In
zoology
Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the animal kingdom, including the structure, embryology, evolution, classification, habits, an ...
, copulation is
animal sexual behavior in which a male introduces
sperm into the female's body, especially directly into her reproductive tract.
This is an aspect of
mating. Many animals that live in water use
external fertilization, whereas
internal fertilization may have developed from a need to maintain
gametes in a liquid medium in the
Late Ordovician epoch. Internal fertilization with many vertebrates (such as all
reptiles, some
fish
Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. Included in this definition are the living hagfish, lampreys, and Chondrichthyes, cartilaginous and bony fish as we ...
, and most
birds) occurs via
cloacal copulation, known as cloacal kiss (see also
hemipenis), while
mammals copulate
vaginally, and many
basal vertebrates reproduce sexually with external fertilization.
In spiders and insects
Spiders are often confused with
insects, but they are not insects; instead, they are
arachnids.
Spiders have separate male and female sexes. Before mating and copulation, the male spider spins a small web and ejaculates on to it. He then stores the sperm in reservoirs on his large
pedipalps, from which he transfers sperm to the female's genitals. The females can
store sperm indefinitely.
For primitive insects, the male deposits
spermatozoa on the substrate, sometimes stored within a special structure;
courtship
Courtship is the period wherein some couples get to know each other prior to a possible marriage. Courtship traditionally may begin after a betrothal and may conclude with the celebration of marriage. A courtship may be an informal and private m ...
involves inducing the female to take up the sperm package into her genital opening, but there is no actual copulation.
In groups that have reproduction similar to spiders, such as
dragonflies, males extrude sperm into secondary copulatory structures removed from their genital opening, which are then used to inseminate the female. In dragonflies, it is a set of modified
sternites on the second abdominal segment.
In advanced groups of insects, the male uses its
aedeagus, a structure formed from the terminal segments of the abdomen, to deposit sperm directly (though sometimes in a capsule called a ''
spermatophore
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. Spermatophore ...
'') into the female's reproductive tract.
In mammals
Sexual behavior can be classified into behavioral states associated with
reward motivation ("
wanting"), reward consummation aka pleasure ("liking"), and
satiety ("inhibition");
these behavioral states are regulated in mammals by reward-based sexual learning, fluctuations in various neurochemicals (i.e.,
dopamine −
sexual desire aka "wanting";
norepinephrine −
sexual arousal;
oxytocin and
melanocortins −
sexual attraction), and gonadal hormone cycles and further influenced by
sex pheromones and
motor reflexes (i.e.,
lordosis behaviour) in some mammals.
These behavioral states correlate with the phases of the
human sexual response cycle: motivation − excitement; consummation − plateau and orgasm; satiety − refraction.
Sexual learning (a form of
associative learning) occurs when an animal starts to associate bodily features, personality, contextual cues, and other stimuli with genitally-induced sexual pleasure.
Once formed, these associations in turn impinge upon both sexual wanting and sexual liking.
In most female mammals, the act of copulation is controlled by several innate neurobiological processes, including the motor sexual reflex of
lordosis.
[PFAFF Donald W. , SCHWARTZ-GIBLIN Susan, MACCARTHY Margareth M. , KOW Lee-Ming : Cellular and molecular mechanisms of female reproductive behaviors, in KNOBIL Ernest, NEILL Jimmy D. : The physiology of reproduction, Raven Press, 2nd edition, 1994] In males, the act of copulation is more complex, because some learning is necessary, but the innate processes (retrocontrol of penis intromission in the vagina, rhythmic movement of the pelvis, detection of female pheromones) are specific to copulation. These innate processes direct heterosexual copulation.
[MEISEL Robert L. , SACHS Benjamin D. : The physiology of male sexual behavior. in KNOBIL Ernest, NEILL Jimmy D. The physiology of reproduction, Raven Press, 2nd edition, 1994] Female lordosis behaviour became secondary in
hominidae and is non-functional in humans.
[Dixson A.F]
Primate sexuality: Comparative studies of the Prosimians, Monkeys, Apes, and Human Beings
Oxford University Press, 2nd edition, 2012. Mammals usually copulate in a dorso-ventral posture, though there are some primate species that copulate in a ventro-vental posture.
Most mammals possess a
vomeronasal organ
The vomeronasal organ (VNO), or Jacobson's organ, is the paired auxiliary olfactory (smell) sense organ located in the soft tissue of the nasal septum, in the nasal cavity just above the roof of the mouth (the hard palate) in various tetrapo ...
that is involved in pheromone detection, including
sex pheromones.
Despite the fact that humans do not possess this organ, adult humans appear to be sensitive to certain mammalian pheromones that putative
pheromone receptor proteins in the
olfactory epithelium are capable of detecting.
While sex pheromones clearly play a role in modifying sexual behavior in some mammals, the capacity for general pheromone detection and the involvement of pheromones in regulating human sexual behavior has not yet been determined.
The duration of copulation varies significantly between mammal species, and may be correlated with body mass, lasting longer in small mammals than in large mammals.
[Stallmann, Robert R., and A. H. Harcourt.]
Size matters: the (negative) allometry of copulatory duration in mammals
" Biological Journal of the Linnean Society 87.2 (2006): 185-193.
See also
*
Pelvic thrust
Notes
References
Bibliography
*
* Møller, A. P., and T. R. Birkhead.
Copulation behaviour in mammals: evidence that sperm competition is widespread" Biological Journal of the Linnean Society 38.2 (1989): 119–131.
* Birkhead, Timothy R., L. Atkin, and A. P. Møller.
Copulation behaviour of birds" Behaviour 101.1 (1987): 101–138.
*
*
*
*
*
*Carlson, Debra A
Reproductive biology of the coyote (Canis latrans): integration of behavior and physiology Utah State University, 2008.
*Castro, Ana Mafalda Lopes Sardica Velez
Mexican gray wolf courtship and mating: behavior & basic endocrinology during breeding season Diss. Universidade de Lisboa. Faculdade de Medicina Veterinária, 2016.
* Szykman, Micaela, et al.
Courtship and mating in free-living spotted hyenas. Behaviour 144.7 (2007): 815–846.
* Dixson, Alan F.
Baculum length and copulatory behavior in primates. American Journal of Primatology 13.1 (1987): 51–60.
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