Testudo Marginata Research Articles

The fossil record of turtles from the Pleistocene of Crete (Greece)

The Isle of Crete contains an important endemic fossil fauna that has been studied extensively in the past. An endemic fossil tortoise, Testudo marginata cretensis Bachmayer, Brinkerink & Symeonidis, 1975, had previously been named from Pleistocene cave deposits in the island, presumably being larger than the mainland species and having some important morphological differences as well. In this paper I revise these type specimens and describe for the first time numerous additional fossil specimens from the Pleistocene sites of Gerani IV, Zourida, Koumpes, Liko, Mavro Mouri IV, and Simonelli Caves (near Herakleion), Rethymnon fissure, and from the open site of Sitia in the eastern part of the Island. These specimens belong mostly to the marginated tortoise, but the presence of a terrapin is confirmed as well. These new fossils help to refute the validity of the Cretan subspecies, and change the range of the marginated tortoise during Pleistocene/Holocene times in the southern Balkans.

Thyroid Hormone Concentrations in Testudo spp. by Season and Sex

Thyroid hormones and the factors influencing them are rarely studied in tortoises. This study therefore aimed to calculate reference intervals (RI) for thyroid hormones and iodine concentrations by species, sexes, and seasons in four species of adult Mediterranean tortoises (Testudo spp.) and to evaluate possible correlations between plasma thyroid hormones, serum iodine, plasma protein, and increased liver and kidney values. Thyroid hormones (total tetraiodothyronine [tT4], free tetraiodothyronine [fT4], total triiodothyronine [tT3], and free triiodothyronine [fT3]) were measured in plasma from adult, healthy Hermann's (Testudo hermanni, n = 255), spur-thighed (Testudo graeca, n = 89), marginated (Testudo marginata, n = 72), and Russian tortoises (Testudo horsfieldii, n = 30). Species, sex, and seasonal variations were determined by Bayesian information criterion (BIC), and correlations between thyroid hormones, protein, iodine, and increased liver/kidney values were evaluated by Spearman's rank correlation test. Total T4 did not reveal any species, sex, or seasonal differences (RI: 0.102–0.455 µg/dl), while seasonal differences were found for fT4 (RI: spring 0.624–9.012; summer 0.379–5.476; fall 0.376–5.426 pmol/L). The tT3 concentrations differed significantly depending on species, season, and the interaction of species × season. Seasonal differences were also found for fT3 and iodine. Several significant (P ≤ 0.05) correlations were detected between the analytes, including a positive correlation between tT4 and fT4. These results provide a tool for the evaluation of thyroid hormone concentrations in Mediterranean tortoises and confirm the influence of season on thyroid function in these animals.

Thyroid hormone levels in Tortoises (Testudo spp.) depending on Season and Sex

Thyroid hormones and the factors influencing them are rarely studied in tortoises. This study therefore aimed to calculate reference intervals (RI) for specific species, sexes, and seasons for thyroid hormones and iodine levels in blood of four adult Mediterranean tortoise species and to evaluate possible correlations between thyroid hormones, serum iodine, plasma protein and increased liver and kidney values. Thyroid hormones (total tetraiodothyronine [tT4], free tetraiodothyronine [fT4], total triiodothyronine [tT3], and free triiodothyronine [fT3]) were measured in plasma from adult, healthy Hermann´s (Testudo hermanni, n = 255), spur-thighed (Testudo graeca, n = 89), marginated (Testudo marginata, n = 72), and Russian tortoises (Testudo horsfieldii, n = 30). Species, sex and season specific variations were determined by Bayesian information criterion (BIC) and correlations between plasma thyroid hormones, protein, iodine and increased liver/kidney values were evaluated by Spearman’s rank correlation test. Total T4 did not reveal any species, sex, or seasonal differences (RI 0.102 to 0.455 µg/dL), while seasonal differences were found for fT4 (RI spring 0.624 to 9.012; summer 0.379 to 5.476; fall 0.376 to 5.426 pmol/L). The tT3 levels differed significantly depending on species, season, and the interaction of species x season. Seasonal differences were also found for fT3 and iodine. Several significant (p < 0.05) correlations were detected between the tested analytes, especially positive correlations between tT4 and fT4. These results provide a tool for the evaluation of thyroid hormone levels in Mediterranean tortoises and indicate the influence of season on the thyroid in these animals.

