Spermdependent

Sperm-dependent is a descriptive term used in reproductive biology to refer to processes or reproductive modes that require the presence or input of sperm in order to proceed. It is not a formal taxonomic category, and usage varies across disciplines. In many contexts, "sperm-dependent" highlights that a successful reproductive event relies on sperm, either for fertilization of eggs or for triggering developmental steps, rather than implying that paternal genetic material is incorporated in every case.

In some systems, sperm activates the egg but does not contribute genetically to the offspring. This phenomenon is commonly described as gynogenesis. In gynogenetic species, fertilization by sperm is required to initiate embryogenesis, yet the resulting offspring are predominantly clones of the mother. Occasional leakage of paternal DNA can occur in some species, but is not typical.

Examples of sperm-dependent reproductive strategies include the amazon molly (Poecilia formosa) and some other fish and amphibian lineages that rely on sperm to stimulate egg development. By contrast, parthenogenesis represents a reproductive mode that proceeds without sperm. In broader usage, many sexually reproducing organisms are sperm-dependent to some degree, because fertilization by sperm is necessary for producing viable offspring.

Because the term is descriptive rather than a formal classification, its meaning can vary by context. When encountered in scientific literature, it is important to check how the authors define it and whether they refer to fertilization, activation, or paternal genome contribution.