Trichogalumna trowella, Nakamura & Nakamura & Fujikawa, 2013

Nakamura, K., Nakamura, Y. - N. & Fujikawa, T., 2013, Oribatid Mites (Acari, Oribatida) From Tohoku (Northeast Japan), Collected After A Tidal Wave In 2011, Acarologia 53 (1), pp. 41-76 : 71-74

Trichogalumna trowella n.sp.

[Japanese name: Hana-furisodedani] ( Figures 22 – 23 )

Diagnosis — Body length 321 µm; width 250 µm. Pteromorphae lineate; other integument of body smooth. Rostrum broadly rounded with rostral trowel. Setae ro, le and in short. Sensilli fusiform, composed barbed head and thin, smooth stem. Ten pairs of short notogastral setae, four pairs of porose areas, five pairs of lyrifissures present. Movable pteromorphs bearing short furrow, c and ia. Pteromorphae notch distinct. Dorsophragmatic apophysis (hy) small circular in shape. Genito-anal setal formula: 6-1-2-3. Epimeral setal formula: 3-0-3-3. Heterotridactyl Subcapitulum diarthric, subcapitular setae.

Material examined — Holotype (Female) (NSMT-Ac 13628) from litter and humus at the point C.

Etymology — After rostral trowel.

Measurements and body appearance — Body length 321 µm; width 250 µm. Body colour light brown. Integument on pteromorphae lineate; other body surface punctulate.

Prodorsum — Rostral tip broadly rounded with rostral trowel ( Fig. 22A ). Setae ro (21 µm) thin, short, smooth setiform, inserting on lateral margins of rostrum, not reaching rostral tip. Lamellar and sublamellar lines near each other actuate, parallel. Setae le (39 µm) short, setiform, minutely barbed through the length, inserting between lines L and L, extending for a short distance in front of rostral tip. Setae in (12 µm) short, thin, smooth setiform. Bothridia opening dorso-laterally. Sensilli (ss) (66 µm) composed of thin, long, smooth stem and expanded fusiform head bearing sparsely spicules. Setae ex (4 µm) short, smooth, setiform.

Notogaster — Ten pairs of short notogastral setae (4 µm), six pairs of porose areas, five pairs of lyrifissures present. Anterior notogastral margin absent. Movable pteromorphs bearing short furrow, c and ia; pteromorphal notch distinct. Dorsophragmatic apophysis (hy) small circle. Porose areas (major axis, minor axis: µm) A l (9,8) located outer lateral to insertion of in; Ad (9,6) posterior to A l; Aa (9,6) outer lateral to lm; A 1 (6,5) latero-posteriorly to lp or im; A 2 (7,6) latero-posteriorly to A 1 or gla; A 3 (9,6) posterior to h 1. Distance between A 1 and A 2 about one-third as long as that between A 2 and A 3. Lyrifissures ia on pteromorphae aligned almost parallel to the joint line between pteromorpha and notogaster; im transversely latero-posteriorly to lp; ih, ip perpendicular to notogastral outline; ip between p1 and p2;? ips between p2 and p 3. Opening gla situated posterior to h 3. Relative distances: (lp -lp: 38 µm)> (lm -lm: 34 µm)> (h 1 - h 1: 29 µm)> (p 1 - p 1: 14 µm).

Ventral region — Genital (45 µmin length) and anal (62 µmin length) apertures almost trapezoid length of anal aperture slightly shorter than distance (66 µm) between genital and anal apertures ( Figs. 23 A-B). Genito-anal setal formula: 6-1-2- 3; all setae short, thin, smooth setiform. Setae g1 - g 3 (9 µm) aligned at the anterior margin of the plates; other setae longitudinally in a row at the medial portion of the plates. Setae ag (7 µm) inserting posterior-lateral to genital aperture. Anal setae (5 µm) inserting far from anterior margin of anal plates. Setae ad 1 and ad 2 (4 µm) aligned in postanal position; ad 3 in adanal, at the level of almost mid-distance along the anal aperture. Lyrifissures iad located longitudinally, antero-laterally to ad 3. Epimeral borders short. Epimeral setal formula: 3-0-3-3; setae short, thin, smooth setiform; 1 b (4 µm) the shortest, 1 c (24 µm) the longest ( Fig. 23C ). Subcapitulum bearing 3 pairs of setae; setae short, setiform; a (0.7 µm), m (11 µm) sparsely, minutely barbed; h (14 µm) roughened.

Legs — Heterotridactyl; claws (23 µm) minutely dentate. Setal formula: I (1-5-3-4-19), II (1-4-3-4-16), III (2-3-1-3-15), IV (1-2-2-3-12). Measurements (µm) of segments of left legs: I (25-46-25-39-55), II (31-75- 21-25-36), III (49-45-16-36-39), IV (54-43-17-43-46). On tarsus I ( Fig. 22B ), famulus ε (6 µm) obtuse, situated posterior to solenidia ω 1; ω 1 (24 µm) bacilliform; ω 2 (29 µm) setiform, situated latero-posterior to ω 1; ft ’ (31 µm) smooth, setiform, inserting just lateral to ω 1. On tibia I, solenidia ’ 1 (86 µm), ’ 2 (23 µm) setiform situated at anterior portion of the segment; ’ 2 originating from a small apophysis; dorsal seta (34 µm) smooth setiform, inserting contiguous to ’ 1. On genu I, σ (69 µm) longer than seta d (11 µm).

Remarks — The new species is very similar to Trichogalumna chimaera Ohkubo, 1984 in ornamentation of the pteromorphal integument, length of rostral and interlamellar setae, shape of sensilli and insertion of genital-anal setae. However, the former is different from the latter in having a round rostrum with rostral trowel, and the body surface is punctulate except for pteromorphae.

Figures

FIGURE 22: Trichogalumna trowella n.sp. (Holotype NSMT-Ac 13628): A – Dorsal view; B – Solenidial region of left leg I.

FIGURE 23: Trichogalumna trowella n.sp. (Holotype NSMT-Ac 13628): A – Anterior region of ventral side; B – Posterior region of ventral side; C – Left lateral side of epimerata.