The peptide fraction of Bothrops jararaca snake venom induces toxicological effects on the male reproductive system after local envenomation in mice

Bothrops envenomation is complex and provokes prominent local tissue damage and systemic disturbances,but little is known about their effects on the male reproductive system.After intratesticular injection,the bioactive peptide fraction(Bj-PF)obtained from Bothrops jararaca snake venom changes the structure of different stages of the seminiferous epithelium cycle in adult mice.For the first time,we investigated whether local envenomation of Bj-PF induces toxicological effects on the male reproductive system,particularly on the seminiferous epithelium and Sertoli cells.Male adult mice were treated with 0.24 mg.kg^(-1) by intramuscular(i.m.)injection for 24 h.The testes samples were collected for morphological and morphometric evaluation.The toxicological effects of Bj-PF were also analyzed on mitochondrial metabolism and nitrite(NO2)production in 15P-1 Sertoli cell culture.Bj-PF changed the structure and function of the seminiferous epithelium,particularly the disruption of the epithelium and the presence of degenerated germ cells in the adluminal compartment,but there were no alterations in the basal compartment.Bj-PF increased the thickness of the seminiferous epithelium and decreased the lumen diameter of the tubule.Semiquantitative histological assessment of the degree of tubule degeneration revealed that Bj-PF also increased the number of hypospermatogenic tubules compared to control.Bj-PF reduced NO2 levels in 15P-1 Sertoli cells without changing the mitochondrial metabolism.Overall,the fact that Bj-PF alters the structure and function of the seminiferous epithelium suggests that bioactive peptides found in B.jararaca snake venom can have toxicological effects on the reproductive systems of affected male mice,providing new insight into the biological characteristics of snake venom and therapeutic strategies for envenomation inflammation.

Role of Estrogens on Human Male Reproductive System

This review focuses on estrogen role on human male physiology. Biological estrogen actions on male reproductive system are summarized with particular regard to the effects of congenital estrogen deprivation in men. The effects of estrogen on spermatogenesis, hormonal secretion and gonadotropin feedback and on sexual behavior are discussed. It is remarked that the role of estrogens in male reproduction is a very recent acquisition in reproductive endocrinology, but it promises new future fields of research to be investigated as well as the possible disclosure of new strategies in clinical practice.

Association Between Fine Particulate Matter (PM_(2.5)) and the Reproductive System: A Narrative Review

In the last two decades,the issue on exposure to air pollution,especially fine particulate matter(PM_(2.5)),and its health effects has been a global concern.PM2.5 can enter the bronchi,lung cells,and subsequently the body,thus causing adverse health effects.One of these health effects include damage to the reproductive system.However,this has not gained much attention.In addition,PM_(2.5) contain toxic compounds,such as heavy metals or PAHs,which can cross various barriers,including epithelial barrier and blood-testis barrier,causing hormonal disorders in both,men and women,thus resulting in infertility.In this review,an attempt was made to provide useful information about effects of PM_(2.5) on the reproductive system.

Toxic Effects of Atrazine on Reproductive System of Male Rats

Objective This study was designed to evaluate the toxic effects of Atrazine （ATZ） on the reproductive system of male rats. 〈br〉 Methods Male Sprague-Dawley rats were exposed to ATZ by gavage at dosages of 0, 38.5, 77, and 154 mg/kg bw/day for 30 d. The toxic effects of ATZ to rats were assessed through histopathologcal observation, spermatozoa quality evaluation, testicular marker enzyme indicators, antioxidant capacity and reproductive hormone levels. Results Significant adverse effects on reproductive system were observed in rats exposed to ATZ at different dosages compared with 0 mg/kg group, including an irregular and disordered arrangement of the seminiferous epithelium in 154 mg/kg group;a decreased spermatozoa number and an increased spermatozoa abnormality rate in 77 and 154 mg/kg groups;decreased levels of acid phosphatase （ACP）, alkaline phosphatase （AKP）, lactic dehydrogenase （LDH）, and succinate dehydrogenase （SDH） with the increasing of ATZ concentration; a decreased level of total antioxidant capacity （TAC） in a dose-dependent manner, and a decreased reduced glutathione （GSH） level and an increased malondialdehyde （MDA） content in 154 mg/kg group;and decreased serum levels of testosterone （T） and inhibin-B （INH-B） and an increased serum level of follicle stimulating hormone （FSH） in 77 and 154 mg/kg groups, and an increased serum level of luteinizing hormone （LH） in 154 mg/kg group. Conclusion These results suggested that relatively high doses of ATZ could exert reproductive toxicity of male rats.

