Introduction

The genus Euscorpius Thorell, 1876 is one of the most studied taxa of scorpions. According to the present taxonomy, it includes 18 species grouped in four subgenera (Alpiscorpius Gantenbein et al. 1999; Euscorpius Thorell, 1876; Polytrichobothrius Birula, 1917; Tetratrichobothrius Birula, 1917) (Fet et al. 2004; Vignoli and Salomone 2008; Tropea 2012). However, its taxonomy is still not totally clear, especially in the Balkans and Turkey but also in Western Europe. The Euscorpius populations of Turkey have been poorly studied up to now, and only two valid species are recognized; Euscorpius (Polytrichobothrius) italicus (Herbst, 1800) and Euscorpius (Alpiscorpius) mingrelicus (Kessler, 1874). The latter is a species complex with six subspecies in Turkey (Euscorpius mingrelicus mingrelicus (Kessler, 1874), Euscorpius mingrelicus ciliciensis Birula, 1898, Euscorpius mingrelicus phrygius Bonacina, 1980, Euscorpius mingrelicus ollivieri Lacroix, 1995, Euscorpius mingrelicus legrandi Lacroix, 1995, and Euscorpius mingrelicus uludagensis Lacroix, 1995) that need clarification. Presence of the “carpathicus complex” have been reported by several authors; Hadži (1930) reported it from İstanbul; Schenkel (1947) from Havza (Samsun); Vachon (1951) from Acıpayam and Honaz Mountain (Denizli), Eğridir (Isparta), Korikos (Mersin) and İstanbul; Tolunay (1959) from Sinop; Kinzelbach (1975, 1982) from Amasya, the Middle Taurus, Borçka (Artvin), Çanakkale, Trakya and Efes (Izmir); Karatas (2006) from Marmara area, Sinop, Ada vicinity, Alanya, Avsallar, Fethiye and Kelebekler Valley; Koç and Yağmur (2007) from Dilek peninsula.

Kinzelbach (1975) divided Euscorpius carpathicus into two species, Euscorpius carpathicus and Euscorpius mesotrichus Hadži, 1929. According to Kinzelbach (1975), Euscorpius tergestinus is a synonym of Euscorpius mesotrichus, but the latter name is not available because it is a junior homonym of Euscorpius italicus mesotrichus Hadži, 1929 (Di Caporiacco 1950; Fet 1997; Fet and Braunwalder 2000). Euscorpius mesotrichus was synonymized with Euscorpius tergestinus by Di Caporiacco (1950) and according to Fet and Braunwalder (2000) the correct name for this species should be Euscorpius tergestinus, but further studies (Gantenbein et al. 2001; Fet et al. 2003) reported that “Euscorpius mesotrichus” of Kinzelbach also refers to other species such as Euscorpius balearicus and Euscorpius sicanus, besides Euscorpius tergestinus and other forms waiting for clarification. “Euscorpius mesotrichus” was recorded in Turkey from Şile (İstanbul) and Prinkipos Island (Büyükada Island) in the Marmara Sea by Kinzelbach (1975).

Koç and Yağmur (2007) reported a population from Dilek Peninsula in Western Turkey as Euscorpius sp. (“carpathicus complex”). A Dilek specimen was also listed by Vignoli and Salomone (2008) as Euscorpius. cf. tergestinus (AMNH, Söke, Davutlar, 44 m a.s.l., 28.IV.2005, H. Koç). This population is described in this study as a new species, Euscorpius avcii sp. n. According to our preliminary studies on Turkish Euscorpius populations, more species and forms ranging from polytrichous to oligotrichous are present and of these, the latter exhibits diagnostic characters that appear intermediate between the subgenus Euscorpius and Alpiscorpius. The new species, Euscorpius avcii sp. n. is oligotrichous and differs from other forms of the genus Euscorpius enough to justify its description as the first species of the subgenus Euscorpius to be registered in Turkey.

