Tectocepheus iheyaensis, 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 : 451-452

Tectocepheus iheyaensis sp. nov.

[Japanese name: Iheya-kuwagatadani] ( Figs. 8 and 9 )

Diagnosis — Body length 307 µm; width 179 µm. Rostral anterior margin without incision, bearing narrow projection at lateral sides, ending abruptly anteriorly, not extending anterior of rostral anterior margin. Lamellar cuspis with inner swelling, without dens, not extending to level of rostral anterior margin. Depression on notogaster absent. Genitoanal setal formula 6-1-2-3. Monodactyl.

Material examined — Holotype (Female) (NSMT-Ac 13591) from point D.

Etymology — After the name of sampling area, Iheya Village.

Measurements and body appearance — Body length 307 µm; width 179 µm. Body colour light yellowish brown. Whole body surface covered with cerotegument; cerotegument irregularly granulate.

Prodorsum — Rostral anterior margin broadly rounded without incision, bearing narrow projection at lateral sides, ending abruptly anteriorly, not extending anterior of rostral anterior margin ( Fig. 8A ). Lamellar cuspis with inner swelling, without dens, not extending to level of rostral anterior margin. Rostral and lamellar transverse ridges distinct. Setae ro and le spiniform, barbed unilaterally, extending for a short distance anterior of rostral anterior margin. Setae ro (41 µm) nearly as long as le. Setae in smooth, small bacilliform. Sensilli (38 µm) composed of thin, smooth stem and globular head which bears dark coloured spines. Setae ex (7 µm) smooth, short, shorter than setae in (11 µm). Bothridia opened dorsally.

Notogaster — Depression on notogaster absent. Dorsosejugal scissure reduced behind setae in ( Fig. 9A ). Ten pairs of notogastral setae short, smooth, setiform. Lyrifissures ia aligned obliquely to notogastral outline, antero-laterally to setae c 2; im obliquely, laterally to almost mid-distance between lm and lp; ih and ips obliquely to, ip perpendicular to notogastral outline; ih postero-laterally to im; ips antero-laterally to h 3; ip anterior to p 2. Setae h 3 inserted postero-lateral to gla. Posterior margin of notogaster with broadly truncate elevation bearing setae h 2 at corners.

Ventral region — Genital (42 µm) and anal (76 µm) apertures almost pentagonal in form; distance (24 µm) between them appreciably one-third as long as length of anal aperture ( Fig. 9B ). Genito-anal setal formula 6-1-2-3; all setae smooth setiform. Setae g 1 and g 2 inserted nearer anterior margin of plates; setae g 1 (14 µm) about more than twice as long as the rest setae (6 µm). Setae ag (6 µm) inserted lateroposteriorly to genital aperture. Setae ad 1 and ad 2 aligned in postanal position; ad 3 in adanal. Lyrifissures iad located transversely near anterior margin of anal aperture. Sternal ridge indistinct. Epimeral borders bo. 1, 2, sj distinct. Epimeral setal formula 3-1-3-3; setae smooth, setiform. Diarthric subcapitulum bearing 3 pairs of setae: a, m and h; setae a

Nakamura Y.-N. et al.

and h thin smooth; a spiniform; m and h setiform; m sparsely barbed; relative lengths: a ≈ m (19 µm) ≈ 2x h (10 µm) ( Fig. 8B ).

Legs — Monodactyl. Setal formula: I (1-5-3-5- 17), II (1-4-2-4-14), III (2-3-1-3-12), IV (1-2-2-3-12). On tarsus I, famulus ε bacilliform situated beside solenidion ω 1 originating from apophysis; solenidion ω 1 bacilliform and ω 2 setiform; ω 2 situated anterior to ω 1 ( Fig. 8C ). Solenidia ’ 1 and ’ 2 on tibia I originating from apophysis; ’ 1 (79 µm) about four times longer than the length of ω 1 (18 µm); ’ 2 situated anterior to ’ 1. Trochanter III bearing well developed carina, long and protruding. Carina of trochanter IV rounded. Tarsi II, tibiae I and II bearing thick setae different from other setae ( Fig. 8D ).

Remarks — The new species is similar in rostrum, cuspis, sensillus, setae on tarsi II, tibiae I and II, and carina of trochanter IV, and direction of lyrifissures iad to Tectocepheus velatus ( Michael, 1880) and T. velatus sarekensis Trägårdh, 1910 ( Fujikawa, 1988; Laumann et al., 2007; Weigmann, 2002). However, the new species differs from all the species of the genus in the characteristics of the rostrum with lateral projection, small smooth bacilliform interlamellar setae, notogaster with truncate elevation posteriorly without depression, genital setae g 1 longer than the remains and tochanter III bearing developed carina.

Figures

FIGURE 8: Tectocepheus iheyaensis sp. nov. A, Prodorsal region; B, Camerostome and epimeral region; C, Solenidial region on tarsus and tibia of leg I; D, Tarsus and tibia of leg II.

FIGURE 9: Tectocepheus iheyaensis sp. nov. A, Notogaster; B, Genito-anal region.