Sexual Maturity Of Females Research Articles

Пубертатний стрес спричиняє статевоспецифічні репродуктивні ефекти у дорослих щурів

Adolescence is one of the critical periods of individual development, which is highly sensitive to changes caused by stress factors. Stress-related hormonal imbalances can negatively affect puberty and reproductive function. The aim of the study was to investigate the long-lasting reproductive effects of chronic pubertal stress in rats. Animals were subjected to immobilization stress daily from 30 to 45 postnatal day by placing them for 1 h in cylinders 4.5 cm in diameter and 10 cm in long, equipped with breathing holes. The timing of puberty in animals was studied and their somatic development was assessed. Further studies were conducted in 6-month-old sexually mature rats. The results were compared with the corresponding parameters in intact animals. Pubertal stress delayed sexual maturation in females and decreased weight gain in males. In adult animals of both sexes, pubertal stress did not change testosterone levels or the weight and morphology of the gonads significantly, except for minor vacuolation of the spermatogenic epithelium. The spermatogenesis index in the experimental group was significantly lower than in the control, due to a decrease in the number of late spermatids. Pubertal stress led to a 25.9% decrease in the number of spermatozoa in epididymal washes, an increase in the number of their pathological forms and a 2.4-fold slowdown in oxidative-reductive processes in spermatozoa. The content of malonic dialdehyde increased in the testes and ovaries, which indicates the activation of lipid peroxidation. Thus, chronic pubertal stress led to a decrease in the reproductive potential of male rats. Females are less susceptible to the negative effects of pubertal stress.

Insights into reproductive dynamics and feeding biology of Sphyraena putnamae Jordan and Seale, 1905 exploited in the Indian EEZ

The sawtooth barracuda Sphyraena putnamae, widely distributed in the Indo-Pacific region, isone of the commercially important barracuda species exploited by trawls in the Indian EEZ.The present study examined 2,135 S. putnamae collected during 2014-2020 from differentfish landing centres along the Indian coast, to elucidate their reproductive and feedingbehaviour. The fork length of sampled females and males varied from 12.5 to 130.9 cm and16.5 to 90.0 cm respectively. Negative allometric growth was observed with a significantdifference (p<0.05) between the sexes. The observed sex ratio (Female:Male) was 1.23:1,indicating the dominance of females. Size at sexual maturity for females and males wereestimated at 55.3 and 45.4 cm fork length respectively. The higher proportion of spawningcapable individuals and higher gonadosomatic index (GSI) values in females observedduring March to May and November-December revealed the bimodal and protractedspawning nature of this species. Absolute fecundity increased with fork length and weightand varied from 70,080 to 10,18,068 oocytes with an average of 3,16,568 oocytes. Thestomach vacuity index of females and males was 49.09 and 47.92% respectively. Fifty-nineprey items were identified in the diet, with a predominance of fishes confirming S. putnamaehas a piscivorous feeding behaviour. Keywords:Management, Protracted spawners, Piscivore,Sawtooth barracuda, Sex ratio

A genomic predictor for age at sexual maturity for mammalian species.

Age at sexual maturity is a key life history trait that can be used to predict population growth rates and develop life history models. In many wild animal species, the age at sexual maturity is not accurately quantified. This results in a reduced ability to accurately model demography of wild populations. Recent studies have indicated the potential for CpG density within gene promoters to be predictive of other life history traits, specifically maximum lifespan. Here, we have developed a machine learning model using gene promoter CpG density to predict the mean age at sexual maturity in mammalian species. In total, 91 genomes were used to identify 101 unique gene promoters predictive of age at sexual maturity across males and females. We found these gene promoters to be most predictive of age at sexual maturity in females (R 2 = 0.881) compared to males (R 2 = 0.758). The median absolute error rate was also found to be lower in females (0.427 years) compared to males (0.785 years). This model provides a novel method for species-level age at sexual maturity prediction without the need for long-term monitoring. This study also highlights a potential epigenetic mechanism for the onset of sexual maturity, indicating the possibility of using epigenetic biomarkers for this important life history trait.

