Karyological study reveals a putatively distinctive population of the European flat oyster (Ostrea edulis) in Mali Ston Bay, Croatia

Abstract

          The European flat oyster (Ostrea edulis) was described in Mali Ston Bay (Eastern Adriatic coast, Croatia). Metaphase spreads were made from the flat oyster larvae and studied using conventional karyotyping methods. The study revealed the presence of 5 metacentric and 4 submetacentric pairs of chromosomes as well as a single pair of subtelocentric ones with an arm ratio of 3.72 ± 0.42 and a centromeric index of 21.42 ± 1.87 which has not been described previously. This suggests that the oyster population cultured in Mali Ston Bay in Croatia represents a genetically different lineage of the species.