Metellina orientalis (Spassky, 1932)

Oezkuetuek, Recep Sulhi, Marusik, Yuri M., Kunt, Kadir Bogac & Elverici, Mert, 2017, Taxonomic notes on two sibling species of Metellina from Asia (Araneae, Tetragnathidae), ZooKeys 695, pp. 75-88 : 76

Metellina orientalis (Spassky, 1932) Figs 1-6, 9-10, 17-19, 23-25, 29, 30-33, 34-36, 39, 47

Meta orientalis Spassky, 1932: 184, f. 5-8 (♂♀).

Metellina orientalis : Marusik 1985: 139; Marusik 1986: 19, f. 1.1-3 (♂♀); Malek Hosseini et al. 2015: 92, f. 3 a–c (♂).

Examined specimens.

TURKEY: Konya Province: 1♂, 2♀ (AUZM), Seydişehir District, Kuyucak Mountain, Kalafat Hill, Ferzene Cave (37°22'49.24"N 31°50'2.10"E), 27.03.2011 (R.S. Özkütük); 5♀ (AUZM), Derebucak District, Çamlık Town, Körükini Cave (37°20'53.94"N 31°37'38.53"E), 10.06.2011 (K.B. Kunt); 1♂, 2♀ (AUZM), Derebucak District, Çamlık Town, Döllüönüini Cave (37°20'20.38"N 31°37'15.12"E), 10.07.2011 (R.S. Özkütük). Erzincan Province, 2♂, 4♀ (AUZM), Kemaliye District, Kozlupınar Village, Ala Cave (39°13'5.63"N 38°34'20.71"E), 20.03.2015 (M. Elverici) Sivas Province, 3♂, 1♀ (AUZM), Şarkışla District, Alaman Village, Camızlı Cave (39°35'8.91"N 36°15'12.13"E), 18.04.2016 (K.B. Kunt). ARMENIA: syntype 1♂ (ZISP), Goktscha Lake (=Sevan), Yelenovka, 13-16.08.1931 (M. Karpova). IRAN: Kohgiluyeh and Buyer-Ahmad Province, 1♂ 1♀ (ZMUT), Nevel Cave, 28.08.2011 (M.J. Malek Hosseini).

Diagnosis.

Males of M. orientalis can be easily distinguished from all congeners, except for M. kirgisica , by having strong cymbial spines (Figs 17-19, 23, 25) lacking in other species. The two sibling species can be distinguished by the shape of paracymbial spur (Ps), which are rounded and claw-like in M. orientalis (Figs 19, 23) and spine-like in M. kirgisica (Figs 21-22). Females of M. orientalis are also very similar to those of M. kirgisica by having three pairs of abdominal humps (can be almost indistinct in some specimens) and a very similar epigyne. The epigyne in M. orientalis has a larger and wider median plate (cf. Fig. 36, 39-40, 42) and a thinner “septum” (1/3 of median plate width vs. 1/2). Females can be easily distinguished by carapace pattern, poorly developed in M. orientalis (Fig. 4-5) and very complex in M. kirgisica (Figs 11-12).

Description.

Measurements (♂/♀): total length 6.48/6.60; carapace 2.88/2.70 long, 2.24/2.04 wide; chelicerae 1.20/1.20 long; abdomen 3.60/3.90 long, 2.40/3.12 wide.

Female carapace with weak pattern (Fig. 5) or almost lacking any pattern (Fig. 4). Legs with numerous spines, stronger in males than in females. Legs light-coloured; femora, tibia and metatarsi of all legs with two dark rings (Figs 1, 4-6). Tibia-metatarsi of legs I and II with prolateral row of stiff, inflexible setae forming kind of catching basket. For leg measurements see Table 1.

Abdomen with three pairs of humps, almost indistinct in males. Anterior pair large and distinct in all females examined, two posterior pairs much smaller and can be indistinct. Pattern not distinct, in contrast to sibling species; venter with wide dark median band.

Male chelicera with five strong stridulating ridges and some smaller ones above and below. Male palp as in Figs 17-19, 23, 24, 30-33. Cymbium with more than a dozen strong macrosetae in distal half. Paracymbium with finger-like ventral arm (Pv) covered with setae and a large extending dorso-retrolateral arm (Pd). Dorso-retrolateral arm gradually widens, its width subequal to width of cymbium. Dorso-distal part of the arm with deep depression dorsally (Dd), spur like process (Ps) and several rows of fine spines (Fs) clearly visible with SEM, but indistinct with light microscopy. Tegulum thin, as wide as conductor, transverse. Conductor (Co) long, with parallel margins, tip abrupt, with small membranous outgrowth (Mo), conductor entirely hides embolus in ventral view; embolus (Em) with large base (Eb) formed by two lobes; embolus gradually tapering, with widened tip.

Epigyne as in Figs 34-36, 39; simple, heavily sclerotized plate more than twice as wide than long, without any outgrowths; median plate (Mp) with septum-like sclerotised outgrowth (Se) three times thinner than width of median plate; median plate hexagonal, weakly sclerotized, wider than long. Anterior from epigynal plate with pair of transversal sclerotized plates (Sp, Fig. 34).

Distribution and notes.

World Spider Catalog (2017) indicates distribution of the species as "Central Asia, Iran" although it was described from Armenia, located in the Caucasus and neighbouring with Turkey, which belong to the Middle East. Mikhailov’s catalogue ( Mikhailov 2013) indicates the distribution of M. orientalis in the former USSR as Armenia, Kazakhstan, and Turkmenistan: Metellina orientalis was reported from Kazakhstan (Almaty) and Turkmenistan (Akhal-Teke) by Spassky (1952) but the two records of the species from Central Asia undoubtedly refer to the sibling species M. kirgisica , previously reported from Kyrgyzstan, Uzbekistan, Turkmenistan ( Mikhailov 2013), and northwestern China, Xinjiang ( Marusik et al. 2007).

This species was reported from Turkey for the first time by Karol (1967). She referred to Spassky (1932) and Charitonov (1936), although none of these publications deal with spiders of Turkey. Spassky (1932) described it from Armenia, and Charitonov (1936) just listed the species in his catalogue. Several surveys and checklists of Turkish spiders listed this species as occurring in Turkey with reference to Karol’s (1967) publications ( Bayram 2002; Topçu et al. 2005; Bayram et al. 2017). Now we are able to confirm the presence of M. orientalis in Turkey.