Oribatid fauna (Acari, Oribatida) from the Kumaya cave of Iheya village in Central Ryukyu arc, South Japan, with a description of several new species

Eleven oribatid species were collected from the Kumaya Cave of Iheya village in Central Ryukyu Arc, South Japan. The cave is a descending horizontal tunnel of a deep-sea abysmal quartziferous deposit formed in the Permian period of the Palaeozoic era and excavated by sea erosion. The floor of the cave was covered with sand, three to four meters deep. Fragments of psephite are found at the end of the cave. Each sample of about 200 ml was collected by hand from the following five marked points of the cave on 17 March 2010: A, Sand and a fragment of psephite; B, Sand and a fragment of psephite; C, Sand, a fragment of psephite, and litter of Ficus microcarpa; D, Litter and humus of F. microcarpa and Cassytha filiformis, and sand; E, Litter and humus of F. microcarpa and C. filiformis, and sand. All species belonged to Brachypylina: Oppiella (O.) nova from A; Mabulatrichus kumayaensis sp. nov., Protoribates kumayaensis sp. nov. and Zygoribatula iheyaensis sp. nov. from B; Tectocepheus kumayaensis sp. nov. from C; Tectocepheus iheyaensis sp. nov., Oribatula kumayaensis sp. nov., Protoribates hirokous sp. nov. and Haplozetes makii sp. nov. from D; Eupelops kumayaensis sp. nov. from E; Neoliodes iheyaensis sp. nov. from C, D and E.


INTRODUCTION
In Central Ryukyu Arc of South Japan, faunistical research of soil animals began in the early 1970's (Aoki, 1973;Aoki and Nakatamari, 1974). From Iheya Village, fifty seven oribatid species were already recorded by Aoki (2009). However, the present paper is the first contribution to the knowledge of the oribatid fauna in the Kumaya Cave of Iheya Village. Six species of soil animals in addition to oribatid mites were found. Eleven oribatid species, on which ten were new to Science were recorded. The objective of the present paper is to provide the description of these ten species. All examined oribatids belong to Brachypylina.
Remarks -Two species of genus Neoliodes, N. bataviensis Sellnick, 1925 andN. zimmermanni (Sellnick, 1959) have been recorded from Iheya Island (Aoki, 2009). However, descriptions of these latter specimens (Aoki, 2006;2009) are different from the original descriptions of N. bataviensis and N. zimmermanni in regards to insertion of rostral setae, form of lamellar-interlamellar region and size of sensilli, and from the new species in insertions of setae in, form of lamellar-interlamellar region and notogaster, and absence of conspicuous hollows and porose area (Apo) at the notogastral center. The new species differs from all the species of the genus by having porose area (Apo) at the notogastral center, opisthobital gland as conspicuous hollows laterally on the notogaster, form of lamellar region, notogaster and carina on genu and femur of all legs, and mentotectum separated medially.
Diagnosis -Body length 314 µm; width 150 µm. Parallel lamellar ridges connected with transversal ridge. Medial anterior part of notogaster not extending anterior crista. Setae c 2 glabrous. Epimeral grooves I, II and IV distinct. Setae ft' on tarsi I long.
Supplementary description -Morphological variation in form of lamellar region, anterior part of notogaster, setae c 2 and epimeral region, type A, A, A, and C, respectively (Pl. 2). The nomenclature used in the Figs. 15 and 16 is the one used by Fujikawa (1999).

