Cytogenetic Analysis of Alburnus escherichii (Teleostei: Leuciscidae) in Turkey

In this study, cytogenetic properties of A. escherichii were investigated using standard Giemsa staining, C-banding, and Ag -NOR staining techniques. The karyotype of Sakarya bleak, the diploid chromosome number was 2n = 50, consists of six pairs of metacentric, 12 pairs of submetacentric, and seven pairs of acrocentric autosomes (NF=86). No morphologically distinguishable heteromorphic sex chromosomes were detected in the karyotype. While most autosomes had centromeric and pericentromeric C-heterochromatin (some chromosomes slightly) blocks, the other autosomal pairs were C-negative. Also, the short arm of the eleventh submetacentric chromosome pair was entirely C-positive. The nucleolar organizer regions were localized in medium-sized submetacentric autosomal pairs. Active NORs associated with the C-heterochromatin were observed in the whole of the short arm of the eleventh chromosome pair, and their active NORs were homomorphic. The banded karyotypes of A. escherichii were reported in this study for the first time. Significant findings obtained in this research may contribute to cytotaxonomy of Alburnus species in Anatolian and Europe.