Pregnancy in fish

Pregnancy has been traditionally defined as the period of time a creature's young are incubated in the body after the egg-sperm union. Although the term generally refers to placental mammals, it is also sometimes used in the context of fish, including in scientific literature. In fish the term can refer to a variety of modes where the developing young are retained by the parent, including both internally and externally, and with varying degrees and methods of parental supplementation.

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