Materials and methods

A number of 79 specimens collected at Dilek Peninsula, in Turkey, were examined. Furthermore, 56 specimens from MZUF (Euscorpius tergestinus (C.L. Koch, 1837): 132/5856, 84/5847, 5848, 5861, 5862, 5863, 131/5838, 5839, 5840, 5841, 5842, 5843, 132/5854, 5856, 5857, 5860, 135/5699, 161/5850, 5851, 162/5864, 5865, 5866, 5867, 163/5987, 5988, 5889, 5990, 5991, 5992, 5993, 5994, 5995, 5996, 5997, 5998, 180/5852, 1417/5999, 6000, 6001, 6002, 6003, 6004, 6005, 6006, 6007, 6008, 6009, 6010, 6011, 6012, 165/6226, 73/6032, 1149/6238; Euscorpius oglasae Caporiacco, 1950 lectotype 122/5974, paralectotypes 123/5975) and 13 specimens of the private collection of Gioele Tropea (10 Euscorpius tergestinus (C.L. Koch, 1837) from Italy (Abruzzo, Latium and Umbria) and 3 Euscorpius carpathicus sensu stricto(Linnaeus, 1767) from Romania) were included in this study as comparison material.

Abbreviations: V: trichobothria on ventral pedipalp chela manus; Pv: trichobothria on patella ventral surface; Pe: trichobothria on the pedipalp patella external surface; et: external terminal; est: external sub-terminal; em: external medium; esb: external suprabasal; eba: external basal a; eb: external basal; DPS: dorsal patellar spur; DD: distal denticle; MD: median dentition; OD: outer dentition; ID: inner dentition; IAD: inner accessory denticles; AMNH: American Museum of Natural History, New York, USA; MZUF: Museo Zoologico ‘La Specola’ dell’Università di Firenze, Florence, Italy; GTC: private collection of Gioele Tropea; MTAS: Museum of the Turkish Arachnological Society; ZMSU: Zoology Museum of Sinop University; KUAM: Arachnological Museum of Kırıkkale University; ARC: private collection of Andrea Rossi.

The trichobothrial notations follow Vachon (1974). The morphological measurements are given in millimeters (mm) following Stahnke (1970). The morphological nomenclature follows Stahnke (1970), Hjelle (1990) and Sissom (1990); the chela carinae and denticle configuration follows Soleglad and Sissom (2001) and sternum terminology follows Soleglad and Fet (2003); description of hemispermatophore and terminology follows Soleglad and Sissom (2001) and Fet and Soleglad (2002).

Taxonomy Family Euscorpiidae Laurie, 1896 Genus Euscorpius Thorell, 1876 Subgenus Euscorpius Thorell, 1876 Discussion

Euscorpius avcii sp. n. is an oligotrichous form with Pv = 7 and Pe-et = 5/6. Most of the species belonging to the subgenus Euscorpius have generally higher trichobothrial numbers, with some exceptions e.g. Euscorpius oglasae Di Caporiacco, 1950 (Pv = 7, Pe-et = 5) (Vignoli et al. 2007) and an unnamed form from the island of Samos in Greece (Pv = 5, Pe-et = 5) (Vignoli and Salomone 2008). Kinzelbach (1975) mentions Euscorpius carpathicus (Linnaeus, 1767) and Euscorpius mesotrichus from some localities in Turkey, according to the author the specimens with Pv 7/8 are Euscorpius carpathicus, with Pv 10/14 are Euscorpius mesotrichus. According Kinzelbach (1975) Euscorpius tergestinus is a synonym of Euscorpius mesotrichus, but the latter name is not available because it is a junior homonym of Euscorpius italicus mesotrichus Hadži, 1929 (Di Caporiacco 1950; Fet 1997; Fet and Braunwalder 2000). Euscorpius mesotrichus was synonymized with Euscorpius tergestinus by Di Caporiacco (1950) and according to Fet and Braunwalder (2000) the correct name for this species should be Euscorpius tergestinus. Further studies (Gantenbein et al. 2001; Fet et al. 2003) reported that “Euscorpius mesotricus” of Kinzelbach also refers to other species such as Euscorpius balearicus and Euscorpius sicanus besides Euscorpius tergestinus and other forms that need clarification. Euscorpius carpathicus s. str. is now restricted to the populations of the type locality in Romania (Fet and Soleglad 2002). Among the specimens studied by Vignoli and Salomone (2008), there is one from Turkey of the AMNH collection labeled as Euscorpius cf. tergestinus (1 juvenile, Aydın Davutlar, Söke 44 m a.s.l., 28.IV.2005, H. Koç coll.) from the same population as presented in this study as a new species. The specimens of our study certainly do not fall within the range of Euscorpius mesotrichus “of Kinzelbach” nor in Euscorpius carpathicus s. str. and Euscorpius tergestinus s. str., as we shall see from morphological and trichobothrial data below.

