Spermatophore

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Spermatophores of a mole salamander

A spermatophore or sperm ampulla is a capsule or mass containing spermatozoa created by males of various animal species, especially salamanders and arthropods, and transferred in entirety to the female's ovipore during reproduction. Spermatophores may additionally contain nourishment for the female, in which case it is called a nuptial gift, as in the instance of bush crickets.[1][2] In the case of the toxic moth Utetheisa ornatrix, the spermatophore includes sperm, nutrients, and pyrrolizidine alkaloids which prevent predation because it is poisonous to most organisms.[3] However, in some species such as the Edith's checkerspot butterfly, the "gift" provides little nutrient value. The weight of the spermatophore transferred at mating has little effect on female reproductive output.[4]

Giant squid spermatophores

Arthropods[edit]

Spermatophores are the norm in arachnids and several soil arthropods. In various insects, such as bush crickets, the spermatophore is often surrounded by a proteinaceous 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.[5] Some species of butterflies and moths also deposit a spermatophore into the female during copulation. Examples include the speckled wood butterfly[6] or the ornate moth, where males invest up to 10% of their body mass in creating a single spermatophore.[7] Malaysian stalk-eyed flies also deposit a spermatophore into the female during copulation, but the spermatophore is very small in size and occupies only part of the female's vaginal capacity. This is likely an adaptation to the tendency towards high mating frequency in this species.[8] These butterfly species have been known to use mud-puddling behavior, as demonstrated by Dryas iulia, to obtain the minerals needed in spermatophore production.[9]

Cephalopods[edit]

Most cephalopods use a specialized arm called the hectocotylus to deliver spermatophores to the female. The spermatophores of the giant Pacific octopus are about a meter (or yard) long.[10] A complex hydraulic mechanism releases the sperm from the spermatophore, and it is stored internally by the female.[11] In some cephalopods, like the argonaut octopus, the arm is detachable and capable of autonomous movement and prolonged survival inside the female, to the point that it was mistaken for a parasitic worm by George Cuvier, who gave the hectocotylus (Latin: "hundred" "hollow thing") its name. In some cases, spermatophores from multiple males might be present inside the same female simultaneously.[12]

Salamanders and newts[edit]

Males of most 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.[13]

See also[edit]

References[edit]

  1. ^ 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
  2. ^ 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
  3. ^ Gonzalez, A.; Rossini, C.; Eisner, M.; Eisner, T. (1999). "Sexually transmitted chemical defense in a moth (Utetheisa ornatrix)". Proceedings of the National Academy of Sciences USA. 96 (10): 5570–5574. Bibcode:1999PNAS...96.5570G. doi:10.1073/pnas.96.10.5570. PMC 21901. PMID 10318925.
  4. ^ Jones; Odendaal, Ehrlich (January 1986). "Evidence against the spermatophore as paternal investment in checkerspot butterflies (Euphydras: Nymphalidae)". American Midland Naturalist. 116 (1): 1–6. doi:10.2307/2425932. JSTOR 2425932.
  5. ^ K. Vahed (1998), "The function of nuptial feeding in insects: review of empirical studies" (PDF), Biological Reviews, 73: 43–78, doi:10.1111/j.1469-185X.1997.tb00025.x, S2CID 86644963, archived from the original (PDF) on 2012-03-11
  6. ^ Svärd, L. (1985). "Paternal investment in a monandrous butterfly, Pararge aegeria". Oikos. 45 (1): 66–70. doi:10.2307/3565223. JSTOR 3565223.
  7. ^ Iyengar, Vikram K.; Thomas Eisner (1999). "Female choice increases offspring fitness in an arctiid moth (Utetheisa ornatrix)". Proceedings of the National Academy of Sciences USA. 96 (26): 15013–15016. Bibcode:1999PNAS...9615013I. doi:10.1073/pnas.96.26.15013. PMC 24764. PMID 10611329.
  8. ^ Kotrba, Marion (1996-07-01). "Sperm transfer by spermatophore in Diptera: new results from the Diopsidae". Zoological Journal of the Linnean Society. 117 (3): 305–323. doi:10.1111/j.1096-3642.1996.tb02192.x. ISSN 0024-4082.
  9. ^ Beck, Jan; Mühlenberg, Eva; Fiedler, Konrad (1999-04-01). "Mud-puddling behavior in tropical butterflies: in search of proteins or minerals?". Oecologia. 119 (1): 140–148. Bibcode:1999Oecol.119..140B. doi:10.1007/s004420050770. ISSN 0029-8549. PMID 28308154. S2CID 20103546.
  10. ^ Carefoot, Thomas. "Octopuses and Relatives: Reproduction". A Snail's Odyssey. Archived from the original on 22 April 2017. Retrieved 11 April 2017.
  11. ^ Ruppert, Edward E.; Fox, Richard S.; Barnes, Robert D. (2008). Invertebrate Zoology. Cengage Learning. pp. 363–364. ISBN 978-81-315-0104-7.
  12. ^ Marah J. Hardt, Sex in the Sea: Our Intimate Connection with Sex-Changing Fish, Romantic Lobsters, Kinky Squid, and Other Salty Erotica of the Deep
  13. ^ Wells, Kentwood D. (2007). "The Natural History of Amphibian Reproduction". The Ecology & Behavior of Amphibians. Chicago: University of Chicago Press. pp. 451–515. ISBN 9780226893334.