion, currently Wxed in the homozygous condition of the latter species, changing one pair of acrocentric chromosomes into one pair of m-sm chromosomes. It seems apparent that pericentric inversions correspond to the main chromosomal rearrangements found in Perciformes (Cano et al 1982;Ozouf-Costaz et al 1991;Galetti et al 2000 (Brum et al 2002;Nirchio et al 2002;Costa and Molina 2009), indicating their eVective participation in the karyotypic evolution of these groups.…”

Sequential Steps of Chromosomal Differentiation in Atlantic Surgeonfishes: Evolutionary Inferences

“…Different from pericentric inversions, centric fusions or Robertsonian rearrangements are usually reported in non-Perciformes marine fish, such as flatfish (Pleuronectiformes) [28], toadfish (Batrachoidiformes) [29], and some mullets (Mugiliformes) [30]. Centric fusions are particularly common in Batoidea (stingrays, guitarfish, and skates), the most derived superorder of elasmobranchs [31].…”