Cracking cryptic species: external characters to distinguish two recently recognized banded newt species (Ommatotriton ophryticus and O. nesterovi)

SALAMANDRA 55(2) ISSN 0036-3375 131-134 I 15 May 2019 Correspondence Cracking cryptic species: external characters to distinguish two recently recognized banded newt species {Ommatotriton ophryticus and O. nesterovi) Nazan Uzum\ Aziz Avci\ Kurtulu§ Olgun\ Ufuk BuLBUL^ Michael FAHRBACH^ Spartak N. Litvinchuk'^ & Ben Wielstra^-*^ '' Adnan Menderes University, Aydin, Turkey Karadeniz Technical University, Trabzon, Turkey Niedernhaller Str. 8/2, 74653 Criesbach, Germany Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia Institute of Biology Leiden, Leiden University, Leiden, The Netherlands Naturalis Biodiversity Center, Leiden, The Netherlands Corresponding author: Ben Wielstra, e-mail: ben.wielstra@naturalis.nl Manuscript received: 5 October 2018 Accepted: 9 February 2019 by Stefan Lotters Cryptic species are species found to be genetically distinct, that previously went unrecognized due to their morpho¬ logical similarity (Beheregaray & Caccone 2007, Bick¬ ford et al. 2007, Pfenninger & Schwenk 2007). With the exponential increase in genetic data, many cryptic species have been uncovered. However, their status as cryptic spe¬ cies would only be temporary if diagnostic morphological differences, corresponding to the genetically defined spe¬ cies boundary, were subsequently to be found. This way the genetic revolution could stimulate a renewed interest in morphology (Wielstra & Arntzen 2016). Genetic studies in the family Salamandridae have regu¬ larly revealed cryptic species (e.g. Wielstra et al. 2013, Pabijan et al. 2017), with the most recent example provided by the banded newts (genus Ommatotriton) (Arntzen & Olgun 2000, Litvinchuk et al. 2005, Bulbul & Kutrup 2013, van Riemsdijk et al. 2017). A generally accepted split is Ommatotriton vittatus (Gray, 1835) versus O. ophryticus (BerthOLD, 1846). The latter has recently been further split into O. ophryticus sensu stricto (from here on O. ophryti¬ cus) and O. nesterovi (Litvinchuk, Zuiderwijk, Borkin & Rosanov, 2005). While morphological characters to dis¬ tinguish O. vittatus from the other two species have been described (Table 3 in Borkin et al. 2003), how to separate O. ophryticus from O. nesterovi is currently unclear. A superficial inspection of photographs taken in the field suggests two characters related to the ‘band’ in band¬ ed newts might be able to separate O. ophryticus from O. nesterovi (van Riemsdijk et al. 2018). In O. nesterovi, the lateral white band (I) appears to continue from the front limbs up to the eye and (II) appears to be disrupted by large specks on the tail (with a bluish hue in males), while this is not the case in O. ophryticus (Fig. 1). We conduct¬ ed a survey of museum specimens of known origin to test the reliability of these characters to distinguish between O. ophryticus and O. nesterovi. We surveyed adult specimens of O. nesterovi (n = 95 ( 3 ' 6 '; n = 160 $$) and O. ophryticus (n = 181 ( 5 '( 5 '; n = 148 $ 9 ) stored in the following museum collections: Zoological Museum of Adnan Menderes University (ZMADU), Aydm, Turkey; Karadeniz Technical University Zoology Research Laboratory (KZL), Trabzon, Turkey; Zoological Institute of the Russian Academy of Sciences, St. Petersburg (ZISP), Russia. Specimens could be unambiguously allocated to species based on their geographical origin, with O. nesterovi and O. ophryticus, as identified by genetic data, occurring west and east of the city of Samsun in Turkey (van Riems¬ dijk et al. 2017). For a detailed overview of material see the Supplementary material. For each specimen we determined whether the lateral white band continues from the front limbs up to the eye (la) or not (Ib), and whether the lateral white band is disrupted by large specks on the tail (Ila) or not (Ilb). We also checked these characters in a less exhaus¬ tive survey of O. vittatus (n = 35 cJc^; n = 73 ??)• © 2019 Deutsche Gesellschaft fiir Herpetologie und Terrarienkunde e.V. (DGHT), Mannheim, Germany Available at http://www.salamandra-journal.com 131 Correspondence Table 1. Survey of two ‘band characters’ in the three banded newt species, genus Ommatotriton. For each species it is noted for how many individuals (I) the lateral white band continues from the front limbs up to the eye (la) or not (Ib), and (II) the lateral white band is disrupted by large specks on the tail (Ila) or not (lib). All Neck Tail c?c? Neck Tail 99 Neck Tail Species n la Ib Ila lib n la Ib Ila lib n la Ib Ila lib 0. nesterovi 255 247 8 250 5 95 87 8 94 I 160 160 0 156 4 0. ophryticus 329 72 257 32 297 181 49 132 17 164 148 23 125 15 133 0. vittatus 83 47 36 44 39 31 18 13 20 II 52 29 23 24 28 Results are summarized in Table i and Figure 2 and a detailed overview of the results is in the Supplementary material. We find that for almost all O. nesterovi the lateral white band continues from the front limbs up to the eye (la: 96.9% of total, 91.6% of SS and 100.0% of $$) and the lateral white band is disrupted by