Spinonychiurus issykkulensis, Pomorski, Romuald J. & Kapruś, Igor J., 2015

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 : 111-113

Spinonychiurus issykkulensis sp. nov.

( Figs 36–43 )

Type material. Holotype female (mounted on slide) and 14 paratypes (2 unreproductive males, 11 females, 1 juv., mounted on 6 slides); roots of sedges and grasses, litter with sand in undergrowth of Hippophae sp., ca. 200 m from lakeside of the Issyk-Kul; 20.vii.2005, 7–8.vi.2006, Bozteri, Issyk-Kul district, Kyrgyzstan, leg. R. J. Pomorski (preserved in the collection the Department of Biodiversity and Evolutionary Taxonomy, Zoological Institute, Wrocław University, Wrocław).

Other material. 4 males (1 reproductive, 3 unreproductive), 3 females, 1 juv. of I instar; coarse sand at a stream mouth to the Issyk–Kul Lake 14.vi.2006, Tosor, Ton area, Issyk-Kul district; Kyrgyzstan, leg. R. J. Pomorski.

Etymology. Named after Issyk-Kul Lake.

Description. Color white. Body length: females 0.75–0.9 mm, males 0.6–0.7 mm. Body shape cylindrical with curved anal spines, distinctly shorter than inner edge of claw (in relation 0.75) ( Fig. 36 ). Granulation of body surface fine and rather uniform, distinctly stronger around pseudocelli on the front of head and in the middle part of thoracic terga II and III. Antennal bases not marked.

Antennae nearly as long as head. Subapical organite as in Figs 37 and 38 . Antennal segment IV with two well marked sensilla (dorsal-subapical and internal-subbasal). Microsensillum on antennal segment IV in latero-external position, in proximal whorl of chaetae ( Fig. 37 ). Antennal III sensory organ with 5 guard chaetae, 5 papillae, 2 small sensory rods and 2 bent, smooth with longitudinal ribs sensory clubs, and microsensillum located slightly below antennal III sensory organ ( Figs 37, 39 ).

Postantennal organ consists of 10–12 granulated vesicles ( Fig. 40 ). Labial palp of AB type.

Pseudocellar formula dorsally 43/233/44454, ventrally 1/000/0000. Subcoxae1 of I–III legs with 1 pseudocellus each. Parapseudocellar formula: 2/000/222213 (each anal valve with parapseudocellus). Localization of parapseudocelli on abdominal sterna I–VI as in Fig. 43 . Ventral anterior cephalic parapseudocelli located near labial palp as in Fig. 41 . Subcoxae1 of I–III legs with 1 parapseudocellus each.

Dorsal chaetotaxy as in Fig. 36 , nearly symmetrical, poorly differentiated into meso- and microchaetae. Thoracic terga II and III with microsensilla laterally. Body sensory chaetae s not differentiated. Thoracic tergum I with 7+7 chaetae. Abdominal tergum IV without axial chaetae. Abdominal tergum V with a0 and p0 chaetae. Abdominal tergum VI with 2 axial chaetae and 1+1 prespinal chaetae. Subcoxae1 of I–III legs with 3–4, 4, 4 chaetae respectively.

Thoracic sterna I–III with 0+0, 1+1, 1+1 chaetae respectively. Ventral tube with 7+7 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. 43 ). Claws without teeth. Empodial appendage without basal lamella, shorter than inner edge of claw (ratio 0.9). Tibiotarsi I–III with 9 chaetae in distal whorl ( Fig. 42 ). Male ventral organ absent.

Remarks. S. issykkulensis sp. nov. belongs to the group of species with 9 chaetae in distal whorl of tibiotarsi and it is closely related with S. natashae sp. nov. described below. Among of all members of the genus only these both species have anal spines shorter than inner edge of claw and labial palp of AB type. S. issykkulensis sp. nov. differs from S. natashae sp. nov. by the presence of 4+4 pseudocelli on anterior part of head and abdominal terga I–III and V, versus 3+3 pseudocelli respectively in S. natashae sp. nov.

Figures

FIGURES 36 – 43. Spinonychiurus issykkulensis: 36, habitus, dorsal chaetotaxy and localization of pseudocelli; 37, antennal segments III – IV, antennal III sensory organ; 38, tip of antenna with subapical organite; 39, sensory clubs of antennal III sensory organ; 40, postantennal organ and pseudocelli at base of antenna; 41, ventral side of head, chaetotaxy and localization pseudocelli and parapseudocelli; 42, tibiotarsal chaetotaxy and claw of legs III; 43, abdominal sterna I – VI, chaetotaxy and localization of parapseudocelli.