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  • Author or Editor: Abdullah Altunışık x
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Sexual dimorphism, phenotypic difference between males and females of the same species, has been demonstrated in many invertebrates and vertebrates. In many of these studies, which were especially conducted on amphibians, female individuals were reported to be larger than males. However, this does not necessarily mean that this also applies to body shapes. Therefore, in this study, a total of 31 characters of body size and body shape were measured and analyzed in the Near Eastern fire salamander, in order to understand whether these characters differ between female and male individuals. The results suggest that there is a significant difference between the sexes in terms of both body size and some body shapes (e.g. arm and leg length, arm diameter, cloacal proportions) in this fire salamander. I conclude that both sexual size and shape dimorphism need to be taken into account to help understand an organism’s life-history traits, ecology, population dynamics and behavior.

In: Animal Biology

Abstract

We investigated age structure, age at sexual maturity, lifespan, growth and survival rate and adult life expectancy (as demographic life-history traits) as well as body size of two Darevskia derjugini (Artvin lizard) populations from different altitudes, using skeletochronology. Our findings indicated that age upon attaining sexual maturity was two or three years in the low-altitude population (Fındıklı) while it was three years in the high-altitude population (Murgul) for both sexes. The maximum longevity was seven years in the high-elevation site while it was six years in the low-elevation site. As reported for many lizards, we found a significant positive relationship between age and body size within each sex of Artvin lizard at both altitudes. High- and low-altitude populations did not differ in age structure, survival rates, adult life expectancy and body size. Rather than the effect of altitude, which is hard to compare without replication of other low and high altitude populations, the fact that these two populations have similar growth rates and the similarity of local conditions (food availability and predator density) may indicate similarity between the two regions.

In: Animal Biology

Abstract

Knowing the age structure of endangered species is important in order to contribute to future conservation studies for such species. In this context, we investigated age structure, age at sexual maturity, potential reproductive lifespan and longevity in a population of the Charnali lizard, Darevskia dryada, an endangered species from Turkey. The results show that the Charnali lizard has a longer life span than other lizards of the genus Darevskia that live in the same region. We estimated that these lizards attain their sexual maturity at the age of one or two years and the potential reproductive life span for males and females is six and five years, respectively. As in many other lizards, the Charnali lizard exhibited a low-level male-biased sexual dimorphism in terms of increased size. We believe that this study, in which prior information related to the Charnali lizard is shared, will contribute to future conservation activities for this critically endangered species.

In: Animal Biology

To determine how climate factors influence age, body size and sexual size dimorphism (SSD) in the Mediterranean region, we generated data on age and body size of the European Treefrog, Hyla arborea, in three Turkish populations with a latitudinal gradient. We estimated age structure (total n = 154 ), using skeletochronology. Mean body size of both sexes was smaller in a southern population (Antalya) than in northern populations (Çanakkale and Rize) with female-larger SSD in the northern populations. A positive correlation was found between age and body size in each sex of all the populations, save the Antalya females. Since amphibian growth is reduced after maturity but continues towards the asymptotic size, interpopulation size differences may partly be explained by differences in longevity with four years in Antalya and five years in the other two populations. Comparing age and body size in three Turkish populations with those in three different populations (Greece, Switzerland and Germany) from the literature, there was a trend of South-to-North increase in body size with increased latitude and decreased temperature and aridity. The same trend occurred also in age structure (e.g., age at maturity/first reproduction, longevity). These results suggest that a difference in age structure between populations is a main factor for the geographic variation in body size of this species.

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In: Amphibia-Reptilia