Endonura aibgai, Smolis, Adrian & Kuznetsova, Nataliya, 2016

Smolis, Adrian & Kuznetsova, Nataliya, 2016, Remarkable diversity of the genus Endonura Cassagnau, 1979 (Collembola: Neanuridae: Neanurinae) in the Caucasus, Zootaxa 4200 (1), pp. 47-82 : 55-56

Endonura aibgai sp. nov.

Figs 17–24 , 48 Tab. 3

Type material. Holotype: adult male on slide, Russia, Caucasus , Krasnodarsky Krai , up from Krasnaya Polyana, Aibga Range (ropeway Gornaya Karusel), nothern slope, 2300 m alt., alpine zone, under Rhododendron caucasicum , N43.64175 ˚, E 40.26222 ˚, 29.VI.2014, leg. M. Potapov, N. Kuznetsova, A. Kremenitsa (housed in MSPU) . Paratypes: 4 females, 4 males and 3 juveniles on slides, same data as holotype (preserved in DIBEC and MSPU) .

Etymology. The species name refers to the Aibgai ridge where the species was found.

Diagnosis. Habitus typical of the genus Endonura . Dorsal tubercles present and well developed. 2+2 eyes darkly pigmented. Buccal cone relatively long, 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 5 and 8 chaetae respectively. Tubercles Di and De on th. I not fused. Tubercles De on th. II and III with 3 and 4 chaetae respectively. Tubercles L on abd. III and IV with 4 and 8 chaetae respectively. Abd. IV and V with 8 and 3 tubercles respectively. Claw with inner tooth. Tibiotarsi with chaetae B4 and B5 long.

Description. Habitus typical of the genus. Body length (without antennae): 0.7 (juvenile)– 1.05 mm (holotype: 0.89 mm). Colour of the body bluish grey. 2+2 large dark-pigmented eyes ( Fig. 17 ).

Types of dorsal ordinary chaetae. Macrochaetae Ml slightly thickened, relatively short, arc-like or straight, narrowly sheathed, feebly serrated, apically pointed or rounded ( Figs 17, 21–22 ); macrochaetae Mc and Mcc thickened, straight, pointed or apically rounded; mesochaetae and microchaetae short, thin and pointed.

Head. Buccal cone short. Labrum nonogival, with ventral sclerifications as in Fig. 20 . Labrum chaetotaxy 4/2, 4. Labium with four basal, three distal and four lateral chaetae, papillae x absent. Maxilla styliform, mandible thin with two basal and two apical teeth. Chaetotaxy of antennae as in Figs 18, 19 and Tab. 3 c. Apical vesicle distinct, trilobed. S–chaetae of ant. IV of medium length and relatively thin. Chaetotaxy of head as in Tab. 3 a, b, and Fig. 17 . Tubercle Af on head longer than tubercles Oc. Chaeta D free. Elementary tubercles CD present. Chaeta A shorter than B.

Thorax, abdomen, legs. Body s-chaetae thin and smooth, shorter than nearby macrochaetae ( Figs 17, 22 ). Chaetotaxy of th. and abd. as in Tab. 3 d and in Figs 17, 22 . Tubercles Di on th.I differentiated and not fused with De ( Fig. 17 ). 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. 17 ). 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 Di3 as Mcc or mi ( Fig. 22 ). Male without modified chaetae (“male ventral organ”). Chaetae L' and Vl on abd. V present. No cryptopygy. Chaetotaxy of legs as in Fig. 23 and Tab. 2 d. Claw with small but distinct inner tooth ( Figs 23, 24 ).

b) Cephalic chaetotaxy–ventral side.

c) Chaetotaxy of antennae.

d) Postcephalic chaetotaxy.

Terga Legs

Di De Dl L Scx2 Cx Tr Fe T th. I 1 2 1 - 0 3 6 1 3 1 9 th. II 3 2+s 3+s+ms 3 2 7 6 12 19 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: 4-5; 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 8 Vel: 4; Vec: 2; Vei: 2; Vl: 4

abd. V (3+3) 7+s Ag: 3; Vl: 1

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

Remarks. Because of several characters: large eyes, number of chaetae Dl on head, dorsal chaetotaxy of thorax and abdomen, dentate claws, and long tibiotarsal chaetae B4 and B5, E. aibgai sp. nov. strongly resembles E. lusatica ( Dunger, 1966) , species described from Germany and known to date also from Poland and Ukraine ( Dunger 1966, Smolis 2008a). Nevertheless, the new species can be distinguished from E. lusatica by the following characters: maximum length of the body without antennae (in aibgai 1.05 mm, in lusatica 3.1 mm), presence/absence of chaetae E on head (in aibgai absent, in lusatica present), number of chaetae (L+So) on head (in aibgai 8, in lusatica 9), presence/absence of tubercle Di on first thoracic segment (in aibgai present, in lusatica absent), shape of ventral sclerifications of labrum (in aibgai nonogival, in lusatica ogival) and presence/absence of male ventral organ (in aibgai absent, in lusatica present).

Ecological note. The species was found in litter under shrubs of Rhododendron caucasicum ( Fig. 48 ).

Figures

FIGURE 48. Alpine shrubs of Rhododendron caucasicum in Aibga Range, type locality of Endonura diminutichaeta sp. nov. and Endonura aibgai sp. nov.

FIGURES 17 – 24. Endonura aibgai sp. nov.: 17, dorsal chaetotaxy of head, th. I – III and abd. I (holotype); 18, dorsal chaetotaxy of ant. III – IV; 19, ventral chaetotaxy of ant. III – IV; 20, chaetotaxy of labrum; 21, chaeta Di 1 of abd. V; 22, dorsal chaetotaxy of abd. IV – VI; 23, femur, tibiotarsus and claw III, ventrolateral view; 24, claw III, lateral view.

Tables

TABLE 3. Chaetotaxy of Endonura aibgai sp. nov.: a) Cephalic chaetotaxy – dorsal side.

Tubercle	Number of chaetae	Types of chaetae	Names of chaetae
Cl	4	Ml Mc	F G
Af	9	Ml Mc	B A, C, O, D
Oc	3	Ml Mc Mcc	Ocm Ocp Oca
Di	2	Ml Mcc	Di1 Di2
De	2	Ml Mcc	De1 De2
Dl	5	Ml Mcc	Dl1, Dl5 Dl2, Dl4, Dl6
(L+So)	8	Ml Mcc me	L1, L4, So1 L2 So3–6