Papillacarus polysetosus, Ermilov, Sergey G., Anichkin, Alexander E. & Wu, Donghui, 2012

Ermilov, Sergey G., Anichkin, Alexander E. & Wu, Donghui, 2012, Two new species of the genus Papillacarus (Acari: Oribatida: Lohmanniidae) from caves of Southern Vietnam, Zootaxa 3593, pp. 75-88 : 83-86

Papillacarus polysetosus sp. nov.

( Figs. 23 –35)

Diagnosis. Body size 664–680 × 298–315. Surface of body foveolate. Rostrum rounded. Prodorsal, notogastral, anal and adanal setae setiform, ciliate; c 1, c 2, d 1, d 2, e 2, e 1, f 1, f 2 shorter than others. Sensilli with 10 to 12 branches. Four transverse bands developed on notogaster. One pair of neotrichal setae morphologically similar to notogastral setae; others (more than 80 pairs) short, setiform, ciliate. Subcapitulum with five pairs of setae. Epimeral setal formula 13–11–5–3. Genital setae heterogenous, all ciliate.

Description. Measurements. Large species. Body length 680 (holotype), 664 (paratype); body width 315 (holotype), 298 (paratype).

Integument ( Figs. 23, 24 , 29). Body color yellow to light brownish. Surface of body foveolate. Foveolae of two types: a) large, polygonal, forming polygonal network on prodorsum, notogaster, lateral part of body and anogenital region (length up to 16); b) very small (distinctly visible only under high magnification), polygonal, located on all surfaces of body, also forming polygonal network from very small foveolae on all surfaces of body and legs.

Prodorsum ( Figs. 23, 25–28 ). Roughly triangular in dorsal view, occupying about 1/2 of dorsal length. Rostrum rounded in dorsal view, weakly truncate in dorso-anterior view. Rostral, lamellar, interlamellar and both pairs of exobothridial setae similar: long (131–135), setiform, thickened, with short cilia. Sensilli (98–102) pectinate, with 10 to 12 branches on one side. Postbothridial transverse band visible.

Notogaster ( Figs. 23, 24 , 30–33). Anterior border of the notogaster weakly convex. Four transverse bands developed: S 2 complete; S 3, S 4 and S 5 medially interrupted. Sixteen pairs of primary notogastral setae and more than 80 pairs of additional neotrichal setae present. Notogastral setae setiform, with short cilia, differ in length: c 1, c 2 90; d 1, d 2, e 2 69–77; e 1 61–65; f 1 49–53; f 2 45–49; others longer (131–135), setiform, thickened. Neotrichal setae of two types: one pair (82) morphlogically similar to notogastral setae; others short (36–41), setiform, ciliate, located on posterior half of notogaster. Lyrifissures ia and im distinct.

Gnathosoma. Similar to Papillacarus indistinctus sp. nov. Subcapitulum with one pair of lateral tubercles. Subcapitulum longer than wide (168 × 123). Subcapitular setae h, m 1, m 2 and m 3 short (28), setiform, with cilia; setae a longer (49), setiform, smooth. Three pairs of adoral setae present: or 1 32, wide, lobe-formed, smooth; or 2 36, setiform, thickened, with tooth in distal part, blunt-ended; or 3 28, lobe-formed, smooth. Palps (73) with setation 0–1–0–1–9(+1ω). Distal three setae fused basally. Solenidion longer than palptarsus, thick, not fused with acm. Chelicerae 151; cheliceral seta chb 45, setiform, smooth; seta cha 6, thorn-like.

Epimeral region ( Fig. 24 ). Apodemes III medially interrupted. Sternal apodeme not fused with apodemes. Epimeral setal formula: 13–11–5–3. Medial setae 1a, 2a, 3a, 4a short (12), setiform, smooth; anteriomost pair longer (32), with cilia unilaterally; three pairs of lateral setae on epimeres II (28) straight, setiform, ciliate; other setae (20–28) setiform, with cilia unilaterally.

