Endonura alticola ( Stach, 1951 ) Stach, 1951

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 : 49-50

Endonura alticola ( Stach, 1951) comb. nov.

Figs 1–6 , Tab. 1

Biloba alticola: Stach 1951: 36 .

Neanura alticola: Gisin 1960: 102 .

Detonura alticola: Deharveng 1982a: 81 .

Type material. Holotype: adult female on slide, Russia, Caucasus, Northern Ossetia, Karaugom-glacier , 20.VII.1935, leg. R. Wojtusiak, ( ISEA: coll. J. Stach).

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

Redescription. Habitus typical of the genus. Body length of lectotype (without antennae): 1.25 mm. Colour of the body dark blue. 2+2 large pigmented eyes ( Fig. 1 ).

Types of dorsal ordinary chaetae. Macrochaetae Ml relatively long and thin, almost cylindrical, straight or slightly arc-like, narrowly sheathed, feebly serrated, apically rounded or pointed ( Figs 4–6 ); macrochaetae Mc and Mcc thickened, straight and rounded at apex or pointed; mesochaetae and microchaetae short, thin, feebly serrated and pointed.

Head. Labrum ogival, with ventral sclerifications as in Fig. 2 . Labrum chaetotaxy 2/2, 4. Labium with four basal, three distal and four lateral chaetae, papillae x absent. Maxilla and mandible hardly to recognize. Antennal segments I and II with 7 and 11 chaetae respectively. Chaetotaxy of antennal segments III and IV impossible to recognize. Chaetotaxy of head as in Tab. 1 a, b, and Figs 1, 3–4 . Tubercle Dl with 6 chaetae, chaeta Dl3 present. Tubercle (L+So) with 10 chaetae, chaetae So2, L3 and L4 present ( Figs 1, 2 ). Elementary tubercles BE absent. Chaeta E not connected with tubercle Af. Chaeta A shorter than B. Chaeta D free.

Thorax, abdomen, legs. Body s-chaeta thin and smooth, distinctly shorter than nearby macrochaetae ( Figs 5, 6 ). Chaetotaxy of thorax and abdomen as in Tab. 1 b and in Figs 5, 6 . Tubercles Di on th.I well differentiated and fused with De. Chaetae De2 on th. II–III and De3 on th. III–abd. III free ( Fig. 6 ). The line of chaetae De1-chaeta s parallel to the dorsomedian line on abd. I–III. Tubercles Di on abd. IV and V fused ( Fig. 5 ). No cryptopygy. Chaetotaxy of ventral abdomen and legs in most impossible to recognize. Claw without inner tooth.

Remarks. Stach (1951) described Biloba alticola based on one specimen found “in moss in pine-wood growing on the moraine of Karaugom-glacier (Caucasus, Russia)”. Later the species was considered as member of Neanura (e.g. Gisin 1960, Salmon 1964, Massoud 1967) or Deutonura ( Deharveng 1982a, Deharveng et al. 2015). The assignation of the species to the genus Deutonura was mainly based on original Stach’s figures where tubercles Di and De on head are fused ( Stach 1951: plate VII, figure 1). Nevertheless, a detailed analysis of existing type made it possible to ascertain that the type of B. alticola is characterized by separateness of the mentioned tubercles on head and as a consequence should be classified into another genus, Endonura . Furthermore, this allowed us to redescribe this species using most of the modern characters.

E. alticola is characterized by fusion of tubercles Di on abd. IV along midline, a character till now observed within the genus only in E. dudichi ( Loksa, 1967) , a species from the Carpathians in Central Europe ( Hungary, Slovakia, Poland, Smolis 2008a). However these two species differ in many characters including: colour of body (blue in alticola , white in dudichi ), presence/absence of chaetae O and E on head (present in alticola , absent in dudichi ), presence/absence of non-reticulate area between chaetae A and B on head (absent in alticola , present in dudichi ), fusion/separateness of tubercles Di and De on the first thoracic segment (fused in alticola , separate in dudichi ) and fusion/separateness of tubercles De and Dl on abd. IV (separate in alticola , fused in dudichi ).

Morphologically, E. alticola seems to be most similar to two species, E. quadriseta Cassagnau & Péja, 1979 (known from Greece, Turkey and Crimea) and E. reticulata ( Axelson, 1905) (Scandinavia, North Russia and United States). Besides the above mentioned character, fusion of tubercles Di on abd. IV, E. alticola differ from both in the presence of ogival labrum (non ogival in quadriseta and reticulata ), two prelabral chaetae (four in quadriseta and reticulata ) and fusion of tubercles Di and De on th. I (separated in quadriseta and reticulata ). Among the Caucasian species, E. alticola resembles E. diminutichaeta sp. nov. However, they can be separated using the following features: number of chaetae Dl on head (6 in alticola , 4–5 in diminutichaeta ), presence/absence of elementary tubercle BE on head (absent in alticola , present in diminutichaeta ) and length of chaetae Di1 of abd. IV (relatively long in alticola , notably short in diminutichaeta ).

b) Postcephalic chaetotaxy–dorsal side.

Terga

Di De Dl L th. I 3 1 - th. II 3 2+s 3+s+ms 3 th. III 3 3+s 3+s 3

Figures

FIGURES 1 – 6. Endonura alticola: 1, chaetotaxy of tubercles Oc, Dl and (L + So), dorsolateral view; 2, ventral sclerifications of labrum; 3, chaetotaxy of tubercles Dl and (L + So), ventrolateral view; 4, central area of head, dorsal view; 5, dorsal chaetotaxy of abd. IV – VI; 6 chaetotaxy of tubercles Di and De of th. I – III.

Tables

TABLE 1. Chaetotaxy of Endonura alticola: a) Cephalic chaetotaxy –– dorsal side.

Tubercle	Number of chaetae	Types of chaetae	Names of chaetae
Cl	4	Ml Mc	F G
Af	11	Ml Mc	B A, C. O, D, E
Oc	3	Ml Mc Mcc	Ocm Ocp Oca
Di	2	Ml Mcc	Di1 Di2
De	2	Ml Mc	De1 De2
Dl	6	Ml Mc Mcc	Dl1, Dl5 Dl4, Dl3 Dl2, Dl6
(L+So)	10	Ml Mc Mcc me	L1, L4, So1 L2 L3 So2–6