Spinonychiurus arabelensis, 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 : 118

Spinonychiurus arabelensis sp. nov.

( Figs 65–69 )

Type material. holotype (female); moss and roots of grasses in alpine tundra ca. 3800 m asl.; 14.vi.2006; Arabel valley, Barskoun, Ton area, Issyk-Kul district, Kyrgyzstan, leg. R. J. Pomorski (preserved in the collection the Department of Biodiversity and Evolutionary Taxonomy, Zoological Institute, Wrocław University, Wrocław).

Etymology. Named after the type locality–Arabel valley (the valley of bones).

Description. Color white. Body length of holotype (female) 2.1 mm. Body shape cylindrical with curved anal spines a little shorter than inner edge of hind claw (in relation 0.9) ( Fig. 65 ). Granulation of body surface fine and rather uniform, with areas covered by stronger granules located in anterofrontal part of head and around of submedial pseudocelli on abdominal tergum IV. Antennal bases not marked.

Antennae nearly as long as head with typical subapical organite ( Fig. 66 ). Sensilla on antennal segment IV not marked. Microsensillum on antennal segment IV in latero-external position, in first proximal whorl of chaetae ( Fig. 67 ). 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 ( Fig. 67 ).

Postantennal organ consists of 20 granulated vesicles ( Fig. 68 ). Labial palp of A type.

Pseudocellar formula: dorsally 34/244/5-67694 (thoracic terga II and III with anterolateral pseudocelli), ventrally 1/000/13120. Subcoxae1 of I–III legs with 3 pseudocelli each. Parapseudocelli invisible.

Dorsal chaetotaxy as in Fig. 65 , with numerous asymmetries, poorly differentiated into macro- and microchaetae. Thoracic terga II and III with microsensilla laterally. Body sensory chaetae s not differentiated. Thoracic tergum I with 9+10 chaetae. Abdominal terga IV and V with p0 chaetae. Abdominal tergum VI with 2 axial chaetae and 1+1 prespinal chaetae. Subcoxae1 of I–III legs with 4, 6, 6 chaetae respectively.

Thoracic sterna I–III with 0+0, 1+1, 1+1 chaetae respectively. Ventral tube 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. Claws without teeth. Empodial appendage without basal lamella, as long as inner edge of claw approximately (ratio 0.9). Tibiotarsi I–III with 11 chaetae in distal whorl ( Fig. 69 ). Males unknown.

Remarks. The set of exceptional characters permits on the description of S. arabelensis sp. nov. on the basis of one specimen only. In addition to the largest body size among known species of this genus, new species is characterized by numerous pseudocelli on abdominal terga and subcoxae1 of I–III legs and also by the presence of anterolateral pseudocelli on thoracic terga II and III. It belongs to the group of species with 11 chaetae in distal whorl of tibiotarsi, but his relationship with other members of the genus is difficult to recognize.

Figures

FIGURES 65 – 69. Spinonychiurus arabelensis: 65, habitus, dorsal chaetotaxy and localization of pseudocelli; 66, tip of antenna with subapical organite; 67, antennal III sensory organ; 68, postantennal organ and pseudocelli at base of antenna; 69, tibiotarsal chaetotaxy and claw of legs III.