Rhynchocalamus ilamensis, Fathinia, Behzad, Rastegar-Pouyani, Eskandar, Rastegar-Pouyani, Nasrullah & Darvishnia, Hamid, 2017

Fathinia, Behzad, Rastegar-Pouyani, Eskandar, Rastegar-Pouyani, Nasrullah & Darvishnia, Hamid, 2017, A new species of the genus Rhynchocalamus Günther, 1864 (Reptilia: Squamata: Colubridae) from Ilam province in western Iran, Zootaxa 4282 (3), pp. 473-486 : 477-481

Rhynchocalamus ilamensis sp. nov.

( TableS 1–4; FigS. 2–4 )

Holotype: YUZM-CRh.1: road-kill, adult male, collected at Bina & Bijar No-hunting area (33.640668N, 46.038949E, 724 m aSl), Ilam Province, Iran on June 6th 2011.

Paratypes: YUZM-CRh.2: adult female, collected at Dinaar-Kooh preServed area (32.948156N, 47.333236E, 1383 m aSl), Abdanan , Ilam Province, Iran on AuguSt 3rd, 2013.

YUZM-CRh.3: juvenile, collected at Dinaar-Kooh preServed area (32.952591N, 47.344166E, 1180 m aSl), Abdanan , Ilam Province, Iran on AuguSt 3rd, 2013

Description of holotype ( FigS. 2 a & b, 3a, 4a):

Pholidosis. Elongate, Slender body; head Small, not diStinct from the neck; pupil round; roStral clearly offSet from adjacent ScaleS, wider than height, extending backward, wedging between the internaSalS; naSal undivided; internaSalS trapezoid in Shape; internaSal Suture Shorter than that between the prefrontalS; frontal length greater than width; SupraocularS narrow, narrower anteriorly than poSteriorly; parietalS large, longer than the frontal; right and left lorealS pentagonal in Shape; one preocular and one poStocular, much deeper than long; temporalS 1+1 on each Side; 7 SupralabialS on each Side (3rd and 4th in contact with eye); 9 infralabialS on each Side, the firSt pair in contact behind the mental; a large pair of anterior chin ShieldS, larger than poSterior oneS, in contact with the firSt four infralabialS; poSterior chin ShieldS Separated by one Scale; 13 dorSal ScaleS at level of the 10th ventral plate and 15 ScaleS at midbody and 15 ScaleS at level of the 10th plate before the cloaca; 211 ventralS; anal divided; 70 divided SubcaudalS.

Morphometric characters. Snout-vent length 315 mm; tail length 80.21 mm; head length 9.45 mm; head width 5.72 mm; and head height 3 mm.

Color pattern. Upper Surface of head uniformly lemon, with no darker markingS or bandS; a thin U-Shaped dark marking on neck, with a thickneSS equal that of two adjacent ScaleS; dorSal Surface of body and tail uniformly lemon; ventral SurfaceS from mental to tail tip uniformly white; color pattern paler in alcohol preServed than live SpecimenS.

Description of Paratypes. Pholidosis. Paratype SpecimenS are Similar to holotype except for the following few variationS: 12 dorSal ScaleS at level of the 10th ventral plate in YUZM-CRh.3; 228 ventralS in YUZM-CRh.3 and 227 in YUZM-CRh.2; 64 SubcaudalS in YUZM-CRh.3 and 61 in YUZM-CRh.2.

Morphometric characters. Snout-vent length 163 mm for YUZM-CRh.3 and 260 mm for YUZM-CRh.2; tail length 35.1 mm for YUZM-CRh.3 and 56.12 mm for YUZM-CRh.2; head length 6.33 mm for YUZM-CRh.3 and 7.15 mm for YUZM-CRh.2; head width 3.73 mm for YUZM-CRh.3 and 3.57 mm for YUZM-CRh.2; head height 2.05 mm for YUZM-CRh.3 and 2.34 mm for YUZM-CRh.2.

Color pattern. In general, body color of the paratypeS iS Similar to that of the holotype, except for the following variationS: a Small dark Spot between parietalS in YUZM-CRh.2; neck band not U-Shaped, divided into two Separate blotcheS on either SideS of neck in both paratypeS.

Etymology. Rhynchocalamus ilamensis sp. nov. iS named after Ilam Province, a Small province in the weSt of Iran having diverSe habitatS and ecoSyStemS Such aS high mountainS covered with oak foreStS, weStern limeStone foothillS of the ZagroS MountainS, alluvial plainS and Sand duneS, Supporting a rich diverSity of reptileS.

Comparison. A number of meriStic and multiState characterS differentiate Rhynchocalamus ilamensis sp. nov. from itS congenerS ( R. arabicus , R. melanocephalus and R. satunini ): dorSum lemon in color (black in R. arabicus , yellowiSh brown in R. melanocephalus and pinkiSh in R. satunini ); ventral white (black in R. arabicus , yellowiSh white in R. melanocephalus and pinkiSh in R. satunini ); head uniformly lemon without marking(S) (uniformly black in R. arabicus and R. melanocephalus , and black tranSverS StripeS on parietalS and prefrontalS in R. satunini ); dark neck marking aS a thin U-Shape or two Separated blotcheS (uniformly black in R. arabicus and R. melanocephalus , a thick tranSverSe black marking in R. satunini ); neck band not in contact with ventralS (unknown in R. arabicus ; in contact with ventralS in R. melanocephalus , not in contact with ventralS in R. satunini ); neckband not in contact with head or headband (unknown in R. arabicus ; in contact with headband in R. melanocephalus ; not in contact with headband in R. satunini ); Seven SupralabialS (4–6 in R. arabicus , 6 in R. melanocephalus , 7–8 in R. satunini ); nine infralabialS (8 in R. arabicus , moStly 7 in R. melanocephalus , moStly 8 in R. satunini ).

