Çetin Ilgaz

Neogene climatic oscillations shape the biogeography and evolutionary history of the Eurasian blindsnake.

Typhlops vermicularis is the only extant scolecophidian representative occurring in Europe. Its main distribution area, the eastern Mediterranean, has a complicated geological and climatic history that has left an imprint on the phylogenies and biogeography of many taxa, especially amphibians and reptiles. Since reptiles are sensitive indicators of palaeogeographical and palaeoclimatic events, we investigated the intraspecific genealogy of T. vermicularis in a phylogeographical framework. A total of 130 specimens were analyzed, while the use of formalin and ethanol as preservatives called for a special treatment of the samples. Partial sequences of two mitochondrial (12S and ND2) and one nuclear (PRLR) marker were targeted and the results of the phylogenetic analyses (NJ, ML and BI) and the parsimony-network revealed the existence of 10 evolutionary significant units within this species. In combination with the results of the dispersal-vicariance analysis, we may conclude that the Eurasian blindsnake has encountered a sequence of extinction events, followed by secondary expansion from refugia. Estimation of divergence times showed that severe climatic changes between significantly wetter and drier conditions in the Late Neogene have played a key role on the evolutionary and biogeographical history of T. vermicularis. Additionally, both markers (mtDNA and nDNA) distinguished a largely-differentiated evolutionary lineage (Jordan and south Syria), which could even be reckoned as a full species. Our study reveals the existence of cryptic evolutionary lineages within T. vermicularis, which calls for further attention both on the protection of intraspecific varieties and the respective geographic areas that hold them.

Phylogeography of the ocellated skink Chalcides ocellatus (Squamata, Scincidae), with the use of mtDNA sequences: a hitch-hiker's guide to the Mediterranean.

We analyze geographic genetic variation in C. ocellatus to evaluate the influences of major climatic, paleogeographic and anthropogenic factors in its biogeographic history. Ninety four specimens from 61 populations were collected across all of its geographical range and analyzed based on partial mitochondrial sequences (cyt b, 12S, and ND1). Our results demonstrate that an ancestral form of C. ocellatus, which expanded in northwestern Africa at the end of Miocene, diverged in at least three separate evolutionary lineages approximately 4.57Ma: C. humilis spread south of the Sahara, while the other two (C. ocellatus sensu stricto) were restricted in the coastal North African region. The complicated history of the ocellated skink is a result of multiple vicariant phenomena followed by multiple active or passive dispersals. The Messinian salinity crisis and the re-flooding of the Mediterranean basin, the climatic transition from Middle to Upper Pliocene, and the hyperarid phase of the Sahara, affected the distribution and diversification of C. ocellatus, while in historical times it was introduced in the central Mediterranean islands and eastern Mediterranean region from Tunisia and Cyrenaica, respectively.

Carapacial scute variation in Loggerhead Turtles, Caretta caretta

Abstract The carapacial scutes of 3511 specimens of hatchling and adult Loggerhead Turtles (Caretta caretta) from five different nesting beaches in Turkey and Cyprus (Dalyan, Fethiye, Belek, Kızılot and Karpaz) were examined. Scutes were examined with regard to variation within carapacial scute series and variation in carapacial scute pattern. The vertebral, costal and marginal series were the most variable and the supracaudal scute was extremely stable for the hatchlings. The adult scute pattern showed stability for all scutes except the marginal series. The most common scute pattern observed was 12 pairs of marginals, 5 pairs of costals, 5 vertebrals, 2 supracaudals and a single nuchal.

