New Records of Eurasian Blind Snake, Xerotyphlops Vermicularis (Merrem, 1820) from the Black Sea Region of Turkey and Its Updated Distribution
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BIHAREAN BIOLOGIST 10 (2): 98-103 ©Biharean Biologist, Oradea, Romania, 2016 Article No.: e161301 http://biozoojournals.ro/bihbiol/index.html New records of Eurasian Blind Snake, Xerotyphlops vermicularis (Merrem, 1820) from the Black Sea region of Turkey and its updated distribution Murat AFSAR1,*, Kerim ÇIÇEK2, Yahya TAYHAN3 and Cemal Varol TOK4 1. Department of Biology, Faculty of Arts and Sciences, Celal Bayar University, Manisa, Turkey. 2. Zoology Section, Department of Biology, Faculty of Science, Ege University, 35100, Izmir, Turkey. 3. Hakkari University, Health Vocational College, Hakkari, Turkey. 4. Department of Biology, Faculty of Arts and Sciences, Çanakkale Onsekiz Mart University, 17100, Çanakkale, Turkey. *Corresponding author, M. Afsar, E-mail: [email protected] Received: 07. November 2015 / Accepted: 28. December 2015 / Available online: 30. October 2016 / Printed: December 2016 Abstract. In this study, we report two new localities of Xerotyphlops vermicularis from western and central Black Sea Region. With these records, the distribution of the species is extended about 90km to the north. The specimens were examined morphologically and compared with the relevant literature. In addition, on the basis of the new and literature records, the potential distribution of the species was modelled with ecological niche modelling. The main factors affecting the distribution of the species are the annual mean temperature (bio1, 55.3%), precipitation of driest month (bio14, 18.5%), and annual precipitation (bio12, 10.1%) and account for 84% of the distribution model. Key words: Xerotyphlops vermicularis, Typhlopidae, distribution, new record, ecological niche modeling, Black Sea Region, Anatolia. Introduction Material and Methods Family Typhlopidae is mostly distributed in the Neotropic, Overall Some twelve specimens of X.vermicularis were caught from Sinop (10 specimens) and Samsun (2 specimens) in the Western and Australasian, Indo-Malayan and Afrotropic ecoregions Central Black Sea regions of northern Anatolia during the herpeto- (Kornilios et al. 2013) and consists of 389 species (Uetz & logical excursions carried out between April and August 2014. The Hošek 2015). Genus Xerotyphlops has recently been described morphological characters were taken according to Baran (1976) and by Hedges et al. (2014), consists of 4 valid species (Xeroty- measured by means of digital calipers with 0.02 mm sensitivity and a phlops etheridgei, X.wilsoni, X.socotranus, and X.vermicularis), tape measure with 0.1 mm sensitivity (for the body and tail lengths). and is distributed in the xeric regions of three continents, in- The ventral scales of the specimens were counted according to cluding the Sahara Desert and the Socotra Island (Africa), Dowling (1951) method. Colour and pattern characteristics were re- south-western Asia, and south-eastern Europe (Hedges et corded while the specimens were still alive, and colour slides taken while the animals were alive and utilized in the study. The material al., 2014). Eurasian Blind Snake, X.vermicularis (Merrem is preserved at the department of Zoology at Celal Bayar University 1820), is distributed from the south-east of Europe to the (CBU, Manisa, Turkey) and in the collection of Ondokuz Mayıs Uni- Middle East (Hedges et al. 2014, Pyron & Wallach 2014), and versity. although the genus occurs in xeric regions, X.vermicularis The distribution of the species in Turkey were formed using the generally prefers more humid microhabitats than other con- records provided by Bodenheimer (1944), Clark & Clark (1973), specifics (Kornilios et al. 2011). Baran (1976), Baran (1977 a,b), Baran (1982), Teynie (1991), Mulder In Turkey, the available information on the distribution (1995), Tok (1993), Demirsoy (1996), Arıkan et al. (1994, 1998), Başo- ğlu & Baran (1998), Uğurtaş et al. (2000, 2007), Katılmış et al. (2002), of X.vermicularis particularly in the Western and Central Özdemir & Baran (2002), Baran et al. (2001a,b, 2004, 2006), Kumlutaş Black Sea regions are limited (Baran et al. 1992). To date, et al. (2000, 2004a,b), , Hür et al. (2008), Tosunoğlu et al. (2010), Afsar there are only two old records of the species in the Black Sea et al. (2013), Afsar and Tok (2011), Cihan & Tok (2014), Eser & Eriş- Region (from Trabzon [Bedriagae (1879)] and Amasya miş (2014), Tok & Çiçek (2014), and Özcan & Üzüm (2014). The local- [Boettger (1880)]). Since no material could be obtained from ity information with no coordinate data was obtained by using the Black Sea Region by subsequent researchers (Baran et al. Google Earth vers. 7.1.2 (Google Inc.). All records were georefer- 1992, Baran et al. 1997, Kumlutaş et al. 1998, Baran et al. enced into WGS-84 coordinate system and checked with ArcGIS v9.0 2001b, Kutrup 2001, Dinçaslan et al. 2013), no evaluation (ESRI). Some 20 climatic and topographical variables were used as pre- could be made regarding the distribution and taxonomic dictors for the current distribution. 