Oxidative Stress:Role in Acetamiprid-Induced Impairment of the Male Mice Reproductive System

Acetamiprid has a wide range of influence on physiological functions in mammals.The objective of this study was to examine the effect of acetamiprid on the reproductive function of male mice,and to study the role of oxidative stress in acetamiprid-induced damage to the testes.Fifty adult Kunmin male mice （25-30 g） were divided into five groups （n=10 per group）,i.e.,control,blank,acetamiprid alone,acetamiprid and vitamin E,and vitamin E alone.All groups were treated for 35 d.The results showed that acetamiprid significantly decreased the body weight and the weight of testosterone-responsive organs,such as the testis,epididymis,seminal vesicle,and prostate.Furthermore,acetamiprid also significantly reduced the serum testosterone concentration,and decreased sperm count,viability,motility,and the intactness of the acrosome （P〈0.05 for each parameter）.The mice treated with acetamiprid had damaged seminiferous tubules and Leydig cells based on the histological structure of testes;there was degeneration of the mitochondria and endoplasmic reticulum of Leydig cells.These deleterious effects of acetamiprid may be mediated by increasing oxidative stress,as acetamiprid increased malondialdehyde and nitric oxide in the testes,reduced the activity of catalase,glutathione peroxidase,superoxide dismutase,and activated p38.The concentration of acetamiprid in the testes was lower than that in liver,so did the concentrations of liver function tests,including aspartate transaminase （AST）,alanine transaminase （ALT） and alkaline phosphatase （ALP）,which suggest that male reproductive function may be affected through the indirect action of its metabolites.Vitamin E significantly ameliorated the effects of acetamiprid.We conclude that acetamiprid damages male reproductive function through inducing oxidative stress in the testes.

Seasonal Dynamics of Male and Female Reproductive Systems in the Siberian Salamander, Salamandrella keyserlingii (Caudata, Hynobiidae)

It is not well known how low temperatures, like a subarctic steppe–tundra climate, influence reproductive traits of ectothermic vertebrates. To begin answering this question, we studied male and female reproductive systems of Salamandrella keyserlingii inhabiting a Tomsk population（southeast of Western Siberia）, Russia, in ecological and physiological terms. In males, before spermiation, the testicular size and weight in late April–early May were greatest of all. Spermiation occurred during breeding immigration in spring when mean air temperature was above 10°С, and at the same time rain fell. After spermiation, the testicular size and weight decreased sharply, and the diameter of the vasa deferentia increased. ＂Spawning＂（i.e., simultaneous extrusion of sperm and oviposition） occurred from late April to late May, and this duration fluctuated in temperature and humidity. The testicular size and weight increased in summer. Sperm mass was detected in the testes by the smear method in April–September, except in June when single fragmented unrealized sperm was detected and in July when spermatids were detected. In females, ovarian weight was greatest in spring before ovulation. From late June, vitellogenesis began in ovarian follicles, in which mint green yolks accumulated. Melanin deposited in the surface of the ovary from July when oviducts were hypertrophying. In contrast, some large-sized females did not show any sexual maturity shortly before hibernation（although these females may be subadults）. These results suggest that low temperatures in Siberia induce early timing of gamete maturation in females, but the females＇ reproductive cycle might also be biennial. A reproductive cycle in males was annual with the completion of the gamete maturation process in August.