Feeding dynamics and reproductive biology of the obtuse barracuda Sphyraena obtusata (Cuvier, 1829) from Ratnagiri, central west coast of India

The obtuse barracuda Sphyraena obtusata (Cuvier, 1829) is a commercially important foodfish belonging to the family Sphyraenidae and landed mostly as trawl bycatch along Ratnagiri.Investigations were carried out on the species with respect to the length-weight relationship,condition factor, morphometrics, feeding and reproductive biology. The length-weightrelationship showed positive allometric growth in males, females and pooled individuals. Allmorphometric measurements showed a high degree of correlation with total length. The gutcontent analysis revealed S. obtusata to be a carnivore fish feeding mainly on fish juveniles,fish scales, crustaceans and cephalopod appendages. The male:female sex ratio was foundto be 1:0.90. Gonado-somatic index (GSI), maturity and ova diameter studies indicated thatS. obtusata has a prolonged spawning season with individuals spawning twice in a season.Absolute fecundity ranged from 68355 to 310615 eggs with an average of 137783 eggs. Themean length at sexual maturity for females was found to be 22.92 cm. Keywords:Carnivorous fish, Fish biology, Life history,Trophodynamics, Tropical fisheries

The impact of the cardiovascular component and somatic mutations on ageing.

Mechanistic insight into ageing may empower prolonging the lifespan of humans; however, a complete understanding of this process is still lacking despite a plethora of ageing theories. In order to address this, we investigated the association of lifespan with eight phenotypic traits, that is, litter size, body mass, female and male sexual maturity, somatic mutation, heart, respiratory, and metabolic rate. In support of the somatic mutation theory, we analysed 15 mammalian species and their whole-genome sequencing deriving somatic mutation rate, which displayed the strongest negative correlation with lifespan. All remaining phenotypic traits showed almost equivalent strong associations across this mammalian cohort, however, resting heart rate explained additional variance in lifespan. Integrating somatic mutation and resting heart rate boosted the prediction of lifespan, thus highlighting that resting heart rate may either directly influence lifespan, or represents an epiphenomenon for additional lower-level mechanisms, for example, metabolic rate, that are associated with lifespan.

Biology of the cleftbelly trevally Atropus atropos (Bloch and Schneider, 1801) from Ratnagiri coast of India

The cleftbelly trevally Atropus atropos (Bloch and Schneider, 1801) is one of the important carangid species landed mostly as trawl bycatch along Ratnagiri coast. Investigations were carried out on A. atropos with respect to length-weight relationship, condition factor, morphometrics, feeding and reproductive biology. The length-weight relationship indicated negative allometric growth in A. atropos. Morphometric measurements showed significant correlation with total length. The gut content analysis revealed A. atropos to be a carnivore fish feeding mainly on Acetes spp., small teleostean fishes, cephalopods, and squilla. Sex ratio showed dominance of males. Gonadosomatic index and maturity studies indicated that A. atropos has a protracted spawning season extending from May to December. Length at sexual maturity for females was estimated to be 171 mm. Fecundity ranged from 16458 to 138688 eggs with an average of 70097 eggs. Ova diameter studies showed that A. atropos spawns twice in a protracted spawning season. Keywords: By-catch, Carangidae, Carnivore, Reproductive biology, Spawning season

Electrophysiological and Behavioral Responses of Virgin Female Bactrocera tryoni to Microbial Volatiles from Enterobacteriaceae.

The Queensland fruit fly (Bactrocera tryoni) is a major polyphagous pest widespread in Australia and several Pacific Islands. Bacteria present on the host plant phyllosphere supply proteins, essential for egg development and female sexual maturity. We investigated the role of microbial volatile organic compounds (MVOCs) emitted by Enterobacteriaceae commonly found on the host plant and in the fly gut in attracting virgin females. Bacteria were cultured on artificial media and natural fruits, at various pH, and MVOCs were collected using different headspace volatile absorbent materials. The olfactory responses of virgin females to bacterial MVOCs were assessed via electrophysiology and behavioral assays. The production of MVOCs was strongly influenced qualitatively by the bacterial strain and the type of media, and it semi-quantitatively varied with pH and time. MVOCs emitted by Klebsiella oxytoca invoked the strongest antennal response and were the most attractive. Among the identified compounds triggering an olfactory response, D-limonene and 2-nonanone were both significantly behaviorally attractive, whereas phenol, nonanal, isoamyl alcohol, and some pyrazines appeared to be repulsive. This study deepens our understanding of the chemical ecology between fruit flies and their bacterial symbionts and paves the way for novel synthetic lures based on specifically MVOCs targeting virgin females.

