Reproductive Seasonality and Developmental Characteristics of the Page Springsnail (Pyrgulopsis morrisoni)

Abstract

This paper reports on the reproductive seasonality and developmental characteristics of Page springsnail (Pyrgulopsis morrisoni) observed for two consecutive years in a carefully monitored ex-situ population housed at the Phoenix Zoo's Conservation Center. During 2010 and 2011, Page springsnails exhibited seasonal reproductive activity beginning in mid-July and continuing through November each year, with peak reproductive activity occurring from August to October which differs from previously reported observations. An isolated group of Page springsnails photographed, described and measured weekly for 10 weeks beginning in July in order to determine the rate and characteristics of development. The females deposited a single egg at a time and there was an 8-to-10-day interval between the detection of newly emerged snails. Juvenile snails emerged at 0.3 mm to ≥0.4 mm and reached adult size of at least 2.5 mm with three whorls present, after approximately 6 weeks. The maximum adult snail size recorded in the collection was 3.9 mm, but we only observed one snail at that size.