Sexual Maturity Of Females Research Articles

Eye Tracking of Men’s Preferences for Female Breast Size and Areola Pigmentation

Sexual selection via male mate choice has often been implicated in the evolution of permanently enlarged breasts in women. While questionnaire studies have shown that men find female breasts visually attractive, there is very little information about how they make such visual judgments. In this study, we used eye-tracking technology to test two hypotheses: (1) that larger breasts should receive the greatest number of visual fixations and longest dwell times, as well as being rated as most attractive; (2) that lightly pigmented areolae, indicative of youth and nubility, should receive most visual attention and be rated as most attractive. Results showed that men rated images with medium-sized or large breasts as significantly more attractive than small breasts. Images with dark and medium areolar pigmentation were rated as more attractive than images with light areolae. However, variations in breast size had no significant effect on eye-tracking measures (initial visual fixations, number of fixations, and dwell times). The majority of initial fixations during eye-tracking tests were on the areolae. However, areolar pigmentation did not affect measures of visual attention. While these results demonstrate that cues indicative of female sexual maturity (large breasts and dark areolae) are more attractive to men, patterns of eye movements did not differ based on breast size or areolar pigmentation. We conclude that areolar pigmentation, as well as breast size, plays a significant role in men's judgments of female attractiveness. However, fine-grained measures of men's visual attention to these morphological traits do not correlate, in a simplistic way, with their attractiveness judgments.

Clinical spectrum of Bardet–Biedl syndrome among four Saudi Arabian families

Bardet-Biedl syndrome is an autosomal recessive disorder characterized by rod-cone dystrophy, postaxial polydactyly, obesity, hypogenitalism, mental retardation, and renal dysfunction. It has both interfamilial and intrafamilial clinical variation. We have studied the clinical spectrum of 11 Saudi Arabian patients from four consanguineous families. Postaxial polydactyly was seen in eight individuals and rod-cone dystrophy in almost all patients. Night blindness and diminished visual acuity manifested at varying ages, beginning as early as 36 months. Obesity was found to be common. Renal anomalies were detected in eight patients (72%) and two of them developed end-stage renal failure at 14 and 15 years of age. We also found an increased prevalence of Hirschsprung's disease among these patients. Hypogenitalism was manifested as micropenis in males and delayed sexual maturation in females. Heart defects were uncommon in our series. In contrast, there was increased susceptibility to develop diabetes mellitus and two of our patients developed diabetes at 15 and 22 years of age.

Sexual seasonal growth variation and reproduction biology of the rock pool prawn, <em>Palaemon elegans</em> (Decapoda: Palaemonidae) in the southern Black Sea

The seasonal growth pattern and reproductive biology of the rock pool prawn, Palaemon elegans , were studied in the southern Black Sea between February 2002 and January 2004. The seasonal von Bertalanffy growth parameters, computed from monthly length frequency distributions, were estimated as L ∞ = 47.8 mm total length (TL), K = 1. 115 year -1 for females and as L ∞ = 41.1 mm TL, K = 1.654 year -1 for males. The seasonal oscillation in growth rate for females (C = 0.904) was larger than it was for males (C = 0.586). The slowest period of growth corresponded to June in females and February in males. The size at sexual maturity for females (TL 50 ) was estimated as 33.8 mm TL. Ovigerous females were recorded from March to August and juveniles appeared in the benthic population in August. The ovarian development of the rock pool prawn was most probably initiated by photoperiod, whereas embryo development was accelerated with increasing water temperatures.

Enhancing mating performance after juvenile hormone treatment in Anastrepha fraterculus: a differential response in males and females acts as a physiological sexing system

