Search Results (13)

The Maghreb population of Emys orbicularis extends over a narrow strip of northern Morocco, Algeria, and Tunisia. Our understanding of the presence of this turtle in Algeria, in contrast to Morocco and Tunisia, is quite limited and frequently rests on a few small-scale studies or even reports from a century ago. The present study provides the first complete data on the distribution and level of threat of this species in Algeria. A field survey was carried out based on the data obtained from scattered local reports and available studies that suggested the presence of the species in Algerian wetlands. Data on climatic and habitat preferences, the geographic elevation of inhabited localities, and their conservation status were collected. A total of 45 wetlands were inhabited by E. orbicularis, of which 40 were part of a well-interconnected eastern metapopulation, joined by an extensive hydrographic network. In some places, the species has persisted for over 130 years in the same wetland complex. However, the five remaining populations living in central North Algeria are fragmented, highly isolated, and therefore more threatened. With a few exceptions, turtles inhabit lowlands below 100 m above sea level. Detected sub-populations inhabit mostly stagnant waters (60%), sometimes dams and lakes (24%), and sporadically also slow-moving water bodies (16%). Altogether, the Algerian distribution of E. orbicularis extends to a total area of 2900 km², a 40 km wide strip with a length of 490 km west of the Tunisian border. Although restricted to this narrow strip, the persistence of numerous populations in Algeria, especially in Numidia, testifies to their relatively better conservation status. In order to ensure the sustainability of these efforts, follow-up and monitoring activities should be suggested, with special attention paid to highly isolated populations to maintain their long-term viability. Full article

The eight-year study (2015–2023) was performed on a large sample of poached European pond turtles infected with Haemogregarina stepanowi and held in a pond that belongs to a quarantine section of Belgrade Zoo. The protected species of European pond turtles have been found in poor health, with general weakness, anorexia, and low motility. Comprehensive cytological, hematological, molecular, and postmortem evaluations have been performed. Initially, Diff Quick staining of the blood smears revealed rounded or elongated erythrocytes, often bearing premeront or U-shaped gamont of the hemogregarines inside. The reduced erythrocyte numbers, hemoglobin, and hematocrit values found in the examined population of infected turtles indicated anemia. Macroscopically, shell necrosis and massive skin hemorrhages were the most prominent findings observed in diseased turtles. Microscopically, the lungs, liver, kidneys, and spleen revealed hyperemia, hemorrhages, and the presence of parasitic stages in tissue samples in 31 of 40 necropsied turtles. Cytological and microscopic examination of the samples proved to be sufficient for establishing the infection, but molecular analyses of the 18S sequence were used for phylogenetic studies. Over the years, the number of diseased and dead turtles has decreased, which could be hypothetically attributed to the elimination of leeches as the definitive host. Full article

Haemogregarines are blood parasites with a life-cycle involving a vertebrate as the intermediate host and an invertebrate as the definitive host and vector. Extensive phylogenetic investigations based on 18S-rRNA gene sequences have shown that Haemogregarina stepanowi (Apicomplexa: Haemogregarinidae) is able to infest a large diversity of freshwater turtle species, including the European pond turtle Emys orbicularis, the Sicilian pond turtle Emys trinacris, the Caspian turtle Mauremys caspica, the Mediterranean pond turtle Mauremys leprosa, and the Western Caspian turtle Mauremys rivulata, among others. From the same molecular markers, H. stepanowi is further considered to be a complex of cryptic species predisposed to infect the same host species. While Placobdella costata is known to be the unique vector of H. stepanowi, it is only recently that independent lineages within P. costata have been illustrated—suggesting the presence of at least five unique leech species across Western Europe. The aims of our study were therefore to investigate from mitochondrial markers (COI) the genetic diversity within haemogregarines and leeches infecting freshwater turtles of the Maghreb, in order to identify processes of parasite speciation. We showed that H. stepanowi consists of at least five cryptic species in the Maghreb, while two Placobella species were identified in the same area. Although an Eastern–Western speciation pattern was apparent for both leeches and haemogregarines, we cannot make definitive conclusions regarding co-speciation patterns between parasites and vectors. However, we cannot reject the hypothesis of a very strict host–parasite specificity within leeches. Full article