Euscorpius oglasae has a trichobothrial pattern that is almost identical to Euscorpius avcii sp. n., but the morphology and geographic distribution (Euscorpius oglasae is endemic to the island of Montecristo in the Tyrrhenian Sea in Tuscany, Italy) make easy to separate these two species. Euscorpius oglasae is larger than Euscorpius avcii sp. n. (up to 43 mm) (Vignoli et al. 2007), the lobe of the movable finger is weak in males and obsolete in females, the chela is slender, whereas Euscorpius avcii sp. n. has a very pronounced lobe on movable finger and the notch on fixed finger and the chela is stocky. The DPS is more developed in Euscorpius oglasae as well as the granululation and metasomal carinae. Euscorpius oglasae has a lower pectinal teeth count, 7–7 in males and 6–6 females, whereas Euscorpius avcii sp. n. has 8–8 in males and 7–7 in females.

Samos is a Greek island inhabited by an unnamed oligotrichous form, similar to Euscorpius avcii sp. n. The Samos population is characterized by small size, stocky pedipalps and trichobothrial pattern Pv = 5 and et = 5 (Vignoli and Salomone 2008). This form therefore seems to have a lower Pv count and et constant (Euscorpius avcii sp. n. has Pv = 7 and et = 5/6). Samos Island is very close to the Dilek Peninsula (in some places less than two kilometers), therefore a relationship could be possible between these two populations, but because of the lack of information about the Samos form, we cannot discuss its taxonomical relationship to Euscorpius avcii sp. n.

Euscorpius tergestinus s. str. is easily distinguished from Euscorpius avcii sp. n., even if the color and the trichobothrial pattern eb = 4, eba = 4, em = 4 may suggest that Euscorpius avcii sp. n. is a species belonging to the “tergestinus complex”, but these are the only similar characters, in fact the morphology and the chaetotaxy reveal the great differences between these two species. Euscorpius tergestinus is larger in size (30-40 mm), it has a slender habitus with elongated pedipalps and DPS strongly developed, among the largest in the entire genus Euscorpius.

Its telson is very swollen, above average in both male and female. The metasomal carinae are much more pronounced, granulated and Euscorpius avcii sp. n. has a less swollen telson and the metasomal carinae almost smooth. The pedipalpal chela of Euscorpius tergestinus is slender and long, especially the fingers. In this species, trichobothrium db on the fixed finger is much more distal than in Euscorpius avcii sp. n. that has it in proximal position.

