No abstract

The majority of Haemogregarina species have been based on the morphology of their erythrocytic stages and supposed strict host specificity. The quantity of species with a limited number of overlapping diagnostic traits has led to a considerable mess in haemogregarine taxonomy and significant synonymy. We analysed host specificity, intra- and interspecific variability, evolutionary relationships, and the distribution of the type species of the genus Haemogregarina--H. stepanowi. The morphology of blood stages and 18S rDNA sequences of this haemogregarine from four western Palaearctic hard-shelled freshwater turtles (Emys orbicularis, Mauremys caspica, Mauremys leprosa and Mauremys rivulata) were compared with Haemogregarina balli. Additional sequences of 18S rDNA of Haemogregarina-like isolates collected from three species of African hinged terrapins (genus Pelusios) were used to enlarge the dataset for phylogenetic analyses. Thirteen sequences (1085 bp) of Haemogregarina representing all four western Palaearctic turtle species were identical, corresponding to H. stepanowi, which is closely related to the Nearctic species H. balli. In our analyses, Haemogregarina spp. constituted a monophyletic clade sister to the genus Hepatozoon. Haemogregarina stepanowi possesses a wide distribution range from the Maghreb, through Europe, Turkey and the Middle East to Iran. We consider that the genus Haemogregarina has a low host specificity crossing the family level of its vertebrate hosts and that its distribution is likely to be linked to the vector and definitive host--the leech.

The range dynamics of species distributed in temperate zones was significantly influenced by climatic fluctuations during the Pleistocene. However, little is known on how glacial and interglacial cycles affected the distribution of species occupying lower latitudes. The aim of this study was to assess Quaternary range dynamics of the spur-thighed tortoise (Testudo graeca) in Iran and Transcaucasia and to infer how range fluctuations influenced the species' genetic diversity. We analysed mitochondrial DNA variation of samples from Iran and Transcaucasia and reconstructed the species' palaeogeography by projecting species distribution models (SDMs) onto palaeoclimatic conditions of the mid-Holocene (6000 BP) and the Last Glacial Maximum (LGM, 21 000 BP). We found three mitochondrial lineages in Iran, corresponding to the subspecies T. g. armeniaca, T. g. buxtoni and T. g. zarudnyi, whose current distribution is limited predominately by precipitation. A combination of SDMs and demographic analyses revealed that the ranges of these subspecies experienced only a slight shift during the Quaternary and did not expand significantly after the LGM. These results for T. graeca indicate that range dynamics of ectothermic taxa occupying lower latitudes in the western Palaearctic might be more complex and may not follow a simplistic scenario of glacial retraction and postglacial expansion.

A complex wide-range study on the haemoproteid parasites of chelonians was carried out for the first time. Altogether, 811 samples from four tortoise species from an extensive area between western Morocco and eastern Afghanistan and between Romania and southern Syria were studied by a combination of microscopic and molecular-genetic methods. Altogether 160 Haemoproteus-positive samples were gathered in the area between central Anatolia and eastern Afghanistan. According to variability in the cytochrome b gene, two monophyletic evolutionary lineages were distinguished; by means of microscopic analysis it was revealed that they corresponded to two previously described species-Haemoproteus anatolicum and Haemoproteus caucasica. Their distribution areas overlap only in a narrow strip along the Zagros Mts. range in Iran. This fact suggests the involvement of two different vector species with separated distribution. Nevertheless, no vectors were confirmed. According to phylogenetic analyses, H. caucasica represented a sister group to H. anatolicum, and both of them were most closely related to H. pacayae and H. peltocephali, described from South American river turtles. Four unique haplotypes were revealed in the population of H. caucasica, compared with seven haplotypes in H. anatolicum. Furthermore, H. caucasica was detected in two tortoise species, Testudo graeca and Testudo horsfieldii, providing evidence that Haemoproteus is not strictly host-specific to the tortoise host species.

No abstract