In
biology,
endogamy is the term for
sexual reproduction between organisms which are closely
related to each other.
But it is also used to refer to the production of a zygote (an egg that has been fertilized by a sperm) by a simultaneous hermaphrodite (an organism which produces both sperm and eggs) using only its own gametes (eggs and sperm) without genetic contributions from other individuals.
From the science dictionary at http://biotech.icmb.utexas.edu/