Eupelops kumayaensis, Nakamura & Fukumori & Fujikawa, 2010

Nakamura, Y. - N., Fukumori, S. & Fujikawa, T., 2010, Oribatid Fauna (Acari, Oribatida) From The Kumaya Cave Of Iheya Village In Central Ryukyu Arc, South Japan, With A Description Of Several New Species, Acarologia 50 (4), pp. 439-477 : 452-456

Eupelops kumayaensis sp. nov.

[Japanese name: Kumaya-enmadani] ( Figs. 10 and 11 )

Diagnosis — Body length 607 µm; width 486 µm. Tutorium with sharply pointed apex, without dens. Anterior notogastral tectum broadly concave. Ten pairs of notogastral setae bacilliform, spinose. Four pairs of round porose areas. Genito-anal setal formula: 6-1-2-[2, 1]. Chelicerae bearing two Trägårdh’s organs; Tg1 longer than Tg2. Heterotridactylous.

Material examined — Holotype (Female) (NSMT-Ac 13592) from point E; 1 paratype (NSMT- Ac 13593): same data as holotype.

Etymology — After the name of sampling point, Kumaya Cave.

Measurements and body appearance — Body length 607 µm; width 486 µm. Body colour dark brown. Whole integument except for hypostoma bearing dark granules; hypostome laterally-costate.

Prodorsum — Rostrum protruding with rounded tip ( Fig. 10A ). Setae ro weakly expanded distally, spiculate throughout length, inserted on lateral margins at base of free tip of tutorium, extending for short distance anterior of rostral margin. Tutorium with sharply pointed apex, without dens ( Fig. 11B ). Tips of lamellar cuspis reaching two third-distance along prodorsum, anterodorsally arising lamellar setae. Space between cuspis forming parabola-shape. Setae le bacilliform, spiculate throughout length, reaching anterior margin of rostrum. Setae in large phylliform, spiculate throughout length, reaching anterior margin of rostrum ( Fig. 11A ). Bothridia opening antero-laterally. Sensilli (ss) bowing, expanded distally without narrower apex, spiculate throughout length. Setae ex short, smooth spiniform. Relative lengths of prodorsal setae in (230 µm) ≈ 2.5x [ro ≈ le ≈ ss (92 µm) ≈ 8x ex (11.5 µm)].

Notogaster — Anterior notogastral tectum broadly concave, projecting further anteriorly than anterior margin of movable pteromorphs, covering basal part of prodorsum ( Figs. 10A and C ). Large oval lenticulus visible. Ten pairs of notogastral setae bacilliform, spinose throughout length, variable in length; shortest c 2 ( Fig. 10D ). Four pairs of round porose areas; Aa located postero-laterally to setae c 2; A1, A2, A3 contiguous to lm, lp, h 2, respectively. Setae h 3 laterally inserted mid-distance between A2 and A3.Lyrifissures ia located anterior to la; im aligned obliquely antero-laterally to A2. Relative distances between notogastral setae in central part of notogaster: (c 2 – c 2) (262 µm)>(lp – lp) (235 µm) ≈ (h 2 – h 2)>(lm – lm) (162 µm)>(h 1 – h 1) (108 µm).

Ventral region — Genital and anal apertures roughly circular in shape, almost equal (77 µm) in length; distance (130 µm) between them 1.7x as long as length of each aperture ( Fig.10B ). Genito-anal setal formula: 6-1-2-[2, 1]; all setae short, smooth setiform ( Fig. 10D ); anal setae variable in number. Setae g 1 and g 2 inserted at anterior margines of plates; g 6 at posterior margines. Setae ag inserted lateroposteriorly to genital aperture. Setae an 1 and an 2 inserted near anterior and posterior margin of plates, respectively. Setae ad 1 and ad 2 aligned in postanal position; ad 3 in adanal. Lyrifissures iad located antero-laterally to anterior margin of anal aperture, along outline of aperture. Sternal ridge indistinct. Epimeral borders bo. 1-3, sj distinct. Epimeral setal formula: 3-1-3-3; setae short, smooth setiform. Relative lengths: 1a (18 µm)> g (17 µm)> ag (15 µm)> an (12 µm)> ad (10 µm). Pedipalpal setal formula: 0-2- 1-3-9[1]; solenidion on tarsus short, not extending in front of tarsal anterior margin ( Fig. 10E ). Suctorial subcapitulum bearing 3 pairs of setae: a (32 µm), m (32 µm) and h (17 µm); all setae smooth; a, m spiniform; h setiform ( Fig. 11D ). Chelicerae bearing two Trägårdh’s organs; Tg1 longer than Tg2 ( Fig. 11C ). Setae cha, chb smooth spiniform; cha long, chb short.

Legs — Heterotridactylous; claws dentate dorsally. Setal formula: I (1-5-3-4-19), II (1-5-3-4-16), III (2-3-1-3-15), IV (1-2-2-4-12). All segment except for femur IV and all trochantera bearing thick, spiculate lateral setae ( Fig. 11E ). Carina on every segment indistinct. Solenidiotaxy: I (1-2-2), II (1-1-2), III (1-1-0), IV (0-0-0). Solenidion absent on tibiae IV ( Fig. 11G ). On tarsus I, famulus ε long setiform, situated posterior to solenidia ω 1; ω 2 posteriolaterally to ω 1; ω 1 bacilliform and ω 2 setiform; seta ft ’ contiguous and posterior to ω 1 between ω 1 and ω 2 ( Fig. 11F ). Solenidion ’ 1 on tibia I originating from apophysis; ’ 2 lateral to ’ 1.

Remarks — As far as the authors know, the new species has concave anterior tectum of the notogaster as it is also observed in Eupelops bilobus ( Sellnick, 1928) ( Sellnick, 1929) and E. incompletes Mahunka, 1978 . However, the new species is distinguished from these latter species by form and length of prodorsal setae, insertion of notogastral setae h 3, and chelicera with two Trägårdh’s organs. E. acromios ( Hermann, 1804) ( Grandjean, 1936) and E. kumaensis Fujikawa, 2009 have two Trägårdh’s organs, however they differ from the new species in form of notogastral anterior tectum and notogastral setae, and situation of Aa.

Figures

FIGURE 10: Eupelops kumayaensis sp. nov. A, Dorsal view; B, Ventral view; C, Anterior tectum of notogaster of a depressed specimen; D, Areae porosae and setae; E, Tarsus of pedipalp.

FIGURE 11: Eupelops kumayaensis sp. nov. A, Left bothridial region and right sensillus; B, Tip of tutorium and rostral seta; C, Chelicera; D, Gnathosoma; E, Genu I; F, Solenidial region on tarsus and tibia of leg I; G, Tibia IV.