Abstract

The study investigates the genetic differentiation between the black skinned and white skinned ectotypes of the giant African land snails (Archachatina marginata) from Cross River State in Niger Delta region of Nigeria. The random amplified polymorphic DNA (RAPD) technique was employed in this study. Five (5) oligonucleotide primers (OPAD-09, OPAE-04, OPAE-05, OPAF-07 and OPAF-09) were used to amplify DNA from five samples of A. marginata constituting black skinned and white skinned ectotypes. A total of 58 RAPD bands with 24 polymorphic bands (40.18%) with size range of 150 to 5,500 bp, were scored from the populations. The black skinned ectotype had mean percentage polymorphism of 34.50%, while the white skinned ectotype recorded mean percentage polymorphism of 41.40%. Genetic similarity coefficient ranged from 60 to 63%, while the genetic distance ranged from 0.37 to 0.40. The genetic similarity between the two ectotypes of A. marginata from Cross River State is high and depicted low genetic differences. This reveals that the genetic variability of the species (A. marginata) from Cross River State is gradually eroding. Efforts should be made to conserve the genetic pool of this species, as the erosion of genetic variability is dangerous and could continue unnoticed till extinction is imminent.

Key words: Genetic, differentiation, snail, ectotypes, Niger Delta.