scholarly journals Reproductive aspects of Dendropsophus sanborni (Anura, Hylidae) in northeastern Argentina

2014 ◽  
Vol 104 (4) ◽  
pp. 432-438 ◽  
Author(s):  
Lucila M. Curi ◽  
Gabriela. B. Olea ◽  
Blanca B. Álvarez ◽  
Jorge A. Céspedez ◽  
Daniel M. Lombardo
Keyword(s):  
Sexual Dimorphism ◽  
Body Mass ◽  
Reproductive Activity ◽  
Testicular Volume ◽  
Reproductive Pattern ◽  
Males And Females ◽  
Reproductive Cycles ◽  
Northeastern Argentina

Reproductive aspects of Dendropsophus sanborni (Anura, Hylidae) in northeastern Argentina. The aim of this investigation was to characterize reproductive aspects of Dendropsophus sanborni (Schmidt, 1944) (Anura, Hylidae) in the northwest of Corrientes province, in northeastern Argentina. The reproductive cycles of males and females, the existence of sexual dimorphism and the male’s vocalization period were analyzed. Samplings were made from September 2011 to August 2012. Dendropsophus sanborni showed a prolonged reproductive pattern because reproductive activity was observed during most part of the year. Calling males were recorded all months except in July. The spermatogenic cycle can be characterized as potentially continuous. In males, snout-vent length was significantly correlated with mean testicular volume. The species showed sexual dimorphism in body mass, with females larger than males. Post-ovulatory females were found from March to June and most females had oocytes at different stages of maturity, with abundant post-vitellogenic oocytes from August to December.

Reproductive biology of the false coral snake Oxyrhopus guibei (Colubridae) from southeastern Brazil

2002 ◽  
Vol 23 (4) ◽  
pp. 495-504 ◽  
Author(s):  
Otavio Marques ◽  
Lígia Pizzatto
Keyword(s):  
Body Size ◽  
Reproductive Biology ◽  
Rainy Season ◽  
Reproductive Activity ◽  
Climatic Conditions ◽  
Southeastern Brazil ◽  
Coral Snake ◽  
Males And Females ◽  
Reproductive Cycles ◽  
Number Of Individuals

AbstractThe reproductive biology of the false coral snake, Oxyrhopus guibei, was studied through dissection of 496 specimens, combined with observations on captive individuals. Males mature with smaller body size than females, females attain much larger body size, and male-male combat is not expected. Clutch size ranged from 3 to 20, and was correlated with female length. Reproductive cycles in both males and females seem to be continuous, with vitellogenesis and spermatogenesis occurring throughout the year. Reproductive activity in both sexes decreased at the end of the rainy season possibly due to previous intense reproductive activity in more favorable climatic conditions. The smaller number of individuals collected at the end of the rainy season apparently occurs due to the decrease of reproductive activity of this snake.

scholarly journals Sex-specific body mass ageing trajectories in adult Asian elephants

2020 ◽  
Author(s):  
Lucas D. Lalande ◽  
Virpi Lummaa ◽  
Htoo H. Aung ◽  
Win Htut ◽  
U. Kyaw Nyein ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Body Mass ◽  
Life Histories ◽  
The Body ◽  
Captive Population ◽  
Natural Death ◽  
Asian Elephants ◽  
Female Body Mass ◽  
Males And Females ◽  
Longitudinal Dataset

Sex-specific life-histories are thought to shape senescence patterns differently for males and females. In species with marked sexual dimorphism and where one sex is undergoing stronger intrasexual competition, it is expected that this sex ages earlier or quicker. Here, we utilise a unique, longitudinal dataset of a semi-captive population of Asian elephants (Elephas maximus) to describe the body mass ageing trajectories in this species with marked sexual dimorphism in size and lifespan, with males being larger and living shorter. Our results show sex-specific ageing trajectories: males gained weight throughout their life, at a diminishing rate until natural death. In contrast, adult female body mass did not change significantly with age until an abrupt decline during the last year of life. Our study shows that sex-specific life-histories shape ageing patterns contrary to those predicted by classical theory and expands the previously described diversity of ageing dynamics.

Reproductive tactics of Ameiva ameiva (Lacertilia: Teiidae) in a seasonally fluctuating tropical habitat

1982 ◽  
Vol 60 (12) ◽  
pp. 3113-3120 ◽  
Author(s):  
Laurie J. Vitt
Keyword(s):  
Body Mass ◽  
Egg Size ◽  
Fat Body ◽  
Reproductive Activity ◽  
Female Size ◽  
Northeast Brazil ◽  
Reproductive Tactics ◽  
Males And Females ◽  
Fat Bodies ◽  
Fat Body Mass