Anogenital region ( Figs. 24 , 34–35). Transverse genital suture distinct. Genital setae ciliate, heterogenous: four lateral pairs longer (24–30) than medial pairs (16–20). Two pairs of anal (45–49) and four pairs of adanal (ad 1– ad 3 65–69; ad 4 49–53) setae setiform, thickened, with cilia. A pair of ventrolateral bands indistinct. Lyrifissures iad, ih and ip distinct, ips not visible.

FIGURES 29–35. Papillacarus polysetosus sp. nov., adult: 29—foveolae of notogaster; 30—notogastral seta d 1; 31—notogastral seta d 3; 32, 33—neotrichal setae; 34—genital plate, left; 35—anal and adanal plates, left. Scale bar (29–33) 20 μm; scale bar (34, 35) 50 μm.

Legs. Morphology of leg segments, setae and solenidia typical for Papillacarus ( Ermilov & Anichkin 2011 f, Ermilov et al. 2011) and similar to Papillacarus indistinctus sp. nov. All legs with one claw, with small tooth on ventral side. Femora with large ventral ridge. Formulae of leg setation and solenidia: leg I (0– 6 –3–4–18) [2–1–2], leg II (0– 6 –3–4–13) [1–1–2], leg III (2–4–2–3–12) [1–1–0], leg IV (2–3–2–3–11) [1–0–0]; homology of setae and solenidia indicated in Table 1. Majority of setae ciliate. Setae it on tarsi II, III short, thin, smooth. Famulus conical, small, thickened. Solenidia ω1 on tarsi I, ω1 and ω2 on tarsi II, φ on tibiae III thickened, blunt-ended; other solenidia longer, setiform, with thinner tips.

Material examined. Collection data for holotype and three paratypes: VC-2.

Type deposition. The holotype (in alcohol) is deposited in the collection of the Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russia; one paratype (dissected) is in the personal collection of the first author.

Etymology. The specific name “ polysetosus ” refers to the numerous neotrichal setae.

Remarks. In having the combination of setiform prodorsal, notogastral and neotrichal setae and also in having numerous neotrichial setae, Papillacarus polysetosus sp. nov. is very similar to Papillacarus jinggangshanensis Chen, Yang & Liang, 2010 and Papillacarus konglinensis Chen & Yang, 2011 (both from China). However, it clearly differs from both by the larger body size (664–680 × 298–315 versus 432–441 × 232–238 in P. jinggangshanensis , 426–432 × 219–228 in P. konglinensis ), the presence of polygonal ornamentation on prodorsum and notogaster (versus polygonal ornamentation absent in P. jinggangshanensis and P. konglinensis ), longer lateral notogastral setae (versus shorter in P. jinggangshanensis and P. konglinensis ), the presence of three pairs of subcapitular setae m (versus four pairs in P. jinggangshanensis and P. konglinensis ), epimeral setal formula 13–11–5–3 (versus 8–7– 3–4 in P. jinggangshanensis , 7–5– 3–4 in P. konglinensis ).

In having the combination of foveolate body surface, setiform prodorsal, notogastral and neotrichal setae, Papillacarus polysetosus sp. nov. is also similar to Papillacarus chamartinensis Pérez-Íñigo, 1967 from Spain. However it clearly differs from the latter by the larger body size (664–680 × 298–315 versus 500 × 220 in P. chamartinensis ), long notogastral setae c 1 and d 1, which are a little shorter than c 3 and d 3 (versus considerably shorter in P. chamartinensis ), longer lateral notogastral setae (versus shorter in P. chamartinensis ), considerably more neothrichal setae (less number in P. chamartinensis ), absence of body papillae (present in pygidial part of notogaster in P. chamartinensis ), epimeral setal formula 13–11–5–3 (versus 7–4– 3–4 in P. chamartinensis ).

Figures

FIGURES 23 – 28. Papillacarus polysetosus sp. nov., adult: 23 — dorsal view; 24 — ventral view, gnathosoma and legs not shown; 25 — rostrum; 26 — rostral seta; 27 — sensillus; 28 — exobothridial seta exp. Scale bar (23, 24) 200 μm; scale bar (25 – 28) 20 μm.