Protogyny

Protogyny is a term used in biology to describe two related patterns involving the timing of sexual function. In animals, it refers to sequential hermaphroditism in which an individual begins life as a female and later changes into a male. In plants, protogyny describes a floral strategy in which female reproductive organs mature before male ones, reducing the likelihood of self-pollination.

In animal systems, protogynous species include some reef fishes where sex change occurs during adulthood. Social structure often governs the transition: when a dominant male is removed, the largest female may change sex to assume male roles and reproductive duties. The transformation is driven by hormonal shifts and gradual changes in gonads, coloration, and behavior. The timing of the change can enhance reproductive success by aligning sex with size, age, or social status.

In botany, protogyny is one form of sequential floral sexuality. A protogynous flower or plant exhibits female function first, with stigmas receptive and ovules ready, followed by the onset of male function through pollen production. This pattern promotes cross-pollination and reduces self-fertilization. Protogyny can occur across flowers or within a single flower and is often discussed alongside protandry, where male function precedes female function.

See also sequential hermaphroditism, protandry, and plant reproductive strategies.