Effects of Parental Dietary Exposure to GM Rice TT51 on the Male Reproductive System of Rat Offspring

Objective To evaluate the health effects of parental dietary exposure to GM rice TT52 on the male reproductive system of rat offspring. Methods Rice-based diets, containing 60% ordinary grocery rice, MingHui63, or TT51 by weight, were given to parental rats （15 males/30 females each group） for 70 days prior mating and throughout pregnancy and lactation. After weaning, eight male offspring rats were randomly selected at each group and fed with diets correspondent to their parents＇ for 70 days. The effects of exposure to TT52 on male reproductive system of offspring rats were assessed through sperm parameters, testicular function enzyme activities, serum hormones （FSH, LH, and testosterone levels）, testis histopathological examination, and the relative expression levels of selected genes along the hypothalamic-pituitary- testicular （HPT） axis. Results No significant differences were observed in body weight, food intake, organ/body weights, serum hormone, sperm parameters, testis function enzyme ACP, LDH, and SDH activities, testis histopathological changes, and relative mRNA expression levels of GnRH-R, FSH-R, LH-R, and AR along the HPT axis. Conclusion The results of this study demonstrate that parental dietary exposure to TT51 reveals no significant differences on the reproductive system of male offspring rats compared with MingHui63 and control.

Harmful effects of pyrethroid ester insecticide on the male reproductive system mainly through affecting testicular function and inflammatory markers

Pyrethroid esters are widely used as insecticides worldwide. In this study, we aimed to evaluate the harmful effect of deltamethrin on the male reproductive system through the assessment of reproductive hormones, inflammatorymarkers, and testicular function. To achieve our aim, eighty male 7-9-week-old, Wistar rats were taken, weighed, and divided into four experimental groups. The first group was kept as a control group, and the other three groups were given deltamethrin orally at different concentrations (0.87, 8.7, and 17.4 mg/kg body weight) for nine weeks. The resultsindicated that deltamethrin administration associated with a significant decrease in reproductive hormones, especially FSH, LH, and significant elevation in the interleukin 2 (IL2), interleukin 6 (IL6), histamine, and cortisol levels. Also, thesignificance of inhibition of sperm motility and viability, decreased testis weights, sperm count, and fructose in semen were noted. These findings clarify the harmful effect of deltamethrin on the male reproductive system by producing a significant alteration in reproductive hormones, inflammatory markers as well as testicular function.

Dose-dependent effects of pentabrominated diphenyl ethers on sexual hormone and histology of male reproductive system in rats

Polybrominated diphenyl ethers (PBDEs) used as flame retardants are widely used in a variety of consumer products, like textiles, foam and building materials. They are persistent in the environment, and increasing levels of PBDEs have been found both biota and human tissue samples. In the present study we examined the dose-dependent effects of pentabrominated diphenyl ether (PBDE-99) on the serum hormone and histology of reproductive system in male rats. 40 health 4-week-old SD rats were divided into 4 groups randomly. The treated rats were orally administered with BDE-99 at the dose of 60,120 or 180 mg/kg, while controls received equal volume of corn oil. We examined the changes of serum hormone levels, histopathology, and PCNA after 30 days exposure to BDE-99. With increasing doses of BDE-99, testis organ coefficient increased, serum hormone levels lower, PCNA positive expression reduced, and the degeneration of seminiferous epithelium were revealed in treated group. These indicators with significant dose-effect relationship showed that BDE-99 can reduce the serum sex hormone levels and cause severe degeneration of seminiferous epithelium.

