Otocepheus (Acrotocepheus) occultatus, Zheng & Chen, 2020

Zheng, Li-Hao & Chen, Jun, 2020, Three new species of the subgenus Otocepheus (Acrotocepheus) (Acari, Oribatida, Otocepheidae) from China, ZooKeys 934, pp. 1-23 : 1

Otocepheus (Acrotocepheus) occultatus sp. nov. Figs 23-26 , 27 , 28-29

Diagnosis.

Body size (n = 4): 1240-1410 × 560-670. Bothridial seta with a long fusiform head and a short peduncle. Lateral prodorsal condyles on prodorsum small, rounded, lateral prodorsal condyles markedly anterior to medial prodorsal condyles. An extra pair of condyles located posterior to lateral prodorsal condyles, covered by lateral notogastral condyles. Lateral notogastral condyles large, width nearly equal with their mutual distance, tips markedly anterior to medial prodorsal condyles. Anterior median part of mentum with a lower lip ridge.

Description.

Measurements. Body length: 1280 (holotype: female), 1240-1410 (three paratypes: one female and two males); notogaster width: 530 (holotype), 560-670 (paratypes). Setae length and mutual distance (holotype): bs 85, in 220, le 235, ro 175, ex 19; c, la, lm, lp, h 1, h 2, h 3, p 1, p 2, p 3 range 150-300; c - c 200, la - la 300, lm - lm 230, lp - lp 350, h 2- h 2 225, h 1- h 1 230.

Integument. Body color light yellow-brownish. Body surface densely foveolate.

Prodorsum. Rostrum rounded. Rostral seta curved inward, densely barbed outside. Lamellar seta inserted behind tip of costula, moderately curved inward, roughened outside. Interlamellar seta barbed, setiform. Bothridial seta with a long fusiform head and a short peduncle. Exobothridial seta short. Costula straight, nearly paralleled. Bothridium opening laterally, dorsal bothridial plate straight, ventral bothridial plate broadly rounded in dorsal view. Lamelliform expansion pointing to bottom of seta ro. Two pairs of prodorsal condyles present. Lateral prodorsal condyles small, rounded, markedly anterior to medial prodorsal condyle. Median prodorsal condyles small, rounded, well separated from each other. An extra pair of condyles located posterior to lateral prodorsal condyles, covered by lateral notogastral condyles. Mutual distance between ventral bothridial plates larger than that between lateral prodorsal condyles. Subpedotectum well developed.

Notogaster. L/W of notogaster about 1.3. Surface of notogaster densely punctate. Lateral notogastral condyles large, triangular and rounded distally, inner part with a narrow base, anteromedial margins distinctly excavated, width nearly equal with their mutual distance, tips markedly anterior to medial prodorsal condyles. Medial notogastral condyles absent. Ten pairs of notogastral setae, slightly barbed, setae located posteriorly tend whip-like at tips. All lyrifissures well visible, ip located between setae p 2 and p 3, ips between setae h 3 and p 3. Opisthonotal gland opening located posterior to lyrifissure im. Vitta marginalis distinct.

Epimeral and lateral podosomal regions. Surface punctured. Apodemes II and sejugal well developed, apodeme III invisible. Carina sterinalis short. Epimeral setal formula 3-1-3-3. Seta 4a inserted between 4b and 4c, and closer to 4c. Postpodosomal ornamentation invisible.

Anogenital region. A pair of longitudinal ridges posterior to epimeral setae 4a. Genital plates with two or three longitudinal ridges on both sides. Four pairs of genital setae smooth (mutual distances g 1- g 1≈ g 2- g 2≈ g 4- g 4<g 3- g 3). Aggenital lyrifissure located close and anterolateral to genital aperture. One pair of aggenital, two pairs of anal (mutual distances an 1- an 1<an 2- an 2), and three pairs of adanal setae. Anal setae barbed and blunt at tips, adanal setae barbed and whip-like at tips. Seta an 2 well separated from outer margin of anal plate. Location of adanal setae normal, inside external margin of ventral plate. Setae ad 3- ad 3 below level of anterior margin of anal opening. Adanal lyrifissure located in diagonal position and close to anal aperture.

Gnathosoma. Anterior median part of mentum with a lower lip ridge. Subcapitular setae relatively smooth. Adoral setae and their alveoli absent. Rutellum pantelobasic, with typical dentition and rutellar brush. Chelicera chelate-dentate; with a minute denticle proximal to seta cha; cha longer than chb, both of them setiform, barbed; Trägårdh’s organ narrowly triangular. Palp with usual setal formula: 0-2-1-3-8 (+ ω); setae of femur to tibia barbed. Tarsus with four short, blunt distal eupathidia- acm, su, (ul); other tarsal setae smooth or with sparse, inconspicuous barbs; solenidion ω connected with seta ul ', seta ul " medioanteriorly. Postpalpal seta erect, smooth.

Legs. Monodactylous. Claw of each leg strong and smooth. Formulae of leg setation and solenidia: I (1-4-3-4-16) [1-2-2], II (1-4-3-3-15) [1-1-2], III (2-3-1-2-14) [1-1-0], IV (1-2-2-2-12) [0-1-0]. Leg seta u setiform (L-type) on tarsi I, thorn-like (S-type) on tarsi II-IV. Homology of setae and solenidia indicated in Table 1 .

Material examined.

Holotype (male, ZLH-12-34): China, Guangxi Province, Wuming County, Daming Mountain, 23°29'42"N, 108°26'17"E, 1223 m a.s.l., in soil and debris under bush, 17 July 2012, collected by Lihao Zheng. Three paratypes (one female and two males, ZLH-12-37): same locality as holotype, 23°28'51"N, 108°27'18"E, 1410 m a.s.l., in soil and debris under tree, 20 July 2012, collected by Lihao Zheng.

Type deposition.

All type specimens are deposited in the collection of IZAS.

Etymology.

The specific name " occultatus " is from Latin for “hiding”, in reference to the extra condyles which are covered by the large lateral notogastral condyles.

Remarks.

The new species is most similar to O. (A.) bajau Mahunka, 2000 from Malaysia and O. (A.) consimilis (Balogh, 1970) from Ceylon in having large lateral prodorsal condyles. However, it differs from O. (A.) bajau by the extra condyles on prodorsum covered by lateral notogastral condyles (versus none), bothridial seta with a long fusiform head (versus with a lanceolate head), tarsus I normal (versus with triangular teeth), and it differs from O. (A.) consimilis by the lateral prodorsal condyles markedly anterior to medial prodorsal condyles (versus lateral prodorsal condyles nearly in same line with median prodorsal condyles), seta an 2 well separated from outer margin of anal plate (versus very close to outer margin of anal plate), notogastral setae located posteriorly tend whip-like at tips (versus not), normal location of adanal setae, and inside external margin of ventral plate (versus arising on and parallel with external margin of ventral plate).

Figures

Figure 27. Otocepheus (Acrotocepheus) occultatus sp. nov., adult: lateral view (legs not shown). Scale bar: 200 µm.

Figures 23 - 26. Otocepheus (Acrotocepheus) occultatus sp. nov., adult 23 bothridial seta 24 ventral view (legs not shown) 25 dorsal view 26 lateral lamelliform expansion. Scale bars: 100 µm (23, 26), 200 µm (24, 25).

Figures 28 - 30. Otocepheus (Acrotocepheus) occultatus sp. nov., adult. 28 subcapitulum, ventral view 29 right palp, abaxial view 30 right chelicera, adaxial view. Scale bars: 50 μm.