microphallus

Snails get sexy when parasites are around

edyong | July 24, 2009

In Lake Alexandrina, New Zealand, a population of snails is under threat from a parasitic flatworm, a fluke aptly known as Microphallus. The fluke chemically castrates its snail host and uses its body as a living incubator for its larvae. But the snails have a weapon against these body-snatching foes - sex. The New Zealand mud snail Potamopyrgus antipodarum is found throughout island's freshwater habitats. They breed either sexually or asexually through cloning, and the two strategies vary in prevalence throughout the lake. In the shallower waters round its margins, sex is the name of the…