Friday, May 27, 2005

Life begins as spat:

Feeling a bit odd today, so I regale you with the following:

Oyster Reproduction: Au Naturel

Members of the genus Ostrea are bisexual, that is, they alternate between being male and female during the course of a single breeding season. During a female phase, the oyster deposits eggs within the shell, and these eggs are fertilized by sperm released when the same oyster switches to a male phase. After a 12-day period of incubation, the larval oysters, or spat, swim away from the parent in search of their own place to settle.
Members of genus Crassostrea are intersexual. They begin life as males, and then change to females the following season. After this, they remain primarily female but revert from time to time into males. Reproduction is quite a bit more haphazard for this genus, because the eggs and sperm are released directly into the water, and fertilization takes place when a pair happens to cross paths. Successfully fertilized eggs, should they survive, rapidly grow into spat, and they, too, swim off in search of a home.

After fourteen days, the spat, whether Ostrea or Crassostrea, must attach themselves to a stationary object - a rock, a mangrove tree, the post of a pier, even another oyster. There they will remain for their entire lives -- unless they happen to be cultured oysters, in which case, the spat has settled on a collector planted there by an oyster farmer

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