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Pseudo-penis
A pseudo-penis is any structure found on an animal that, while superficially appearing to be a penis, is derived from a different developmental path. Mammals In mammals, all intact developmentally typical males have a penis, but the clitoris in the females of the following species is sufficiently enlarged that it is usually termed a pseudo-penis: spotted hyena, juvenile fossa, binturong, lemur ; ; . and spider monkey. The enlarged clitoris in the fossa is supported by an os clitoridis, a bone similar to the os penis found in most mammals. However, the fossa's os clitoridis and pseudo-penis shrink as the juvenile female grows, unlike that of other pseudo-penis species. The mammalian pseudo-penis appears to be simply for display, though the spotted hyena is an exception: the female spotted hyena additionally uses her pseudo-penis for urination, sexual intercourse, and to give birth. In addition, this makes it difficult for males to mate without the full co-operation of females, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clitoromegaly
Clitoromegaly (or macroclitoris) is an abnormal enlargement of the clitoris that is mostly congenital or acquired, though deliberately induced clitoris enlargement as a form of genital body modification is achieved through various uses of anabolic steroids, including testosterone. Clitoromegaly is not the same as normal enlargement of the clitoris seen during sexual arousal. Presentation The different grade of genital ambiguity is commonly measured by the Prader classification, which ranges, in ascending order of masculinisation, from 1: ''female external genitalia with clitoromegaly'' through 5: ''pseudo-phallus looking like normal male external genitalia''. Causes Clitoromegaly is a rare condition and can be either present by birth or acquired later in life. If present at birth, congenital adrenal hyperplasia can be one of the causes, since in this condition the adrenal gland of the female fetus produces additional androgens and the newborn baby has ambiguous genitalia whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Mimicry
Sexual mimicry occurs when one sex mimics the opposite sex in its behavior, appearance, or chemical signalling. It is more commonly seen within invertebrate species, although sexual mimicry is also seen among vertebrates such as spotted hyenas. Sexual mimicry is commonly used as a mating strategy to gain access to a mate, a defense mechanism to avoid more dominant individuals, or a survival strategy. It can also be a physical characteristic that establishes an individual's place in society. Sexual mimicry is employed differently across species and it is part of their strategy for survival and reproduction. Examples of sexual mimicry in animals include the spotted hyena, certain types of fish, passerine birds and some species of insect among others. These are cases of intraspecific sexual mimicry, but interspecific sexual mimicry can also occur in some plant species, especially orchids. In plants employing sexual mimicry, flowers mimic mating signals of their pollinator insects. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spider Monkey
Spider monkeys are New World monkeys belonging to the genus ''Ateles'', part of the subfamily Atelinae, family Atelidae. Like other atelines, they are found in tropical forests of Central and South America, from southern Mexico to Brazil. The genus consistes of seven species, all of which are under threat; the brown spider monkey is critically endangered. They are also notable for their ability to be easily bred in captivity. Disproportionately long limbs and long prehensile tails make them one of the largest New World monkeys and give rise to their common name. Spider monkeys live in the upper layers of the rainforest, and forage in the high canopy, from . They primarily eat fruits, but will also occasionally consume leaves, flowers, and insects. Due to their large size, spider monkeys require large tracts of moist evergreen forests, and prefer undisturbed primary rainforest. They are social animals and live in bands of up to 35 individuals, but will split up to forage durin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Penis
A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males do not bear a penis in every animal species, and in those species in which the male does bear a so-called penis, the penises in the various species are not necessarily homologous. The term ''penis'' applies to many intromittent organs, but not to all. As an example, the intromittent organ of most cephalopoda is the hectocotylus, a specialized arm, and male spiders use their pedipalps. Even within the Vertebrata there are morphological variants with specific terminology, such as hemipenes. In most species of animals in which there is an organ that might reasonably be described as a penis, it has no major function other than intromission, or at least conveying the sperm to the female, but in the placental mammals the penis bears the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red-billed Buffalo Weaver
The red-billed buffalo weaver (''Bubalornis niger'') is a species of bird in the family Ploceidae. It is found in eastern and southern Africa. Its natural habitat is the dry savanna. Description The body length of full grown red-billed buffalo weavers is and body mass averages in males and in females. This may the largest of the Ploceidae (weaver birds). Visually the sexes are not greatly differentiated from one another. The red-billed buffalo weaver is differentiated from the white-billed buffalo weaver (''Bubalornis albirostris'') by the color of its bill. The feathers of the male are dark chocolate brown in color. The front wing edges and the wing tips are flecked with white. His bill is a shade of red. The eyes are brown and the feet are reddish brown. The female's body is also colored dark chocolate brown, without the white flecks on the wings. However, her chin and throat feathers include broad white colored hems. Her eyes are dark brown and her legs lig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudohermaphroditism
