Hermaphrodite Research Articles

Beyond creation: Galatians 3:28, Genesis and the hermaphrodite myth

Galates 3:28 est une citation de Genese 1:27. Cela a pour consequence que Paul ou l'auteur de la formule baptismale pre-paulinienne concoit que l'ordre de la creation qui differencie et separe l'humanite sur la base du sexe, a ete neglige dans la personne de Jesus-Christ. Ceci ne veut neanmoins pas dire que Paul envisage une reunification de l'humanite selon l'ideal androgyne grec. Cette tension entre creation et re-creation a travers le Christ doit avoir ete integree tardivement dans la tradition en faveur de l'ancien ordre de la creation aux depens des consequences de Galates 3:28

Plant Size and Reproductive Success through Female and Male Function

Size differences among individual plants are usually large, with a few individuals in the population producing most of the pollen and seeds (Weiner & Thomas 1986). In hermaphrodite plants, size may have different effects on the male (siring seeds) and on the female side (setting seeds) of reproduction. Both male and female fitness can be a decelerating, linear or accelerating function of plant size. In the literature on the subject all possibilities have been mentioned, but some views are more prevalent than others. With respect to male fitness, some authors emphasized the accelerating function (e.g. Willson & Rathcke 1974). More recently, this idea was clearly formulated by Broyles & Wyatt (1990), who refer to it as 'the pollen donation hypothesis'. The mechanism is that large plants produce more flowers, which attract more pollinators that, in turn, remove a larger fraction of the pollen. The arguments for the linear (Campbell 1989) or decelerating function (Devlin et al. 1992) will be detailed later. With respect to female fitness, the curve is often considered to be linear (Brunet 1992). However, Lloyd (1984) argued for decelerating fitness with size because of competition among seedlings from the same parent. The shape of the size-fitness relationship is important for sex-allocation theory as it is analogous to the socalled 'gain curve', which describes how fitness changes with resources invested (Charnov 1982). This theory addresses questions about the optimal allocation to male vs. female reproduction in hermaphrodites and the evolution of dioecy from hermaphroditism. The basic problem is how the organism should shift allocation of resources to each sexual function in order to maximize fitness (the sum of paternal and maternal offspring), at one (Charnov 1982) or at several resource levels or sizes (Charnov & Bull 1985). Fitness is maximized if the plant invests in that function that yields the highest returns per unit of investment. In this note we first consider female fitness and discuss how post-establishment success differs for small and large plants. The relation between male fitness and size is affected by flower visitation, pollen removal, export to other plants, the success of siring seeds in competition with other pollen and post-establishment success. We list how these factors may differ for small and large plants. The list should be helpful for understanding gain curves, planning experimental work and avoiding some caveats. Next, we briefly discuss the most likely shapes of the fitness curves in animaland wind-pollinated species and their consequence for optimal allocation to each sexual function.

Imagined more than women: lesbians as hermaphrodites, 1671-1766

Imagined more than women: lesbians as hermaphrodites, 1671-1766

Swinburne, Gautier, and the Louvre Hermaphrodite

Swinburne, Gautier, and the Louvre Hermaphrodite

True and Pseudohermaphroditism: A Decade of Experience in Kuwait

Sixty-nine patients with true and pseudohermaphroditism were ascertained by a multispeciahty team during the period from January 1979 until December 1988 and were categorized into three groups: (1) true hermaphroditism and mixed Gonadal dysgenesis; (2) female pseudohermaphroditism, and (3) male pseudohermaphroditism. This study presents a decade of experience and emphasizes the importance of early diagnosis, particularly in female pseudohermaphroditism.

Snails and snail farming: an introduction for the veterinary profession.

In the past veterinary interest in snails has been confined to their role in the transmission of disease; nowadays the trend to keep these animals in captivity--for food, for study, as 'companion animals'--means that the profession is increasingly likely to be consulted about their health, welfare or conservation. An understanding of the biology of snails is an important prerequisite to work with them. Land snails are hermaphrodite and have a complex reproductive system; other organs also show special adaptations. Management methods vary considerably and farmed snails can be maintained under extensive or intensive conditions. Methods for handling and transporting them are important considerations. There is little published information on the diseases and pathology of snails but suboptimum environment, poisons, nutritional deficiencies, predators and parasites are known to cause, or contribute, to their mortality.

First occurrence of hermaphrodite pike, Esox lucius L., in the Esla basin (Spain)

First occurrence of hermaphrodite pike, <i>Esox lucius</i> L., in the Esla basin (Spain)

Cetorhinicola n. g., Shirleyrhynchus n. g. and Stragulorhynchus n. g., three new genera of trypanorhynch cestodes from elasmobranchs in Australian waters

Three new genera of trypanorhynch cestodes are described from Australian elasmobranchs: Cetorhinicola acanthocapax n. g., n. sp. from Cetorhinus maximus (Gunner, 1765), with four bothridia joined by avelum, a typical heteroacanthous armature with the ends of the hook rows not meeting on the external surface, and enlarged hooks on the base of the tentacle; Shirleyrhynchus butlerae n. g., n. sp., from Dasyatis fluviorum Ogilby, 1908 and D. sephen (Forsskal, 1775), with four bothridia, typical heteroacanthous armature, enlarged basal hooks, testes in linear rows, and lacking seminal vesicles; Stragulorhynchus orectologi n. g., n. sp., from Orectolobus tentaculatus (Peters, 1864) (type-host), O. maculatus (Bonnaterre, 1788) and O. ornatus (de Vis, 1882), with four bothridia, poeciloacanthous armature, with a band of hooklets on the external surface of the tentacle, external seminal vesicle, hermaphroditic duct, accessory seminal vesicle and post-ovarian testes. None of the new genera is readily accommodated by the existing classification of the Trypanorhyncha: the first two genera are tentatively allocated to the Gilquiniidae and the last to the Gymnorhynchidae.

