Clams
Posted by Bryan Ensor on November 9, 2003
Q: How do clams give birth?
A: There are two different approaches to reproduction in the clams. In one group of species, each individual is both male and female, in the other group of species, an individual is either male or female, not both.
In the species that are both male and female, once the eggs are fertilized, the eggs move into the gills of the parent and begin development there. These young develop in the parent's gills until quite large and once fully formed (they look like small replicas of the adults) are released to continue life on their own.
In the species that are either male or female, a female's eggs move into its own gills. A constant current of water bathes the female's gills and any sperm that have been released by nearby male clams in this water, pass through the gills and fertilize the eggs. Young develop for only a short time in the mother's gills and then are released to complete development outside the female.
John Wiessinger ( November 10, 2003)