| Abstract |
The aim of this master was to clarify the distribution of Mauremys caspica in Crete, the search for possible differentiations among the populations on the island and the study of the species ecology. Crete was selected as the study area for many reasons: · It is the only Mediterranean island which sustains big populations of the species. · The island's geographic position is very important for a biogeographical point of view since all three surrounding continents affect it. Thus the clarification of the arrival of the animal on the island will provide important data on the colonization of the island. · Crete due to its complicated morphology, includes very many, small, isolated wetlands. The first chapter approaches the systematics of the species and the differentiations among collected populations on the base of morphometric data. The protocol for DNA extraction and amplification by PRC were standardized for the species. The morphometric analysis of a population of Almyros, showed that features as the carapace's height, the tails length and the position of the cloaca on the tail my be used as characters to separate males from females. Juveniles have "rounder" carapaces than adults. Comparison of morphometric data among the other populatins did not show significant differences. The latter may be due to the small number of individuals at our disposition. In the second chapter an analysis of the distribution of the species with emphasis in Crete and Greece is attempted. For the latter we used bibliographical data as well as new data from samplings that were produced from this study. Samplings took place in Crete, the Aegean islands and two countries of the Eastern Mediterranean: Syria and Jordan. Finally data were complemented by a questionnaire distributed to local authorities in Crete. Bibliographic data for Crete were proven poor since they covered only 30% of the distribution found on the island from samplings and questionnaire results. Two localities in Crete (Zakros in the eastern part and Kria Vrisi in the west) are reported here for the first time. In two Aegean islands the species has most probably gone extinct. The ecology and ethology of the species is studied in the third chapter. Habitats in Crete, demographic data of the Almyros (Iraklio) population, feeding behaviour, thermoregulation and possible threats were approached by means of observations in the field and in a population in semi captivity. Mauremys caspica seems to be to some extent unaffected by water quality. Increasing the age the animal tends to herbivory but readily consumes any kind of meat (carrion to fresh). The procedure of egg laying is described here for the first time. Adults follow different thermoregulation patterns than juveniles. The main predators of the animal in Crete are the martin (Martes foina) and the black rat (Rattus rattus). Two responses to danger were recorded here for the first time: when captured the animals urinate in large quantities and excrete an unknown kind of waxy substance with a repulsive odor from the area between their legs
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Οικολογία, κατανομή και διαφοροποίηση της Mauremys caspica(Testudines:Bataguridae)στην Κρήτη