Film the archetype of the hermaphrodite in e. t. and fanny and alexander

Film the archetype of the hermaphrodite in e. t. and fanny and alexander

The Hermaphrodite and the Metamorphosis of Spenserian Allegory

The Hermaphrodite and the Metamorphosis of Spenserian Allegory

Michelangelo's ignudi, hermaphrodism, and creativity.

Michelangelo's ignudi, hermaphrodism, and creativity.

THE EFFECT OF LOW DENSITY ON THE DEVELOPMENT OF SIMULTANEOUS HERMAPHRODITISM IN MALECAPITELLASPECIES I (POLYCHAETA)

ABSTit@crr In this study it was shown that male Capitella species I may develop into si multaneous hermaphrodites ifreared in isolation or at low densities in the laboratory. Since hermaphroditic development is rare in high density non-inbred cultures but becomes frequent in inbred lines which have been selected for high male sex ratios, the ability to become hermaphroditic seems to have a genetic basis. It is also suggested that low density may trigger the hermaphroditic development of males through the absence of animals with female gonads. Excess food resources which could be assim ilated at low density and may be directed into the development of a second set of reproductive structures and female gametes, could also be a factor in the male-to hermaphrodite switch. Capitella sp. I has an opportunistic lifestyle which could ac commodate such a sexual adaption. The larvae are widely dispersed which would often cause adults to be at low density where the advantage of being hermaphroditic is well known. IrsrrRoDUcrION Much ofthe scientific interest in the genus Capitella stems from its “?�opportunistic” life history (Grassle and Grassle, 1974) which has made it an important indicator of environmental disturbance in the benthos (Henrikkson, 1969;Pearson and Rosenberg, 1978; Sanders et a!., 1980). Formerly known as Capitella capitata, electrophoresis has shown it to be a complex of at least ten sibling species (Grassle and Grassle, 1976, 1977; Grassle, 1980). The different species are morphologically similar but differ in life histories and reproductive strategies. The most opportunistic species, which is distinguished by larvae which remain in the planktonic stage for several hours, is Capitella species I. This species is the main one under consideration here. Males, females, and hermaphrodites are found in natural populations or Capitella sp. I. Hermaphrodites are found only infrequently, appearing when mature males develop female gonads. Families raised in the laboratory from individual eggcases have extremely variable sex ratios and successful selection can be made for inbred lines with a high proportion of males and females (Grassle, 1980). Both facts suggest that there may be a polygenic sex determining mechanism (Kossig, 1964). If selection is made for a highly male sex ratio, the proportion of hermaphrodites that develop will also increase. The discovery that motivated this research was that young non inbred males of species I and II developed female gonads, thus becoming hermaph rodites, if reared in isolation. Previously, hermaphrodites were observed to develop in old, high density, non-inbred laboratory cultures only. Hermaphrodites are never

Horses and Hermaphrodites: Metamorphoses in The Taming of the Shrew

Le mythe hermaphrodite de la reconciliation et les metaphores du bestiaire et de la metamorphose dans la comedie de Shakespeare.

Sex and Parthenogenesis in Sparse Populations

A model is developed to predict the minimum population density required (critical density) for successful sexual reproduction in animals. The model predicts that: (1) Hermaphroditic reproduction requires only half the critical density of bisexual reproduction; (2) a linear increase in mortality results in an exponential increase in critical density; and (3) increasing the time interval between clutches reduces critical density but makes a population more sensitive to external mortality. The probability of encountering a mate is dependent on the distance at which a male can detect a female. If predators can also detect females, there is an optimum conspicuousness for a female, which is dependent on the densities of males and of predators. A female should be very conspicuous only when both predators and males are rare. In an application of the model to zooplankton species, the smallest zooplankters are predicted to require relatively high densities for sexual reproduction. These animals reproduce with cycli...

The nonexistence of “hermaphroditic” tracer systems

The nonexistence of “hermaphroditic” tracer systems

A new genus of hermaphroditic freshwater heteronemertean (Nemertinea)

Diagnosis of Apatronemertes nov. gen. Hermaphroditic freshwater lineid heteronemerteans with no eyes, frontal organ or caudal cirrus; outer longitudinal muscle layer mingled with dermal zone, but loosely developed into outer and inner layers separated by dermis; body-wall with outer longitudinal muscle layer externally bounded by thin outer circular muscle zone which extends precerebrally; cephalic glands well developed, ventrally extending beneath the brain; proboscis with outer circular and inner longitudinal muscle layers and two fibre crosses, one more obvious than the other; rhynchocoel three-quarters of body length and rhynchocoel musculature not interwoven with body wall muscles; dorsal cerebral ganglia with posterior fibrous bifurcation, the cerebral organs being attached to the more ventral branch; nervous system without neurochords; excretory system a complex arrangement of ducts and cells, discharching into the gut via specialised cells; blood system extensive, with a postcerebral vascular plexus intimately associated with the excretory system.

Hermaphroditism in Bucephalus-infected oysters

Hermaphroditism in Bucephalus-infected oysters

Hermaphrodisme tubulaire chez un bovin

Hermaphrodisme tubulaire chez un bovin

The Fair Hermaphrodite: Love-Union in the Poetry of Donne and Spenser

The Fair Hermaphrodite: Love-Union in the Poetry of Donne and Spenser

A case of a hermaphroditism in a pig

A case of a hermaphroditism in a pig