Morfološka varijabilnost kinetičkog glavenog skeleta i pileusa zmija iz roda Natrix (N. natrix i N. tessellata)
Morphological variation of kinetic head skeleton and pileus in snake from the genus Natrix (N. natrix and N. tessellata)
Abstract:
Most of the previous investigations on the structure and patterns of cranial skeletons
variability were done in groups with akinetic skull. Research of snake’s kinetic cranial
skeleton can provide a better understanding of the relationship between developmental
and functional integration, influence of allometry on shape variation and morphological
integration of the cranial skeleton, shape changes during ontogeny, as well as
morphological divergence between the sexes. In addition, analysis of pileus variability
may provide insight into general pattern of head variability. The main aim of this thesis
was to define the patterns of morphological variability and factors that affect the
variability of head skeleton and pileus in two sister snakes species from the genus
Natrix (Grass snake, N. natrix and Dice snake, N. tessellata) using the methods of
computed tomography and geometric morphometrics. The results showed that N. natrix
and N. tessellata differ in size and shape of cranial elements. Observed differences
probably reflect differences in the type and size of the prey, hunting environment and
strategies, handling abilities and prey swallowing. Sexual dimorphism in size and shape
of cranial elements are pronounced among Grass and Dice snakes. In both species,
braincase and elements of the trophic apparatus are highly integrated, while the bones of
the snout can be considered as separate modules. The function is the main factor of
morphological integration between cranial elements. Hatchlings of Grass and Dice
snakes differed in pileus shape, while sexual dimorphism in pileus shape was detected
in adults only. For both size and shape, high levels of correlation between braincase and
pileus were estimated.
Keywords:
Morphological variability; Sexual dimorphism; Ontogeny; Morphological integration and modularity; Allometry; Skull; Pileus; Natricinae; 3D models; Geometric morphometricsSource:
University of Belgrade, Faculty of Biology, 2017, 1-107Funding / projects:
- Mechanisms of the immune response to parasitic infection, or exposure to parasite antigens, and the concomitant modulation and/or prevention of unrelated diseases (RS-MESTD-Basic Research (BR or ON)-173047)
- Evolution in the laboratory and adaptations in the wild (RS-MESTD-Basic Research (BR or ON)-173007)
URI
http://uvidok.rcub.bg.ac.rs/handle/123456789/2185https://radar.ibiss.bg.ac.rs/handle/123456789/2880