Annotated checklist of the herpetofauna (Amphibia, Reptilia) of Lefkada Island (Ionian Islands, Greece)

The island of Lefkada is a popular and easily accessible tourist destination; nevertheless, there is no comprehensive checklist of its interesting herpetofauna. Indeed, most records are old, scattered in different papers, and lacking precise locality data. In order to summarize the knowledge on the herpetofauna of the island, we critically reviewed literature, we looked for reliable records in the web and we carried out a field survey in May 2019. The herpetofauna of Lefkada amounts to 28 species (six amphibians and 22 reptiles). The occurrence of Testudo graeca on the island is considered unlikely, while an additional species, Testudo marginata, is here reported based on web sources. Among the species recorded on the island, 25 have been recently confirmed, two of them (Rana dalmatina and Anguis graeca) over a century. For three species (Lissotriton graecus, Chelonia mydas, and Podarcis tauricus) the last records date back to over 30 years ago.

The Herpetofauna of the Monte Albo, Sardinia (Italy)

The Monte Albo (Sardinia, Italy) is a biodiversity hotspot that hosts several species of amphibians and reptiles, some of which are endemic. In the present work, we provide an updated list of the herpetofauna of this important area thanks to surveys carried out 2012 – 2016. We observed 18 species, 17 had already been reported in literature but one of these was not detected during our surveys, while Testudo marginata and Natrix natrix cetti , are here reported for the first time for the Monte Albo.

Pleistocene vertebrates from the Kyparíssia lignite mine, Megalopolis Basin, S. Greece: Testudines, Aves, Suiformes

The mining activities in the Middle Pleistocene lacustrine basin of Megalopolis (Peloponnesus, Greece) have exposed expanded sections of lacustrine sediments. In particular, the northernmost mine of Kyparíssia has yielded numerous vertebrate fossils, recovered during field surveys and small-scale rescue excavations. The stratified specimens indicate the presence of at least two fossiliferous horizons, which are stratigraphically closely situated. The fossils are generally widely dispersed, but they are much more abundant along the western margin of the palaeolake. Four sites showing denser concentration of fossils were located and partially excavated during the 2004–2008 fieldwork. An additional site was identified and excavated in 2012. The fossils were found in organic-rich sediments (mostly lignites), indicating that they were deposited during a warm and humid (i.e., interglacial) time period, in a richly vegetated environment. The recovered fauna is diverse, dominated by hippopotamuses, deer and elephants. The present study presents the chelonian, avian and suiform finds. The following taxa are recognised: Emys orbicularis, Testudo marginata, Sus scrofa, Hippopotamus antiquus, as well as a diverse sample of aquatic birds. This faunal composition indicates a temperate, woodland/forest environment, with continuous presence of a large water body, whilst the presence of the darter (Anhinga sp.) points to relatively warm conditions. Biochronologically it points to an age within the early part of the Middle Pleistocene.

Born to be asocial: newly hatched tortoises avoid unfamiliar individuals

Recognition of familiar individuals is important for modulating social interactions, but it is not clear to what extent this capacity depends on experience gained through repeated interactions with different animals. In wild tortoises, evidence of social interactions is limited to behaviours performed years after hatching, in the context of mating. To investigate the capacity to recognize familiar individuals at the onset of life in tortoises, we used hatchlings of two species (Testudo marginata, Testudo graeca) reared with a single conspecific as their unique social experience. When in a novel environment with the familiar conspecific, tortoises reached the distance expected after running random trajectories. In contrast, tortoises tested with an unfamiliar conspecific first explored the other tested individual, then actively kept a distance from it significantly larger than expected by chance. These results show evidence of spontaneous recognition of familiar individuals in a nonsocial species at the onset of life, and active avoidance of unfamiliar conspecifics. We suggest that this predisposition might be adaptive for young tortoises' dispersal and that evolutionary pressures for social behaviour might be relevant for nonsocial species even at the onset of life.

