Argonychiurus multiocellatus, Djanashvili, Revaz, Barjadze, Shalva, Jordana, Rafael & Burkhardt, Ulrich, 2014

Djanashvili, Revaz, Barjadze, Shalva, Jordana, Rafael & Burkhardt, Ulrich, 2014, Redefinition of the genus Argonychiurus Bagnall, 1949 (Collembola, Onychiuridae) with description of a new species from Georgia, Zootaxa 3835 (3), pp. 381-391 : 382-383

Argonychiurus multiocellatus sp. nov.

Figs 1 – 14 , Table 1

Type material. Holotype: female, Georgia, Tsageri district, Khvamli mountainous massif, Tvishi cave [42°30'55.09"N, 42°47'35.96"E], 446 m alt., 12.ix.1968, leg. Revaz Djanashvili. Code number MZ–19680912–1 (H–090). Holotype deposited at the Museum of Zoology, University of Navarra, Pamplona, Spain. Paratypes: 5 females and one juvenile, same data as holotype, each on different slides; a paratype, code number MZ–19680912–2, is deposited at the Museum of Zoology, University of Navarra, Pamplona, Spain, and 5 paratypes with code numbers GC19680912–3 to 7 are deposited at the Institute of Entomology of Agricultural University of Georgia, Tbilisi, Georgia.

MZ–19681112–1 MZ–19681112–2 GC–19681112–3 GC–19681112–4. GC–19681112–5.

Ant bases 3+3 5+4 4+4 4+4 4+4

Description. Colour white in alcohol. Length of females without antennae: 1.78–2.69 mm. Body cylindrical, little broadened in the region of Abd II–IV ( Fig. 12 ). Antennae 0.73–0.99 times as long as head diagonal. Granulation uniform and slightly coarse on dorsal part of head, antennal base not marked.

Ant IV: subapical organite not guarded by papillae, ms in proximal whorl of chaetae (above Ant III O), ms on Ant III slightly below Ant III O ( Figs 3–4 ). Ant III O with 5 papillae, 5 guard chaetae, 2 sensory rods and 2 bent, morel-like, sensory clubs ( Figs 4–5 ). Labium with 2 proximal, 2 basomedian (E, F, G, and f) and 6 basolateral (a, b, c, d, e, e’) chaetae ( Fig. 6 ); Postlabial chaetae 4+4 along ventral groove. Labial palp ( Fig. 6 ) with papilla A of 3.9 µm wide at its base, with slight sudden narrowing at 30 µm of base. Papilla A a little wider and shorter than B, D and E. Measurements: A= 45, B = 60, C= 35, D = 55 and E = 50 (all in µm). Clypeal/prelabral/labral chaetae: 2 /4 / 3, 4, 2 labral ( Fig. 7 ).

PAO small, with 10–12 granulated vesicles ( Fig. 2 ). Ratio between PAO length and diameter of its closest pso = 3:1.

Dorsal pseudocellar formula per whole tergum (Ant base, interantennal zone, PAO level, middle part, posterior part / Th I, Th II, Th III / Abd I, Abd II, Abd III, Abd IV, Abd V): 6–9, 0–2, 4, 5–7, 6–17/12–19, 20–44, 16–36/ 15–32, 17–36, 13–31, 15–35, 14–30 (Ant base with 3–5 pso each) ( Table 1 , Figs 1–2 ); pso formula ventrally for each half sternum: 0/000/3–6, 8–9, 6–8, 7–9, 3–5; Subcoxae 1 of legs I–III with 8–14, 7–12, 8–14, pso respectively; subcoxae 2 of legs I–III with 0, 3–5, 3–5 pso respectively ( Fig. 9 ). Psx absent.

On Th II–III and Abd I–V pso are arranged in two more or less visible rows.

Dorsal chaetotaxy more or less asymmetric, poorly differentiated into macro-, meso- and microchaetae. Chaetae s indistinct. Th II–III with lateral microsensilla within a shallow pit. Chaeta d0 on the head present ( Fig. 1 ), Th. sterna I–III with 1+1, 1+1, 1+1 chaetae respectively, VT with 2+2 basal and 10–13+10–13 distal chaetae ( Fig. 11 ). Cl I–III without teeth; Tita with 11 chaetae in distal whorl. Emp I–III with small basal lamella, slightly shorter than Cl ( Fig. 10 ). Furcal area reduced to a small finely granulated area with 1+1 chaetae posteriorly ( Figs. 13–14 ).

Furcal zone with a finely granulated area and two microchaetae below. The finely granulated area is clearly visible in paratype GC–19681112–3 ( Fig. 14 a); in holotype ( Figs 13, 14 b) the finely granulated area is hidden in a fold, but in it and in all paratypes two microchaetae are present. These two dental chaetae have 3 rows of manubrial chaetae (ma, mm and mp).

Abd VI tergum with 3 rows of chaetae, a0 and p0 chaeta present. Anal spines absent ( Fig. 12 ).