Relative growth and morphological sexual maturity of the caridean prawn Macrobrachium villosimanus (Tiwari, 1949) (Decapoda: Palaemonidae)

AbstractReproductive success for crustaceans depends on the transition from juvenile to adult, which can be estimated by analysing relative growth. To this end, the present study focused on the relative growth of appendix masculina length (AML), hatchery chamber width (HCW), body length (BL) and body weight (BW) in relation to carapace length (CL) of Macrobrachium villosimanus to estimate the morphological sexual maturity using the least squares method. Data for each relationship were repeatedly partitioned into two size‐delimited subsets (juvenile and adult stages), considering a CL value as a hypothesized transition point. Analysis of the residuals sum of squares indicated two separate linear regressions fit the data better than a single linear regression. The study results indicated a discontinuity in allometry at 17.9 mm CL for CL versus AML, and at 15.6 mm CL for CL versus HCW relationships. These observed transition points could be associated with morphological sexual maturity of M. villosimanus. The BL and BW growth rate in relation to CL significantly decreased in males, but increased in females after reaching the morphological sexual maturity, demonstrating the existence of dimorphic growth. The increased growth rate after reaching sexual maturity in females probably corresponds to more space for the eggs and subsequent increased fertility. Accordingly, the present study indicated the secondary sexual characters (e.g. AML and HCW) play roles in attaining the morphological sexual maturity necessary for reproductive success and for ensuring the life cycle of this species.

Knowledge, attitudes and practices on menstrual hygiene and associated factors among grade 10 schoolgirls in the district of Kalutara, Sri Lanka

Introduction: Menstruation is a natural phenomenon that occurs with sexual maturity of females. However, the topic is taboo for most female adolescents leading to improper practices on menstrual hygiene (MH) management. Objectives: To assess the knowledge, attitudes and practices on MH and associated factors among Grade 10 adolescent girls in Kalutara District, Sri Lanka Methods: A descriptive cross-sectional study was conducted. The final sample size computed was 720, applying a design effect of 3.8. As the cluster size decided was 15, 48 clusters/classes were selected using multi-stage stratified cluster sampling applying probability sampling techniques. A validated self-administered questionnaire was administered using Sinhala and Tamil versions. Bivariate and multivariate logistic regression was conducted to determine the associated factors. Results: Response rate at the time of recruitment was 100%. Satisfactory level of overall knowledge was observed in 25% (95% CI: 21.9, 28.3), attitudes in 67.2% (95% CI: 64.0, 70.9) and practices in 17.3% (95% CI: 14.7, 20.3). Unsatisfactory knowledge was associated with menstrual information not provided by a science teacher (ScT) (p<0.001) school types 1C and 2 combined (p=0.002) and mothers having less than tertiary education (p=0.03). Unsatisfactory attitudes were associated with menstrual information not provided by a ScT (p<0.001) and lack of premenarcheal awareness (p=0.009). Unsatisfactory practices were associated with school types IC and 2 combined (p<0.001), residing in urban sector (p=0.004) and having extended families (p=0.034). Conclusions & Recommendations: Overall knowledge on menstruation and menstrual hygiene related practices were poor, whereas attitudes were satisfactory. School type, maternal educational level, lack of premenarcheal awareness, menstrual information not being provided by a science teacher, residing in urban sector and living with extended family were the factors associated with unsatisfactory knowledge, attitudes and practices.

Growth and reproduction of the two-spot swimming crab Charybdis bimaculata (Miers, 1886) (Decapoda, Brachyura) in Goheung Bay, Korea

Abstract The growth and reproduction of Charybdis bimaculata (Miers, 1886) were investigated in Goheung Bay, Korea, from February 2020 to February 2021. Females were observed more frequently than males. The gonadosomatic index varied monthly, and reached the highest value in July. Ovigerous females peaked in July as well. The main spawning season was summer. The size at sexual maturity of females, corresponding to a proportion of 0.5 sexually mature individuals, was estimated as 20.93 mm carapace width (CW). The relationship between ln number of eggs (EN) and was for noneyed eggs, and for eyed eggs. Males grew faster than females ( mm CW and year−1 for males, and mm CW and year−1 for females).

