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

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.

1994 ◽  
Vol 15 (2) ◽  
pp. 123-133
Author(s):  
H. Saint Girons ◽  
R. Duguy

AbstractThe relative mass of fat bodies of 103 adult male Vipera aspis from western France appeared to be correlated with fasting and feeding periods. There was a slow decline in mass during wintering and a rapid decline during the occurrence of spring mating; a minimum fat body mass was at the first molting time in May. This was the only time when there was a significant decline in the relative mass of the liver; vipers are noticeably emaciated during this period. Changes in relative kidney mass were correlated with the volume of the sexual segment of the kidneys, the minimum being in July. The relative mass of the testes was also linked with the sexual cycle; the minimum appeared to be in July and there was little variation between September and May.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Justina Koubová ◽  
Michala Sábová ◽  
Miloslav Brejcha ◽  
Dalibor Kodrík ◽  
Radmila Čapková Frydrychová

AbstractIn honeybees (Apis mellifera), the rate of aging is modulated through social interactions and according to caste differentiation and the seasonal (winter/summer) generation of workers. Winter generation workers, which hatch at the end of summer, have remarkably extended lifespans as an adaptation to the cold season when the resources required for the growth and reproduction of colonies are limited and the bees need to maintain the colony until the next spring. In contrast, the summer bees only live for several weeks. To better understand the lifespan differences between summer and winter bees, we studied the fat bodies of honeybee workers and identified several parameters that fluctuate in a season-dependent manner. In agreement with the assumption that winter workers possess greater fat body mass, our data showed gradual increases in fat body mass, the size of the fat body cells, and Vg production as the winter season proceeded, as well as contrasting gradual decreases in these parameters in the summer season. The differences in the fat bodies between winter and summer bees are accompanied by respective increases and decreases in telomerase activity and DNA replication in the fat bodies. These data show that although the fat bodies of winter bees differ significantly from those of summer bees, these differences are not a priori set when bees hatch at the end of summer or in early autumn but instead gradually evolve over the course of the season, depending on environmental factors.


2020 ◽  
Vol 10 (24) ◽  
pp. 9022
Author(s):  
Souhail Hermassi ◽  
Maha Sellami ◽  
Georg Fieseler ◽  
El Ghali Bouhafs ◽  
Lawrence D. Hayes ◽  
...  

This study aimed to compare 10-to-12-year-old Qatari male athletes and assess body fat, body mass index, and physical fitness, as well as the difference of these measures between ages. Thirty-five youth handball players volunteered for the investigation and were divided into three groups: 12-year-old players (U12; n = 12), 11-year-old players (U11; n = 11), 10-year-old players (U10; n = 12). Anthropometry was assessed by body mass, body fat percentage (%BF), and body mass index (BMI). Measurements included the Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo IR1), jumping ability (squat and countermovement jumps (SJ and CMJ, respectively)), and sprint tests (10 and 15 m). The power of the upper extremity was measured by a 2-kg overhead medicine ball throw for distance. Except for %BF (p = 0.387) and BMI (p = 0.070), all anthropometric and demographic parameters were different between age groups. The largest differences were found for body mass (p = 0.007) and body height (p = 0.008). Regarding fitness parameters, only the medicine ball throw (p = 0.022) was different between age groups (U10 vs. U12: p = 0.009; U11 vs. U12: p = 0.048). There was no difference between groups for jumping (CMJ: p = 0.586; SJ: p = 0.377), sprinting (10 m: p = 0.211; 15 m: p = 0.194) and Yo-Yo IR1 (p = 0.228). Body fat was the anthropometric parameter with the strongest relationship with physical performance in that lower body fat was related to superior jumping performance and sprint performance. In conclusion, except for %BF and BMI, all anthropometric parameters were different between U10, U11, and U12 handball players. For physical parameters, jumping, sprinting, and endurance performance were not different between age groups. From a practical perspective, coaches can use these findings as reference for the evaluation of their school-aged handball players, as well as for establishing performance goals.


1992 ◽  
Vol 13 (2) ◽  
pp. 121-133 ◽  
Author(s):  
Fabio M. Guarino ◽  
Vincenzo Caputo ◽  
Francesco Angelini

AbstractThis paper describes the reproductive cycle in male and female newts Triturus italicus (Peracca, 1898) from a mountain population living in southern Italy. The male shows a well-defined seasonal testicular cycle: spermatogenesis almost stops from November to March, resuming in April-May; the maturative stage of spermatogenesis occurs in summer and spermiohistogenesis is completed by late October. Spermiation starts in late autumn and culminates in the next spring. The female shows a seasonal ovarian cycle. Vitellogenesis starts in September; ovulation and egg deposition occur between late January and early June. Thus potentially long reproductive activity is demonstrated in both males and females of T italicus. Testicular and ovarian weights seem to be reliable indices of the reproductive status of an animal. Annual variation in gonadal weight appears unrelated to annual variation in fat body weight in both sexes.


2016 ◽  
Vol 29 (2) ◽  
pp. 97-100
Author(s):  
Igor Gunas ◽  
Olexandr Majewski ◽  
Irina Makarchuk

Abstract The article describes the differences in peculiarities of somatotype and body weight component composition in patients with acne, the study population being boys and girls of the Podillya region of Ukraine. In the study subjects, regardless of sex, body muscle mass, bone mass and the mesomorphic somatotype component of those with acne were significantly greater, while fat body mass indicators and the endomorphic somatotype component was smaller – in comparison to that of non-afflicted subjects of similar gender. Regarding the ectomorphic component of somatotype, between the surveyed groups of those with and without acne, whether male or female, no significant differences were revealed. For all indicators, whether the somatotype components or the component composition of body weight, between groups of boys or girls with different degrees of severity of acne, again no significant differences were established.


2004 ◽  
Vol 22 (Suppl. 2) ◽  
pp. S33
Author(s):  
B. Pannier ◽  
J. Raison ◽  
T. Kondo ◽  
J. Blacher ◽  
M. Safar

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