Fissicepheus (Fissicepheus) aokii, Zheng & Chen, 2018

Zheng, Li-Hao & Chen, Jun, 2018, Taxonomic study on the genus Fissicepheus (Acari: Oribatida: Otocepheidae) from China, Zootaxa 4410 (3), pp. 539-550 : 540-542

Fissicepheus (Fissicepheus) aokii sp. nov.

( Fig. 1 )

Material examined: Holotype: adult (in alcohol, DW-12-17), CHINA: Shanxi Province: Jiaocheng County, Shishazhuang (37°38′50″N, 111°44′41″E), 1170m a.s.l., from litter under shrub, 17 Jun. 2012, leg. Wei Duan . Paratypes: 1 adult (in alcohol, DW-12-17), same data as holotype ; 1 adult (mounted on slide, DW-12-106, SSNO: 31934), CHINA: Shanxi Province: Yicheng County, Dahe Village (35°25′58.45″N, 111°54′23.16″E), 1028m a.s.l., from litter under shrub, 19 Jul. 2012, leg. Wei Duan .

Etymology. The name of the new species is dedicated to Dr. Jun-ichi Aoki, who made an initial contribution to the study of the otocepheid mites.

Description. Measurements. Holotype: body length 590, width 300, notogastral length 388, setae lengths: ss 60, in 55, le 100, ro 90, ex 20, mutual distances of setae: c -c 115, la -la 175, lm -lm 130, lp -lp 225, h 2- h 2 165, h 1- h 1 125. Paratypes: body length 480–540, width 220–265.

Prodorsum ( Fig. 1a ). Rostrum rounded. Seta ro slightly barbed unilaterally, curved inward. Seta le inserted almost at tip of lamella, glabrous, curved inward, longer than ro. Fine foveolae present on lateral lamelliform expansion (spa.l). Seta in distinctly barbed in distal third. Distance between outer margins of lamellae on level of apexes of pedotecta I accounting for ca. 47% (holotype) of distance between apexes of pedotecta I. Tutorium (tu) poorly developed. Posterolateral region of prodorsum densely granulate. Bothridium opening laterally, dorsal bothridial plate (tbd) curved inward. Sensillus (ss) club-shaped, head with many blunt thorns ( Fig. 1c ). Two pairs of prodorsal condyles present, lateral prodorsal condyles (co.pl) broadly triangular, median prodorsal condyles (co.pm) large and semicircular, well separated from each other.

Notogaster ( Figs. 1a, 1b ). Length/Width of notogaster about 1.3 (hotlotype). Surface of notogaster densely punctate. Two pairs of notogastral condyles present, opposed to prodorsal condyles, correspondingly; lateral notogastral condyles (co.nl) triangular, median notogastral condyles (co.nm) separated from each other, large and nearly rectangular. Ten pairs of notogastral setae (c, la, lm, lp, h 1, h 2, h 3, p 1, p 2, p 3) nearly same in length (range 50– 60), and distinctly barbed in distal third ( Fig. 1b ). Faint, short ridge present lateral to insertion of seta c. Lyrifissure ih situated anterior to, and ips posterior to h 3.

Venter ( Fig. 1d ). One pair of seta h present on subcapitulum. Surface of ventral plate punctate. Epimeral setal formula: 3-0-2-3. Apo.2 and apo.sj developed distinctly, apo.3 short. Genital plate nearly smooth, with four pairs of genital setae, g 1, g 2, g 4 nearly lined along medial margin, g3 removed to central part. Aggenital condyles (c o.ag) well developed, each with rounded tip. Anal plates punctate, with two pairs of anal setae, mutual distances an 1- an 1<an 2- an 2. Three pairs of adanal setae present, all weakly barbed, ad 3- ad 3 at level of anterior margin of anal opening. Adanal lyrifissure (iad) situated immediately anterior to ad 3.

Legs. All legs monodactyle, all ultimate setae L-type. Several pleats present on dorsal sides of all femora ( Figs. 1e, 1f ). Formulae of leg setation and solenidia: I (1-4-3-4-16) [1-2-2], II (1-4-3-3-16) [1-1-2], III (2-3-1-2-14) [1-1- 0], IV (1-2-1-2-12) [0-1-0].

Remarks. This new species is similar to Fissicepheus vicinus Aoki, 1986 from Japan in having large and semicircular co.pm, similar shape of ss, and le inserted almost at tip of lamella. It differs from F. vicinus as follows: in F. aokii , notogastral setae distinctly barbed in distal third, lateral lamelliform expansion (spa.l) not fused to each other; in F. vicinus , notogastral setae glabrous and with fine tips, spa.l well developed, fused to each other to form a brim-like structure. This new species is also similar to F. thaiensis Mahunka, 2008 from Thailand in having distinctly barbed notogastral setae (in distal third). It differs from F. thaiensis as follows: in F. aokii , seta le glabrous, no tubercle present behind prodorsal condyles, two pairs of notogastral condyles present, co.ag well developed; in F. thaiensis , seta le peculiarly ciliate, some irregularly and weakly developed tubercles present behind prodorsal condyles, only lateral notogastral condyles present, co.ag weakly developed.

Figures

FIGURE 1. Fissicepheus (Fissicepheus) aokii n. sp.: a, dorsal aspect (legs removed); b, notogatral seta la; c, sensillus; d, ventral aspect (legs and mouthparts removed); e–f, femur I, right (e, antiaxial aspect; f, dorsal apsect).