sexual dimorphism

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dimorphism

 [di-mor´fizm]
the quality of existing in two distinct forms. adj., adj dimor´phic, dimor´phous.
sexual dimorphism physical or behavioral differences associated with sex.
having some properties of both sexes, as in the early embryo and in some hermaphrodites.

sex·u·al di·mor·phism

the somatic differences within species between male and female individuals that arise as a consequence of sexual maturation; inclusive of, but not restricted to, the secondary sexual characteristics.
A physical dichotomy between males and females of a particular species

sex·u·al di·morph·ism

(sek'shū-ăl dī-mōr'fizm)
The somatic differences within species between male and female individuals that arise as a consequence of sexual maturation, including, but not restricted to, the secondary sexual characters.

sexual dimorphism

the presence in a population of two sexes each with a different PHENOTYPE, a classic example of a GENETIC POLYMORPHISM. The underlying mechanism varies in different organisms, but is often controlled by genes on special SEX CHROMOSOMES (see SEX DETERMINATION).

sex·u·al di·morph·ism

(sek'shū-ăl dī-mōr'fizm)
Somatic differences within species between male and female individuals that arise as a consequence of sexual maturation.

dimorphism

the quality of existing in two distinct forms.

sexual dimorphism
1. physical or behavioral differences associated with sex; males and females of the same species are different in appearance.
2. having some properties of both sexes, as in the early embryo and in some hermaphrodites.

sexual

pertaining to sex.

sexual behavior
includes masturbation, courtship, mating, estral display.
sexual cycle
estral cycle.
sexual differentiation
identification of the sex of a patient is done usually by an examination of external genitalia; preparation and examination of a karyotype is the preferred laboratory method.
sexual dimorphism
differences in structure or physical characteristics between males and females of the same species, e.g. horns in some breeds of sheep, feather coat color in many species of birds.
sexual intercourse
see mating.
sexual maturity
capable of mating. Occurs at different ages in different species and in different races and even breeds.
sexual receptivity
behavioral changes in female animals at the time of estrus; involves acceptance of male efforts at copulation and, in some species, actively seeking the male.
sexual rest
circumstances in which no sexual intercourse takes place.
References in periodicals archive ?
We used molecular sexing to identify males and females, and employed reflectance spectrometry to characterize the color properties and degree of sexual dichromatism in the rusty head plumage (Fig.
Because of the fine filamentous structure of the rusty feathers, the measurement with the highest brightness score was taken for each head feather for the analyses of sexual dichromatism.
In contrast to our extensive sampling of size measurements, sexual dichromatism was assessed on a preliminary basis in our study, as it was based on a much smaller sample size of individuals for which no clear assignment of breeding status was made at our study colony.
In turn, the detected higher proportion of black rectrices in females constitutes a methodologically conservative calculation of sexual dichromatism in this plumage trait, as all variegated feathers were scored as 0.
In labroids, Robertson & Hoffman (1977) suggested that epigamic selection plays a much more important role than intra-sexual selection in the development of sexual dichromatism (though not for species possessing strictly haremic mating systems), and reasoned that despite being more costly to maintain than permanent dichromatism, natural selection would favor the development of ephemeral dichromatism in environments where continuous display of conspicuous signals would increase the risk of predation.
Thresher (1984), in his review of the occurrence of sexual dichromatism in coral reef fishes, noted that although conspicuous permanent sexual dichromatism most often coincides with polygamous species, temporary dichromatism is not clearly related to a particular mating system but rather is an intraspecific communication channel to express readiness to mate.
A few cases of putative permanent sexual dichromatism have been reported but consisting in rather minor variations in color or pattern.
1995) first documented sexual dichromatism in spotted sand bass as males with high contrast dark bars over a white background with a white chin, whereas females were overall darker with dark bars over a medium toned green-gray background with a yellow chin.
Plumage colour in nestling blue tits: sexual dichromatism, condition dependence and genetic effects.
Color patterns and associated behaviors of temperate serranines are poorly understood, although brief descriptions of sexual dichromatism have been reported in the genus Paralabrax.
Adult Paralabrax clathratus exhibited a pattern of seasonal sexual dichromatism, where most males collected and observed from May to early October had a conspicuous orange color on the snout region of their heads (Figure 2a, OS phase).
Adult Paralabrax clathratus exhibited seasonal sexual dichromatism during the spawning season.