Cytogenetic Analysis of H. obliquidens

We analyzed ninety-six specimens of H. obliquidens (46 males, 33 females and 17 of undetermined sex) obtained from the aquarium trade in Botucatu, SP, Brazil (Table 1). The animal experiments were performed with the approval of the appropriate ethics committee of UNESP - São Paulo State University. Metaphase chromosomes were obtained from cells of the anterior kidney following in vivo treatment with colchicine at 0.025% (1 ml/100 g of body weight) according to the air-drying method [59 ]. Heterochromatin was identified by C-banding [60 (link)], and the nucleolus organizer regions (NORs) were visualized by silver nitrate staining [61 (link)]. Chromosomes were classified as meta/submetacentric (m/sm) and subtelo/acrocentric (st/a), and were organized by decreasing order of size in the karyotype. Meiotic cells from testes were obtained as described by Kligerman and Bloom [62 ].