The reproductive ecology of Ameiva ameiva was studied for 12 months in a caatinga habitat of northeast Brazil. Even though rainfall was seasonal, the female reproductive cycle was not associated with this seasonality. Females reproduced year-round, with peak reproductive periods during August–October and January–February. Clutch size ranged from one to nine and was correlated to female size but egg size was constant. Males showed evidence of reproductive activity throughout the year. Fat body mass of males and females varied greatly among individuals. There was no association between fat storage and wet–dry seasonality. In females, fat body mass tended to decrease during peak reproductive periods. Most striking was the observation that 97.8% of all adult Ameiva possessed enlarged fat bodies, suggesting that resource periods low enough to affect reproduction did not exist during 1977–1978. The reproductive tactics of Ameiva were similar to those of other tropical macroteiids, regardless of their distribution, but very different than reproductive tactics of sympatric iguanid lizards. Compared with iguanid lizards, resources may be less limiting for macroteiids because their widely foraging behavior for prey acquisition may allow them to find rich patches of resources which would be unavailable to habitat specific sit-and-wait foragers, like most iguanid lizards.

The pattern of reproduction in the Libyan jird (Meriones libycus; Rodentia: Muridae) from central Saudi Arabia in the absence of rainfall

2019 ◽  
Vol 97 (3) ◽  
pp. 210-219 ◽  
Author(s):  
D.W. Hart ◽  
A.A. Alghamdi ◽  
N.C. Bennett ◽  
O.B. Mohammed ◽  
N.M. Amor ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Reproductive Tract ◽  
Sampling Period ◽  
Reproductive Activity ◽  
Reproductive Organs ◽  
Early Spring ◽  
Reproductive Pattern ◽  
Plasma Progesterone ◽  
Males And Females ◽  
Tubule Diameter

The reproductive pattern of the Libyan jird (Meriones libycus Lichtenstein, 1823) from central Saudi Arabia was investigated in the absence of rainfall. In this study, body mass, morphometry of the reproductive tract, the histology of the reproductive organs, and the hormone concentrations of males and females were studied over 12 consecutive months in a wild population of the Libyan jird from central Saudi Arabia. Previous studies have found the breeding season of the Libyan jird from the Sahara desert of Algeria to occur during the wet months of spring. In the absence of rainfall, temperature and photoperiod were found to be important activators of reproductive activity. The cooler temperatures and shorter days of winter triggered the onset of ovulation in females and increased testes size and seminiferous tubule diameter in males. Only two pregnancies were found during the sampling period, which occurred during the cooler winter and early spring and coincided with a rise in plasma progesterone concentration in females. The Libyan jird was found to shift its breeding to the cooler months of winter in the absence of rainfall. This study strengthens the findings that changes in rainfall and temperature in dry deserts are critical cues for the onset of reproduction in small mammals.

Observation on the breeding biology of Polypedates teraiensis (Dubois, 1987) (Amphibia: Rhacophoridae)

2017 ◽  
Vol 17 (1) ◽  
pp. 25-32
Author(s):  
Jacinta Lalchhanhimi ◽  
Lalremsanga H.T.
Keyword(s):  
Sexual Dimorphism ◽  
Breeding Season ◽  
Sound Production ◽  
Reproductive Function ◽  
Breeding Biology ◽  
Tree Frog ◽  
University Campus ◽  
Morphometric Measurements ◽  
Advertisement Calls ◽  
Males And Females

The breeding biology of tree frog, Polypedates teraiensis was studied during the breeding season at Mizoram University Campus. It was found that sound production by male during the breeding season was primarily a reproductive function and advertisement calls attract females to the breeding areas and announce other males that a given territory is occupied. The aim of this study was to provide the detailed information on the breeding behaviour and the advertisement calls of Polypedates teraiensis. The morphometric measurements of the amplecting pairs (males and females) for sexual dimorphism along with clutch sizes were also studied.

Sexual Dimorphism among the Kathmandu University Students Assessed by Anthropometric Studies

2018 ◽  
Vol 9 (05) ◽  
pp. 20469-20472
Author(s):  
Shakya R ◽  
Bhattacharya SC ◽  
Shrestha R
Keyword(s):  
Young Adults ◽  
Sexual Dimorphism ◽  
Young Adult ◽  
University Students ◽  
Plastic Surgery ◽  
Age Group ◽  
Adult Age ◽  
Clinically Normal ◽  
Crime Detection ◽  
Males And Females

Objectives: To observe the sexual dimorphism among the young adult age group ranging from 18-21 years, of Kathmandu University students by measuring craniofacial circumference and canthal distances. Rationale of the study: These data could be useful for establishing the craniofacial standards and adds an implementation on plastic surgery, crime detection as well as in the industrial field. Method: 300 clinically normal students of Kathmandu University aged between 18-21 years were examined for the study. Fronto-occipital circumference, outer and inner canthal distances were measured. All the parameters were compared between males and females. Result: The cranial circumference as well as the inner and outer canthal distance in males was found to be significantly higher as compared to the females. Conclusion: The results concluded that sexual dimorphism remarkably exists in young adults of Kathmandu University students.

scholarly journals Sexual dimorphism in the long-term stability (10 years) of skeletal Class III treatment

