Redescription of Euscorpius tauricus (C.L. Koch, 1837), with the description of two new related species from Greece (Scorpiones: Euscorpiidae)

Euscorpius tauricus (C. L. Koch, 1837) was previously known only from the Crimea Peninsula, Ukraine. We report an unexpected presence of this species in the Cyclades Islands (Greece) and northwestern Anatolia (Turkey). In addition we designate a neotype for this species. We synonymize Euscorpius carpathicus aegaeus Di Caporiacco, 1950 syn. n. , from Antiparos Island and Euscorpius rahsenae Yağmur et Tropea, 2013 syn. n. , from Anatolia, with E. tauricus . In addition, we describe two new species related to E. tauricus , from the Cyclades Islands: E. curcici sp. n. , from Ios and Sikinos Islands, and E. amorgensis sp. n. , from Amorgos Island. Identity and level of divergence of these taxa is confirmed by multiple DNA markers.


Introduction
The genus Euscorpius Thorell, 1876, widespread especially in southern Europe and Anatolia, is one of the most studied scorpion taxa. Despite this, the taxonomy of this genus is very complicated and still far from being resolved. This is also true for the Euscorpius of Greece, where, especially due to the unavailability of lack of specimens from many areas, this genus has been insufficiently studied. In addition, the taxonomic studies of Euscorpius are hindered by existence of cryptic species complexes, which are difficult to resolve even with phylogenetic analysis using multiple DNA markers. However, recently several studies delineated and described various new and old forms of this genus resulting in a significant increase of the number of species in Greece (Fet et al., 2013a(Fet et al., , 2013b(Fet et al., , 2014Parmakelis et al., 2013;Tropea et al., 2013Tropea et al., , 2014a. In this study, with the use of multiple DNA markers, as a part of an ongoing revisionary study of scorpions of Greece and adjacent areas, we confirm the unexpected especially very long metasomal segment V (L/H 3.1 in females, 3.7 in males of E. tauricus), versus 2.7 and 2.8 in E. carpathicus; he also noted obsolete granulation on metasomal segment V. E. tauricus was redescribed and discussed in a great detail by . Origins and relationships of this isolated form have been unclear. Fet (1989aFet ( , 1989b reviewed all the Crimean specimens available in the main Russian museums.  first compared a DNA marker (16S rRNA) from Crimea to several Euscorpius species, and argued that DNA data supported species status for E. tauricus as an endemic, strongly isolated taxon. Distribution and ecology of E. tauricus in Crimea has been recently studied in detail by Kukushkin (2013). Brewer et al. (2005), based on a DNA marker sequence (16S rRNA), first reported that the specimens from Paros Island (Cyclades, Greece) showed affinity with those from Crimea. Several years later, Parmakelis et al. (2013) addressed the Paros population, and some populations of other Cycladic Islands, as E. tauricus complex.
Specimens of Euscorpius from the Western Cyclades are very rare in zoological museums. Pavesi (1878: 339) studied five juvenile specimens collected "near the entrance of a cave" on Antiparos Island during the Mediterranean travel of the cutter Violante in July-October 1876. This naturalistic expedition was led by the Marquis Giacomo Doria , an Italian naturalist and the founder of Museo Civico di Storia naturale di Genova (MCSNG), and Captain Enrico D"Albertis (1846-1832) of Genoa, Italy. The Antiparos specimens were identified by Pavesi as Euscorpius carpathicus. Pavesi (1878) reported number of Dp = 8 (2), 9 (2), 10 (1), and Pv = 8 (4) and 7 (1).

Diagnosis:
A medium small to medium large Euscorpius species, total length 26 to 38 mm. Colour of adults from very light brown-yellowish to brown-reddish, without reticulations or marbling. The carapace and pedipalps could be darker reddish. The number of trichobothria on the pedipalp manus ventral surface is 4 (V 1-3 +Et 1 ); trichobothrium et on fixed finger is located distally to the notch of the fixed finger; est is located distally to the centre of the notch; and dsb is located proximally to the notch. The number of ventral trichobothria on the pedipalp patella mostly is 8 (7-9); the number of external trichobothria on pedipalp patella mostly is: eb = 4, eb a = 4, esb = 2, em = 4, est = 4, et = 6 (5-7). The pectinal teeth number most is 9 (8-10) in males and 7 (6-9) in females. Chela carina V1 follows a direction toward the external side of the trichobothrium Et 1 . Dorsal patellar spur well developed. Femur of pedipalp more or less as long as the patella; both could be slightly shorter or slightly longer than patella (average Lfem/Lpat ratio = 1). Carapace can be both slightly shorter than wide or slightly longer than wide (average ratio Lcar/Wcar = 0.98). Longlimbed metasoma (Lmet/Wmet = 1.70-1.96); metasoma segment I can be more or less as long as wide (L/W segment I = 0.90-1.06); metasoma segment V usually with small and serrulated granules on the ventrolateral carinae while the ventromedian is less developed, it can be more or less present with small and spaced granules.