AbstractMethoprene (a mimic of juvenile hormone) treatment can reduce the time required for sexual maturation in Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) males under laboratory conditions, supporting its use as a treatment for sterile males within the context of the sterile insect technique (SIT). We evaluated sexual behaviour, mating competitiveness of methoprene‐treated males, and female readiness to mate after methoprene‐treatment in field cages. The study involved two strains of A. fraterculus from Argentina and Peru, which show several polymorphisms in relation to their sexual behaviour. We also analyzed whether methoprene treatment affected male and/or female behaviour in the same way in these two strains. Methoprene‐treated males were equally competitive with untreated mature males, and became sexually competitive 6 days after emergence (3–4 days earlier than untreated males). In contrast, methoprene did not induce sexual maturation in females or, at least, it did not induce a higher rate of mating in 7‐day‐old females. These results were observed both for the Argentina and the Peru strains. Altogether, our results indicate that methoprene treatment produces sexually competitive males in field cages. In the absence of a genetic sexing system, and when sterile males and females of A. fraterculus are released simultaneously, the fact that females do not respond as do males to the methoprene treatment acts as a physiological sexing effect. Therefore, in the presence of mainly sexually immature sterile females, released sexually mature sterile males would have to disperse in search of wild fertile females, thereby greatly reducing matings among the released sterile insects and thus enhancing sterile insect technique efficiency.

민들조개 (Gomphina melanaegis) 생식주기에 관한 조직.생화학적 연구

The seasonal reproductive cycle of Gomphina melanaegis collected in the coastal area of Jumunjin, between April 2006 and March 2007, was analyzed. Maturation cycle parameters such as the gonad index (GI), ovarian egg diameter, frequency of developmental stages, protein content, and RNA/DNA variation in the gonads were analyzed monthly for the 40 samples. According to the indices from histological sections, the frequency of gonad developmental stages, and the oocyte diameter, this clam has a long-term partial spawning pattern from March to October. However, GI and nucleic acid values showed that the mature stage is from March to July and that the main spawning season is August. The peak RNA and DNA contents were good indicators of sexual maturation in females and males, respectively. The variation in protein content corresponded with the RNA/DNA ratios.

Preputialectomised and intact adult male mice exhibit an elevated urinary ratio of oestradiol to creatinine in the presence of developing females, whilst promoting uterine and ovarian growth of these females

Exposure to novel adult males and their urine can hasten the onset of sexual maturity in female mice. Some evidence implicates chemosignals from males' preputial glands, while other evidence suggests that male urinary steroids, especially 17beta-oestradiol, contribute to this effect. The present experiment was designed to determine whether preputial gland removal would influence the capacity of males to accelerate female sexual development, and to measure male urinary oestradiol and testosterone in the presence or absence of these glands. Juvenile females aged 28 days were housed for two weeks in isolation or underneath two outbred males that had undergone preputialectomy or sham surgery. Urine samples were collected non-invasively from males that were isolated or exposed to females, then assayed for oestradiol, testosterone and creatinine. Combined uterine and ovarian mass from females sacrificed at 43 days of age was increased by exposure to males, regardless of whether or not these males had been preputialectomised. Male urinary creatinine was reduced by exposure to developing females. Creatinine-adjusted oestradiol and testosterone were significantly greater in female-exposed than in isolated males, in both preputialectomised and intact males. These data suggest that the preputials are not necessary for the capacity of males to hasten female uterine and ovarian growth. As exogenous oestrogens can promote uterine growth and other parameters of female reproductive maturation, oestradiol in males' urine may contribute to earlier sexual maturity in male-exposed females.

Seasonal growth and reproduction biology of the Baltic prawn, Palaemon adspersus (Decapoda: Palaemonidae), in the southern Black Sea

Seasonal growth pattern and reproductive biology of the Baltic prawn, Palaemon adspersus, were studied in the southern Black Sea between February 2002 and January 2004. The seasonal von Bertalanffy growth parameters, computed from monthly length–frequency distributions, were estimated as L∞ = 62.99 mm TL, K = 1.190 year−1, C = 0.815, and WP = 0.847 for females and as L∞ = 49.63 mm TL, K = 1.085 year−1, C = 0.011, and WP = 0.407 for males. Growth performance index of females (Φ′ = 3.67) was greater than it was for males (Φ′ = 3.43). Based on latitudinal gradients, water temperature negatively affected Φ′ of P. adspersus. Sexual dimorphism in size was evident, females being larger than males. This typically shallow water species was observed in water depths as deep as 30 m. Compared to shallower water depths, larger individuals were observed in deeper water depths. The size at sexual maturity for females (TL50) was estimated as 53.60 mm TL. Ovigerous females were recorded from March to August and juveniles appeared in the benthic population in August. Ovary development was related to photoperiod and occurrence of ovigerous females was linked to increased water temperature.

