Cariótipos inéditos de Anomalocardia brasiliana (Gmelin, 1791) (Bivalvia: veneridae) e Donax striatus (Linnaeus, 1767) (Bivalvia: donacidae) de praias do Litoral Potiguar.

Abstract

The mariculture is expanding and there are few studies on native mollusks, including those that may elucidate the taxonomy of Brazilian species. Cytogenetic information is important to assist in species identification. The objective of this study was to identify the karyotypes of Anomalocardia brasiliana and Donax striatus. For this collection in September 2011, and February and April 2012 were held on the of Barra, and Pernambuquinho Alagamar beaches in Thick, RN, and the Emanuelas Beach, in Tibau, RN. The gills were removed and the cell suspension was prepared in vitro, hipotonizada, fixed with Carnoy and dropped later on microscope slides stained with Giemsa. Slides were analyzed and the best metaphases were photographed under a light microscope with digital camera. The chromosomes were cut out, grouped and classified according to the centromeric index to obtain the diploid number (2n) and fundamental number (NF). The diploid number found in A. brasiliana was 2n = 14 and NF = 22 with karyotype consist of four pairs of submetacentric chromosomes and three acrocentric pairs arranged in descending order of size, the last one being a miniature pair. For D. striatus, the diploid number was 2n = 16 and FN = 16, with eight acrocentric pairs. Although not morphologically distinguishable sex chromosomes in any species studied, this work brings unpublished cytogenetic data for these species.