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Natalia Tejedor ◽  
Conchita Martín ◽  
José Antonio Alarcón ◽  
María Dolores Oteo-Calatayud ◽  
Juan Carlos Palma-Fernández
Keyword(s):  
Sexual Dimorphism ◽  
Class Iii ◽  
Class Iii Malocclusion ◽  
Skeletal Class ◽  
Term Stability ◽  
Long Term Stability ◽  
Fixed Appliances ◽  
Males And Females ◽  
Class Iii Treatment

Abstract Background Class III malocclusion is associated with high sexual dimorphism, especially in individuals older than 13 years of age, with significant differences in growth between males and females during the pubertal and postpubertal stages, and in adulthood. The aim of this research was to examine differences between males and females in long-term stability (10 years) of treatment for skeletal Class III malocclusion. Methods Thirty patients (15 males and 15 females) with skeletal Class III malocclusion, who had been treated with rapid maxillary expansion (RME) combined with face mask protraction followed by fixed appliances, were selected sequentially. Thirty patients (15 males and 15 females) with skeletal Class I and mesofacial patterns treated only with fixed appliances for dental problems served as the control group. Differences between groups and sexes were evaluated using lateral cephalograms taken at the start of treatment (T0), immediately after the end of treatment (T1), and after 10 years (T2). The long-term treatment success rate was calculated. Results Ten years after Class III treatment, overjet and overbite relapse occurred similarly in females (− 0.68 ± 0.7 mm; − 0.38 ± 0.75 mm, respectively) and males (− 1.09 ± 1.47 mm; − 0.64 ± 0.9 mm, respectively); the ANB angle and Wits appraisal became significantly more negative in males (− 1.37 ± 1.06°; − 2.7 ± 2.53 mm) than in females (− 0.18 ± 1.26°; − 0.46 ± 1.94 mm). The success rate was 73.3% in males and 80% in females. Conclusions Significant differences in the long-term stability of Class III treatment outcomes have been found between males and females, with a larger skeletal Class III relapse and lower long-term success rates in males.

scholarly journals Safe sex: male–female coalitions and pre-copulatory mate-guarding in a fiddler crab

2009 ◽  
Vol 6 (2) ◽  
pp. 180-182 ◽  
Author(s):  
Richard N. C. Milner ◽  
Michael D. Jennions ◽  
Patricia R. Y. Backwell
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Success ◽  
Observational Data ◽  
Fiddler Crab ◽  
Lower Boundary ◽  
Mate Guarding ◽  
Maintenance Costs ◽  
Boundary Maintenance ◽  
Uca Annulipes ◽  
Males And Females

In fiddler crabs both males and females defend territories that are essential for survival. Given pronounced sexual dimorphism in weaponry, how do weaponless females defend their territory from well-armed males? Using observational data and two simple experiments, we test whether male Uca annulipes protect their female neighbours from conspecific intruders. We show that males defend their female neighbours against male but not female intruders. We also show that females sometimes mate with their immediate neighbours. Male defence of female neighbours appears to represent both pre-copulatory mate-guarding and a territorial coalition. Males who ensure that their neighbour remains female could benefit through increased opportunity for future reproductive success and lower boundary maintenance costs.

Sex differences in white adipose tissue expansion: emerging molecular mechanisms

2021 ◽  
Vol 135 (24) ◽  
pp. 2691-2708
Author(s):  
Simon T. Bond ◽  
Anna C. Calkin ◽  
Brian G. Drew
Keyword(s):  
Sex Differences ◽  
Sexual Dimorphism ◽  
Gene Networks ◽  
Large Scale ◽  
Molecular Mechanisms ◽  
Association Studies ◽  
Tissue Expansion ◽  
Economic Systems ◽  
Genomic Association ◽  
Males And Females

Abstract The escalating prevalence of individuals becoming overweight and obese is a rapidly rising global health problem, placing an enormous burden on health and economic systems worldwide. Whilst obesity has well described lifestyle drivers, there is also a significant and poorly understood component that is regulated by genetics. Furthermore, there is clear evidence for sexual dimorphism in obesity, where overall risk, degree, subtype and potential complications arising from obesity all differ between males and females. The molecular mechanisms that dictate these sex differences remain mostly uncharacterised. Many studies have demonstrated that this dimorphism is unable to be solely explained by changes in hormones and their nuclear receptors alone, and instead manifests from coordinated and highly regulated gene networks, both during development and throughout life. As we acquire more knowledge in this area from approaches such as large-scale genomic association studies, the more we appreciate the true complexity and heterogeneity of obesity. Nevertheless, over the past two decades, researchers have made enormous progress in this field, and some consistent and robust mechanisms continue to be established. In this review, we will discuss some of the proposed mechanisms underlying sexual dimorphism in obesity, and discuss some of the key regulators that influence this phenomenon.

Sign in / Sign up

Export Citation Format

Share Document