Sexual size and shape dimorphism in Salamandra salamandra (Amphibia, Caudata, Salamandridae) from the central Balkans

Sexual size dimorphism is one of the key evolutionary features that has been studied in many organisms. On the other hand, sexual shape dimorphism has not been examined as well despite being as important as size dimorphism. Therefore, we analyzed the sexual size and shape dimorphism (SSSD) of Salamandra salamandra from the territory of the central Balkans. In addition, we wanted to reconsider if there is some regularity in the geographical distribution of SSSD in the investigated area. Significant differences in size and shape between the sexes were found for the whole sample and among the analyzed groups. Females were larger than males and had bigger heads, interlimb distances and a parotid gland, while males had bigger tails, forelimbs, hindlimbs, and forefoot and hindfoot length. Our results reveal a strong effect of locality on trait variation. This variation from the general pattern of SSSD is not substantial but still has to be considered.nul

Breeding site traits of European newts (Triturus macedonicus, Lissotriton vulgaris, and Mesotriton alpestris: Salamandridae) in the Montenegrin karst region

We recorded the occurrence of three European newt species - the smooth newt (Lissotriton vulgaris), the eastern alpine crested newt (Triturus macedonicus), and the alpine newt (Mesotriton alpestris) - in the Montenegrin karst, as well as their breeding site characteristics. In terms of long-lasting breeding site numbers and occupation rate, the most common species is the smooth newt, followed by the alpine newt and the crested newt. The examined water bodies with­out newts showed no significant differences of aquatic habitat characteristics compared to water bodies with newts. The factors that explained most of the observed variation in newt breeding site traits were the habitat category and habitat origin. The alpine newt primarily inhabits natural lakes, while the crested newt inhabits artificial breeding sites such as lithotelma and ubao. The smooth newt is less choosy and occurs in different types of natural and artificial habitats. The aquatic requirements of Montenegrin newt species do not differ substantially in many respects from requirements of the core species range populations.Istraživano je prisustvo tri vrste evropskih mrmoljaka u crnogorskom karstu, malog (Lissotriton vulgaris), istočnog glavatog (Triturus macedonicus) i planinskog mrmoljka (Mesotriton alpestris), kao i karakteristike njihovih reproduktivnih staništa. U pogledu broja reproduktivnih staništa, mali mrmoljak je najčešća vrsta, zatim sledi planinski i na kraju istočni glavati mrmoljak. Istraživana vodena staništa bez mrmoljaka nisu pokazala značajne razlike u karakteristikama u poređenju sa vodenim staništima sa mrmoljcima. Faktori koji najbolje objašnjavaju uočenu varijabilnost karakteristika reproduktivnih staništa mrmoljaka su tip i poreklo staništa. Planinski mrmoljak primarno naseljava jezera prirodnog porekla, dok istočni glavati mrmoljak naseljava antropogena staništa (najčešće kamenice i ublove). Mali mrmoljak naseljava različite tipove staništa prirodnog ili antropogenog porekla. Osobine reproduktivnih staništa mrmoljaka Crne Gore ne razlikuju se umnogome od osobina reproduktivnih staništa populacija iz centra areala ovih vrsta.Projekat ministarstva br. 14305

Morphological differentiation of the common toad Bufo bufo (Linnaeus, 1758) in the central part of the Balkan Peninsula

This study analyzes the degree of morphological differentiation among populations of the common toad Bufo bufo in the central part of the Balkan Peninsula. Variations in a number of morphometric and qualitative characters in 14 population samples were analyzed using univariate and multivariate statistics. We found a high degree of female-biased sexual size dimorphism. Morphological variation among the samples was more expressed in morphometric than in qualitative characters. The significant size differences that exist between northern and southern population groups could be the result of phenotypic plasticity. Our results do not support a clear split between northern and southern populations, contrary to the current taxonomic treatment of these groups as B. b. bufo and B. b. spinosus, respectively. [Projekat Ministarstva nauke Republike Srbije, br. 173043

