Spinonychiurus tianshanicus ( Martynova, 1971 ) Martynova, 1971

Pomorski, Romuald J. & Kapruś, Igor J., 2015, Revision of the genus Spinonychiurus Weiner 1996 (Collembola: Onychiuridae) with description of five new species, Zootaxa 3914 (2), pp. 101-121 : 106-109

Spinonychiurus tianshanicus ( Martynova, 1971) comb. nov. nov.

( Figs 21–29 )

Onychiurus tianshanicus Martynova, 1971: 598 .

Type material. holotype female and three paratypes (females); soil of spruce forests on the slopes of Terskey-Alatau ridge; 17–24.V.1965; Tian-Shan Mt., Kyrgyzstan, leg. Vtorov (preserved in the Martynova’s Collection in Zoological Institute of RAS, St. Petersburg, Russia).

Other material. More than 100 spp. collected in a different habitats around of the Issyk-Kul lake; 18–26.vii.2005 and 9–16.vi.2006; Issyk-Kul district; Kyrgyzstan, leg. R.J. Pomorski.

Redescription. Color white. Body length of adults: females 1.0– 1.2 mm, reproductive males 0.95–1.15 mm. Body shape cylindrical with curved anal spines, shorter than inner edge of claw (ratio 0.66) ( Fig. 21 ). Granulation of body surface fine and uniform, distinctly stronger around anterior and posterior cephalic pseudocelli. Antennal bases poorly marked by fine granulation.

Antennae nearly as long as head or slightly longer. Microsensillum of antennal segment IV located in lateroexternal position, in proximal whorl of chaetae ( Fig. 23 ). Antennal IV sensilla difficult to recognize ( Fig. 23 ). Antennal III sensory organ with 5 guard chaetae, 5 papillae, 2 sensory rods, 2 smooth with only two ribs and slightly bent sensory clubs, and microsensillum located slightly below antennal III sensory organ ( Figs 22, 23 ).

Postantennal organ consists of 13–17 granulated vesicles ( Fig. 24 ). Labial palp of A type ( Fig. 28 ).

Pseudocellar formula dorsally: 33–4/233/34454, ventrally: 1/000/0001. Subcoxae1 of I–III legs with 1 pseudocellus each. Parapseudocellar formula: 1/000/222113 (each anal valve with parapseudocellus). Localization of parapseudocelli on abdominal sterna I–VI as in Fig. 26 . Subcoxae1 of I–III legs with 1 parapseudocellus each.

Dorsal chaetotaxy as in Fig. 21 , nearly symmetrical (some asymmetries in subaxial chaetotaxy of abdominal terga IV and V), well differentiated into apically rounded macro-, mesochaetae and apically pointed microchaetae. Thoracic terga II and III with microsensilla laterally. Body sensory chaetae s difficult to recognize. Thoracic tergum I usually with 8+8 chaetae. Abdominal tergum IV with m0 and a0 chaetae (often asymmetries in adults). Abdominal tergum V with m0 and a0 chaetae (rare asymmetries in adults). Subcoxae1 of I–III legs usually with 4, 5, 5 chaetae respectively.

Thoracic sterna I–III with 0+0, 1+1, 1+1 chaetae respectively. Ventral tube of females with 9+9 chaetae and 1+1 chaetae at base. Furca reduced to small area of fine granulation and three rows of manubrial chaetae behind its posterior edge ( Fig. 27 ). Claws without teeth. Empodial appendage without basal lamella, shorter than inner edge of claw (ratio 0.75–0.8). Tibiotarsi I–III with 11 chaetae in distal whorl ( Fig. 25 ). Males with ventral organ consisting of 3+3 thickened and serrated chaetae, located on ventral tube in posterolateral position ( Fig. 29 ).

Remarks. S. tianshanicus is one of the most common onychiurid species living in different habitats of the Issyk-Kul district in the Kyrgyzstan. The most often it was collected in moist soil near rivers and streams and in wet forest humus between rocks and stones on slopes (1600–2300 m alt.). The species is also common in soil of alpine meadows and even in alpine tundra at altitude ca. 4000 m.

S. tianshanicus belongs to the group of species with 11 chaetae in distal whorl of tibiotarsi and the most similar to S. pamirensis from which it differs in smooth sensory clubs in antennal III sensory organ and presence of 1+1 pseudocelli on abdominal sternum IV.

Figures

FIGURES 21 – 26. Spinonychiurus tianshanicus: 21, habitus, dorsal chaetotaxy and localization of pseudocelli; 22, sensory clubs of antennal III sensory organ; 23, antennal segments III – IV, antennal III sensory organ; 24, postantennal organ and pseudocelli at base of antenna; 25, tibiotarsal chaetotaxy and claw of legs III; 26, abdominal sterna I – VI, chaetotaxy and localization of parapseudocelli.

FIGURES 27 – 29. Spinonychiurus tianshanicus: 27, remnant of furca; 28, labial palp; 29, lateral viev of ventral tube, male ventral organ and parapseudocellus.