Otocepheus (Acrotocepheus) duplicornutus Aoki, 1965: new record in China

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) duplicornutus Aoki, 1965: new record in China Figs 31-33 , 34-36 , 37-39

Otocepheus (Acrotocepheus) duplicornutus Aoki 1965: 303.

Otocepheus (Acrotocepheus) duplicornutus discrepans ( A. ): Balogh & Mahunka 1967: 49.

Diagnosis.

Body size (n = 4): 1150-1400 × 480-600. Body ratio (length/width): 2.3-2.4. Lateral notogastral condyles appears to be double-structured, the outer portion of lateral notogastral condyles triangular anteriorly. Medial notogastral condyles absent. Postpodosomal ornamentation well developed. A pair of longitudinal ridges posterior to epimeral setae 4a present.

Description.

Measurements. Body length: 1150-1400 (four males), notogaster width: 480-600 (four males). Setae length and mutual distance (one male, ZLH-12-73): bs 150, in 215, le 190, ro 150, ex 35; c, la, lm, lp, h 1, h 2, h 3, p 1, p 2, p 3 range 250-300; c - c 110, la - la 190, lm - lm 160, lp - lp 260, h 2- h 2 180, h 1- h 1 190.

Integument. Body color light brown, but genital plates and legs dark brown. Body surface densely foveolate.

Prodorsum. Rostrum rounded. Seta ro moderately curved inward, densely barbed outside. Seta le removed backward from tip of costula, curved inward, roughened externally. Setae le and in slightly barbed, with blunt tips. Bothridium opening laterally, dorsal bothridial plate nearly straight, ventral bothridial plate broadly triangular in dorsal view. Bothridial seta with lanceolate head, slightly roughened. Seta ex short, setiform. Tutorium developed. Lamelliform expansion pointing to bottom of seta ro. Costula well developed. Prodorsal condyles broadly rounded, well separated from each other. Subpedotectum well developed. Extra condyles posterior to lateral prodorsal condyles invisible.

Notogaster. Anterior margin of notogater weakly concaved. Lateral notogastral condyles appears to be double-structured, the outer portion of lateral notogastral condyles triangular anteriorly. Medial notogastral condyles absent. Notogaster with ten pairs of setae, setiform, slightly barbed. Lyrifissures distinct, ip between setae p 2 and p 3, ips between setae h 3 and p 3, ih anterior to seta h 3, im interiorly to opisthonotal gland opening.

Epimeral and lateral podosomal regions. Apodemes II and sejugal well-developed, apodeme III invisible, epimeral foramen small and rounded. Epimeral setal formula: 3-1-3-3. Setae setiform, 4a inserted between 4b and 4c, and closer to 4c. Postpodosomal ornamentation well developed.

Anogenital region. Aggenital lyrifissure located close and anterolateral to genital aperture. A pair of longitudinal ridges posterior to epimeral seta 4a present. Genital plates smooth. Four pairs of genital setae (mutual distances g 1- g 1≈ g 2- g 2≈ g 4- g 4<g 3- g 3) and one pair of aggenital setae present, setiform and slightly barbed. Three pairs of adanal and two pairs of anal setae (mutual distance an 1- an 1<an 2- an 2) slightly barbed. Setae ad 3- ad 3 below level of anterior margin of anal opening. Adanal lyrifissure located in diagonal position and close to anal aperture (in some specimens one of the adanal lyrifissures aligned transversely while the other one aligned diagonally), below level of anterior margin of anal opening.

Gnathosoma. Subcapitular setae fistulous, barbed. 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. 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 (2-3-1-2-15) [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.

One male (ZLH-12-72): China, Guangxi Province, Longzhou County, 22°25'19"N, 106°58'12"E, 149 m a.s.l., in soil and debris beside deadwood, 3 August 2012; one male (ZLH-12-73): same locality as ZLH-12-72, 22°25'11"N, 106°58'6"E, 154 m a.s.l., in soil and debris beside deadwood, 3 August 2012; one male (ZLH-12-74): same locality as ZLH-12-72, 22°25'7"N, 106°58'2"E, 166 m a.s.l., in soil and debris under liana, 3 August 2012; one male (ZLH-12-77): China, Guangxi Province, Fusui County, 22°27'36"N, 107°53'24"E, 100 m a.s.l., in soil and debris under leaf wood, 8 August 2012. All specimens were collected by Lihao Zheng.

Specimen deposition.

Specimens are deposited in the collection of IZAS.

Remarks.

The morphological characters of specimens checked in this study are almost coincident with the original description of this species by Aoki (1965), which was based on material collected from Sara Buri, Thailand, except for the following delicate differences: arc degrees of prodorsal condyles (broadly rounded versus semicircular) and alignment of adanal lyrrifissure (located in diagonal position versus generally aligned transversely). Though these characters are relatively constant in our limited specimens, the shape of prodorsal or notogastral condyles, as well as the alignment of adanal lyrrifissure, sometimes vary. So, we temporarily treat these minor differences as normal individual variation.

Figures

Figures 31 - 33. Otocepheus (Acrotocepheus) duplicornutus Aoki, 1965, adult 31 Dorsal view 32 bothridial seta 33 ventral view (legs not shown). Scale bars: 200 µm (31, 33), 100 µm (32).

Figures 34 - 36. Otocepheus (Acrotocepheus) duplicornutus Aoki, 1965, adult, microscope images 34 dorsal view 35 ventral view 36 lateral view. Scale bars: 200 µm.

Figures 37 - 39. Otocepheus (Acrotocepheus) duplicornutus Aoki, 1965, adult 37 subcapitulum, ventral view 38 right palp, abaxial view 39 left chelicera, adaxial view. Scale bars: 50 μm.