Observations of the reproduction and population structure of the caenogastropod, Gabbia vertiginosa Frauenfeld, 1862 (Rissooidea : Bithyniidae)

Abstract

Aspects of the reproduction and population structure of Gabbia vertiginosa (Bithyniidae) in the New England Tablelands, New South Wales, Australia, are described. The pattern of embryo growth from encapsulation in the pallial oviduct, deposition of fully formed embryonic snails in the habitat, to sexual maturity in the adult snail are examined. A three-year population study has shown the reproductive period of G. vertiginosa to commence in December and end in June/July with the possibility of three reproductive events per season.

Additional keywords: Bithynia, embryo.