Adults of the conical snail,Cochlicella acuta, laid eggs in laboratory cultures from autumn to spring, with a peak in autumn-early winter. There was no evidence to suggest that large adults produced more eggs than small adults over the whole breeding season, nor that crowding of adults reduced production/snail when food was abundant. In experiments where snails were kept in pairs and size varied between pairs, an overall average of 7.1 clutches and 257.7 eggs per pair were produced during the laboratory breeding season. Where density of snails varied, an overall average of 9.2 clutches and 372.6 eggs per pair was recorded.