New data on the reproductive biology of the common guitarfish of the Gulf of Gabès (southern Tunisia, central Mediterranean)

The common guitarfish Rhinobatos rhinobatos is abundanly captured along the coast of the Gulf of Gabès (southern Tunisia). The sizes at the first sexual maturity of females and males are 790 and 700 mm total length (TL) respectively. Females are larger than males; the maximum TL for males and females is 1000 and 1200 mm respectively. The smallest gravid female observed is 750 mm TL. Rhinobatos rhinobatos is an aplacental viviparous species. The two ovaries and the two uteri are functional. Mature oocytes and foetuses are symmetrically distributed respectively in ovaries and uteri. Vitellogenesis and gestation occur simultaneously. Gestation lasts 10 to 12 months; parturition occurs from the end of summer to the beginning of autumn. Mating and ovulation take place after parturition. Ovarian fecundity is higher than uterine fecundity; means of 8.95 and 5.34 young per year are respectively calculated. There is a positive relationship between the two categories of fecundity and size of females. The size at birth ranges from 250 to 290 mm TL. The common guitarfish is purely a lecithotrophic species. The chemical balance of development is estimated at 1.02.

Spatial and temporal variation in a suite of life‐history traits in two species of wolf spider

Abstract 1. Life‐history traits and density were assayed in seven populations of two sympatric species of wolf spider for three consecutive years. The goal of the study was to quantify population dynamics and its relation to spatial and temporal life‐history variation.2. Adult female body size and fecundity varied significantly, among field sites and among years, in both species. Female spiders of both species differed in mean relative reproductive effort among sites, but not among years. The size of offspring was invariable, with no significant differences due to site or year.3. All populations of both species tended to either decrease or increase in density during a given year and this was tightly correlated with changes in prey consumption rates.4. Since life‐history patterns are determined primarily by selection, it is concluded that size at sexual maturity for females is phenotypically plastic and responds to changes in prey availability. Offspring size however is not plastic and it is likely that other selection forces have determined offspring size. Temporal fluctuations in population size are correlated over a large area relative to dispersal capabilities for these species and conservation efforts for invertebrates must take this into consideration.

Growth and Maturity in the Manicou Crab Eudaniela Garmani (Brachyura: Pseudothelphusidae) from Trinidad, West Indies

The Manicou or mountain crab, Eudaniela garmani (Pseudothelphusidae), is a freshwater land crab found at high elevations in the forests of Trinidad, Tobago, Margarita, and Eastern Venezuela. Anecdotal data suggest that the Manicou crab reaches sexual maturity at an unusually large size, and, by implication, at a relatively old age. Therefore, management and harvesting of this species need to be informed by accurate determination of the size and estimated age at maturity. Laboratory growth increment and intermoult period data were used to estimate the time for both sexes to mature. Breakpoint analyses and analyses of covariance (ANCOVA) of field-collected data were used to determine male and female morphometric or structural maturity while gross and histological examinations of ovaries were used to determine the size of onset of female sexual maturity. Morphometric maturity was initiated at about 42 and 47 mm carapace width (CW) in female and male crabs, respectively. Female morphometric or structural maturation ceased at about 67 mm CW, about the same size as the onset of female functional maturity (69 mm CW). It is estimated that female crabs attained functional maturity at about 3 years. A minimum capture size is thus recommended between 75 and 80 mm CW for female crabs. Patterns of allometric growth in the major propodus of males and the pleon width in females may be related to territorial and/or courtship behaviour in males and the use of the pleon as an incubation chamber in females.

Strong Variations of Mitochondrial Mutation Rate across Mammals--the Longevity Hypothesis

Mitochondrial DNA (mtDNA) is the most popular marker of molecular diversity in animals, primarily because of its elevated mutation rate. After >20 years of intensive usage, the extent of mitochondrial evolutionary rate variations across species, their practical consequences on sequence analysis methods, and the ultimate reasons for mtDNA hypermutability are still largely unresolved issues. Using an extensive cytochrome b data set, fossil data, and taking advantage of the decoupled dynamics of synonymous and nonsynonymous substitutions, we measure the lineage-specific mitochondrial mutation rate across 1,696 mammalian species and compare it with the nuclear rate. We report an unexpected 2 orders of magnitude mitochondrial mutation rate variation between lineages: cytochrome b third codon positions are renewed every 1-2 Myr, in average, in the fastest evolving mammals, whereas it takes >100 Myr in slow-evolving lineages. This result has obvious implications in the fields of molecular phylogeny, molecular dating, and population genetics. Variations of mitochondrial substitution rate across species are partly explained by body mass, longevity, and age of female sexual maturity. The classical metabolic rate and generation time hypothesis, however, do not fully explain the observed patterns, especially a stronger effect of longevity in long-lived than in short-lived species. We propose that natural selection tends to decrease the mitochondrial mutation rate in long-lived species, in agreement with the mitochondrial theory of aging.

