Protoribates 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 : 466

Protoribates kumayaensis sp. nov.

[Japanese name: Kumaya-kosodedani] ( Figs. 19 and 20 )

Diagnosis — Body length 314 µm; width 150 µm. Rostral with a pair of tooth-like tubercles (rt) in the interior. Setae le inserted far from lamellae, not reaching the insertions of rostral setae. Pteromorphs immovable. Pleurophrag-mata (hl) and dorsophragmatic apophyses (hy) conspicuously. Ten pairs of notogastral setae short. Four pairs of porose areas. Genito-anal setal formula: 5-1-2-3. Epimeral setal formula: 3-1-3-4. Monodactyle.

Material examined — Holotype (Female) (NSMT-Ac 13597) from point B.

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

Measurements and body appearance — Body length 314 µm; width 150 µm. Body colour light yellowish brown. Body surface smooth. Body partly covered with tunic bearing dark granules.

Prodorsum — Rostral tip broadly rounded, with a pair of tooth-like tubercles (rt) in the interior, about 9 µm in length ( Fig. 19A ). Setae ro (22 µm) smooth setiform, inserted on lateral margins of rostrum. Lamellae thin, situated at lateral sides, extending for two-third length (65 µm) of prodorsum, without sharply pointed apex or dens. Translamellar absent. Setae le (26 µm) short, smooth spiniform, inserted far from lamellae, not reaching the insertions of rostral setae. Setae in (58 µm) spiniform, barbed throughout length, extending for short distance anterior of setae le. Bothridia opened anterolaterally. Sensilli (ss) (65 µm) consisting of fusiform head and thin long stem, pectinate unilaterally ( Fig. 19C ). Setae ex (5 µm) short, barbed setiform. Relative lengths and distances of prodorsal setae: ss ≈ in ≈ 2x le; le> ro; (in – in) (62 µm)> (le – in) (47 µm)> (le – le) (42 µm)> (ro – ro) (37 µm)> (ro – le) (31 µm).

Notogaster — Pteromorphs immovable, not extending anteriorly beyond level of arched dorsosejugal scissure ( Fig. 19B ). Pleurophrag-mata (hl) and dorsophragmatic apophyses (hy) conspicuously long and dark colourful. Ten pairs of notogastral setae short, smooth setiform. Four pairs of porose areas present; Aa situated at the center of the isosceles triangle given by insertions of c 2 (7 µm), la and lm as three vertices; A1 immediately lateral to lp; A2 immediately antero-laterally to h 2; A3 anterolaterally to p 1. Lyrifissures ia aligned obliquely postero-laterally to c 2; im transversely anterior to h 3; ih transversely antero-laterally to h 3; ip obliquely lateral to p 1; ips obliquely postero-laterally to p 3. Opening gla situated between im and h 3.

Ventral region — Genital (40 µm) and anal (62 µm) apertures almost pentagonal and circle in form, respectively; length of anal aperture about 1.5x as long as that of genital aperture; distance (88 µm) between them twice as long as length of genital aperture ( Figs. 20A and B ). Genito-anal setal formula: 5-1-2-3; all setae smooth setiform. Genital setae (6 µm) aligned in a row; g 1 remote from anterior margin of plates. Setae ag (6 µm) inserted posterior to genital aperture. Setae an 2 inserted about half-way along length of anal plates. Setae ad 1 aligned in postanal position; ad 2 in adanal; ad 3 in preanal. Lyrifissures iad located along outline of anal aperture, at the level anterior of the insertions of an 2. Sternal ridge and bo. 4 indistinct. Other epimeral borders interrupted medially. Epimeral setal formula: 3-1-3- 4; setae short, smooth setiform. Diarthric subcapitulum bearing 3 pairs of setae; setae short, smooth; a, m thin, setiform; h spiniform. Relative lengths of ventral and subcapitular setae: an (15 µm) ≈ ad> a (13 µm) ≈ m> h (10 µm)> g (6 µm) ≈ ag ≈ 1a.

Legs — Monodactyle. Trochantera IV bearing carina protruding in a sharp point. Legs not studied.

Remarks — The new species has remarkable characters, a pair of tooth-like tubercles (rt) of rostrum in the interior and conspicuously pleu- rophragmata (hl) such as found in Protoribates capucinus Berlese, 1908 according to Hammer, 1961. However, the new species is distinguished from P. capucinus by the form of tubercles (rt), thickness of lamellar and interlamellar setae, and distances (le – in)> (le – le) and (ro – ro)> (ro – le). According to Hammer (1973), P. capucinus has eleven pairs of notogastral setae, however the new species has ten pairs of notogastral setae. The new species has smaller body size than Italian specimen 420 µm in length and 250 µm in width ( Berlese, 1908).

Figures

FIGURE 19: Protoribates kumayaensis sp. nov. A, Prodorsum; B, Right half of notogaster; C, Right sensillus.

FIGURE 20: Protoribates kumayaensis sp. nov. A, Anterior half of ventral region; B, Posterior half of ventral region.