DETECTION OF INTRANUCLEAR COCCIDIOSIS IN TORTOISES IN EUROPE AND CHINA

Intranuclear coccidiosis of tortoises (TINC) has been described in association with systemic disease in various species of tortoises. TINC has been detected in numerous tortoises from the United States, but there are only a few reports from tropical tortoises in Germany and no reports from Asia. Using a real-time polymerase chain reaction assay, samples from 1,011 tortoises were screened for the presence of TINC. Samples originated from animals kept in captivity in Europe and in China. Coccidia were detected in a total of 27 chelonians (2.7%), including the first description of TINC in a marginated tortoise ( Testudo marginata ), Hermann's tortoise ( Testudo hermanni ), African spurred tortoise (Centrochelys sulcata), and yellow-footed tortoise (Chelonoidis denticulatus). The highest percentage of positive animals was found in radiated tortoises ( Astrochelys radiata ). Although the percentage of positive animals was relatively low, this study demonstrates the global distribution of TINC in captive chelonians as well as expanding the known host range for these pathogens.

The diverse fossil chelonians from Milia (late Pliocene, Grevena, Greece) with a new species of Testudo Linnaeus, 1758 (Testudines: Testudinidae)

AbstractThe late Pliocene (early Villafranchian, MN 16a) locality of Milia (Grevena, Greece) has yielded numerous remains of mammals, such as zygodons, mastodons, rhinocerotids, hipparions, bovids, cervids, suids, carnivorans and tapirs. Several specimens of chelonians have also been discovered and comprise a small testudinid, a geoemydid and a giant tortoise. The presence of a giant tortoise and the presence of a geoemydid with large dimensions are further examples of the trend towards gigantism evidenced by the diverse fauna of Milia. In terms of taxonomic abundance of extinct turtles, this is the richest locality in Greece. The small testudinid is of particular importance because it preserves a posteriorly flared carapace, as in the extant Testudo marginata, but the posterior carapace is much taller and anteroposteriorly shorter. These characters allow us to erect a new species, Testudo brevitesta sp. nov., and to discuss the presence of the marginated tortoise and closely related forms in Greece. The new taxon is analysed in a phylogenetic context within other extant and extinct testudinids, providing new information on the clade Testudona.

Cloacal swab sampling is a reliable and harmless source of DNA for population and forensic genetics in tortoises

Testudo graeca, Testudo hermanni and Testudo marginata are endangered species listed in the IUCN Red List and Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Correct identification of species and distinct population units can support sound conservation projects and forensic applications. However, the collection of biological samples is not always easy or harmless. Blood sampling is usually invasive and risky. Salivary swab sampling is commonly used in other reptiles but can be unsafe for tortoises by the reason of their head retraction escape response. Cloacal swab sampling should be easier and less risky. In this study, we genotyped 37 tortoises at eight microsatellite loci and compared the reliability of individual genotypes obtained from blood, cloacal and buccal swabs. Results showed that performances of cloacal samples are comparable with those of buccal and blood samples, and proved that cloacal sampling is an alternative and reliable source of DNA for tortoise genotyping.

Evaluation of pulmonary function in European land tortoises using whole-body plethysmography

The aim of this study was to evaluate the use of whole-body plethysmography as a non-invasive method to determine the respiratory parameters and profiles in two tortoise species belonging to...