Euscorpius tergestinus has a more granulated carapace, and body, and developed furrows on the carapace whereas Euscorpius avcii sp. n. has almost smooth carapace, and body, with weak furrows, causing the appearance of a fairly flat carapace. The trichobothrial pattern of the pedipalp patella of Euscorpius tergestinus is reported as Pv = 7/11 (9), Pe-et = 5/8 (6 +) in Fet and Soleglad (2002). Based on this data, Euscorpius avcii sp. n. would fall within its range, but it actually does not. Fet and Soleglad (2002) synonymized Euscorpius carpathicus oglasae, with its low trichobothrial values, with Euscorpius tergestinus, but Vignoli et al. (2007) raised Euscorpius oglasae to the rank of species, therefore the range of Euscorpius tergestinus is Pv = 8/11 (9), Pe-et = 6/8 (6 +) (Tropea 2012). In fact, this species presents lowest values (Pv = 8, Pe-et = 6) in populations in central Italy (Euscorpius carpathicus picenus, Euscorpius carpathicus apuanus, of Di Caporiacco (1950)), however normally its trichobothrial numbers are Pv = 9 and Pe-et = 6. These values increase toward the northeast of Italy and in the Balkans (Tropea 2012), but they are never less, therefore Euscorpius avcii sp. n. does not share the trichobothrial range of Euscorpius tergestinus s. str.

Other species and subspecies of subgenus Euscorpius s.str. that are relatively geographically close, from the Aegean area: Euscorpius sicanus (C. L. Koch, 1837), Euscorpius koshewnikowi Birula, 1900, Euscorpius carpathicus candiota Birula, 1903, Euscorpius carpathicus ossae Di Caporiacco, 1950, Euscorpius carpathicus aegaeus Di Caporiacco, 1950 and Euscorpius carpathicus scaber Birula, 1900. Euscorpius sicanus has never been reported in Turkey; furthermore, it is easy to separate because of its particular trichobothrial pattern; Pe: eb=5 and eba = 4/5 (Fet et al. 2003; Vignoli and Salomone 2008; Tropea 2012). Euscorpius koschewnikowi has been well redescribed by Fet and Soleglad (2002) as a species quite large in size and medium to dark brown colored, exceptionally smooth, with all segments of the metasoma longer than wide, and DPS highly developed. The description of this species contrasts completely with Euscorpius avcii sp. n. because the latter is a small species, colored clear reddish brown, squat, with DPS very weakly developed, and not all metasomal segments are longer than wide. Euscorpius carpathicus candiota, among other differing characters, has a higher trichobothrial pattern as well as Euscorpius carpathicus aegaeus (Fet 1985; Di Caporiacco 1950), whereas Euscorpius carpathicus ossae is overall blackish with legs and telson slightly lighter and larger size (up to 37 mm) (Di Caporiacco 1950).

Euscorpius carpathicus scaber is a scorpion from the northern Aegean area, has a dark coloration with a high number of pectinal teeth, a higher trichobothrial pattern, and in addition, its whole body is covered with granules of various size, as also the name suggests, whereas Euscorpius avcii sp. n. has a light coloration, and its granulation is very little accentuated, almost smooth.

In our opinion, Euscorpius avcii sp. n. is well divided from all described Euscorpius forms including those that await taxonomic clarification. At present there are no described species or subspecies that corresponds to the morphology and to the trichobothrial pattern of this new species. We are confident that these data are enough to describe this form as a new species of the genus Euscorpius, and the first described species of the subgenus Euscorpius in Turkey.

Ecology

Specimens of Euscorpius avcii sp. n. were collected from the northern side of Dilek Peninsula (Fig. 7). Vegetation in this area is composed of both deciduous forest (Quercus cerris, Tilia rubra subsp. caucasica, Tilia argentea and Castanea sativa) and evergreen forest (which are Pinus brutia and Laurus nobilis). Coastal areas include scrub vegetation. Furthermore, northern side of Dilek Peninsula has a humid climate and in both summer and winter, flowing streams and wetlands exist. Specimens of Euscorpius avcii sp. n. were collected during the day under bark of decomposed wood, under stones and in rock crevices and at night with UV light from rocky places, roadsides and under pine forests (Fig. 8 and 9). Euscorpius avcii sp. n. specimens are sympatric with Mesobuthus gibbosus Brullé, 1832 and Iurus kinzelbachi Kovarik, Fet, Soleglad, Yagmur, 2010. We report an example of intraguild predation, we witnessed Mesobuthus gibbosus feeding on Euscorpius avcii sp. n. during one of our night trips (Fig. 10).