Female reproductive system of <i>Amaranthus</i>as the target for <i>Agrobacterium</i>-mediated transformation

Agrobacterium-mediated transformation through floral dip and rapid selection process after transgenic event had become a preference as it will overcome the difficulties faced in tissue culturing procedures and lengthy time for screening transformed progenies. Therefore, in this study, three constructs, p5b5 (14,289 bp), p5d9 (15,330 bp) and p5f7 (15,380 bp) in pDRB6b vector which has hygromycin as a selectable marker gene were introduced individually into Agrobacterium tumefaciens strain (AGL1). The cell suspension was applied to Amaranthus inflorescence by drop-by-drop technique and was left to produce seeds (T1). The T1 seeds were germinated and grown to produce seedlings under non-sterile condition. Hygromycin selection on seedling cotyledon leaves results in identification of 12 putative transformants, three from p5b5, four from p5d9 and five from p5f7. All positive putative transformants that were selected at the first stage through hygromycin spraying showed positive result in leaf disk hygromycin assay and in a construct specific polymerase chain reaction-based assay. A ~750 bp amplified hygromycin gene was further verified through sequencing. Our results suggest that Amaranthus inflorescences were able to be transformed and the transformed progenies could be verified through a combination of simple and rapid methods .

Effects of Environmental Water Contamination in the Reproductive System of Mice

This study investigated the effects on the reproductive system of balb-c mice exposed to water collected from different sources near to a deactivated fertilizer waste depositary. Eighty male mice were separated in four groups: Group A (mineral water);Group B (water from the water treatment station);Group C (water from Cubatao city);Group D (water from the waste depositary region). They were exposed to water since they were weaned until they reached sexual maturity, then they were coupled with females in reproductive age and after this mating time they were sacrificed. The evaluated parameters were testicle weight, sperm analysis, pregnancy rate, sex ratio of the offspring and Sertoli cell count. The analysis of the water did not show presence of pollutants in the Group “A” and Group “C” water. Group “B” showed low level of cadmium, 3.58 ± 0.50 μg/L. Group “D” showed the presence of PAH’s and high levels of lead (221 ± 16 μg/L), cadmiun (12.6 ± 1.2 μg/L) and mercury (5.3 ± 1.1 μg/L). The tests of Levene and Kolmogorov-Smirnov were employed to verify the homogeneity of the variances and the tack to the normal curve, respectively. ANOVA was used for parametric tests and Kruskall-Wallis was used for non-parametric tests, while Turkey tests were employed for multiple comparisons. There were no differences between groups in testicle weight, sperm analysis, pregnancy rate and Sertoli cell count. There was a significant reduction in sex-ratio of the offspring in Group B. This alteration cannot be explained by the cadmium levels in Group B water. In the present study we cannot associate the exposition to contaminated water from the waste depositary and reproductive alterations.

Male reproductive system and simulated high-altitude environment:preliminary results in rats

This study assessed the effects of a simulated high-altitude environment on the reproductive system of prepubertal male rats and the reversibility of these effects upon return to a normal environment.Three-week-old male Wistar rats were randomly allocated to 4 groups that were exposed to different conditions:a normal environment for 6 weeks and 12 weeks,respectively,hypobaric hypoxia for 6 weeks,and hypobaric hypoxia for 6 weeks followed by a normal environment for 6 weeks.Multiple pathophysiological parameters were evaluated at the histological,endocrine,and molecular levels.Hypobaric hypoxia exposure for 6 weeks during the prepubertal phase significantly altered physiological parameters,body functions,blood indices,and reproductive potential.Six weeks after returning to a normal environment,the damaged reproductive functions partially recovered due to compensatory mechanisms.However,several changes were not reversed after returning to a normal environment for 6 weeks,including disorders of body development and metabolism,increased red blood cells,increased fasting blood glucose,abnormal blood lipid metabolism,decreased testicular and epididymis weights,abnormal reproductive hormone levels,excessive apoptosis of reproductive cells,and decreased sperm concentration.In summary,a hypobaric hypoxic environment significantly impaired the reproductive function of prepubertal male rats,and a return to normal conditions during the postpubertal phase did not fully recover these impairments.

