Contribution to the biology of Hippeutis complanatus (Linnaeus, 1758) (Gastropoda:Planorbidae): life cycle in Silesian woodland ponds (Southern Poland)

Abstract

In spite of the common occurrence of Hippeutis complanatus (L.) in some regions of Poland, it is considered to be a rare species with scattered sites. A study on its life cycle and shell growth in various conditions was possible due to the existence of very abundant populations in several woodland ponds of Silesia. The snails breed twice in a lifetime, and two generations reproduce in one year. The main breeding period is July/August. Some individuals breed also in the spring of the next year. The first appearance of the smallest individuals is clearly related to the water temperature.