Duration of reproductive activities (courtship latency, courtship and mating) were studied in three (3) species of Giant African land snails (GALs) namely, Achatina fulica, Archachatina marginata and Achatina achatina using mature snails gathered from rural Nigeria. The snails were housed singly for 90 days to acclimatize; shed already fertilized eggs from previous mating and develop strong desire to mate. Thereafter, monocultures of each species were formed namely, A. fulica x A. fulica (F x F); A. marginata x A. marginata (M x M) and A. achatina x A. achatina (A x A) for pre-mating trials. These were observed for one week and any two snails that showed consistent association for more than 10 min were isolated and kept together as potential mating pairs. Parameters measured were duration of courtship latency (DCL), duration of courtship (DC), duration of mating (DM), duration from mating to oviposition (DMO), egg weight (EW), egg length (EL) and weight of hatchlings (WH). Number of mated pairs and ovipositors per species were noted and mating propensity was calculated as the percentage of tested snails that mated in each species. Result shows significant (P 0.05) differences between snail species in all traits studied.

Three populations of Archachatina marginata snails (P 1 , P 2 and P 3 ) obtained from natural snail habitats located in three states of Nigeria (one population per state) namely Enugu, Edo and River States were evaluated for pre-mating reproductive isolation using mate-choice tests. Total number of mated snails were very small (19.2%) compared to the number tested. Mating propensity (MP) varied significantly (P ≤ 0.05) among snail populations in two test groups and observed MP in the test groups differed significantly (chi-square test, P < < < <0.05; 0.001) from that expected under random mating. Pair formation was significantly (chi-square test, P < < < < 0.05; 0.001) influenced by differences in MP and within-population (homotypic) and between population (heterotypic) mating occurred in frequencies that differed significantly (chi-square test, P ℜ ℜ ℜ ℜ 0.05; 0.001) from that expected under random mating. Whereas observed heterotypic pair formation were less than that expected under random mating, homotypic pair formation were either equal or more than that expected under random mating. Duration of reproductive activities differed significantly (P ≤ 0.05) among test populations. It was concluded that reduced pair formation, elongated duration of courtship, and reduced mating between populations of A. marginata, indicate partial or incomplete pre-mating reproductive isolation.