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 ?
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.
Goodwin (1960) reviewed the subject of sexual dichromatism in columbiforms and noted that species graded from color monomorphism between the sexes (as in P.
A few studies have examined sexual dichromatism in birds within the context of a phylogeny.
In this study, I first examine the pattern of evolution of sexual dichromatism within tanagers using the phylogeny of the group.
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).
Similar differences in species richness have previously been associated with sexual dichromatism (Barraclough et al.
Similarly, nest predation has been argued to constrain male brightness and sexual dichromatism based on observations that dichromatism is reduced for ground-nesting birds compared to off-ground nesters and an assumption that nest predation is greater for ground-nesting birds (Shutler and Weatherhead 1990, Johnson 1991).
Information on sexual dichromatism, mating system, and body mass is provided in the Appendix.
Comparative studies of polygynous birds controlling for the effects of phylogeny have described relatively weak associations between sexual dichromatism and male mating success (Hoglund 1989; Oakes 1992).