Euscorpius sp. 2 (“ mingrelicus complex” (Kessler, 1874)

Teruel, Rolando, Fet, Victor & de Armas, Luis F., 2004, A note on the scorpions from the Pirin Mountains, south- western Bulgaria (Scorpiones: Buthidae, Euscorpiidae), Euscorpius 14 (14), pp. 1-11 : 7-8

Euscorpius sp. 2 (“ mingrelicus complex” )

Figs. 18–19 , Table 1

Material examined. BULGARIA: Pirin Mountains , under stones in open areas, 1,200–1,300 m asl, July 1972 (coll. Gallia), 1 subadult ♂ ( IES) .

Morphology. Small scorpion (subadult male about 23 mm long, adults probably under 30 mm). Body light orange brown, with prosoma, tergites, metasoma and legs strongly marbled with dark brown; pedipalps reddish with carinae conspicuously darker; chelicerae, legs and telson yellowish. Metasoma short, slender and cylindrical in shape, with all carinae obsolete to absent; telson vesicle moderately enlarged. Trichobothrial patellar pattern: eb = 4, eba = 4, esb = 2, em = 3, est = 3–4, et = 4, v = 6; fixed finger et -est / est -dsb ratio = 2.17. Pectinal tooth count 7–7.

Comments. Even though the studied specimen is not an adult, it clearly shows all characters defining the “ mingrelicus complex” of the subgenus Alpiscorpius (obsolescence of metasomal carination, et -est / est -dsb ratio ≥ 1.5), which otherwise are not age correlated. This represents the first record of this species complex and subgenus from Bulgaria. Its presence in this country is not surprising, however, as members of this complex are widely distributed over the western Balkan Peninsula (Fet, 2000; Fet & Sissom, 2000).

Fet (1993) reviewed all known distribution and taxonomic composition of the species (sensu lato) Euscorpius mingrelicus (Kessler, 1874) which was originally described from Georgia (Caucasus) but later redefined (Bonacina, 1980) as a part of the former species Euscorpius germanus (C. L. Koch, 1837) . The latter species is in fact limited to the Alpine zone of Europe (Gantenbein et al., 2000a). Traditionally treated as one species widespread from the Alps to Caucasus (Bonacina, 1980; see Fet & Sissom, 2000 for the taxonomic history), “ E. mingrelicus complex” is currently under revision using both morphological and molecular techniques (Fet, 2000; Gantenbein et al., 2000a; Sherabon et al., 2000; Fet et al., 2003; etc.). Currently, three species are recognized in this complex, with E. mingrelicus (Kessler, 1874) sensu stricto ranging from Bosnia to Caucasus (Fet, 1993; Fet & Sissom, 2000); however, this division is clearly not satisfactory. Fet (2000) described E. beroni from the high mountains of Albania (Prokletije), and Scherabon et al. (2000) demonstrated a separate status of E. gamma Caporiacco from the northeastern part of the geographic range of this complex (northeastern Italy, Slovenia, Croatia, and Austria). For ecology and distribution of E. gamma in Slovenia and Austria, see also Scherabon (1987), Fet et al. (2001), and Komposch et al. (2001). Together with “ germanus complex”, the “ mingrelicus complex” comprises the subgenus Alpiscorpius Gantenbein et al., 1999 .

For the large part of the “ mingrelicus complex”, the taxonomy is not defined or is defined partially. There are formally seven valid subspecies of E. mingrelicus from Balkans to Anatolia (Fet & Sissom, 2000), and status of these forms is still unclear. The high genetic diversity of populations within Turkey (Fet et al., 2003a) indicates a possibility of cryptic species as recently discovered in the related Alpine “ germanus complex” (Gantenbein et al., 2000a). Further investigation of the “ mingrelicus complex” from the Balkans and Anatolia will be needed to establish into the species structure of this complex. The Pirin specimen falls into the range of “ mingrelicus complex” for which taxonomic identity of populations is not yet determined. It is an important biogeographic find—the first specimen of this complex from Bulgaria, and most likely a glacial relict.

General Remarks

Even though the examined material is scarce (only 12 specimens), it demonstrates a rather high species diversity (four species) for a single locality in the Pirin Mountains of Bulgaria. While it is not unusual to find two or three different species of Euscorpius sympatrically in Europe (Fet, 2000; Fet & Braunwalder, 2000), their precise cohabitation depends on ecological heterogeneity of the area, and the Alpine-like Pirin massif in southwestern Bulgaria indeed provides such diversity of habitats. In addition, Mesobuthus gibbosus record from Pirin represents the most peripheral record of this species in the northern part of its geographic range. Combination of Mesobuthus and Euscorpius scorpion faunal elements is a typical Aegean-Anatolian feature, as representatives of these two genera are very common and sympatric all over Greece and Turkey, including most islands of the Aegean Sea.

Figures

Figure 18: Subadult male of Euscorpius sp. 2 (“mingrelicus complex”) from Pirin Mountains. Telson and metasomal segments IV-V, ventral view, showing partially developed ventral median and ventral lateral carinae on segment V.

Figure 19: Trichobothrial patterns of the external aspect of left and right pedipalp patellae of the same specimen as in Fig. 18.