Discussion. In this new species, the dorsal pso formulae given above are very variable due to asymmetries, the intersegments have numerous pso, and in most cases the specimens are artificially shortened due to ‘telescoping’ artifacts and folding of intersegments under the posterior edges of head or thoracic and abdominal terga, in which cases the pso are difficult to see and to separate tergal and intersegmental pso from each other. The new species shares with A. fistulosus ( Gisin, 1956) the presence of pso on the medio-dorsal area of the head ( Gisin 1956). It differs from A. fistulosus by the number of pso at the antennal base (3–5+ 3–5 in A. multiocellatus sp. nov. v. 2 + 2 in A. fistulosus ), by presence of chaeta d0 on the head in A. multiocellatus sp. nov. (absent in A. fistulosus ), absence of pso on the head ventrally in A. multiocellatus sp. nov. (vs. 1+1 pso present in A. fistulosus ), the absence of an inner tooth on Cl I–III in A. multiocellatus sp. nov., while a distinct inner tooth is present on Cl I–III in A. fistulosus . A. bertrandi , A. lenticularius comb. nov., A. papulosus comb. nov. and A. perforatus differ from of the new species by the absence of pso in the medio-dorsal area of the head. The new species differs from A. lenticularius comb. nov. by the shape of its sensory clubs in Ant III O, which are granulated (morel–like) as in all Argonychiurus species except A. lenticularius comb. nov., which has smooth clubs with 2 ribs.

Etymology. The new species name is derived from the Latin names multi (numerous) and ocellus (small eye), which is suitable for this new species with its distinct morphological character, the multiplication of pseudocelli.

Ecology. A. multiocellatus is found in the aphotic zone of caves. So far it is only known from Georgia.

Figures

FIGURE 12. Argonychiurus multiocellatus sp. nov. (holotype). Chaetotaxy and localization of pso on Abd terga I-VI. Scale bar = 50 µm.

FIGURES 1 – 2. 1, Argonychiurus multiocellatus sp. nov. (holotype). 1, chaetotaxy and localization of pso on head and Th tergum I. a = Antennal base; b = interantennal zone; c = PAO zone; d = central zone; e = Posterior zone; 2, detail of antennal base. Scale bars: for 1 = 50 µm, for 2 = 20 µm.

FIGURES 3 – 5. Argonychiurus multiocellatus sp. nov. (holotype). 3, dorsolateral view of Ant.; 4, ventrolateral view of Ant.; 5, sensorial club of AIIIO, 5 a surface level view, 5 b, middle level slice, 5 c, deeper level. Scale bars: for 3 – 4 = 50 µm, for 5 = 8 µm.

FIGURES 6 – 7. Argonychiurus multiocellatus sp. nov. (paratype Gc – 19681112 – 7). 6, labial chaetotaxy and labial palps; 7, clypeal, prelabral and labral chaetotaxy. Scale bars: for 6 = 50 µm, for 7 = 20 µm.

FIGURE 8. Argonychiurus multiocellatus sp. nov. (holotype). Chaetotaxy and localization of pso on Th terga I – III. Scale bar = 50 µm.

FIGURES 9 – 11. Argonychiurus multiocellatus sp. nov. 9, localization of pso on subcoxae 1 and 2 of I – III legs; 10, claw and empodium; 11, VT. Scale bars: for 9 = 200 µm, for 10 – 11 = 50 µm.

FIGURE 13 – 14. Argonychiurus multiocellatus sp. nov.: 13, chaetotaxy and localization of pso on Abd sterna III-VI (holotype); 14 a, chaetotaxy of furcal area (Paratype GC – 19681112 – 3); 14 b, chaetotaxy of furcal area of Holotype. Scale bars: for 13 and 14 b = 50 µm, for 14 a = 100 µm.

Tables

TABLE 1. Argonychiurus multiocellatus sp. nov. Variability of number of dorsal pso for 5 specimens.

On PAO level 2+2 2+2 +1(unpaired anterior)	2+2	2+2 +1(unpaired anterior)	2+2 +2 (central asymmetric)
middle part of 2+4 3+3 head	3+3	2+3	4+3
posterior part of 5+5 dorsal 12 dorsal head 3+4 interseg.? interseg.	8 dorsal 9 interseg.	6 dorsal? interseg.	8 dorsal 9 interseg.
Th I 7+8 tergal 9 tergal 1+1interseg. 6 interseg.	10 tergal 9 interseg.	8 tergal 4 interseg.	7+7 tergal 4 interseg.
Th II 14+18 tergal 11 tergal 5+7 interseg. 9 interseg.	15 +15 tergal 5+3 interseg.	14 tergal 6 interseg.	14+14 tergal 16 interseg.
Th III 12+16 tergal 9 tergal 4+3 interseg 7 interseg.	15 tergal 17 interseg.	13 tergal 10 interseg	18 tergal 18 interseg.
Abd I 11+9 tergal 11 tergal 4+5 interseg. 7 interseg.	16 tergal 16 interseg	12 tergal 3 interseg	12+12 tergal 8 interseg
Abd II 10+11 tergal 11 tergal 6+5 interseg 6 interseg	18 tergal 18 interseg	9+5 tergal 7 interseg	11+11 tergal 11 interseg
Abd III 15+16 tergal 13 tergal 0 interseg? interseg	14 tergal 15 interseg	8+8 tergal 11 interseg	13+13 tergal 0 interseg
Abd IV 15+16 tergal 11+10 tergal 0 interseg 0 interseg	19+16 tergal 0 interseg	8+7 tergal 0 interseg	9+9 tergal 10 interseg
Abd V 7+7 tergal 15+15 tergal 0 interseg 0 interseg	8+8 tergal 0 interseg	9+9 tergal 0 interseg	16 tergal 8 interseg