Scheloribates yamaeensis, Nakamura & Hashimoto & Nishi & Nakamura & Fujikawa, 2015

Nakamura, Y. - N., Hashimoto, S., Nishi, Y., Nakamura, Y. & Fujikawa, T., 2015, Two new species of Eremellidae and Scheloribatidae (Acari, Oribatida) from the Kuma district of southern Japan, Acarologia 55 (2), pp. 171-187 : 180-186

Scheloribates yamaeensis n. sp.

[Japanese name: Yamae-shiwadani] ( Figs. 6 - 10 )

Diagnosis — Prodorsum triangular. Rostrum rounded. Lamellae narrower situated laterally, with prolamellae, without cusps and translamella. Sensillus barbed fusiform. Anterior margin of immovable pteromorphae not extending anteriorly beyond level of dorsosejugal scissure; pteromorphae with inward curve. Notogaster elongate with ten pairs of minute setae and four pairs of sacculi; each sacculi diverged. Notogastral integument plicate near posterior margin. Genito-anal setae 4(3, 5)-1(2)-2- 3; genital and aggenital setae variable in number. Adanal setae ad 3 situated in preanal position. Lyrifissures iad aligned along outline of anal aperture in adanal position. Posterial anal locking-pieces remarkable. Diarthric subcapitulum bearing 3 pairs of setae a, m, h. Epimeral setae 3-1-3-3, pedipalpal setae 0-2-1-3-9[1]. All legs heterotridactyl. Solenidiotaxy: I (1-2-2); II (1-1-2); III (1-1-0); IV (0-1-0). Femora II, III and IV with small leg-fin. Solenidia ω 1 and ω 2, famulus, and fastigial seta ft " aligned in a line; setae ft " smooth.

Material examined — Holotype (Male) (NSMT- Ac 13034) from litter, humus and soil materials at the chestnut Castanea crenata Sieb. et Zucc. plantation of Yamae Mura in Kumamoto Prefecture on 25 th Oct. 2007, by S. Hashimoto; 24 paratypes (NSMT-Ac, 13035: female): the same data as holotype. The type series with number of NSMT-Ac 13034 & 13035 is deposited in the National Museum of Nature and Science , Tokyo. The remainder of paratypes are deposited in the National Agricultural Research Center for Kyushu Okinawa Region, Kumamoto Prefecture.

Etymology — After the name of sampling locality.

Measurements and body appearance — Female (n = 13): Body length: 471 (508) 564 µm; width: 300 (345) 400 µm, male (n = 12): Body length: 457 (486) 514 µm; width: 293 (320) 379 µm. Body color light brown. The whole integument without granulation except for exobothridial region. Description of features in common of male and female:

Prodorsum — Triangular ( Fig. 6A ). Rostrum rounded. Rostral setae ro sparsely barbed, inserted at lateral sides, extending in front of the rostrum for a distance equal to about two-third of their length. Lamellar ridges narrower, situated at the lateral sides, with prolamellae but without cusps nor translamella, extending forward from underneath of anterior notogastral margin for a distance equal to almost two-third length of the propodosoma (ca. 125 µm) ( Fig. 9A ). Lamellar setae le sparsely barbed throughout length, inserted at the end of lamellae ( Fig.8B ), extending anterior to rostral setae. Interlamellar setae in sparsely spiculate throughout length ( Fig. 6C ), inserted anterior to the level of bothridia. Bothridial basal part covered by anterior margin of notogaster, opening anteriorly ( Fig. 9D ). Sensilli ss fusiform, ciliate ( Fig. 7A ). Exobothridial setae ex smooth, minute. Relative lengths and distances of prodorsal setae: ro: le: in: ss: ex = 1: 1.68:1.68: 1.13: 0.05; (ro-ro): (le-le): (in-in): (ro-le): (le-in) = 1: 1: 1: 0.3: 0.8.

Notogaster — Elongate, with broadly rounded anterior margin ( Fig. 9C ). Anterior margin of immovable pteromorphae not extending anteriorly beyond level of anterior notogastral margin; pteromorphae curved inward ( Figs. 6D , 10D ). Notogaster bearing 7 to 14 transverse plications near posterior margin ( Fig. 9F ). A number of light spots arranged peripherally. Dorsophragmatic apophyses hy small. Ten pairs of notogastral setae minute, smooth; c 2 and la on pteromorphae. Sacculi Sa, S1, S2 and S3 diverged ( Figs. 8A , 9E , 10C ): Sa situated antero-laterally to lm, S1 lateral to lp, S2 posterior to h 3, S3 postero-laterally to h 2, respectively. Lyrifissures ia located parallel to suture between pteromorpha and body posterior to c 2; im aligned obliquely at the antero-laterally to setae lp; ip longitudinally to outline of body between p 1 and p 2. Opisthosomal gland-opening situated posterolaterally to im. Relative distances between notogastral setae in central part of notogaster: (c 2 - c 2): (la-la): (lm-lm): (lp -lp): (h 3 - h 3): (h 2 - h 2): (h 1 - h 1): (p 1 - p 1) = 9: 11: 7: 7: 6: 5: 1: 2.