Latitudinal Variation in Population Structure and Reproductive Pattern of the Endemic South American Shrimp Artemesia Longinaris (Decapoda: Penaeoidea)

Population structure and reproductive maturity of females were investigated in the shrimp Artemesia longinarisBate, 1888 from coastal waters of northern São Paulo State (Brazil, |$23^\circ {\rm{S}}$|⁠) and Mar del Plata (Argentina, |$38^\circ {\rm{S}}$|⁠) from June 2001 to May 2002. Monthly collections were taken by commercial shrimp fishing boats equipped with bottom trawl nets. Population parameters from size frequency distributions and size (carapace length = CL) of female reproductive maturity were analyzed and compared from the two sampling areas. Latitudinal trends in reproductive parameters of A. longinaris were shown in overall body size and size of reproductive maturity, both of which were smaller in females from the tropical location than those from the cold-temperate sampling area. Largest females |$( \gt \;30\;{\rm{mm}}\;{\rm{CL}})$| were collected in Argentina, while Brazilian specimens reached maximum size at |$27\;{\rm{mm}}\;{\rm{CL}}$|⁠. The smallest size of female sexual maturity was estimated at |$13.6\;{\rm{mm}}\;{\rm{CL}}$| in Brazilian samples compared to |$22.1\;{\rm{mm}}\;{\rm{CL}}$| calculated for those from Argentina. Populations from both regions exhibited a bimodal size distribution in the spring, with the peak at small body size probably corresponding to recent recruits and the peak at larger body size to reproductive females or shrimps migrating in from deeper waters or other latitudinal regions. In late spring and summer, an intrusion of the cold South Atlantic Coastal Water mass was observed which lowered water temperature and stimulated plankton production, the primary food source for the larvae of a typically cold-temperate species such as A. longinaris. The trend of increasing body size and delay of sexual maturity with increasing latitude appears to be correlated with the decreasing water temperature and increasing plankton productivity at higher latitudes.

ASSESSMENT OF FEMALE REPRODUCTIVE STATUS IN ANASTREPHA SUSPENSA (DIPTERA: TEPHRITIDAE)

Reliable methods are needed for assessing sexual maturity in field-captured tephritid fruit flies. To provide such a tool for female Caribbean fruit flies, Anastrepha suspensa (Loew), this study documented changes in ovarian development over a four-week period following adult eclosion. The ovarian maturation process was classified into six developmental stages. Stages 1-4 described sequential steps in the development of immature ovaries, stage 5 indicated presence of mature oocytes, and stage 6 was the ovipositional phase. For each stage, four morphometric characters were examined-length of ovary, width of ovary, an ovarian index (length of ovary multiplied by width of ovary), and length of terminal follicle. Ovarian characters were compared by stage and correlated with the number of mature oocytes per ovary (egg load). Ovarian index maximized the differences between sexually mature and immature ovaries, and ovary length provided the best separation of immature stages. All four characters were positively correlated with egg load, but ovarian index and ovary width were the two best indicators of mature oocytes. Use of these parameters to assess egg load would eliminate the need to tease apart ovaries and count mature oocytes, thereby providing an efficient method for processing large samples of flies. Classification of female sexual maturity based on an ovary staging system, in conjunction with assessment of egg load in mature stages, would facilitate evaluation of the physiological age structure of a fly population captured in field deployed traps.