Pseudohermaphroditism is a condition in which an individual has a matching chromosomal and gonadal tissue (ovary or testis) sex, but mismatching external genitalia. Female pseudohermaphroditism refers to an individual with ovaries and external genitalia resembling those of a male. Male pseudohermaphroditism refers to an individual with testes and external genitalia resembling those of a female. In some cases, external sex organs associated with pseudohermaphroditism appear intermediate between a typical clitoris and penis. Thus, pseudohermaphroditism is sometimes not identified until puberty or adulthood. The term contrasts with true hermaphroditism, a condition describing an individual with both female and male reproductive organs. Associated conditions include 5-α-reductase deficiency and androgen insensitivity syndrome. Mechanism Sex is determined by chromosomes during fertilization. In the early stages of human development, a human embryo has the precursors of female ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Androgen
An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This includes the embryological development of the primary male sex organs, and the development of male secondary sex characteristics at puberty. Androgens are synthesized in the testes, the ovaries, and the adrenal glands. Androgens increase in both males and females during puberty. The major androgen in males is testosterone. Dihydrotestosterone (DHT) and androstenedione are of equal importance in male development. DHT ''in utero'' causes differentiation of the penis, scrotum and prostate. In adulthood, DHT contributes to balding, prostate growth, and sebaceous gland activity. Although androgens are commonly thought of only as male sex hormones, females also have them, but at lower levels: they function in libido and sexual arousal. Al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testosterone
Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristics such as increased muscle and bone mass, and the growth of body hair. In addition, testosterone in both sexes is involved in health and well-being, including moods, behaviour, and in the prevention of osteoporosis. Insufficient levels of testosterone in men may lead to abnormalities including frailty and bone loss. Testosterone is a steroid from the androstane class containing a ketone and a hydroxyl group at positions three and seventeen respectively. It is biosynthesized in several steps from cholesterol and is converted in the liver to inactive metabolites. It exerts its action through binding to and activation of the androgen receptor. In humans and most other vertebrates, testosterone is secreted primarily by the testicles of m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Androstenedione
Androstenedione, or 4-androstenedione (abbreviated as A4 or Δ4-dione), also known as androst-4-ene-3,17-dione, is an endogenous weak androgen steroid hormone and intermediate in the biosynthesis of estrone and of testosterone from dehydroepiandrosterone (DHEA). It is closely related to androstenediol (androst-5-ene-3β,17β-diol). Biological function Androstenedione is a precursor of testosterone and other androgens, as well as of estrogens like estrone, in the body. In addition to functioning as an endogenous prohormone, androstenedione also has weak androgenic activity in its own right. Androstenedione has been found to possess some estrogenic activity, similarly to other DHEA metabolites. However, in contrast to androstenediol, its affinity for the estrogen receptors is very low, with less than 0.01% of the affinity of estradiol for both the ERα and ERβ. Adrenarche In children aged 6 to 8 years old, there is a rise in androstenedione secretion along with DH ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gynosome
''Neotrogla'' is a genus of barklice noted for its reversed sex roles and organs, traits shared by all species of the genus. Habitat ''Neotrogla'' are found in dry cave systems throughout Brazil. They feed primarily on bat guano. Description ''Neotrogla'' are about the size of fleas. The genus can be distinguished from other genera of Speleketorinae by the presence of articulated spines on the anterior side of their legs, and by their unique genitalia. Both sexes have hairs on their tarsus, but the hairs on females are markedly longer. ''Neotrogla'' have branched hindwings and brown forewings. Sexual reversal Female ''Neotrogla'' possess a penis-like organ, properly termed a "gynosome", but interchangeably called a penis. They aggressively seek out mates, while males are more selective. During mating, the female mounts the male and penetrates his small genital opening from behind. Her gynosome swells and tiny barbs on the organ lock the individuals tightly together; when a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neotrogla
''Neotrogla'' is a genus of barklice noted for its reversed sex roles and organs, traits shared by all species of the genus. Habitat ''Neotrogla'' are found in dry cave systems throughout Brazil. They feed primarily on bat guano. Description ''Neotrogla'' are about the size of fleas. The genus can be distinguished from other genera of Speleketorinae by the presence of articulated spines on the anterior side of their legs, and by their unique genitalia. Both sexes have hairs on their tarsus, but the hairs on females are markedly longer. ''Neotrogla'' have branched hindwings and brown forewings. Sexual reversal Female ''Neotrogla'' possess a penis-like organ, properly termed a "gynosome", but interchangeably called a penis. They aggressively seek out mates, while males are more selective. During mating, the female mounts the male and penetrates his small genital opening from behind. Her gynosome swells and tiny barbs on the organ lock the individuals tightly together; when a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barklouse
Psocoptera are a paraphyletic group of insects that are commonly known as booklice, barklice or barkflies. The name Psocoptera has been replaced with Psocodea in recent literature, with the inclusion of the former order Phthiraptera into Psocodea (as part of the suborder Troctomorpha). These insects first appeared in the Permian period, 295–248 million years ago. They are often regarded as the most primitive of the hemipteroids. Their name originates from the Greek word ψῶχος, ''psokhos'' meaning gnawed or rubbed and πτερά, ''ptera'' meaning wings. There are more than 5,500 species in 41 families in three suborders. Many of these species have only been described in recent years. They range in size from 1–10 millimetres (0.04–0.4 in) in length. The species known as booklice received their common name because they are commonly found amongst old books—they feed upon the paste used in binding. The barklice are found on trees, feeding on algae and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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