Description of the female neotype
Coloration: Whole colour light brown, with darker brown/reddish carapace and pedipalps; sternites, pectines and genital operculum light brownish; chelicerae brown-orange. Carapace: a fine granulation is present on most of surface, behind the lateral eyes it is formed by slightly larger granules; anterior edge slightly leaning forward at the centre; anterior median, posterior lateral and posterior median furrows are presents; two pairs of lateral eyes and a pair of median eyes, situated distally of the middle; distance from centre of median eyes to anterior margin is 43.50% of carapace length. Mesosoma: Tergites laterally finely granulated, except the segment VII, which is all finely granulated; sternites finely punctated. Spiracles small, oval shaped and inclined about 45° downward towards outside.    anterior median formed by about 9-11 conical tubercles, of which three bear a macrosetae each; intercarinal spaces with granules of different size. Patella: dorsal and ventral internal carinae tuberculated, the latter slightly serrulated; dorsal external carinae from almost smooth and rounded in proximally to dark and slightly crenulated in distally; ventral external carinae crenulated; intercarinal surface with scattered minute granules positioned in a non-uniform way. Dorsal patellar spur well-developed. Chela carina D1 from rough to slightly crenulated; D4 formed by very low and little marked tubercles; V1 is distinctly strong, dark and crenulated; V3 rounded, with a few very small and scattered granules and dark in the distal half; intercarinal tegument with very minute spaced granules. Finger dentition: in the most distal part is present a DD on the tip; MD is formed by very small denticles closely spaced forming a more or less straight line, discontinued at level of the OD; fixed finger has 6/6 OD and 10/9 ID; movable finger has 7/7 OD and 13/13 ID. Etymology: Named after the late Serbian zoologist and arachnologist Prof. Dr. Božidar Ćurčić whose early work on Euscorpius has been an inspiration for many zoologists.
Geographic distribution: Greece: Cyclades Islands: Sikinos and Ios (Fig. 55). Diagnosis: A medium Euscorpius species, total length around to 30 mm. Colour of adults very light brown/yellowish without reticulations or marbling, with slightly darker carapace and chelae. The number of trichobothria on the pedipalp manus ventral surface is 4 (V 1-3 +Et 1 ); trichobothrium et on fixed finger is located distally to the notch of the fixed finger; est is located distally to the centre of the notch; and dsb is located proximally to the notch. The number of ventral trichobothria on the pedipalp patella mostly is 9 (8-9); the number of external trichobothria on pedipalp patella mostly is: eb = 4, eb a = 4, esb = 2, em = 4, est = 4, et = 6 (6-7). The pectinal teeth number is 9 in male and 7 in female. Chela carina V1 follows a direction toward the external of the trichobothrium Et 1 . Dorsal patellar spur well developed. Femur of pedipalp more or less as long as the patella (Lfem/Lpat ratio is 1.03 in the two specimens examined). Carapace can be both slightly shorter than wide or slightly longer than wide. Long-limbed metasoma (Lmet/Wmet is 1.81-1.89 in the two specimens examined); metasoma segment I more or less as long as wide (L/W segment I is 0.996-1.036 in the two specimens examined); metasomal carinae poorly developed; metasoma segment V usually with small and serrulated granules on the ventrolateral carinae while the ventromedian is less developed, it can be more or less present with small and spaced granules.

Trichobothrial and pectinal teeth count variation
The variation observed in 2 studied specimens (1 ♂ and 1 ♀) is given below.

