Aspects of the reproduction and activity of two sympatric Mastus (Beck, 1837) species in Crete (Gastropoda : Pulmonata : Buliminidae)

摘要

The present study reports an investigation into the reproductive biology and ecology of two sympatric species of Mastus endemic to the island of Crete (southern Greece). The study lasted 6 months, from September 1997 to March 1998, and involved field observations on single and copulating individuals, and the study of the spermatophores within the genital tract. The two species have different aestivation habits and emergence times. Mastus olivaceus, which aestivates closer to the surface of the soil or in the litter, emerges soon after the first rains, while Mastus cretensis emerges later. Additionally, M. olivaceus starts aestivating over a month earlier than M. cretensis. M. olivaceus reproduces from late September till early January, while M. cretensis starts in early November and ends in early March. The bursa-like diverticulum of M. cretensis bears only one spermatophore, but in M. olivaceus from one to three spermatophores were found. The 91 spermatophores of M. olivaceus examined indicate intrapopulation variability in the number of transverse ridges and number of spines in the ornamentation of its distal part. These types of difference in spermatophore morphology should not, therefore, be considered species-specific.