Monitoring of aphid flight activities in seed potato crops in Serbia

Aphid flight activities in seed potato fields have been studied by the yellow water traps. It is a good method for monitoring aphids as vectors of viruses, but this study also showed it is a suitable method for insect-diversity research. During the four-year studies, over 11.500 specimens were collected and a total of 107 different taxa of aphids were identified. The most abundant species were polyphagous species, such as: Acyrthosiphon pisum (Haris), Aphis fabae Scopoli, Aphis gossypii Glover and Brachycaudus helichrysi (Kaltenbach). The results of the studies show that diversity of aphids in different regions of Serbia is similar regardless of the altitude and the diversity of terrain. At most sites it ranged from 2 to 3. The highest value was recorded in Begec, locality in northern part of Serbia, in year 2008, and it was 2.92. The maximum values of the Shannon-Weaver diversity index at all sites were recorded in the first weeks of the monitoring of aphid flight activities. Morisita-Horn similarity index shows no significant differences between sites regardless of altitudes. The sites are grouped by year, not by similarity of relief. In spite of these results, the Chi-square analysis showed highly significant difference in vector frequencies among seasons and sites with more pronounced differences for PVY. As a consequence of differences in vector frequencies, the vector pressure index in some regions was different also. The number of vectors and vector pressure index vary depending on the altitude of localities. At localities at altitudes under 1000 m, they were high. The highest index was at Kotraza, locality in central part of Serbia, in 2007, when PVY index exceeded the value of 180, while for PLRV it was 60. At high altitudes on mountain Golija, above 1100 m, the number of aphids was low, as well as the vector pressure index which indicates that these regions are suitable for producing virus-free seed potato

Sexual size and shape dimorphism in Salamandra salamandra (Amphibia, Caudata, Salamandridae) from the central Balkans

Sexual size dimorphism is one of the key evolutionary features that has been studied in many organisms. On the other hand, sexual shape dimorphism has not been examined as well despite being as important as size dimorphism. Therefore, we analyzed the sexual size and shape dimorphism (SSSD) of Salamandra salamandra from the territory of the central Balkans. In addition, we wanted to reconsider if there is some regularity in the geographical distribution of SSSD in the investigated area. Significant differences in size and shape between the sexes were found for the whole sample and among the analyzed groups. Females were larger than males and had bigger heads, interlimb distances and a parotid gland, while males had bigger tails, forelimbs, hindlimbs, and forefoot and hindfoot length. Our results reveal a strong effect of locality on trait variation. This variation from the general pattern of SSSD is not substantial but still has to be considered.nul

Patterns of cranial sexual dimorphism in the yellow-bellied toad (Bombina variegata, Bombinatoridae)

This study provides first insight into patterns of adult cranial size and shape sexual dimorphism in the yellow-bellied toad (Bombina variegata). Our results revealed significant cranial sexual size and shape differences in this species, with a very small impact of allometry on the shape diversity. The pattern of cranial sexual dimorphism indicates early differentiation of the sexes followed by parallel growth trajectories. Males have a larger cranium than females. Shape differences between the sexes are pronounced in the trophic part of the cranium. In comparison to females males have the lateral part of the nasal displaced posteriorly, a shorter anterior pterygoid process and the posterior part of the quadratojugal and pterygoid displaced toward the snout. Therefore, males have a wider but shorter posterior part of the cranium. Adaptation to divergent trophic niches driven by natural selection rather than sexual selection could have led to sexual size and shape differences in the yellow-bellied toad. However, further analysis of cranial variation patterns including ontogenetic aspects of cranial variation and ecological niche analyses are crucial to elucidate how different developmental and evolutionary mechanisms act on the cranium and result in size and shape sexual dimorphism

On the Asymptotic Distortion Behavior of the Distributed Karhunen-Loève Transform