Cluster analysis. ThiS analySiS baSed on 13 characterS (nine multiState and four meriStic) reSulted in a tree topography, with R. arabicus at the baSe of the tree, SiSter to a clade compoSing of R. melanocephalus , R. ilamensis sp. nov. and R. satunini . The tree topology ShowS that R. satunini iS SiSter to R. ilamensis sp. nov. ( Fig. 5 ).

Habitat. Rhynchocalamus ilamensis sp. nov. inhabitS the limeStone weStern foothillS of the ZagroS MountainS. Habitat cover iS made of annual to perennial plantS Such aS Gramineae (annual graSSeS), buSheS and ShrubS ( Capparidaceae : Capparis spinosa , Cleome oxypetala ; Caryophyllaceae : Gypsophyla linearifolia , G. pallida ; Chenopodiaceae : Halocharis sulphurea , Noaea mucronata , Salsola imbricate ; CompoSitae: Achillea conferta ; RoSaceae : Amygdalus arabica ), and SparSe treeS ( Quercus brantii and Pistachia atlantica ).

Sympatric reptiles. Some reptile SpecieS Sympatric to Rhynchochalamus ilamensis sp. nov. are aS follow: Agamidae : Laudakia nupta , Trapelus ruderatus ; Lacertidae : Ophisops elegans , Acanthodactylus boskianus ; Eublepharidae : Eublepharis angramainyu ; Gekkonidae : Hemidactylus persicus , Mediodactylus heteropholis , M. ilamensis ; Phyllodactylidae : Asaccus elisae ; Scincidae : Ablepharus panonicus , Heremites auratus ; Varanidae : Varanus nesterovi ; Typhlopidae : Xerotyphlops vermicularis ; Leptotyphlopidae : Myriopholis macrorhyncha ; Boidae : Eryx jaculus ; Colubridae : Eirenis persicus , E. punctatolineatus , E. coronelloides , Hemorhois ravergieri , Platyceps rhodorachis , Spalerosophis microlepis , Malpolon insignitus , Psammophis schokari , Telescopus tessellatus ; Elapidae : Walterinnesia morgani ; Viperidae : Macrovipera lebetina , Pseudocerastes persicus , P. urarachnoides .

Phylogenetic reconstruction. The concatenated dataSet compriSed 1182 aligned SiteS of which 221 were parSimony informative. Nucleotide frequency diStribution iS 30.7 % for A, 24.2% for C, 28.9% for T and 16.2% for G. Saturation analySeS revealed that the concatenated data-Set haS little SubStitution Saturation, i.e., the ISS value of 0.29 (the obServed index of SubStitution Saturation) iS Significantly lower than ISSc value of 0.77 (critical index of SubStitution Saturation), indicating that our data are Suitable for phylogenetic analySeS.

The ML phylogenetic tree ( Fig. 6 ) ShowS that R. ilamensis sp. nov. iS phylogenetically related to Rhynchocalamus . Rhynchocalamus began diverging with R. melanocephalus which formS a SiSter taxon to a clade compoSed of the other three SpecieS ( R. arabicus , R. satunini and R. ilamensis sp. nov.). The Second dichotomy SeparateS R. arabicus from a clade compoSed of R. ilamensis sp. nov. and R. satunini . ReconStructed ML tree baSed on Cytb SequenceS Showed a Similar topology to the concatenated dataSet, except for a polytomy at the baSal diviSion of Rhynchocalamus clade leading to an ambiguity in determining the moSt baSal clade within thiS genuS. The BI concatenated tree reSulted in a topology identical to the ML tree.

Kimura 2-parameter (K2P) method of meaSuring genetic diStance uSed for both the concatenated and Cytb dataSetS ShowS that R. ilamensis sp. nov. Separated from itS cloSeSt relative, R. satunini , by 6% and 9% in the concatenated and the Cytb SequenceS, reSpectively ( Table 4). ThiS method alSo revealS the low genetic variability within theSe SpecieS ( Table 5).

Cytb Concatenated

D. S.E. D. S.E. R. arabicus ---- ---- ---- ---- R. ilamensis sp. nov. 0.030 0.006 0.007 0.003 R. melanocephalus 0.003 0.002 0.002 0.001 R. satunini 0.022 0.005 0.014 0.003

Figures

FIGURE 2. Dorsal (a) and Ventral (b) Views of the preserVed holotype specimen of Rhynchocalamus ilamensis sp. nov. (YUZM-CRh. 1).

FIGURE 3. Dorsal head and neck View of Rhynchocalamus ilamensis sp. nov. (a) holotye (YUZM-CRh. 1); (b) paratype (YUZM-CRh. 2); (c) paratype (YUZM-CRh. 3).

FIGURE 4. Ventral head and neck View of Rhynchocalamus ilamensis sp. nov. (a) holotye (YUZM-CRh. 1); (b) paratype (YUZM-CRh. 2); (c) paratype (YUZM-CRh. 3).

FIGURE 5. Hierarchical cluster analysis of four species of Rhynchocalamus (R. arabicus, R. melanocephalus, R. satunini and R. ilamensis sp. nov.) based on multisate and meristic characters.

FIGURE 6. Maximum likelihood tree of Rhynchocalamus based on the concatenated dataset of partial mitochondrial (Cytb) and nuclear (C-mos) genes. Numbers aboVe and below the lines denote ML bootstrap and posterior probability support Values, respectiVely. Photos of the different species include R. arabicus, R. satunini and R. melanocephalus from Šmíd et al. (2015), Muhtarophis barani from AVcı et al. (2015) and Lytorhynchus diadema from the Reptile-Database (http: // www. reptiledatabase. org /).