Population decline of loggerhead turtles: two potential scenarios for Fethiye beach, Turkey

Based on nesting data over a 12-year period (1993–2004), this study points to a negative population trend of the loggerhead turtle population at Fethiye beach, Turkey. The number of nests fluctuated from a maximum of 186 in 1995 to a minimum of 58 in 2004. Successively smaller peaks at 3-year intervals were followed by successively smaller troughs. Two analyses—one representing a dampened oscillation, the other retaining the period and the amplitudes of the nesting cycles—predict that nest number will drop to about 40–50 by 2015, i.e. to about 22–27% of its highest value. This drop at Fethiye does not correspond with a visible increase at neighboring beaches, leading to the interpretation that the number of nesting turtles here is declining. Moreover, the carapace size of emerging adult females is apparently decreasing, as are clutch sizes. Such a potential negative trend at a key Turkish nesting beach is cause for concern, an incentive for continued study, and a call for more coordinated and effective conservation programs in this region of the Mediterranean.

Reproduction biology of the marine turtle populations in Northern Karpaz (Cyprus) and Dalyan (Turkey)

Abstract The reproduction biology of Green Turtles, Chelonia mydas, and Loggerhead Turtles, Caretta caretta, was studied at Northern Karpaz, northern Cyprus, and Dalyan, Turkey, in 1996–1997. A total of 22 C. mydas and 7 C. caretta nests were recorded at Northern Karpaz in 1996, and 135 Loggerhead Turtle nests at Dalyan in 1997. The Green Turtle nesting density was 9.2 nests/km, the Loggerhead Turtle density 2.9 nests/km at Northern Karpaz and 28.7 nests/km at Dalyan. For Green Turtles, 78.9% of the hatchlings were able to reach the sea. The corresponding values for Loggerheads are 55.5% at Northern Karpaz and 87.1% for Dalyan. The mean incubation period for C. mydas was 58.0 days at Northern Karpaz and for C. caretta this period was 52.4 days on Dalyan Beach. Nests which were threatened by the tide or human activities were transplanted to safe areas of the beach. The hatching success of transplanted nests (72.8%) was significantly higher than nests left under natural conditions (55%).

Impact of some invertebrates on eggs and hatchlings of the Loggerhead Turtle, Caretta caretta, in Turkey

Abstract The damage caused by some invertebrates to the eggs and hatchlings of Loggerhead Turtles, Caretta caretta, was investigated during 1999 and 2000 on Fethiye beach, Turkey. Nematoda, Acarina, Myrmeleonidae, Elateridae, Scarabeidae, Muscidae and Tenebrionidae were recorded as infesting nests of Loggerhead Turtles. Tenebrionidae (Coleoptera) larvae were found to have the heaviest impact on Loggerhead Turtle eggs and hatchlings. A total of 185 randomly selected nests was examined. Of the nests examined in 2000, almost 50% contained tenebrionid larvae. Tenebrionid larval damage was recorded in 8.1% of the eggs that were counted in the nests containing larvae and in 0.6% of the hatchlings. However, it could not be determined whether the larvae destroy viable eggs and hatchlings. In comparison to previous years, a remarkable increase in tenebrionid larval damage was recorded.

A reinvestigation of phylogeny and divergence times of the Ablepharus kitaibelii species complex (Sauria, Scincidae) based on mtDNA and nuDNA genes

Morphological and DNA data support that the East Mediterranean snake-eyed skink Ablepharus kitaibelii represents a species complex that includes four species A. kitaibelii, A. budaki, A. chernovi, and A. rueppellii, highlighting the need of its taxonomic reevaluation. Here, we used Bayesian and Maximum Likelihood methods to estimate the phylogenetic relationships of all members of the complex based on two mitochondrial (cyt b, 16S rRNA) and two nuclear markers (MC1R, and NKTR) and using Chalcides, Eumeces, and Eutropis as outgroups. The biogeographic history of the complex was also investigated through the application of several phylogeographic (BEAST) and biogeographic (BBM) analyses. Paleogeographic and paleoclimatic data were used to support the inferred phylogeographic patterns. The A. kitaibelli species complex exhibits high genetic diversity, revealing cases of hidden diversity and cases of non-monophyletic species such as A. kitaibelii and A. budaki. Our results indicate that A. pannonicus branches off first and a group that comprises specimens of A. kitaibelli and A. budaki from Kastelorizo Island group (southeast Greece) and southwest Turkey, respectively is differentiated from the rest A. kitaibelli and A. budaki populations and may represent a new species. The estimated divergence times place the origin of the complex in the Middle Miocene (∼16Mya) and the divergence of most currently recognized species in the Late Miocene. The inferred ancestral distribution suggests that the complex originated in Anatolia, supposing that several vicariance and dispersal events that are related with the formation of the Mid-Aegean Trench, the Anatolian Diagonal and the orogenesis of the mountain chains in southern and eastern Anatolia have led to current distribution pattern of A. kitaibelii species complex in the Balkans and Middle East.

