Endonura schwendingeri, Smolis & Skarżyński, 2020

Smolis, Adrian & Skarzynski, Dariusz, 2020, Contribution to the knowledge of Neanurinae of north-western Iran with description of seven new species (Collembola, Neanuridae), ZooKeys 992, pp. 105-138 : 105

Endonura schwendingeri sp. nov. Figs 28-41 , Tables 7, 8, 9

Type material.

Holotype: female on slide, Iran, Gilan Province, Paresar, tree holes, leaves, sifting, 2.VII.1973, leg. A. Senglet, sample 7310. Paratypes: 3 females and male on slide, same data as holotype.

Other material.

Iran, 3 females and male on slide, Gilan Province, Lunak, 600 m a.s.l., forest, leaves, trunk, sifting, 6.VII.1973, leg. A. Senglet, 7313.

Etymology.

The new species is dedicated to Peter J. Schwendinger, curator of the Muséum d’histoire naturelle in Geneva and prominent Austrian Arachnologist.

Diagnosis.

Habitus typical of the genus Endonura . Dorsal tubercles present. 2+2 large pigmented eyes. Buccal cone relatively long, labrum nonogival. Head with chaetae B, C and D. Chaeta O absent. Tubercles Cl and Af separate. Tubercles Dl and (L+So) on head with 5 and 7 chaetae, respectively. Tubercles Di on Th. I absent. Tubercles De on Th. II and III with 3 and 4 chaetae, respectively. Tubercles L on Abd. III and IV with 2 and 4 chaetae, respectively. Abd. IV and V with 8 and 3 tubercles, respectively. Furcal rest without mi. Claw with inner tooth. Tibiotarsi with chaetae B4 and B5 long.

Description.

General. Body length (without antennae): 0.5 (juvenile) to 1.15 mm (holotype: 1.1 mm). Colour of the body bluish-grey. 2+2 large black eyes, in a typical arrangement for the genus (Fig. 29 ).

Chaetal morphology. Dorsal ordinary chaetae of five types: long macrochaetae (Ml), short macrochaetae (Mc), very short macrochaetae (Mcc), mesochaetae and microchaetae. Long macrochaetae relatively thin, straight or slightly arc-like, narrowly sheathed, feebly serrated, apically rounded (Figs 29 , 39 , 40 ). Macrochaetae Mc and Mcc morphologically similar to long macrochaetae, but much shorter (Figs 29 , 39 ). Mesochaetae similar to ventral chaetae, thin, smooth and pointed. Microchaetae similar to mesochaetae, but clearly shorter (Figs 29 , 39 ). S-chaetae of terga thin, smooth and short, notably shorter than nearby macrochaetae (Figs 29 , 39 , 41 ).

Antennae. Typical of the genus. Dorsal chaetotaxy of Ant. III-IV as Fig. 36 and Table 8 . S-chaetae of Ant. IV of medium length and thickened, sensillum sgd short and straight (Fig. 36 ). Apical vesicle distinct, trilobate (Figs 34 , 35 ). Ventral chaetotaxy of Ant. III-IV Table 8 , sensillum sgv as Fig. 37 .

Mouthparts. Buccal cone relatively short with labral sclerifications nonogival (Fig. 30 ). Labrum chaetotaxy: 4/2, 4. Labium with four basal, three distal and three lateral chaetae, papillae x absent (Fig. 28 ). Maxilla styliform (Fig. 32 ), mandible relatively thin with two basal and two apical teeth (Fig. 31 ).

Dorsal chaetotaxy and tubercles. Head without chaetae A, E, Ocp, Dl3, So2, L2 and L3 absent (Fig. 29 ), chaeta D free. Tubercles Di on Th. I not differentiated (Fig. 29 ). On Th. III chaetae De2 and De3 free, on Abd. I-III chaetae De3 free (Figs 29 , 39 ). On Abd. I-III, the line of chaetae De1-chaeta s non perpendicular to the dorsomedian line. Cryptopygy present, but weakly developed, Abd. VI partially visible from above (Fig. 39 ).

Ventral chaetotaxy. On head, groups Vea, Vem and Vep with 3, 4 and 4 chaetae, respectively. Group Vi on head with 6 chaetae. On Abd. IV, furca rudimentary without microchaetae (Fig. 38 ). On Abd. IV, group L without free chaeta. On Abd. V, chaetae Vl present, chaetae L’ absent (Fig. 38 ). Male with thick and forked chaetae (male ventral organ) on anal plates (Abd. VI) and in groups: Ag (Abd. V); Vei, Vec and Vel (Abd. IV) and Fu (Abd. III) (Fig. 38 ).

Legs. Chaetotaxy of legs as in Table 9 . Claw with internal tooth. On tibiotarsi, chaeta M present and chaetae B4 and B5 relatively long and pointed (Fig. 33 ).

Remarks.

Since E. schwendingeri sp. nov. is characterised by chaetotaxic features unknown in other members of the genus, for example, the absence of chaetae A and Ocp on the head, its closer affinities with other Endonura species are currently uncertain and hard to assess. However, taking into account the weak development of tuberculation, delicate buccal cone and the presence of well-developed male ventral organ, the new species seems to be most similar to E. quadriseta Cassagnau & Péja, 1979, a form shortly described from Greece ( Cassagnau and Péja 1979), but recently re-described, based on types and a new material from the Crimea ( Smolis et al. 2007). Nevertheless, besides characters mentioned above, these taxa differ in numerous features: the number of lateral labial chaetae (in schwendingeri , three, in quadriseta , four), the presence of chaetae C and O on the head (in schwendingeri , absent, in quadriseta , present), the number of chaetae (L+So) on the head (in schwendingeri , 7, in quadriseta , 9), the number of chaetae Dl on the head (in schwendingeri , 5, in quadriseta , 6), the number of chaetae L on Abd. III and IV (in schwendingeri , 2 and 4, in quadriseta , 4 and 7) and the presence of an internal tooth on claws (in schwendingeri , present, in quadriseta , absent).

Figures

Figures 28 - 41. Endonura schwendingeri sp. nov.: 28 chaetotaxy of labium 29 chaetotaxy of head and Th. (holotype), dorsolateral view 30 apical part of labrum 31 Mandible 32 Maxilla 33 tibiotarsus and claw of leg III, lateral view 34 apical bulb, ventral view 35 apical bulb, dorsal view 36 dorsal chaetotaxy of Ant. III-IV 37 sensillum sgv and microsensillum of Ant. III 38 ventral chaetotaxy of Abd. II-VI (adult male) 39 dorsal chaetotaxy of Abd. III-VI 40 chaeta Di 1 of Abd. V 41 sensillum of Abd. V.