A spermatophore or sperm ampulla is a capsule or mass created by males of various animal species, containing spermatozoa and transferred in entirety to the female's ovipore during copulation. It may contain nourishment for the female, in which case it is called a nuptial gift, although in many species the "gift" provides little nutrient value (one group in which it usually is nutritious are the bush crickets). The alternative hypothesis of its usefulness is that the process of eating the spermatophore prevents the female from subsequent copulation, thereby giving the male's sperm more time to fertilize.
Spermatophores are the norm in arachnids. In various insects, such as bush crickets, the spermatophore is often surrounded by a proteonaceous spermatophylax. The function of the spermatophylax is to cause the female to relinquish some of her control over the insemination process allowing full sperm transfer from the spermatophore.
Some vertebrates also reproduce via spermatophores. Males of many salamander and newt species create spermatophores, which the females may choose to take up or not, depending on the success of the male's mating display.
- Nina Wedell, Tom Tregenza & Leigh W. Simmons (2008), "Nuptial gifts fail to resolve a sexual conflict in an insect", BMC Evolutionary Biology 8: 204, doi:10.1186/1471-2148-8-204, PMC 2491630, PMID 18627603
- Peter D. Sozou & Robert M. Seymour (2005), "Costly but worthless gifts facilitate courtship", Proceedings of the Royal Society B 272 (1575): 1877–1884, doi:10.1098/rspb.2005.3152, PMC 1559891, PMID 16191592
- K. Vahed (1998), "The function of nuptial feeding in insects: review of empirical studies" (PDF), Biological Reviews 73: 43–78, doi:10.1017/S0006323197005112