Cytogenetics has been established as a significant tool which often provides relevant data that are used in taxonomy, identification of species and in understanding the mechanisms of speciation and evolution (Burch, 1968). Several
rearrangements of the systematic of pulmonates have proved that their evolutionary relationships are largely unresolved (Solem,1984). It was believed that cytogenetic studies may contribute valuable systematic characters which may be used to resolve some taxonomic problems in the group. However, literatures on karyotypic analysis of molluscs are not abundant due to difficulties of obtaining mitotic fields with enough quality to carry out chromosome studies (Park et al., 1999). Approximately 60,000 species of Gastropods are known, out of which only 332 species have been worked out cytogenetically till date (305 were karyotyped and 27 included banding techniques), showing the increasing knowledge of chromosome morphology over the last three decades. It includes three subclasses: the Prosobranchia, which contained the majority of gastropods; the Pulmonata, which included the land snails; and the Opisthobranchia, which included
the sea hares and sea slugs (Thiriot-Quievreux, 2003).