An Assessment of Initial Body Size in Loggerhead Sea Turtle (Caretta caretta) Hatchlings in Turkey

Abstract Eggs, hatchlings, and adult loggerhead turtles, and incubation durations of clutches, were measured on three Turkish beaches (Dalyan, Fethiye and Göksu Delta), and some physical features of nests were compared. These features were not statistically different among the beaches, except for nest depth and distance to the high water mark. There was a positive relationship between hatchling mass and egg size. The carapace length of hatchlings was correlated with both egg diameter and incubation duration. The duration of asynchronous emergence of hatchlings on Fethiye beach was slightly longer than on the other two beaches, and the size of hatchlings decreased as asynchronous emergence proceeded. Of the hatchlings that emerged first, those that died were significantly smaller in SCL and mass than those that lived. These results suggest that smaller hatchlings may not be vigorous enough to emerge earlier from nests, and that they may be less fit.

NEST SITE FACTORS AND INVERTEBRATE INFESTATION OF LOGGERHEAD TURTLE NESTS

This paper reports the physical nest parameters of loggerhead turtle (Caretta caretta) nests at Fethiye Beach, Turkey that predispose individual nests to invertebrate infestation. All data were collected between June and September 2001 and were analyzed using logistic regression. Pimelia sp. (Tene-brionidae), Musca sp. (Muscidae), Myrmeleon sp. (Myrmeleontidae), and Cryptositigmata were established as infesting the loggerhead turtle nests on Fethiye Beach in 2001. When all groups were combined as invertebrates, distance to low vegetation (t-test, b = -0.13) and grain size (t-test, b = -1.30) were found to be the best subsets of the model indicating whether invertebrates infested a nest. Both factors were negatively correlated with the presence of invertebrates. The same analysis was applied for each individual group of invertebrates. The implications of these results are discussed.

Phylogeny of Trachylepis sp. (Reptilia) from Turkey inferred from mtDNA sequences

Abstract The taxonomic status of the species included into the genus Trachylepis in Turkey are doubtful. So far, three morphological species have been attributed to this genus in Turkey; Trachylepis aurata. T. vittata, and T. septemtaeniata. Here, we investigated the taxonomy of the Turkish Trachylepis species by employing phylogenetic and phylogeographic approaches and using mitochondrial DNA (cytochrome b and 12 S rRNA). In total, 45 Trachylepis and 6 Mabuya specimens were used analyzed. Phylogenetic analyses were carried out using Maximum Likelihood (ML) and Bayesian Inference (BI) methods. The phylogenetic relationships and the genetic distances retrieved, revealed that the Turkish species, which currently recognized as Trachylepis, are highly diversified, forming a distinct clade that shows closer phylogenetic affinity with the species of the genus Mabuya rather than the other Trachylepis species. In this clade, the three Turkish species are monophyletic with T. vittata to branch off first in late Miocene (10.54 Mya). The other two species (T. septemtaeniata and T. aurata) seem to have sister group relationship that diverged at the end of Messinian Salinity Crisis (5.27 Mya). As a whole, the examination of mtDNA lineages in the Turkish lizards of the genus Trachylepis may contribute substantially to the refining of their taxonomic status, since the three species of Turkey, although monophyletic, represent a distinct radiation that would could probably recognized as a different genus in Mabuya sensu lato.