Plonaphacarus rotundus, Liu, Dong, Wu, Donghui & Chen, Jun, 2011

Liu, Dong, Wu, Donghui & Chen, Jun, 2011, Review of Plonaphacarus (Acari: Oribatida: Steganacaridae), with descriptions of eight new species from China, Zootaxa 2739, pp. 1-26 : 18-20

Plonaphacarus rotundus sp. nov.

( Figs. 59–64 )

Material examined. Holotype: adult (in alcohol, W-97-7), China: Guangdong Province, Zhaoqing City, Dinghushan National Nature Reserve (23° 9'35.51"N, 112°33'15.05"E), from litter under Gnetum sp., 20 Oct., 1997, leg. Hui-Fu Wang.

Etymology. The new specific name “ rotundus ” is from Latin, and refers to the rounded head of sensilli.

Measurements: Holotype: Prodorsum: length 256, width 165, height 95, setae: ss 38, ro 36, in 99, le 30, distance between setae: ro -ro 25, in -in 60, le -le 90; notogaster: length 445, width 299, height 287; setae: c1 95, c2 81, c3 90, c p 81, d1 90, d2 65, e1 98, e2 73, h1 100, h2 79, h3 57, ps1 92, ps2 80, ps3 65, ps4 55; distance between setae: c1-d1 105, d1-e1 133, e1-h1 95, h1-ps1 95; ventral region: ad1 50, ad2 120, ad3 40, an1 50, an2 50; genitoaggenital plate 117×115, anoadanal plate 130×85.

Colour brown. Surface of body covered with concavities.

Prodorsum with two pairs of distinct dorsal carinae; lateral carina absent; dorsal and lateral region invisible; posterior furrows present; sensilli short with narrow pedicel and rounded head, covered with small spines; interlamellar setae robust, erect, with blunt distal end and covered with small spines in distal half; lamellar setae short, smooth and semi-erect; rostral setae short, smooth and procumbent; exobothridial setae not observed; comparative length: in>ss>ro>le.

Notogaster with 15 pairs of setae, moderately long (c1>1/2 c1-d1), robust, covered with small spines in distal half, setae h1 longest, setae ps4 shortest; setae c1-3 remote from anterior border, setae c2 much more so than c1 and c3; vestigial setae f1 not observed; two pairs of lyrifissures ia and im present.

Nine pairs of genital setae present, arranged in two rows with formula: 6(4+2): 3; one pair of aggenital setae present; anoadanal plates each with five well-developed setae, setae ad2 longest, setae ad3 shortest, shorter than anal setae.

Setae d on femora I situated near distal end of article; setae d on tibiae IV long, independent of solenidions; all legs monodactylous.

Distribution. Known only from type locality.

Remark. This new species is similar to P. scrupeus Niedbała, 1989 in having two pairs of dorsal carinae but differs by the following characters: In P. rotundus , lateral carina absent; sensilli short with narrow pedicel and round head; rostral setae procumbent. In P. scrupeus , lateral carinae strong and long, extend beyond sinus and reach end of rostrum; sensilli long with narrow pedicel and fusiform head, covered with short spines; rostral setae semi-erect.

Figures

FIGURES 59 – 64. Plonaphacarus rotundus sp. nov.: 59, lateral view of body (legs removed); 60, prodorsum, dorsal view; 61, sensillus, dorsal view; 62, left side of ventral plate; 63, femur of leg I; 64, tibia of leg IV. Scale bars: 59 – 60, 62 – 64 = 100 μm; 61 = 50 μm.