Haemogregarines (Apicomplexa: Adeleorina) are the most common and widespread reptilian blood parasites. Haemogregarina stepanowi was the first haemogregarine described from a reptile, the European pond turtle Emys orbicularis, and initial assessments indicated it was widespread across different pond turtle host species across much of Europe, the Middle East and North Africa. However, recent molecular assessments have indicated the presence of multiple genetically distinct forms in North Africa and the Iberian Peninsula, and extensive mixed infections which may be associated with a negative impact on the hosts. Here, we screened two native species, E. orbicularis and Mauremys rivulata, and the introduced Trachemys scripta from Serbia and North Macedonia for haemogregarines by amplifying and sequencing part of the 18S rRNA gene of these parasites, and used a standard DNA barcoding approach to identify leeches, the final host, attached to pond turtles. Our results again demonstrate the occurrence of considerable diversity of parasites in the analysed pond turtle species, and that T. scripta are likely infected by local haemogregarine parasites, and not those that are found in its native range. Leeches were identified as Placobdella costata, part of a lineage from Northern Europe. Mixed infections within pond turtles were again common. Current haemogregarine taxonomy does not reflect the genetic diversity identified, and a full taxonomic reassessment is needed. Full article

This multiproxy work presents the archeozoological analysis of fish and microvertebrate remains from the Middle Bronze Age tell site of Borsodivánka (Borsod Plain, North-eastern Hungary). The fish faunal assemblage provides valuable data on the choice of exploited consumption patterns, taphonomy, and aquatic paleoenvironmental conditions at the site during the Bronze Age. Only freshwater taxa are present in the assemblage, for example, northern pike (Esox lucius); cyprinids: roach (Rutilus rutilus), common carp (Cyprinus carpio), common chub (Squalius cephalus) and common nase (Chondrostoma nasus); and percids: European perch (Perca fluviatilis) and pikeperch (Sander lucioperca). Herpetofaunal and micromammal remains are also part of this study, improving our knowledge of the site’s freshwater ecosystem. The grass snake (Natrix cf. natrix) and the European pond terrapin (Emys orbicularis), typical of aquatic ecosystems, are associated with the Aesculapian ratsnake (Zamenis longissimus), more typical of forest, shrubland, and grassland. The presence of amphibians such as toads (Bufo/Bufotes sp.) and frogs (Rana sp.) complete the herpetofaunal list. The microvertebrates also support a mature fluvial system, as represented by taxa like the European water vole (Arvicola amphibius). Other micromammals are present, such as the wood mouse (Apodemus sylvaticus), the group of the common/field vole (Microtus arvalis/agrestis), the European mole (Talpa europaea), and the house mouse (Mus musculus). All of them are common in forests, shrubland, and grassland. However, the commensal house mouse is more commonly associated with anthropogenic areas. In conclusion, Borsodivánka is characterized by a diverse landscape mosaic, displayed by the co-existence of a well-developed forest and a freshwater inland ecosystem with agricultural land in the wider area. Finally, the Tisza River and its flood plain represented the main water source close to the site, distinguished by the dominance of fish species from deep and slow-flowing waters. Full article

Nest predation significantly impacts the population decline of the long-living European pond turtle (Emys orbicularis). Kis-Balaton is one of the most important habitats of this species in Hungary, and in May 2017 more than 400 damaged nests were counted. To reveal predation pressure, we conducted a study with artificial nests on three sites in this area. On each site, we used 11 depredated real nests, and near each of them, we created new artificial nests; then in every nest we put one quail egg, one plasticine egg and several turtle egg shells. After that, we sprayed the smoothed surface of the covered holes with water-diluted turtle urine, imitating the turtle’s behaviour. Already in the first three nights, 94% of all nests were depredated by the red fox (Vulpes vulpes) and in one case by the European badger (Meles meles), which was confirmed by the bite marks preserved on the plasticine eggs, by the footprints and excrements found near the nests, as well as by camera recordings. Only 6% of the nests survived during the three weeks of our study. Daily survival rates of quail eggs in artificial nests established in both real (damaged) and in new nests were similar, suggesting that estimates obtained with artificial nests reflect the degree of predation pressure on real nests. On the site where the nests were scattered, their daily survival rate (33%) was significantly lower than on the sites where their arrangement was partly scattered, partly linear (83%), or only linear (76%). On two additional sites, by using simulated turtle nests we showed that spraying the nests with diluted turtle urine and marking them with a flag did not affect their survival, although further methodological testing is needed. The information obtained with artificial nests enables the organization of the protection of the nests of the European pond turtle and selective predator control. Full article