Study on Breeding Practices and Reproductive Performance of Black-Head Somali Sheep under Traditional Management System: The Case of Awbarre District, Eastern Ethiopia

The study was conducted in the Awbarre district of the Fafen zone of the Somali regional state of Ethiopia. The objective of the study was to assess the breeding practices and reproductive performance of Black-head Somali sheep under a traditional management system. Purposive and simple random sampling techniques were used to select targeted kebeles and households, respectively. A total of 120 households were selected from four kebeles, each of 30 households, based on the production system and sheep population. Semi-structured questionnaires, group discussions, key informants interviews and field observations were used to generate the required data. The primary purpose of keeping sheep was for income generation, followed by saving as a future asset. The majority (89.2%) of the respondents separated male and female animals during herding. The selection criteria for breeding rams were appearance, growth, pedigree, and color while for breeding ewes were appearance, adaptability, pedigree, color, and lamb growth. The overall weaning age of Black-head Somali sheep in the study area was 3.7 months for both males & females. The castration of male sheep was common for the purpose of fattening, fattening with breeding control and breeding control as well. The castration is mainly performed during the summer and autumn and the methods of castration were both traditional and modern methods, the traditional castration method being the most important one in pastoral areas. The age of sexual maturity was 7.64 months for rams and 8.97 months for ewe’s male and female lambs in the pastoral area and 8.42 & 8.38 for rams & ewes in agro-pastoral and overall lambing interval was 11 months. On average, the ewe of Black-head Somali sheep in pastoral & agro-pastoral could produce 9.49 & 9.57 lambs, respectively in their lifetime. As the pastoralists and agro-pastoralists indicated the source of the breeding ram was their own, so the exchange of breeding ram is recommended to minimize the risk of inbreeding and further studies of on-farm performance investigation would be necessary to be carried out so as to understand the uniqueness of the breed better.

Occupational,environmental and psychosocial factors impacting reproductive health of women working in manufacturing sector in India:a systematic review

Background:Women working in manufacturing are exposed to harmful chemicals and gases;environmental and psychosocial factors such as stress,anxiety,and burnout severely affect their reproductive health.Like physiological factors,psychosocial factors equality disrupts women’s reproductive health who are working in such aversive circumstances.Method:The current study is a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis checklist.The primary sources of articles were central databases such as SCOPUS,Web of Science,PubMed,and others.Cambridge Quality Checklist was used to measure the quality of the review articles.Result:A total of 14 articles were found eligible for the review;5 studies were on occupational health in general,3 studies addressed menstrual distress,3 studies on pregnancy,and 3 on menopausal issues.Pandemic experiences increase the health risk with the rise in food and financial insecurity among manufacturing workers.Conclusion:Psychosocial factors such as stress,anxiety,loneliness,discrimination,and depression are associated with a risk to reproductive health.The uncertainty caused by the pandemic was a major stressor for the manufacturing workers in India.The findings would represent significant challenges and factors affecting women’s reproductive health.Proper interventions and measures could be taken to regulate health risks.

Dietary supplementation of laminarin improves the reproductive performance of sows and the growth of suckling piglets

Background Maternal nutrition is essential in keeping a highly efficient production system in the pig industry.Laminarin has been shown to improve antioxidant capacity,reduce the inflammatory response,and favor the homeostasis of intestinal microbiota.However,the effect of dietary supplementation of laminarin on the reproductive performance of sows and the growth of suckling offspring remains unknown.Methods A total of 40 Landrace×Yorkshire multiparous sows on d 85 of gestation,similar in age,body weight(BW),parity and reproductive performance,were randomly divided into four dietary treatments with 10 sows per treatment,receiving a control diet(basal pregnancy or lactating diets)and a basal diet supplemented with 0.025%,0.05%and 0.10%laminarin,respectively.The experiment lasted from d 85 of gestation to d 21 of lactation.Results Laminarin supplementation linearly increased number born alive per litter(P=0.03),average daily feed intake(ADFI,P<0.01),and total milk yield of sows during the lactation of 1–21 d(P=0.02).Furthermore,maternal laminarin supplementation increased the average daily gain(ADG)of piglets while tending to reduce the culling and death rate before weaning.In addition,alterations to the composition of colostrum and milk,as well as to serum inflammatory cytokines and immunoglobulins of sows were observed.The fecal microbiota profile of sows supported the improvement of reproductive performance in sows and the growth performance in suckling offspring.Conclusions Dietary supplementation of laminarin during late pregnancy and lactation could significantly improve reproductive performance of sows and growth performance of piglets.