Gambaran Menarche pada Remaja Siswi di Sekolah Menengah Pertama Negeri-14 Palangka Raya

Background: Adolescence is a transition period from childhood to adulthood marked by accelerated physical, mental, emotional, and social development and takes place in the second decade of life. Adolescence is marked by puberty, which is when a girl can experience conception, namely menarche / first menstruation. Menarche is a biological characteristic of female sexual maturity that generally occurs at about 10-14 years old. Objective: To discover the description of menarche in adolescent girls at SMPN-14 Palangka Raya. Method: This study uses a descriptive design, which is research conducted with the main objective of making a description or descriptive. This study used a saturated sampling method with a total of 39 female adolescent respondents who had experienced menarche, and the technique of collecting data was using a questionnaire. Result: The most age in adolescents who experienced menarche at 11-14 years were 37 people (94.8%), with normal BMI as many as 20 respondents (51.3%), adolescent girls exposed to adult information media, and as many as 25 respondents. (64.1%), the highest number of mothers education for students who had menarche was in basic education, 20 respondents (51.3%), with mothers who did not work as many as 23 people (59%), and high family incomes ((≥Rp.1,676 .058,-/month) as many as 20 respondents (51.3%). Conclusion: Menarche in adolescents aged 11-14 years occurs not only due to endogenous (genetic) factors but also exogenous factors, namely nutritional status, exposure to adult media, both print and electronic, sports activities, socioeconomic status, and education level of parents. as the closest person to the teenager.

Microbial community characteristics of the intestine and gills of medium-form populations of Sthenoteuthis oualaniensis in the South China Sea

Sthenoteuthis oualaniensis (purpleback squid) is an excellent biological resource in the South China Sea. However, the microbiological characteristics of this South China Sea squid, especially those of the medium-form of different sexes and gonadal maturities, are poorly understood. In this study, the characteristics of the bacterial community in the intestinal and gill tissues of female and male S. oualaniensis with different gonadal maturities, collected from the Nansha Sea of China in spring 2020, were analyzed. The results showed that Tenericutes, Proteobacteria, Firmicutes, and Bacteroidetes were the dominant phyla in the intestinal microbial samples of female immature gonad (FN), male immature gonad (MN), and male sexual maturity (MY) samples of the S. oualaniensis populations. Proteobacteria, Firmicutes, Bacteroidetes, and Tenericutes were the dominant phyla in the intestinal microbial sample of the female sexual maturity (FY) group. The microbial community in the gills differed from that of the intestinal flora. The dominant phyla in the gill samples were Proteobacteria, Firmicutes, and Bacteroidetes, regardless of sex or gonadal maturity. According to the random forest analysis, the gill samples had significantly (p<0.001) more Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in the top 20 than the intestinal samples. Correlation analysis showed that the mantle length of S. oualaniensis was significantly (p<0.05) negatively correlated with the abundance of Tenericutes, but significantly (p<0.01) positively correlated with Firmicutes and Bacteroidetes. The mantle length of FY was significantly (p<0.05) longer than that of the other types. The results indicated that the differences in the intestinal bacterial community were related to the growth and feeding characteristics of S. oualaniensis of different sexes and maturities.

Effects of pesticides on reproductive parameters in hoplobatrachus occipitalis (günther, 1858), an edible frog living in the drainage furrows of a banana plantation in the locality of dabou

Sexual maturity size, gonado-somatic index, sex ratio and fecundity were studied during four seasons, from January to December 2020, in Hoplobatrachus occipitalis which lives in the water of drainage furrows of banana plantations treated with phytosanitary products in the locality of Dabou. Our results reveal that the sizes of first sexual maturity in females and […]

Reproductive biology of the red starfish Echinaster sepositus (Echinodermata, Asteroidea) from the Algerian west coast

ABSTRACT This work aims to describe for the first time the reproductive biology of the red starfish Echinaster sepositus at the western region of Algeria (Mostaganem). The population of E. sepositus is characterized by a sex ratio of 1:2 (female: male). The relation between arm length and wet body weight indicate a negative allometric growth. Histological study reveals six stages of sexual maturity in females (I: development; II: pre-mature; III: mature; IV: partly spawned; V: post – spawning; VI: recovery) and five stages in males (I: development; II: pre-mature; III: mature; V: post-spawning; VI: recovery). The gonadosomatic index shows that there is only one spawning period per year, which happens from July to November. The gonadal maturity and gametogenesis of E. sepositus are correlated with the environmental factors namely temperature and photoperiod.

