Plonaphacarus protrusus, 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 : 15-18

Plonaphacarus protrusus sp. nov.

( Figs. 50–58 )

Material examined. Holotype: adult (in alcohol, W-89-31'), China: Fujian Province, Wuyi Mt. (27°45'23.97"N, 118° 2'7.11"E), Guadun, from litter under bamboo, 30 Apr., 1989, leg. Hui-Fu Wang. Paratypes: two adults (in alcohol, W-89-31'), same data as holotype; one adult (in alcohol, Wu-Y-21), same data as holotype, Dazhulan, from litter under broadleaf, 31 Jul., 1983, leg. Hui-Fu Wang and Xiao-Mei Zhang.

Etymology. The new specific name “ protrusus ” is from Latin, and refers to the protrudent part of notogaster.

Measurements: Holotype: Prodorsum: length 355, width 280, height 150, setae: ss 140, ro 50, in 205, le 75, ex 44, distance between setae: ro -ro 35, in -in 90, le -le 140; notogaster: length 842, width 590, height 549; setae: c1 270, c2 228, c3 100, c p 210, d1 230, d2 185, e1 200, h1 220, h3 97, ps1 208, ps2 200, ps3 130, ps4 70; distance between setae: c1-d1 220, d1-e1 350, e1-h1 190, h1-ps1 140; ventral region: ad1 148, ad2 160, ad3 50, an1 85, an2 102; genitoaggenital plate 195×180, anoadanal plate 265×160. One paratype: Prodorsum: length 298, width 205, height 95; notogaster: length 615, width 340, height 330.

Colour grey-yellowish to brown. Surface of body covered with concavities.

Prodorsum with one remarkable dorsal carina; lateral carinae weakly developed and moderately long, not reaching sinus; sigillar fields invisible because of strong sculpture; posterior furrows present; sensilli long with narrow pedicel and sickle-like head, covered with small spines; interlamellar setae long, robust, semi-erect, densely covered with small spines; lamellar setae thin, short, semi-erect and densely barbed; rostral setae spiniform, thin, smooth and procumbent; exobothridial setae short and fine; comparative length: in>ss> le>ro> ex.

Anterodorsal part of notogaster protrudent to form a hook-like projection covering posterior part of prodorsum; 15 pairs of notogastral setae in different length and shape, setae c3, h3, ps3 and ps4 shorter and thinner, covered with spines in distal half (except setae c3 densely barbed), other setae long (c1> c1-d1), robust and densely barbed; setae c1 and c3 close to anterior border, setae c2 more remote than them; vestigial setae f1 positioned posterior to setae h1; two pairs of lyrifissures ia and im present.

Nine pairs of genital setae present, arranged in two rows with formula: 7(4+3): 2; one pair of aggenital setae present; anoadanal plates each with five well-developed setae, setae ad1 and ad2 barbed, longer than anal setae, setae ad3 shortest; setae an2 longer than an1.

Setae h of mentum slightly longer than distance between them; chaetotaxy of legs (without tarsi): I: 1-4-2(2)- 5(1); II: 1-3-2(1)-3(1), III: 2-2-1(1)-2(1), IV: 2-1-1-2(1); v’’ / v’ (femora I)=3; setae d on femora I forked distally and situated near distal end of article; setae a’’ on tarsi I and II and setae ft’’ on tarsi II straight distally; setae s and pv’ on tarsi IV and setae s on tarsi I and II present; setae l’ on genua IV reduced; 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. i n s i g n i t u s Niedbała, 1989 and P. i s h ik aw a i ( Aoki, 1980) in having one dorsal carina, but differs from them by the following combined characters: sensilli long with narrow pedicel and sickle-like head, covered with small spines; rostral setae procumbent; exobothridial setae not vestigial; anterodorsal part of notogaster protrudent to form a hook-like projection covering posterior part of prodorsum; setae h of mentum slightly longer than distance between them; genital setae with formula: 7(4+3): 2; setae d on femora I forked distally.

Figures

FIGURES 50 – 58. Plonaphacarus protrusus sp. nov.: 50, lateral view of body (legs removed); 51, prodorsum, dorsal view; 52, mentum of infracapitulum; 53, left side of ventral plate; 54, sensillus, dorsal view; 55 – 58, trochanter, femur, genu and tibia: 55, leg I; 56, leg II; 57, leg III; 58, leg IV. Scale bars: 50 = 200 μm; 51 – 53, 55 – 58 = 100 μm; 54 = 50 μm.