Genome-wide SNP markers provided insights into the reproductive strategy and genetic diversity of the green tide causative species Ulva prolifera in China

Ulva prolifera is the causative species of the annually occurring large-scale green tides in China since 2007.Its specific biological features on reproductivity strategies,as well as intra-species genetic diversity,are still largely unknown,especially at the genome level,despite their importance in understanding the formation and outbreak of massive green tides.In the present study,the restriction site-associated DNA genotyping approach(2b-RAD)was adopted to identify the genome-wide single-nucleotide polymorphisms(SNPs)of 54 individual thalli including samples collected from Subei Shoal in 2019 and Qingdao coast from 2019 to 2021.SNPs genotype results revealed that most of the thalli in 2019 and 2020 were haploid gametophytes,while only half of the thalli were gametophytes in 2021,indicating flexibility in the reproductive strategies for the formation of the green tides among different years and the dominance of asexual and vegetative reproductive mode for the floating period.Besides,population analysis was conducted,and it revealed a very low genetic diversity among samples from Subei Shoal and the Qingdao coast in the same year and a higher divergence among samples in different years.The results showed the efficiency of 2b-RAD in the exploration of SNPs in U.prolifera and provided the first genome-wide scale evidence for the origin of the large-scale green tides on the Qingdao coast.This study improved our understanding of the reproductive strategy and genetic diversity of the green tide causative species and will help further reveal the biological causes of the green tide in China.

Patterns and drivers of plant sexual systems in the dry-hot valley region of southwestern China

Sexual systems play important roles in angiosperm evolution and exhibit substantial variations among different floras. Thus, studying their evolution in a whole flora is crucial for understanding the formation and maintenance of plant biodiversity and predicting its responses to environmental change. In this study, we determined the patterns of plant sexual systems and their associations with geographic elements and various life-history traits in dry-hot valley region of southwestern China, an extremely vulnerable ecosystem. Of the 3166 angiosperm species recorded in this area, 74.5% were hermaphroditic,13.5% were monoecious and 12% were dioecious, showing a high incidence of diclinous species. Diclinous species were strongly associated with tropical elements, whereas hermaphroditic species were strongly associated with temperate and cosmopolitan elements. We also found that hermaphroditism was strongly associated with showy floral displays, specialist entomophily, dry fruits and herbaceous plants.Dioecy was strongly associated with inconspicuous, pale-colored flowers, generalist entomophily, fleshy fruits, and woody plants, whereas monoecy was strongly associated with inconspicuous, pale-colored flowers, anemophily, dry fruits, and herbaceous plants. In addition, hermaphroditic species with generalist entomophily tended to flower in the dry season, whereas diclinous species with specialist entomophily tended to flower in the rainy season. However, independent of sexual systems, plants that produce dry fruits tended to flower in the rainy season and set fruits in the dry season, but the opposite pattern was found for fleshy fruit-producing plants. Our results suggest that in the dry-hot valleys, plant sexual systems are associated with geographic elements as well as various life-history traits that are sensitive to environmental change.