Description of the male holotype
Diagnosis: A small Euscorpius species, total length around to 23-25 mm. Colour of adults very light brown/yellowish to light brown-reddish without reticulations or marbling, with carapace and pedipalps that can be darker. The number of trichobothria on the pedipalp manus ventral surface is 4 (V 1-3 +Et 1 ); trichobothrium et on fixed finger is located distally to the notch of the fixed finger; est is located distally to the centre of the notch; and dsb is located proximally to the notch. The number of ventral trichobothria on the pedipalp patella mostly is 8 (7-8); the number of external trichobothria on pedipalp patella mostly is: eb = 4, eb a = 4, esb = 2, em = 4, est = 4, et = 6. The pectinal teeth number is 8 in male and 6-7 in female. Chela carina V1 follows a direction toward the external side of the trichobothrium Et 1 . Dorsal patellar spur well developed. Femur of pedipalp more or less as long as the patella (Lfem/Lpat ratio is 0.97-1.04). Carapace can be both slightly shorter than wide or slightly longer than wide (Lcar/Wcar = 0.98-1.03). Long-limbed metasoma (Lmet/Wmet is 1.70-1.83); metasoma segment I more or less as long as wide (L/W segment I is 0.90-1.00); metasomal carinae poorly developed; metasoma segment V with serrulated granules on the ventrolateral carinae while the ventromedian is less developed, it can be more or less present with small and spaced granules.

