Clam

-fertilize: gonad
-100,000-1,000,000 eggs (only few reach maturity)
-hatch in 6-12 hours
-about 1-2 years to mature
-ex: marine clams - external fertilization (1 sex their entire life)
-ex: fresh water clams - internal fertilization (turn to hermaphrodites)

-Most are sexual, possible to be hermaphroditic.(asexual)
-partner copulation

Ex: Scallop