Delineating yellowfin sole (Limanda aspera) reproduction in the northern Bering Sea provides information across the eastern Bering Sea continental shelf

Yellowfin sole (Limanda aspera) is an abundant, commercially harvested flatfish that ranges across the northern and southeastern Bering Sea continental shelf. In recent years, the summer bottom trawl survey of the southeastern Bering Sea (SEBS) conducted by the National Marine Fisheries Service’s Alaska Fisheries Science Center (AFSC) extended into the northern Bering Sea (NBS) in August. This opportunity allowed for describing yellowfin sole reproductive parameters in the NBS, such as female length and age at maturation, reproductive status, and sex ratio distribution. Estimates of 50% female sexual maturity were 10.11 years (A50; 95% CI: 9.47–10.76 years; n = 209) and 28.47 cm (L50; 95% CI: 27.16–29.68 cm; n = 212). Histology indicated much of the mature population was approaching the end of spawning. Yellowfin sole spawning timing (summer) appears to be synchronous across the NBS and SEBS. There is evidence that part of the yellowfin sole spawning population in the NBS is connected to a recognized spawning migratory group from the SEBS. A higher proportion of females than males was observed, which varied by year and stratum. This was negatively related to warmer bottom temperature and positively related to location (western longitudes and northern latitudes). Yellowfin sole females in the NBS exhibit a similar size and age of maturation, depth of spawning, and sex ratio proportions with those females inhabiting the SEBS. These results provide further information for fisheries managers on the yellowfin sole stock throughout this region. Spatial and temporal aspects of reproduction, however, should be more thoroughly investigated.

Reproductive Dynamics of Coryphaena hippurus (Linnaeus, 1758) Recorded from the Bay of Bengal, India

Ghosh, S.; Satishkumar, M.; Manas, H.M.; Rohit, P.; Abdussamad, E.M., and Gopalakrishnan, A., 2022. Reproductive dynamics of Coryphaena hippurus (Linnaeus, 1758) recorded from the Bay of Bengal, India. Journal of Coastal Research, 38(2), 369–376. Coconut Creek (Florida), ISSN 0749-0208. Coryphaena hippurus, one among the large pelagic species landed from Bay of Bengal, forms an important bycatch in drift gillnets and hook and lines. The present study, first from the region, is aimed at elucidating the reproductive biology from 1150 fishes from 2017 to 2019. Fork length of sampled fishes ranged from 25 cm to 110 cm and females contributed to the catch only up to a length of 88 cm. Growth was negatively allometric and length composition varied between sexes. Sex ratio was 1M:2.04F, significantly favouring females in most months, and more so in fishes measuring below 60.0 cm. Size at sexual maturity for females and males was 54.57 cm and 59.97 cm. Monthly percent contribution of spawning females and males ranged between 20.00 to 60.61 and 29.17 to 53.57. Monthly gonadosomatic index for females and males varied between 1.48 to 3.82 and 0.89 to 1.94. The values differed significantly; higher values during August to November indicated a peak in spawning. However, spawning occurred round the year, as evident by the presence of spawners and moderate values of the gonadosomatic index. Absolute fecundity ranged from 115,200 eggs to 1,501,808 eggs, with an average of 434,688 eggs. Egg size distribution demonstrated asynchronous gonadal development and batch spawning. Egg diameter of most abundant oocytes ranged from 0.60 mm to 0.69 mm, followed by another peak at 0.80 mm to 0.89 mm. Present study, first from region, provides detailed insights on reproductive biology, some of which are maiden information from Indian Ocean and knowledge generated would contribute significantly to stock management.

Oymapınar Baraj Gölü’ndeki (Antalya, Türkiye) Beyşehir Tatlısu Kefalinin (Squalius anatolicus Bogutskaya, 1997) Bazı Üreme Özellikleri

This study was conducted in Oymapınar Dam Lake from March 2016 to February 2017. The study investigated the age composition, spawning season, sex ratio, first sexual maturity, and fecundity of chub (S. anatolicus). The ages of the 422 chubs sampled from Oymapınar Dam Lake ranged from II to VIII of which 200 (47.39%) were females and 222 (52.61%) were males. The fork lengths and weights of female chubs varied between 20.0 cm and 55.1 cm and 93.37 g and 2307.88 g respectively. The oldest age group was VIII for females and VII for males. The length at first sexual maturity for females and males were 26.0 cm and 23.0 cm, respectively and the age at first sexual maturity for females and males were III and II, respectively. This shows that males mature earlier than females. Monthly gonadosomatic index values showed that the peak spawning period for chubs was between April and June. The fecundity (F) - length relationship of S. anatolicus was LogF = -0.44697 + 3.33868 * LogL (R² = 0.7168). The mean egg diameter of S. anatolicus was 0.93 mm and the average fecundity was 78408.