Reproduction in Bagre marinus (Ariidae) off Pernambuco, northeastern Brazil

Throughout 1997, the catches of artisanal gillnetters working of the coast of northeastern Brazil were sampled monthly for Bagre marinus (Mitchill 1815). Significantly more females (n = 207) than males (n = 82) were caught, although there was no significant difference in their size compositions (21 - 47 cm fork length, FL). All males sampled (21-40 cm FL) had developed gonads and were classified as sexually mature. According to macroscopic and microscopic examination of their reproductive tract, females were separated into four reproductive stages (immature, maturing, mature, and resting). Size at 50% sexual maturity for females was estimated to be 33 cm FL. A positive linear relationship was detected between the size of mature females and their fecundity (between 11 and 32 oocytes). Clear reproductive progress indicated a spawning period between March and May. We conclude that further fishery-independent data are required to determine patterns of male abundances and distributions.

Biologia reprodutiva de Ligia exotica (Crustacea, Isopoda, Ligiidae) em Rio Grande, Rio Grande do Sul, Brasil

Com o objetivo de elucidar alguns aspectos da biologia reprodutiva de Ligia exotica Roux, 1828, duas populações que habitam o Estuário da Lagoa dos Patos (Molhe Oeste da Barra de Rio Grande e Ilha do Leonídeo) foram analisadas. A amostragem foi realizada quinzenalmente entre o verão/2003 e o inverno/2004. Os animais foram coletados manualmente durante uma hora. O período reprodutivo da espécie foi registrado para os meses de outubro a junho. Nenhuma fêmea ovígera foi observada de julho a setembro. No Molhe Oeste da Barra de Rio Grande, 5.376 indivíduos foram capturados (1.494 juvenis, 1.748 machos e 2.134 fêmeas, das quais 245 eram ovígeras). A proporção sexual estimada foi 0,78 (M:F). Para a análise da fecundidade, 178 fêmeas ovígeras com o marsúpio intacto foram analisadas. O comprimento total destas fêmeas variou entre 20,73 a 34,3 mm, e o número de ovos-embriões variaram de 33 a 142. O comprimento médio de primeira maturação sexual das fêmeas foi 24,65 mm e o número médio de ovos-embriões foi 88. Na Ilha do Leonídeo, 5.519 animais foram coletados (510 juvenis, 1.956 machos e 3.053 fêmeas, das quais 129 eram ovígeras). A proporção sexual foi 0,68 (M:F). Pequenas porcentagens de fêmeas ovígeras foram encontradas de setembro a maio, sendo a mais alta porcentagem observada no final de março. Neste local, 101 fêmeas ovígeras foram analisadas, com o comprimento total variando entre 17,62 a 28,61 mm e o número de ovos-embriões entre 25 e 113. O comprimento médio de primeira maturação sexual das fêmeas e o número médio de ovos-embriões foram, respectivamente, 21,43 mm e 73,8.

Demography of a large grouper, Epinephelus fuscoguttatus, from Australia’s Great Barrier Reef: implications for fishery management

Epinephelus fuscoguttatus is widespread throughout the Indo-Pacific and features strongly in regional fisheries, including the live reef fish trade. We investigated age-specific demographic and reproductive characteristics of E. fuscoguttatus from the Great Barrier Reef, Australia, and examined implications for resource management. Age, growth, longevity, and the relationships between size or age and female sexual maturity and the recruitment of males into the study population were examined. Age validation using both oxytetracycline marking and edge-type analysis demonstrated that a single annulus formed each year. This grouper is long-lived (>40 yr) and relatively slow-growing. The size and age distributions of the sexes strongly suggested protogynous hermaphroditism. Histological data suggested infrequent spawning in small mature females. Females contribute very little to reproductive output until about 566 mm fork length and 9 yr of age. Larger females make important reproductive contributions during their 30+ yr reproductive lifespan. Their relatively long lifespan, restriction of males to large size groups, and the disproportionate contribution of large females to reproduction have important implications for the harvest of E. fuscoguttatus. For example, current Queensland size regulations are poorly matched to the species’ biology because they do not protect the reproductive elements of populations.