Ventral region — Genital and anal apertures roughly circular in outline ( Figs. 6B, 6E , 10A ); the latter about 1.5 × as long as the former; distance between them appreciably 1.5 × as long as anal aperture. Genito-anal setae: 4(3, 5)-1(2)-2-3; setae thin, smooth setiform ( Fig. 7B ); genital g and aggenital ag setae variable in number, but generally (4-4) and (1- 1), respectively. Genital setae g 1 and g 2 remote from g 3 and g 4. Setae ag inserted postero-laterally remote from genital aperture. Adanal setae ad 1 inserted in postanal position; ad 2 postero-laterally; ad 3 preanal. Lyrifissures iad aligned in the paraanal position, between the level of anterior margin of anal aperture and insertion of setae an 2. Posterial anal lockingpieces remarkable ( Fig. 10B ). Sternal ridge and epimeral border IV indistinct. Custodium extending at the level of trochanter II; discidium small ( Fig. 8C ). Epimeral setal formula: 3-1-3-3; setae thin, smooth setiform ( Fig. 7B ), variable in length. Diarthric subcapitulum bearing 3 pairs of setae; setae thin, smooth setiform ( Fig. 7C ). Mentum without remarkable transverse slit connected with inner pharynx. Chelicera bearing short Trägårdh’s organ ( Fig. 7G ). Two setae, cha and chb pilose; cha long, chb short. Pedipalpal chaetotaxy: 0-2-1-3-9[1]; tarsus with a short solenidion (ca. 9 µm) not extending forwards from tip of tarsus ( Figs. 7F , 9B ). Relative lengths of some of the ventral setae: 4c> 4a> g> ad> ag> an.

Legs — All tarsi heterotridactylous; claws dorsally serrate. Setal formula of legs including famulus but excluding solenidia: I (1-5-3-4-18), II (1-5- 2-4-16), III (2-3-1-3-14), IV (1-2-2-3-12). Femora of leg II, III and IV bearing small carina ( Fig. 7E ). Solenidiotaxy I (1-2-2), II (1-1-2), III (1-1-0), IV (0- 1-0). Famulus on tarsus I short, spiniform, situated between ω 2 and fastigial seta ft "; solenidion ω 1 and ω 2 short bacilliform; ω 2 longer than ω 1, inserted posteriorly to ω 1; ω 1, ω 2, famulus and ft " aligned almost in a line ( Fig. 7D ).

Description of different characters between male and female: Female with genital aperture and distance between genital and anal apertures longer than those of male.

Remarks — The new species has dorsal aspect similar to those of Scheloribates maoriensis Hammer (1968) and S. gunini Bayartogtokh (2000) . However, the plications of posterial margin of notogaster and diverged sacculi are particular characters of the new species.

Figures

FIGURE 6: Scheloribates yamaeensis n. sp.: A – Dorsal view; B – Ventral view; C – A part of interlamellar seta; D – Left pteromorpha of a depressed specimen; E – Genito-anal region of female. Posterial anal locking-pieces (black arrow). A, B: (NSMT-Ac 13034; male); C – E: (NSMT-Ac 13035; female).

FIGURE 7: Scheloribates yamaeensis n. sp. (NSMT-Ac 13035; female). A – Sensillus (ss) and exobothridial seta (ex); B – Setae: ag, an, ad: aggenital, anal and adanal setae, respectively; 4a, 4c: Epimeral setae; C – Gnathosoma. a, m, h: Anterior, medial and posterior subcapitular setae, respectively; D – Solenidial region of tarsus-tibia of leg I. C: Famulus; ω1-2, Ƥ1-2: Solenidia; ft": fastigial seta; E – Femur IV; F – Pedipalp; G – Chelicera. cha, chb: cheliceral setae, Tg: Trägårdh’s organ.

FIGURE 8: Scheloribates yamaeensis n. sp.: A – Tip of left lamella (NSMT-Ac 13034); B – Left sacculi Sa (NSMT-Ac 13035); C – Right trochantera II – IV region (NSMT-Ac 13034).

FIGURE 9: Scheloribates yamaeensis n. sp. scanning electron micrographs (photos by Nakamura Y.-N., Hashimoto S.): A – Lateral view; B – Camerostomal region; C – Dorsal view; D – Left bothridial region; E – Sacculus S2 and notogastral seta h3; F – Plications near posterior margin of notogaster.

FIGURE 10: Scheloribates yamaeensis n. sp. scanning electron micrographs (photos by Nakamura Y.-N., Hashimoto S.): A – Ventral view; B – Anal aperture; C – Sacculi S2, S3; D – Left pteromophal region.