Female sex inversion as a reason for an unbalanced sex ratio in the neotropical species Brycon orbignyanus

The objective of this study was to temporally identify sex differentiation to morphologically characterize the formation of female and male germinal epithelium and verify the occurrence of the sex disproportion reported for this species in aquaculture. Specimens of Brycon orbignyanus cultivated in water recirculation systems with a constant temperature of 27 ± 0.5°C were used. Monthly samplings of B. orbignyanus (n = 15) were performed from two months of age until 1 year of age, and posteriorly isolated sampling was performed on specimens of two and three years of age. The gonads of the specimens were removed and processed for light microscopy. In the beginning, the undifferentiated gonads develop into ovaries (females; at three months of age) and functional testicles (primary males; at five months of age); however, some of the females go through a sex inversion process creating intersex individuals and posteriorly secondary males (at five months of age). Due to the processes of sex inversion and gonadal remodelling, the population sex proportion fluctuates until it is finally established at 1♀:2♂. Females above 15 cm are differentiated, while in males (primary and secondary), differentiation will only occur after the animal reaches 20 cm. At the end of the first year of age, primary males and secondary males reach sexual maturity, while female sexual maturity is only observed at three years of age.

Life History Traits, Elasticity Analyses, and Phenotypic Plasticity of Squaliobarbus curriculus in the Pearl River Estuary, China

Squaliobarbus curriculus, commonly known as red-eye fish, is widely distributed in East Asia. It is one of the important aquatic germplasm resource and economic species in the Pearl River. To give suggestions for better protection and management, we investigated its life history and conducted elasticity analyses. Samples (n= 451) were collected between 2016 and 2017 from the western Pearl River estuary. There were no significant differences between the length-weight relationships of females and males (W= 0.00001SL3.121). The von Bertalanffy growth function was Lt= 553.2 [1 − e−0.111(t+1.009)]. The estimated length at 50% sexual maturity for females was 209.6 and 200.0 mm for males, both at 3 years of age. Oocyte size-frequency distribution suggested batch spawning. Fecundity ranged between 9,407 and 175,086 eggs per fish (mean = 51,040, or 143.9 eggs/g of fish weight). To better understand the ecological phenotypic plasticity ofS. curriculuswe conducted meta-analyses on all available life history data for this species. Our results showed that the standard lengths at ages 2 and 3 in the estuary were significantly smaller than in the upper reaches of the Pearl River basin, and there were also obvious differences in fecundity and oocyte size. For more, the standard lengths at ages 2 and 3 were correlated negatively with latitude. Elasticity analysis showed that juveniles’ (aged 1–3) survival had the largest contribution to the population growth rate, which suggests that management efforts should focus on the early life stages.

Maturity of a giant: age and size reaction norm for sexual maturity for Atlantic leatherback turtles

AbstractLeatherback marine turtles are the largest extant turtles with some individuals measuring up to 2 m in carapace length. In addition, this species remains in oceanic habitat during much its life, making it difficult to investigate its ontogeny from hatchling to adult stage. Furthermore, distinct chondro‐osseous (cartilage and bone) tissue morphology has led to speculation that sexual maturity may be reached as early as 3 years while others have estimated a minimum of 25 years to reach adulthood. Using a combination of reanalysis of the growth trajectories of juveniles maintained in captivity, and the age–size relationship of individuals in the field, we demonstrate and quantify the indeterminate growth of this species. Using comparisons of female size distribution on nesting beaches and stranded or captured‐at‐sea size distributions adjusted with a new asymmetric sigmoid function, we were able to model the size reaction norm for female sexual maturity. Combining these two models, we show that some females may reach maturity at 14 years in natural conditions, while others will take 50 years or more. Sexual maturity may even be reached at 5 years when individuals experience exceptionally good environmental conditions. This extreme plasticity in the age of sexual maturity has been demonstrated in loggerhead turtles in natural conditions and in green turtles in captivity. It may be a general life‐history feature of marine turtles.