Adolescent menstrual disorders

The age of puberty represents a very critical time in the life history of every young woman. The menarche stands as primary indicator of the onset of sexual maturation in females. By late adolescence, 75% of girls experience some problem associated with menstruation. Delayed, irregular, painful, and heavy menstrual bleeding are leading reasons for physician office visits by adolescents, and dysmenorrhea is the leading reason for school absenteeism among girls. This article discusses normal menstrual function during adolescence, then reviews the clinical presentation, evaluation, and management of adolescent dysmenorrhea, dysfunctional uterine bleeding, amenorrhea, and polycystic ovary syndrome

Research cruise data on the biology of the lesser flying squid,Todaropsis eblanae, in the North Sea

A total of 324 specimens of the ommastrephid squid Todaropsis eblanae, collected from bottom trawl surveys in the North Sea was examined. Information on seasonal length frequency distributions and relationships of beak size to mantle length and wet body mass from the northernmost distribution of the species is supplied. The overall male: female ratio was 1: 0.78. Maturing males and females were found in winter and summer, while fully mature animals were observed only in summer. Sexual maturity in females occurred in bigger sizes than in males. Specimens were caught in water depths between 56 and 170 m throughout the whole investigated area except from the German Bight. This paper presents the first biological data on T. eblanae in the North Sea derived from scientific surveys.

Preliminary assessment of the biology and fishery for the narrow-barred Spanish mackerel, Scomberomorus commerson (Lacépède, 1800), in the southern Arabian Gulf

The population biology and fishery for Scomberomorus commerson in the southern Arabian Gulf were investigated using a combination of size frequency, biological and size-at-age data. Transverse sections of sagittal otoliths showed structural increments consisting of alternating translucent and opaque bands, which were used to estimate age. Edge analysis revealed an annual periodicity of formation with opaque zones being deposited between May and July in association with increasing seawater temperatures. The maximum absolute age estimates were 16.2 years (males) and 15.3 years (females). Initial growth was rapid with fish reaching more than half the asymptotic size by their second year and there were no significant differences in growth characteristics between sexes. Parameter values of the von Bertalanffy growth function fit to size-at-age data (males and females combined) were: k = 0.21, L ∞ = 138.6 cm ( L F) and t 0 = −1.9 years. Spawning occurred between April and August, the mean sizes and ages at first sexual maturity were 72.8 cm L F (1.9 years) for males and 86.3 cm L F (2.1 years) for females. The size at which fish were fully recruited to the fishery (62.6 cm L F) was considerably smaller than both the mean size at first sexual maturity for females and the size at which yield per recruit would be maximised (95.6 cm L F). Furthermore, the annual instantaneous fishing mortality rate of 0.62 year −1 (0.46–0.79 year −1 95% CI) was by far in excess of the precautionary target ( F opt = 0.13 year −1) and limit ( F limit = 0.17 year −1) biological reference points, indicating that the resource is heavily over-exploited. The results suggest that an increase in mesh size regulations for gillnets in combination with a substantial reduction in fishing effort will be required if resource conservation and stock rebuilding objectives are to be achieved. The study also highlights the need for a strategic regional approach to the assessment and management of this highly migratory species.

Population biology and assessment of the orange-spotted grouper, Epinephelus coioides (Hamilton, 1822), in the southern Arabian Gulf

Abstract The demography and status of Epinephelus coioides in the southern Arabian Gulf were established using a combination of size frequency, biological and size-at-age data. Transverse sections of sagittal otoliths were characterised by alternating translucent and opaque bands. Edge analysis revealed an annual periodicity of formation with the opaque zone being deposited during the summer months in association with increasing seawater temperature. Parameter values of the von Bertalanffy growth function fit to size-at-age data (males and females combined) were: k = 0.14, L ∞ = 97.9 cm ( L T ) and t 0 = −1.5 years. There was a well defined peak in reproductive activity with spawning occurring during May and a significant female bias in the male:female sex ratio (1:48). The mean size at first capture (28.9 cm L T ) was considerably smaller than both the mean size at sexual maturity for females (43.5 cm L T ) and the size at which yield per recruit would be maximised (59.1 cm L T ). The fishing mortality rate ( F = 0.78 year −1 ) was by far in excess of the precautionary target ( F opt = 0.10 year −1 ) and limit ( F limit = 0.13 year −1 ) biological reference points. In addition to growth overfishing, the stock was considered to be recruitment overfished as the biomass per recruit was less than 10% of that at the theoretical unexploited level. The results suggest that an increase in the mesh size of traps in combination with a substantial reduction in fishing effort will be required if resource conservation and stock rebuilding objectives are to be achieved for E. coioides in the southern Arabian Gulf.