Teratological changes in tick morphology in ticks feeding on exotic reptiles

The paper describes 13 teratological cases of anomalies in the morphology of exotic ticks from three species: Amblyomma latum, Amblyomma flavomaculatum and Hyalomma aegyptium. The ticks parasitized reptiles (Python regius, Varanus exanthematicus, Testudo marginata), that were imported into Poland from Africa and suthern Europe for the purpose of breeding in terraria. General anomalies were found that were related to the asymmetry and bifurcation of the idiosoma and local anomalies, which are related to structures on the surface of the body: oligomely of the porose area, anomaly in the form and course of the anal groove, and anomalies of the legs: heteromorphism, oligomely and atrophy of the leg, as well as cases of complex anomalies. Knowledge of cases of morphological anomalies in ticks can help to greatly reduce taxonomic errors in determining the species affiliation of the teratologically altered tick.

Effects of landscape features and demographic history on the genetic structure of Testudo marginata populations in the southern Peloponnese and Sardinia

Testudo marginata, the largest European land tortoise, is suffering habitat degradation and destruction. Some populations, in markedly degraded habitats, are characterized by divergent morphotypes. However, the evolutionary significance of these morphotypes is of debate. Using 11 polymorphic microsatellites, we studied: (1) marginated tortoises from Sardinia that display a divergent morphotype – this population was potentially introduced from Greece; and (2) an area in the southern Peloponnese that includes a small and degraded zone in which marginated tortoises are dwarf. Genetic analyses run without any a priori assignment clearly acknowledge the specimens sampled in the territory of the dwarf form as a single group whilst Sardinian specimens are clustered with other specimens from the northern part of the area sampled in Greece. Demographic analyses suggest that Sardinian tortoises originated recently from some of the populations sampled in the northern part of the area sampled in Greece. Over locations sampled in Greece, a landscape-genetic analysis allowed us to detect potential landscape features that may reduce gene flow between the dwarf form territory and surrounding areas. Our results suggest that the territory of the dwarf form is particularly propitious for marginated tortoises and that conservation regulations in Greece should be reinforced to protect this area from increasing impact of human activities changing from traditional agriculture to mechanization and extensive use of chemicals. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105, 591–606.

Courtship Displays Are Condition-Dependent Signals That Reliably Reflect Male Quality in Greek Tortoises,Testudo graeca

The courtship behavior of male Greek tortoises (Testudo graeca) is based on a multiple signaling system that involves tactile, visual, olfactory, and acoustic signals. In some recent studies on marginated (Testudo marginata) and Hermann's tortoises (Testudo hermanni) we showed that male mounting success was significantly and positively correlated to the intensity of courtship displays. This was due to the number of rams and bites and the number of calls emitted during mounting, which are considered to be condition-dependent signals that reliably convey information on male quality. In this correlative study, we analyzed relationships between male morphology, hematological profile, courtship intensity, vocalizations, and mounting success in a group of 104 Greek tortoises breeding in seminatural enclosures. As expected, our study showed that mounting success of males was positively correlated to the number of rams and the frequency of interactions during courtship and negatively correlated to the call duration. Moreover the hematocrit was positively correlated with the call rate and the number of rams. Therefore, courtship signals exhibited by male Greek tortoises, including vocalizations, reliably reveal different components of male condition, and females may use these signals to choose high-quality partners, as previously observed in marginated and Hermann's tortoises.

Life cycle of tortoise tick Hyalomma aegyptium under laboratory conditions

The tortoise tick Hyalomma aegyptium has a typical three-host life-cycle. Whereas its larvae and nymphs are less host-specific feeding on a variety of tetrapods, tortoises of the genus Testudo are principal hosts of adults. Ticks retained this trait also in our study under laboratory conditions, while adults were reluctant to feed on mammalian hosts. Combination of feeding larvae and nymphs on guinea pigs and feeding of adults on Testudo marginata tortoises provided the best results. Feeding period of females was on average 25days (range 17-44), whereas males remain after female engorgement on tortoise host. Female pre-oviposition period was 14days (3-31), followed by 24days of oviposition (18-29). Pre-eclosion and eclosion, both together, takes 31days (21-43). Larvae fed 5days (3-9), then molted to nymphs after 17days (12-23). Feeding period of nymphs lasted 7days (5-10), engorged nymphs molted to adults after 24days (19-26). Sex ratio of laboratory hatched H. aegyptium was nearly equal (1:1.09). The average weight of engorged female was 0.95 (0.72-1.12)g. The average number of laid eggs was 6,900 (6,524-7,532) per female, it was significantly correlated with weight of engorged female. Only 2.8% of engorged larvae and 1.8% of engorged nymphs remained un-molted and died. Despite the use of natural host species, feeding success of females reached only 45%. The whole life-cycle was completed within 147days (98-215).