Description of the male holotype
Coloration: Whole colour light brownish, with darker brown/reddish carinae of the chelae; chelicerae, sternites, pectines and genital operculum very light brownish. Carapace: A very fine and homogeneous granulation is present on most of its; anterior edge straight; anterior median, posterior lateral and posterior median furrows are presents; two pairs of lateral eyes and a pair of median eyes, situated distally of the middle, are present; distance from centre of median eyes to anterior margin is 41.41 % of carapace length. Mesosoma: Tergites finely granulated; sternites very finely punctated. Spiracles small, oval shaped and inclined about 45° downward towards outside. Metasoma: Dorsal carinae on segments I-IV with small and spaced granules; ventrolateral carinae on segment I absent, on segment II obsolete or absent, on segment III smooth and little notable, on segment IV two, three small, low, spaced and barely visible granules are present, on segment V marked serrulated granules are present; ventromedian carina on segments I-IV absent, on segment V with a few small and spaced granules; intercarinal spaces most smooth. Pedipalps: Coxa and trochanter with tuberculated carinae. Femur: dorsal and ventral internal carinae tuberculated and dark; dorsal external carinae formed by tubercles slightly serrulated and spaced; ventral external carinae irregular, present mostly in the proximal 1/3; external median carinae serrulated; anterior median formed by about 13 conical tubercles, of which three bear a macroseta each; intercarinal spaces mostly with very small granules. Patella: dorsal and ventral internal carinae tuberculated, the latter slightly serrulated; dorsal external carinae mostly smooth and rounded, but distally is slightly crenulated and reddish; ventral external carinae slightly crenulated; intercarinal surfaces are from almost smooth ventrally to very finely granulated dorsally. Dorsal patellar spur well-developed. Chela carina D1 almost smooth with a few low tubercles proximally; D4 and V3 dark with a few small and scattered granules; V1 is distinctly strong, dark and from smooth to slightly crenulated; intercarinal tegument from smooth to granulated with very minute granules. Finger dentition: in the most distal part is present a DD on the tip; MD is formed by very small denticles closely spaced forming a more or less straight line, discontinued at level of the OD; fixed finger has 6/6 OD and 11/11 ID; movable finger has 7/7 OD and 14/14 ID. Trichobothria: Chela: trichobothria on the pedipalp manus ventral surface V = 3/3 (V 1-3 ) + Et 1 = 1/1; the trichobothrium V 4 is situated a bit on the external surface near the carina V 1 ; the trichobothrium est on fixed finger is situated distally to the centre of the notch of the fixed finger;   (the first is smaller and darker than the second) showed the same identical haplotype. Also, these two populations share the same haplotype with the populations from Paros Island (from Petaloudes) and Sifnos Island in both 16S rRNA and COI sequences. The divergence between these populations and E. tauricus from Crimea ranges between 1.0% and 1.1% in 16S rRNA, and between 1.0% and 1.2% in COI. Interestingly, on Paros, despite being a small island, there are two haplotypes (at least). In fact, the population from Marathi (Paros) (for which we only have COI sequence, not included in our phylogeny) is closer to the Crimean population showing just a divergence of 0.2%, while the divergence with the population from Petaloudes (Paros) is 0.9%. A relatively higher divergence is shown by the specimens from Naxos when compared to other populations of E. tauricus (0.9% to 1.6% for 16S rRNA, and 2.7 to 3.8 for COI). Probably, Paros population has been separated for a longer time from Naxos than from Sifnos, or has been introduced on the latter. However, the divergence is very low compared to other species, thus all these populations (Paros, Sifnos, Antiparos, Naxos, Crimea, and northwestern Turkey) are considered as belonging to E. tauricus. We do not have sequence data of specimens from Antiparos, i.e. E. carpathicus aegaeus Di Caporiacco, 1950, but the second author (VF) had the opportunity to examine a syntype of this subspecies, held in MZUF, who despite being young and damaged, fits the characters of E. tauricus, which is quite expected considering that this small island is located less than 2 km apart from Paros.
Herein we described two new species, E. amorgensis sp. n. from Amorgos Island and E. curcici sp. n. from Sikinos and Ios Islands, genetically well-separated. E. tauricus has a divergence with E. amorgensis sp. n. ranging from 3.4% to 6.0% for 16S rRNA, and 4.9 to 6.3 for COI, and with E. curcici sp. n. ranging from 2.2% to 4.6% for 16S rRNA, and 4.9% and 6.6% for COI. The divergence between E. amorgensis sp. n and E. curcici sp. n. is 4.2% and 4.4% for 16S rRNA and 4.7% and 5.5% for COI. The divergence values are within the limits reported for other valid species. According to the phylogeny in Parmakelis et al. (2013) and our additional data, E. vignai Tropea et al., 2014 (Dodecanese Islands) forms the sister clade of the "E. tauricus clade" (E. tauricus + E. curcici sp. n. + E. amorgensis sp. n. + E. avcii). The phylogenetic relationships within "E. tauricus clade" are not well resolved, and can change depending on the marker sequence (e.g. 16S rRNA or COI mtDNA) and/or the method used to construct the phylogenetic tree (e.g. Maximum Likelihood or Bayesian). In some cases (e.g. 16S ML) E. amorgensis sp. n. grouped with E. avcii as a sister clade of E. tauricus, and E. curcici sp. n. was basal to this group, while in another phylogeny (e.g. COI ML), E. avcii has been basal to this group, well separated from E. amorgensis.
Our data clearly show that E. tauricus not only is not endemic to Crimea, but is allochthonous there, as well as in the northwestern Turkey. It was previously suggested (Fet, 1997) that the existence of the Crimean scorpion was a result of a (possibly recent) migration from the Balkans or Anatolia during Pleistocene interglacials. E. tauricus could disperse to Crimea from Anatolia, to which the Crimean Peninsula had many connections during the Tertiary (Fet, 1997). The Crimean Peninsula itself originated as an island in the Tethys Sea during the Mesozoic Era and throughout the Tertiary Period was connected many times to different land masses (Caucasus, Balkan Peninsula, Anatolia, and/or modern Ukraine). Golovach (1984) analyzed the diplopod fauna in the Crimea, and suggested that its age is primarily Pleistocene and that the source of migration was the eastern Mediterranean, especially the Balkan Peninsula. Severe Pleistocene glaciations could have eliminated most of the ancient thermophilic and mesophilic biota in the Crimea. However, considering the data available in this work, such as the almost inexistent divergence between the population from Crimea (Ukraine) and the population from Marathi (Paros, Greece) (0.02% for COI), it seems plausible that a recent introduction of the Cycladic species to Anatolia and Crimea has taken place, e.g. by the ancient Greeks, who have been great navigators and founded colonies throughout the Mediterranean, including Crimea.
As for the morphological differences, the low number of specimens from Amorgos, Sikinos, and Ios islands, did not allow us to find or to ascertain well-defined and fixed characters in the populations to entirely separate the discussed species. These populations are closely related, and as often happens in these cases, it becomes even less easy to find the diagnostic characters for species identification, especially with such a low number of specimens (2 specimens E. curcici sp. n. and 4 specimens E. amorgensis sp. n.); e.g. of 4 examined pedipalps of E. curcici sp. n., three have Pv = 9 and one Pv = 8. This might suggest that this species may have a higher Pv than E. tauricus and/or E. amorgensis sp. n. Thus, additional specimens from these, and other Aegean islands are needed to understand the true variation and distribution of these and other possible new species of Euscorpius.