Reproductive biology of Hemitripterus villosus in the Bohai Strait,China

To understand the reproductive biology of Hemitripterus villosus in the Bohai Strait,and fill the key knowledge gap in verifying reproductive seasonality and documenting gonadotropin dependent reproductive cycle of this species,a year-round detail study was conducted for the first time.In total,263 individuals were randomly sampled off the coasts of the Bohai Strait.Results show that and the overall female-to-male ratio(1.35:1)did not differ significantly from the 1:1 sex ratio.The length and weight relationship for females and males were regressed,depicting an isometric growth for both sexes.Four reproductive phases of the complete gonadotropin dependent reproductive cycle in both sexes were identified.The monthly variations in the gonadosomatic and hepatosomatic indexes for both sexes further indicated that this species spawns a single batch of eggs per year and the peak spawning period is from October to December.The average diameter of eggs ranged from 2.10 to 3.57 mm.The length at first sexual maturity was 224.87 mm for females and 241.26 mm for males.Significant positive relationships between absolute fecundity and fish size,and also gonadal weight were observed.H.villosus from the Bohai Strait exhibited smaller body size,smaller egg diameter,lower gonadosomatic index,lower absolute fecundity,and higher population extinction risk than the other populations’studied previously.Our findings contribute to understanding the status of this isolated westernmost population,and we emphasize that more efficient protection measures for the species and control measures are urgently required to improve the coastal environment in the Bohai Strait.

Correlation of personality with individual reproductive success in shrub-nesting birds depends on their life history style

Two questions in the research of animal personality—whether there is a correlation between a personality trait and individual reproductive success,and what is the genetic basis underlying a personality trait—remain unresolved.We addressed these two questions in three shrub-nesting birds,the Azure-winged Magpie(Cyanopica cyanus,AM),White-collared Blackbird(Turdus albocinctus,WB),and Brown-cheeked Laughingthrush(Trochalopteron henrici,BL).The personality type of an individual was first identified according to its response to a territorial intruder.Then,we compared the fleeing distance,breeding parameters,and differential expressed genes(DEGs) in the brain transcriptome between bold and shy breeders.In the three species,bold breeders exhibited more aggressiveness towards an intruder of their territory than did shy breeders.The reproductive success of bold breeders was significantly higher than that of shy breeders in AM but not in WB and BL.The three species shared one DEG,crabp1,which was up-regulated in bold relative to in shy individuals.By regulating the expression of corticotropin-releasing hormone,higher crabp1 gene expression can decrease cellular response to retinoic acid.Therefore,bold individuals are insensitive to external stresses and able to exhibit more aggressiveness to intruders than their shier counterparts.Aggressiveness is beneficial to bold individuals in AM but not in WB and BL because the former could evoke neighbors to make the same response of defending against intruders but the latter could not.Although a personality trait may have the same genetic basis across species,its correlation with reproductive success depends largely on the life history style of a species.

Sexual Dimorphism and Female Reproductive Characteristics in the Hainan Water Skink(Tropidophorus hainanus)from Hainan,South China

We studied sexual dimorphism in body size and shape and female reproductive characteristics in the Hainan Water Skink(Tropidophorus hainanus)from Hainan,South China.In our sample the largest female and male were 61.1 and 55.2 mm snout-vent length(SVL),respectively.The mean SVL was larger in adult females(52.0 mm)than in adult males(48.3 mm).Juveniles were sexually dimorphic in head length but not in other examined morphological variables.Adult males were longer in head length and shorter in abdomen length and fore-limb length than adult females of the same SVL.Ontogenetic shifts in sexual dimorphism in body shape were evident,as revealed by the fact that morphological differences between the sexes were more pronounced in adults than in juveniles.Females produced a single litter of 3–6 offspring per season from early August to early September.Litter size,litter mass and offspring(neonate)mass were positively related to female SVL.Neonate mass was independent of relative fecundity.From the above findings we draw three main conclusions.First,females are the larger sex in T.hainanus,and sexual dimorphism in body shape is more pronounced in adults than in juveniles.Second,larger female T.hainanus produce more and larger offspring and thus heavier litters than smaller ones.Third,the offspring size-number trade-off does is not evident in T.hainanus.