Cytogenetic study of four species of land snails of the family Achatinidae in South-Western Nigeria

Abstract

The chromosomal study of the four species of achatinid snails was carried out with the aim of determining their chromosome numbers as part of a preliminary attempt to understand the cytogenetics of land snails of Nigeria. The haploid chromosomes of various species of snails studied were obtained from their ovotestis while the meiotic metaphase chromosome of the four snail species were x= 28, x= 30, x= 27 and x= 24 for Archachatina marginata (Swanson, 1821) Achatina achatina (Linnaeus, 1758), Achatina fulica (Bowdich, 1822) and Archachatina papyracea (Pfeiffer, 1845) respectively. The meiotic metaphase chromosome numbers observed in species studied fell within the range reported for haploid chromosome numbers of the Stylommatophoran i.e. x=17 to x= 34. From this study, it is clear that chromosome number alone cannot be used to distinguish gastropod species but further studies employing banding techniques to study the karyotypes may provide better diagnostic criterion for separating the species.

Keywords: Cytogenetics, Achatinidae, Chromosomes, Taxonomy.