A description of the reproductive cycle of the gastropod Lepsiella vinosa on the West Head rocky shore in Victoria

This study used histological methods to describe the reproductive cycle of Lepsiella vinosa. L.vinosa was collected from the West Head rocky shore on 12 occasions between April 1975 and March 1976. Individual shell lengths were measured and the soft tissue of the animals removed to determine the sex. Four to six animals of each sex were used for histological examination by excising a 5 mm section of the visceral coil from each animal. Ovarian sections at 100 micron intervals were examined under a compound binocular microscope and the numbers of immature and mature oocytes were counted. The area of the testis in the visceral coil was used as an estimate of the maturity of males.

There were 177 males and 169 females collected and the females (average 0.86 ± 0.09 cm) were generally larger than males (average 0.82 ± 0.09 cm). The sex ratio was female bias throughout the year. There were significantly more immature oocytes present in the ovary throughout the year with a peak in May and June. The testis occupied a proportionally larger cross-sectional area of the visceral coil in summer and early autumn and then decreased in size to a minimum in August. This testis size correlated with observations of copulating pairs of L.vinosa during autumn and winter at West Head.