The results of a review of the chelonian remains retrieved in the excavations carried out in Mealhada (Coimbra, central Portugal) are presented here. Mealhada is a Portuguese Middle Palaeolithic classical site, discovered at the end of the 19th century, and chronologically ascribed to the interglacial Riss-Würm (ca. 120 ka BP). This study has allowed the identification, justification, and figuration of remains attributed to three Iberian chelonian taxa, Testudinidae indet., Mauremys leprosa, and Emys orbicularis, the last one being recognized for the first time in this site. Thus, an update on the data concerning the chelonian record from Mealhada has been achieved, offering new justified taxonomic evidence regarding Iberian chelonian taxa distribution during the Upper Pleistocene. Furthermore, chelonian consumption amongst pre-Upper Palaeolithic hunter-gatherer groups has been documented worldwide. Frequently a locally captured resource, archaeological turtle remains offer relevant information concerning the role that small prey has played in hominid nutritional choices. The potential presence of anthropic alterations (e.g., cutmarks) in some of the chelonian remains from Mealhada is here analysed and the human consumption hypothesis assessed. Full article

Island wetlands are considered crucial to biodiversity due to their unique ecological, biogeographical, and socioeconomic dynamics. However, these habitat types are particularly vulnerable to invasion; invasive species can cause severe ecological, evolutionary, and epidemiological impacts on native species. One of the most important invasive species, the common slider Trachemys scripta, an opportunistic inhabitant of freshwater habitats, has been released in multiple localities across Greece in recent years, and has expanded its range through random and unintentional releases in the Aegean islands. Since its first documented record on the island of Crete in 1998, the species has been observed on six more islands. Here, we report, for the first time, two subspecies of the common slider (T. scripta scripta and T. scripta elegans) on the wetlands of the island of Lesvos. We discuss the potential threats to native terrapins and we examine whether the introduction of this invasive species has affected native terrapins by monitoring their populations for 12 consecutive years (2010–2022). We found the common slider in 3 out of 110 wetlands surveyed. At one site, we document the presence of invasive terrapins belonging to two different subspecies. In all surveyed wetlands, we found stable populations of the two native freshwater terrapins, Mauremys rivulata and Emys orbicularis, with the first species found in much larger populations than the second. Despite these reassuring findings, the presence of this introduced species on the island of Lesvos raises serious concerns regarding its negative effects on the local terrapin populations. We propose that systematic and thorough monitoring of insular wetlands, as in the case of Lesvos, should be adopted on other islands as well, with priority on those where the common slider has been recorded. Full article

The aim of the study was to isolate and identify species belonging to the Aeromonas genus and evaluate the antimicrobial resistance and virulence patterns of isolates colonizing European pond turtles (Emys orbicularis) from natural environment of Eastern Poland. In total, 74 turtles and 15 samples of water from their natural environment were examined. More than 40 strains were isolated and identified: A. bestiarum (n = 1), A. hydrophila (n = 13), A. allosaccharophila (n = 2), A. salmonicida (n = 3), and A. veronii (n = 23). The highest incidence of resistance was noted for ampicillin (100%) and sulfamethoxazole (62.0%), followed by erythromycin and colistin (both 40.5%). Moreover, eight strains were intermediately resistant to meropenem (19%). Most Aeromonas isolates were found to possess more than one virulence gene among fla, aer, hlyA, act, ela, alt, and ast. We showed that the population of free-living European pond turtles was highly colonized by Aeromonas spp. Such strains may be an infectious agent not only for the population of turtles but also for other species of animals inhabiting their natural environment. Moreover, the undesirable properties of water quality caused by the presence of drug-resistant aeromonads could have a negative impact on human health. Full article