Distribution -Cosmopolitan.
Remarks -The examined specimen has longer setae ft' on tarsi I than that of specimens collected in a nature farm in Hokkaido (Fujikawa, 1981) (Fig.  5). The present species is known as fungivorous, parthenogenetic and cosmopolitan species, with a fossil history of about 8,000 years ago (Karppinen and Koponen, 1973). Only the present species has been found in a deep horizontal drift of gold mine (Fujikawa, private information). Only the present species was collected from the point A where the wall and floor were covered with only sand or fragment of psephite without organic matter. It was observed that a total of 12,803 adults were issued from one female (for twelve years) and that this species was able to crawl in any crevice (Fujikawa, 1999). While Tectocepheus velatus (Michael, 1880) was not found from crevice the species rared with the same condition with O. nova. TECTOCEPHEIDAE GRANDJEAN, 1953 Tectocepheus kumayaensis sp. nov.
Etymology -After the name of sampling point, Kumaya Cave.
Notogaster -Depression and dorsosejugal scissure absent. Humeral region with small triangular projection. Ten pairs of notogastral setae short setiform, roughened throughout length. Lyrifissures ia aligned perpendicular to notogastral outline, antero-laterally to setae c 2 ; im obliquely, later-ally to lp; ip perpendicular to notogastral outline between p 1 and p 2 . Setae h 3 inserted antero-lateral to gla.
Remarks -Rostrum with two concavities of the new species is similar in appearance to those of Tectocepheus alatus Berlese, 1913 andT. shirakamiensis Fujikawa, 2001. However, the new species differs from them in form of cuspis, dorsosejugal region, humeral region, and situation or direction of lyrifissures ia and iad. The new species has a small body size, verrucose globular sensilli and subpallel lyrifissures iad to anal aperture as is the case of T. minor Berlese, 1903Berlese, [1904 sensu Bernini (1973) and Japanese specimens collected by Fujikawa. At first she considered these Japanese specimens as T. cuspidentatus Knülle, 1954(Fujikawa, 1988, because (1) she could not find out similar characters like rostrum with two deep incisions between Japanese specimens and Berlese Collection (204/6, in addition slides in the Berlese Collection were hardly examinable for her, and (2) she could find that Japanese specimens beared a stricking resemblance in the rostrum shape, sensilli and lamellar cusps, and situation of lyrifissures iad with a specimen of T. cuspidentatus in Zoological Museum Copenhagen. Latter the Japanese specimens were identified as T. minor (Fujikawa, 2001) according to Nübel-Reidelbach (1994). After that, Mahunk and Mahunka-Papp (1995) and Laumann and al (2007) pointed out that T. minor has medially weakly protruding rostral anterial margin, cusps bearing inner and outer dens, globular sensilli, notogaster without depressions, bothridium ventrally expanded, trochanter IV bearing a dorsal spur and lyrifissures iad situated subparallel to anal aperture. Fujikawa (1995;1999) could not observe individual variation in presence or absence of rostral incisions, form of rostral anterior margin, presence or absence of dens of cusps, and situation of iad subparallel to anal aperture. Now we consider that the abovementioned Japanese specimens should be reidentified as T. cuspidentatus. Tectocepheus minor by Fujita and Fujiyama (2001) should be also included in the species, T. cuspidentatus, Fujita and Fujiyama (2001) suggested that, unlike T. velatus, T. cuspidentatus could migrate in response to seasonal environmental changes. The new species differs from all the species of the genus in having rostral anterior margin with two concavities without incisions, cusps without dens and swelling, trigonal pyramidal interlamellar setae, and form of carina on trochanter III and IV.
Etymology -After the name of sampling area, Iheya Village.
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.
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). How-ever, 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. PHENOPELOPIDAE PETRUNKEVITCH, 1955 Eupelops kumayaensis sp. nov.
Etymology -After the name of sampling point, Kumaya Cave.
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.
Notogaster -Oval, bearing four pairs of porose areas like deep cavity (about 4 µm in depth, 9 µm in diameter), surrounded by clearly sclerotized areas (Fig. 16A). Fourteen pairs of notogastral setae present; c 1 (23 µm) barbed spiniform, thicker than the remainder; other setae thin, smooth setiform. Porose areas Aa situated posterior to c 1 and lateral to c 2 ; da posterior to c 2 . Lyrifissures ia aligned obliquely lateral to c 1 ; im obliquely immediately an-terior to A1; ih and ips obliquely to notogastral outline; ip obliquely behind h 1 . A number of light spots arranged peripherally on notogaster.
Remarks -The new species resembles in some respects of Oribatula (Oribatula) sakamorii Aoki, 1970(Fujikawa, 1983Bayartogtokh and Aoki, 2000). However, the new species differs from this latter species in having short lamellar setae, porose areas like deep cavity, sensilli with club-shaped head, long custodium, and mutual distances, (1a -1a) ≈ (2a -2a). As far as the authors know, form of porose areas such as found in the new species, was also, recorded in O. magniporosa Hammer, 1958, O. exsudans Travé, 1961, and Zygoribatula dubita Coetzer, 1967-1968. However, the new species has different insertion of lp, h 2 and h 3 than the ones of O. magniporosa, different form of humeral region, length of le, insertion of c 2 and direction of im than those of O. exsudans, and different form of rostral anterior margin and lamellae than those of Z. dubita. Sensilli and lamellar tips of the new species are similar in appearance to those of O. parisi Travé, 1961 andO. interrupta (Willmann, 1939). However, the new species can be distinguished from them by relative distances between their mutual distances of ro, le and in, and from O. interrupta by situation of porose areas Aa.
Etymology -After the name of sampling area, Iheya Village.
Remarks -The new species resembles in some respects Zygoribatula truncata Aoki, 1961, however, it differs from this latter species by long interlamellar setae, rounded tip of head of sensilli, protruding anterior medial margin of notogaster, and different situation of porose areas Aa, A1 and A3: Aa at a short distance from la, A1 posterior to lp, A3 near to h 1 . Notogastral setae p 2 of the new species is absent as it is in Z. connexa substriata Grobler et Kok, 1993. However, the new species is different from Z. connexa substriata in notogastral surface without faint yellow striations. Situation of notogaster setae and porose areas of the new species are very similar in appearance to those of Z. glabra (Michael, 1890) and Z. propinguus (Oudemans, 1902). However, the new species differs from them because of a rounded rostrum.
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.
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 .
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, 1908according 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).
Etymology -The new species is dedicated to Miss Hiroko Fukumori who gave the authors helpful suggestions for sampling.
Remarks -The new species is similar in form of rostrum and sensilli, length of notogastral setae and size of lamellae to Haplozetes angustus (Hammer, 1967) and H. nudus (Hammer, 1961). However, the new species differs from them in having sacculi S2 posterior to setae h 2 and their mutual distance of lp smaller than those of lm and h 2 .