All rights reserved.Investigation of sexual dimorphism patterns give us insight in how organisms adapt to fulfill their roles (reproductive, ecological, social) and enhance fitness. We examined sexual size and shape dimorphism in traits related to locomotion of nine anuran species from Serbia and Montenegro (Hyla arborea, Bombina variegata, Bufotes viridis, Rana temporaria, R. graeca, R. dalmatina, Pelophylax kl. esculentus, Pelobates fuscus and P. syriacus). Sexual size dimorphism in studied species ranges from female and male-biased, to absence of dimorphism. Sexual shape dimorphism was most pronounced in the forelimbs while the differences were small or did not exist in the hindlimbs and sacral traits. Males of most species were characterized by longer proximal parts (humerus and radioulna) and shorter distal forelimb parts, while the opposite pattern was observed in females. Also, some cases of significant intersexual shape differences are size-dependent. This indicates that these male traits are under stronger selective pressures to increase relative to body size, which may allow them to outcompete other males. Different types of behaviour can indirectly shape the limb morphology and lead to differences between the sexes. More data on the ecology and natural history of these animals are needed to explore the factors underlying the observed sex differences.Folia Zoologica (2017), 66(1): 11-2

Post-metamorphic ontogenetic changes in head size and shape of the pool frog (Pelophylax lessonae, Ranidae)

Post-metamorphic ontogenetic variations of head size and shape were investigated in the pool frog (Pelophylax lessonae, Ranidae). We showed that allometry is an important aspect of the post-metamorphic ontogeny of the pool frog as most of the differences between the head shape of subadults and adults were size-related adjustments. The largest changes affected by size variations included the posterior part of the head and the snout and eye region. In comparison to subadults, adults have wider heads, shorter snouts and relatively smaller eyes. Analyses of the relationships between head size and shape and the maximum size of the prey indicated the absence of correlations in adults. A positive correlation was found in subadults, but only between head width and the maximum size of the prey. Further studies will allow us to draw more generalized conclusions about the ecological relevance of the variations in head size and shape during post-metamorphic development of the pool frog

Amphibian and reptile road mortality in the protected area of Obedska Bara, Serbia

Millions of animals are roadkilled every year. Amphibians and reptiles are among the most prone to roadkill, especially near ponds and wetlands. We examined the impact of traffic on amphibian and reptile populations on the edge of Special nature reserve “Obedska bara”, Serbia. The aim of our study was to examine the temporal and spatial patterns of amphibian and reptile road mortality. From March to December 2018, we surveyed the road on foot for roadkills on a road section of 4.2 km, with two different habitat types (forest-pond and agricultural area-pond). Within 32 fieldwork days, we recorded 20457 roadkills (nine amphibian and eight reptile species). Amphibians (93%) were more vulnerable to traffic than reptiles (7%). Specimens of Pelophylax esculentus complex are the most frequently killed amphibians, followed by Pelobates fuscus, while specimens of Natrix natrix were the most frequently killed reptile species, followed by Emys orbicularis. The numbers of killed amphibians and reptiles varied with the season, indicating that species do not have the same roadkill patterns among the different seasons. Amphibian roadkills were the most frequent during the summer, while reptile roadkills were the most frequent in spring and late summer. Habitat type significantly affected the vulnerability of animals on roads. In addition to the different number of individuals killed in two different habitat types (higher in forest habitat), there was a difference in species composition. This study indicates that detailed monitoring and actions that will mitigate road mortality are urgently needed in the Special nature reserve “Obedska bara“

Morphological differentiation of the common toad Bufo bufo (Linnaeus, 1758) in the central part of the Balkan Peninsula

This study analyzes the degree of morphological differentiation among populations of the common toad Bufo bufo in the central part of the Balkan Peninsula. Variations in a number of morphometric and qualitative characters in 14 population samples were analyzed using univariate and multivariate statistics. We found a high degree of female-biased sexual size dimorphism. Morphological variation among the samples was more expressed in morphometric than in qualitative characters. The significant size differences that exist between northern and southern population groups could be the result of phenotypic plasticity. Our results do not support a clear split between northern and southern populations, contrary to the current taxonomic treatment of these groups as B. b. bufo and B. b. spinosus, respectively.Projekat ministarstva br. 17304