19 climate data were obtained situation of the species in this region. In the recent years, X. from WorldClim ver.1.4 data set (Hijmans et al. 2005, vermicularis was also phylogenetically evaluated (Kornilios http://www.worldclim.org) at the spatial resolution of 30 arc sec- et al. 2011, 2012) and populations from Turkey except for onds (approx. 1 km), which represents monthly temperature and Black Sea Region were divided into six clades. Most of these rainfall data as averages of the period 1950–2000. Elevation data clades are deeply divergent what suggests that X. vermicu- were resampled from Shuttle Radar Topography Mission (SRTM) in laris is a complex of several morphologically cryptic species. UTM projection at 90 m resolution (Jarvis et al. 2008; http://srtm.csi.cgiar.org/). Besides, Gül et al. (2015) have tried to reveal the climatic To reduce the negative effect that might result from multicollin- preferences and distributions of these six isolated lineages in earity among the environmental variables (Heikkinen et al. 2006), we Anatolia. In this study, we report two new localities for selected a subset of the bioclimatic variables based on the ecological X.vermicularis from Western and Central Black Sea region, requirements of the species and a pairwise Pearson correlation (R2 < and the distributional range of the species is extended with 0.75). We chose 8 environmental variables [bio1 = annual mean tem- these new localities. Besides, the potential distribution of the perature, bio2= mean diurnal range (mean of monthly (max temp - species was modelled by ecological niche model. min temp)), bio3 = isothermality (bio2 / bio7) (* 100), bio7 = annual temperature range (bio5 - bio6), bio8 = mean temperature of wettest New records of Xerotyphlops vermicularis from the Black Sea region of Turkey and its updated distribution 99 quarter, bio14 = precipitation of driest month, and bio15 = precipita- of the dorsum is particularly light or dark brown in the eight tion seasonality (coefficient of variation)] that underlay the current specimens under examination, while it is pinkish pale brown distribution model for the species. in the two specimens from Çarşak (Sinop). The ventral side MAXENT vers. 3.3.3k (Phillips et al. 2006, 2008, 2009) program is yellowish white in all specimens. The tail width and was used to model the potential distribution of the species. The MAXENT algorithm estimates the potential distributions of species length are almost equal to each other. There is a spike at the from locality point data by finding the probability distribution of the tip of the tail. The eyes have become blind and look like maximum entropy (i.e. closest to uniform) subject to the constraint black points under the ocular plates. The rostral scale, the that the expected value of each of a set of features (environmental largest plate among the head plates, originates from the rim variables or functions thereof) under this estimated distribution of the mouth in the lower part and continues as far as the top closely matches its empirical average (Phillips et al. 2006, 2008). of the head. There is a pair of nasalia. The preocular scale is MAXENT logistic outputs represent the habitat suitability ranging 1/1; the supralabial scales are 4/4; the sublabial scales are from 0 (unsuitable) to 1 (suitable). The randomly selected back- 4/4; the midbody scale rows are counted as 24 in 11 speci- ground (pseudo-absences) approach (Phillips et al. 2006) and 15-fold cross-validation were used in modeling. We applied the 10 percentile mens and as 22 in one specimen; and the midtail scale rows training presence logistic threshold approach as recommended by are 17 in one specimen, 18 in four specimens, 19 in two Liu et al. (2005), and the logistic output was transformed into a con- specimens, 20 in four specimens, and 21 in one specimen. tinuous map of the presence-absence distribution. Model accuracy The number of scales in the anal region is 5. The head+body was evaluated from Area under the receiver-operator curve (AUC), length ranges from 185 to 248 mm in the specimens under and the average of all models was imported and visualized with Ar- examination. The tail length was measured to be between cGIS v9.0. 2.01 and 5.08 mm. The pholidosis characteristics and the sta- tistical values of the body measurements and rates are pre- Results sented in Table 1. Biological and ecological observations: The four speci- Xerotyphlops vermicularis (Merrem, 1820) mens caught within the city walls of the Boyabat Castle were Material: N= 2 OMUK student material, between Ladik and found under the stone fragments in the rocky regions where Taşova, the Collection of Ondokuz Mayıs University, leg. the Gramineae vegetation partially prevailed (Fig. 1). On the Y.Tayhan, coordinates= 40.8739190N, 36.0957440E, Material: other hand, the specimens detected from the Çarşak village N=10: CBU 1/2014, 1-4 ♂♂+♀♀, Boyabat, Sinop, 28.04.2014, were collected from the sparsely vegetated and stony areas Leg. M.Afsar, Coordinates= 34.761930N, 41.467020E, 445 m by a desiccated stone channel.