Endonura paracantabrica sp. nov.

Figs 7–16, Tab. 2

Type material. Holotype: adult male on slide, Russia, Caucasus, Krasnodarsky Krai, up from Krasnaya Polyana, Aibga Range (ropeway Gornaya Karusel), 960 m alt., litter from mountain mixed forest ( Picea orientalis, Abies nordmanniana, Fagus orientalis), N43.66693 ˚, E40.25630 ˚, 29.VI.2014, leg. M. Potapov, N. Kuznetsova, A. Kremenitsa (housed in MSPU) . Paratypes: 3 females and one male on slides, same data as holotype (preserved in DIBEC and MSPU) .

Etymology. The species name refers to the similarity to the Iberian species E. cantabrica Deharveng, 1979 .

Diagnosis. Habitus typical of the genus Endonura . Dorsal tubercles present and well developed. 2+2 pigmented eyes. Buccal cone rather short, labrum nonogival. Head with chaetae A, B, O, C, D, F and G. Chaetae E absent. Tubercles Cl and Af separate. Tubercles Dl and (L+So) on head with 6 and 10 chaetae respectively. Tubercles Di and De on th. I fused. Tubercles De on th. II and III with 3 and 4 chaetae respectively. Tubercles L on abd. III and IV with 4 and 7 chaetae respectively. Abd. IV and V with 8 and 3 tubercles respectively. Claw without inner tooth. Tibiotarsi with chaetae B4 and B5 relatively long.

Description. Habitus typical of the genus. Body length (without antennae): 0.77–1.65 mm (holotype 1.23 mm). Colour of the body bluish grey. 2+2 medium pigmented eyes (Fig. 7).

Types of dorsal ordinary chaetae. Macrochaetae Ml relatively long, slightly thickened, almost cylindrical, straight or arc-like, narrowly sheathed, serrated, apically rounded (Figs 7, 14–15); macrochaetae Mc and Mcc thickened, straight or arc-like, serrated, pointed or rounded at apex; mesochaetae and microchaetae short, thin, feebly serrated and pointed.

Head. Labrum nonogival, with ventral sclerifications as in Fig. 9. Labrum chaetotaxy 4/2, 4 (Fig. 8). Labium with four basal, three distal and four lateral chaetae, papillae x absent. Maxilla styliform (Fig. 11), mandible thin with two basal and two subapical teeth (Fig. 10). Chaetotaxy of antennae as in Figs 12, 13 and Tab. 2 c. Apical vesicle distinct, trilobed. S-chaetae of ant. IV relatively long and thin. Chaetotaxy of head as in Tab. 2 a, b, and Fig. 7. Chaeta D not connected with tubercle Cl. Tubercle Af on head longer than tubercles Oc. Elementary tubercles CD present. Chaeta A shorter than B.

b) Cephalic chaetotaxy–ventral side.

Group Number of chaetae Vi 6

Vea 3

Vem 4

Vep 4

labium 11, 0x

c) Chaetotaxy of antennae.

d) Postcephalic chaetotaxy.

Terga Legs

Di De Dl L Scx2 Cx Tr Fe T th. I 3 1 - 0 3 6 1 3 1 9 th. II 3 2+s 3+s+ms 3 2 7 6 1 2 1 9 th. III 3 3+s 3+s 3 2 8 6 1 1 1 8

Sterna

abd. I 2 3+s 2 3 VT: 4

abd. II 2 3+s 2 3 Ve: 5; chaeta Ve 1 present

abd. III 2 3+s 2 4 Vel:5–6; Fu: 5–6 me, 0 mi

abd. IV 2 2+s 3 7 Vel: 4; Vec: 2; Vei: 2; Vl: 4

abd. V (3+3) 7–8+s Ag: 3; Vl: 1

abd. VI 7 Ve: 14; An: 2mi

Thorax, abdomen, legs. Body s-chaetae thin and smooth, distinctly shorter than nearby macrochaetae (Figs 7, 15). Chaetotaxy of thorax and abdomen as in Tab. 2 d and in Figs 7, 15. Tubercles Di on th. I differentiated and fused with tubercles De (Fig. 7). Chaetae De3 on th. III and abd. I–III as Mcc. Chaetae De2 on th. II–III and De3 on th. III free. Chaetae De3 on abd. I–III free (Fig. 7). The line of chaetae De1–chaeta s parallel to the dorsomedian line on abd I–III. Furca rudimentary without microchaetae. Tubercles Di on abd. V fused, with chaetae Di2 as Mc or Mcc, and chaetae Di3 as mi (Fig. 15). Male without modified chaetae (“male ventral organ”). Chaetae L' on abd. V present. Abd. IV 3 +3 chaetae Ag. No cryptopygy. Chaetotaxy of legs as in Fig. 16 and Tab. 2 d.

Remarks. In general appearance (size and colour of body, shape of dorsal chaetae, chaetotaxy of central area of head and dorsal side of thorax and abdomen, and absence of cryptopygy), E. paracantabrica sp. nov. is the most similar to Iberian species E. cantabrica Deharveng, 1979 known to date from north Spain and Portugal (Deharveng 1979, Jordana et al. 1997). Nevertheless, the two species differ in a few essential characters, important from taxonomic point of view: presence/absence of elementary tubercle BE on head ( paracantabrica sp. nov. absent, cantabrica present), number of chaetae (L+So) on head (in paracantabrica sp. nov. 10, in cantabrica 8–9) and presence/absence of fusion of tubercles Di and De on the first thoracic segment (separated in cantabrica).

Ecological note. The species was collected in leaf litter of a mountain mixed forest.