In order to use an integrated approach for studying the influence of risk factors on the distribution of the native turtle species E. orbicularis and accompanying invasive species (T. scripta and N. procyonoides) in the northeast of their range, we used GIS modelling and a database (GAEZ, human footprint, CliMond) of 55 preselected variables, which represent a system of bioclimatic and anthropogenic factors. The main variables that influenced the results were factors related to temperature. There was a high correlation (r = 0.6) between the species distribution model’s habitat suitability for E. orbicularis and the corresponding “human footprint” values within the European part of the species’ natural range. Its unpretentiousness towards anthropogenic factors would likely help the further expansion of its range in eastern Europe, because the areas with the highest habitat suitability (r > 0.7) were projected to increase 3.3-fold. When comparing the E. orbicularis model to those obtained for N. procyonoides and T. scripta, we concluded that N. procyonoides could be dangerous because it occupies similar habitats (the degree of correlation is reasonably high in the north of their range (r = 0.5) in Latvia). An expansion of the range of Trachemys scripta is also possible in the future within the northern territories. Therefore, when developing the turtles’ protection algorithms, it is also necessary to take into account the influence of invasive species. Full article

Few species of reptiles are known to establish stable social structures and among these, chelonians provided scarce and conflicting results. Moreover, studies on turtles are usually performed on adult individuals. In this study, we checked whether and when hatchlings of the European Pond Turtle (Emys orbicularis galloitalica) established stable hierarchical structures in their first year of life, whether hierarchies were stable in time and how steady they were. We also verified whether social ranks were associated to the individuals’ size. We observed dyadic interactions daily within three small groups of turtles reared in a controlled environment for seven months. After two months, the hatchlings started to interact and progressively established stable hierarchical structures. However, the effectiveness of the three types of observed aggressive behaviors in reversing social ranks was low and the resulting hierarchies were flat. We did not find a significant effect of the turtles’ size on their interactions’ outcome and hierarchy structure. Our results provide clear evidence of the development and the characteristics of social behaviors in young reptiles in captivity. This study could be a starting point for investigating social structures in wild populations. Full article

Turtles, a speciose group consisting of more than 300 species, demonstrate karyotypes with diploid chromosome numbers ranging from 2n = 26 to 2n = 68. However, cytogenetic analyses have been conducted only to 1/3rd of the turtle species, often limited to conventional staining methods. In order to expand our knowledge of the karyotype evolution in turtles, we examined the topology of the (TTAGGG)_n telomeric repeats and the rDNA loci by fluorescence in situ hybridization (FISH) on the karyotypes of two emydids: the Sicilian pond turtle, Emys trinacris, and the yellow-bellied slider, Trachemys scripta scripta (family Emydidae). Furthermore, AT-rich and GC-rich chromosome regions were detected by DAPI and CMA₃ stains, respectively. The cytogenetic analysis revealed that telomeric sequences are restricted to the terminal ends of all chromosomes and the rDNA loci are localized in one pair of microchromosomes in both species. The karyotype of the Sicilian endemic E. trinacris with diploid number 2n = 50, consisting of 13 pairs of macrochromosomes and 12 pairs of microchromosomes, is presented here for first time. Our comparative examination revealed similar cytogenetic features in Emys trinacris and the closely related E. orbicularis, as well as to other previously studied emydid species, demonstrating a low rate of karyotype evolution, as chromosomal rearrangements are rather infrequent in this group of turtles. Full article

The study of the dynamics of the European pond turtle’s Emys orbicularis range and distribution as an indicator of climate change in the past, present, and future is most relevant in connection with the protected status of this species in Europe. Based on our original finds, 25 archaeological sites yielding 1623 remains of 1504 individuals of subfossil pond turtles, current marginal distribution in Latvia, Ukraine, Russia, and literature data, we analyzed 437 records of Holocene turtles and 2847 current records of pond turtles. We identified areas that could serve as refugia for E. orbicularis, as a result of GIS modeling, while using 19 bioclimatic variables from the Worldclim and PaleoClim data bases. The data obtained confirm current hypotheses regarding the origin of more than 10 mtDNA lineages of E. orbicularis and the existence of multiple glacial refugia, and considerable Holocene home range dynamics. Full article