Calcium and phosphorus values and their derivatives in captive tortoises (Testudo species)

To evaluate the relationships between total calcium and phosphorus and ionised calcium and phosphorus values in clinically healthy tortoises. Jugular blood samples were obtained from 25 tortoises, as part of a health screen of the population. These comprised Hermann's tortoises, Testudo hermanni boettgeri, spur-thighed tortoises, Testudo graeca ibera, marginated tortoises, Testudo marginata, and horsfield tortoises, Testudo horsfieldi. Plasma from these samples were analysed for total calcium, ionised calcium and phosphorus levels. These samples were taken in the immediate posthibernation period, before the onset of reproductive activity. Females exhibited statistically significantly higher levels of phosphorus. Ionised calcium and total calcium levels were elevated in females compared with males, but this was not statistically significant. Females did have statistically significantly higher calculated solubility indexes and statistically significantly lower ratios compared with males. This study has provided an insight into the ratios and solubility indexes in tortoises, and this information may lead to further understanding of the significance of these parameters in chelonians.

Comparison of total calcium, ionised calcium and albumin concentrations in the plasma of captive tortoises (Testudo species)

Plasma total calcium, ionised calcium and albumin levels in Hermann's tortoises (Testudo hermanni), spur-thighed tortoises (Testudo graeca), marginated tortoises (Testudo marginata) and Horsfield's tortoises (Testudo horsfieldi) were investigated. The animals...

Variations in the concentration of ionised calcium in the plasma of captive tortoises (Testudo species)

The concentration of ionised calcium was measured in the plasma of 13 Hermann's tortoises (Testudo hermanni boettgeri), nine spur-thighed tortoises (Testudo graeca ibera), two marginated tortoises (Testudo marginata) and six...

Plasma concentrations of 25‐hydroxycholecalciferol in 22 captive tortoises (Testudo species)

The plasma concentration of 25-hydroxycholecalciferol was measured in 13 adult Hermann's tortoises (Testudo hermanni), seven adult spur-thighed tortoises (Testudo graeca) and two adult marginated tortoises (Testudo marginata) during 2004. They were healthy, of both sexes, and kept in captivity under natural unfiltered sunlight in southern England with no dietary sources of cholecalciferol. Blood samples were taken in March, June and August, and the concentration of 25-hydroxycholecalciferol did not vary significantly with the seasons. However, the concentrations in the female tortoises were always significantly lower than in the males.

Cryptosporidium from tortoises: Genetic characterisation, phylogeny and zoonotic implications

Cryptosporidiosis is a disease caused by apicomplexan parasites of the genus Cryptosporidium, which affect the gastrointestinal tract of humans and animals worldwide. In the present study, Cryptosporidium isolates from captive European tortoises ( Testudo graeca, Testudo hermanni and Testudo marginata) in Italy were genetically characterised using gene/s encoding Cryptosporidium oocyst wall protein (COWP) and/or the hypervariable segment internal to the SSU rDNA. Six isolates from T. graeca, T. hermanni and T. marginata revealed 100% sequence identity with the zoonotic Cryptosporidium pestis ( Cryptosporidium parvum ‘bovine genotype’), while a sequence from one T. marginata was a unique uncharacterised genotype ( Cryptosporidium sp. ex T. marginata). The new genotype is phylogenetically characterised as belonging to the intestinal cryptosporidial lineage. The present study indicates that tortoises may disseminate Cryptosporidium oocysts in the captive environment. The identification of the zoonotic genotype in the faeces of captive European tortoises indicates a potential risk for humans within the household.