Decapauropus annulicordatus Qian

Qian, Changyuan, Dong, Yan, Bernard, Ernest C. & Sun, Hongying, 2015, Records of Pauropoda (Pauropodidae, Brachypauropodidae, Eurypauropodidae, Sphaeropauropodidae) from China, with a key to the species and descriptions of three new species of Decapauropus, Zootaxa 4006 (3), pp. 521-539 : 524-526

Decapauropus annulicordatus Qian sp. n.

Fig. 1

Type material. Holotype: ad.9 (female), Taojiang, Hunan, 4 October 2012, leg. Qian. loc. TJ 20121004. Paratypes: 1 ad. 9 (female), Taojiang, Hunan, 5 October 2012, leg. Qian. loc. TJ 20121005, 1 ad. 9 (female), Mao’er Mountains, Guangxi, 4 December 2012, leg. Qian. loc. MES 20121204.

Etymology. From Latin annulus- = annulate (little ring) and cordatus = heart-shaped (referring to the shape of the anal plate and the appendages).

Description. Holotype length 0.6 mm, paratypes length 0.5 mm. Dorsal head (Fig. 1A) setae of short to median lengths, subcylindrical, striate, blunt. Relative lengths of setae, 1st row: a 1 = 10, a 2 = 13.5 (14.6‒15.9); 2nd row: a 1 = 15.9 (14.7‒15.9), a 2 = 20.6 (21‒24.7), a 3 =22.9 (20.5‒21.7); 3rd row: a 1 =18.2 (13‒17.8), a 2 = 18.2 (17.1‒18.2); 4th row: a 1 =14.7 (11.1‒13.8), a 2 = 15.3 (?), a 3 missing on the holotype (11.6‒13.5), a 4 = 17.6 (?); the ratio a 1/ a 1– a 1 in 1st row 0.63 (0.6‒0.70), 2nd row 0.45 (0.36‒0.5), 3rd row 0.59 (0.48‒0.6) and 4th row1.0 (0.80‒0.88). Temporal organs oval in tergal view, their length 2.2 times as long as their shortest distance apart. Head cuticle glabrous.

FIGURE 1. Decapauropus annulicordatus sp. n., holotype. A) Head, submedian and right part, tergal view. B) Pygidium, tergal view. C) Right antenna, tergal view. D) Tarsus of leg 9. E) Seta on trochanter and tarsus of leg 9. F) Collum segment, median and left part, ventral view. G) Bothriotrix T 3. H) Bothriotrix T 4. I) Bothriotrix T 5.

Antennal (Fig. 1C) segment 4 with four cylindrical setae; relative lengths of setae: p = 100, p ’ = 55.4 (54‒61), p ” = 45.7 (40.9‒44.8), r = 32.6 (31‒33); tergal seta p 1.0 (1.1‒1.2) times as long as tergal branch t. The latter cylindrical, 2.5 (2.5‒2.7) times as long as its greatest diameter and 1.1 longer than sternal branch s, which itself is 1.8 (2.0) times longer than its greatest diameter. Seta q cylindrical, blunt, 0.59 times length of s. F 2 very thin with small base segment. Relative lengths of flagella (base segments included) and base segments: F 1 = 100, bs 1 = 6 (5‒6); F 2 = 47 (44‒49), bs 2 = 3 (2‒3); F 3 = 86 (86‒89), bs 3 = 7 (7‒8). F 1 5.5 (5.2‒5.8) times longer than t, F 2 and F 3 2.6 (2.4‒2.6) and 4.8 (4.3‒4.7) times as long as s respectively. Distal calyces small; F 1 and F 2 with fusiform flagella axes just below calyx. Distal calyces spherical; distal part of flagella axes fusiform. Globulus g 1.5 (1.2) times as long as wide; about nine bracts, capsule subspherical; width of g 0.9 (0.7) times the greatest diameter of t. Antennae nearly glabrous.

Setae of collum segment (Fig. 1F) clavate, striate, and appearing simple. Sublateral setae 2.3 times as long as submedian setae; sternite process triangular, pointed; appendages narrowing distally and with flat caps; process with coarse surface. Setae on tergites thin, cylindrical; 4 + 4 setae on tergite I, 6 + 6 on II–IV, 6 + 4 on V, 4 + 2 on VI. Tergites glabrous.

Relative lengths of bothriotricha: T 1 = 100, T 2 = 106 (99‒105), T 3 (Fig. 1G) = 81 (76‒80), T 4 (Fig. 1H) = 95 (96‒110), T 5 (Fig. 1I) =128 (124‒155). Axes simple, straight, in all but T 3 very thin; axes of T 3 thickened in distal half. Pubescent hairs simple, short, thin, strongest on distal half of T 3.

Setae present on coxa and trochanter of leg 9 (Fig. 1E), furcate with subcylindrical blunt branches. Tarsus of leg 9 (Fig. 1D) short, tapering, 3.1 times longer than its greatest diameter. Proximal seta long, tapering, with pubescence; distal seta clavate, blunt, striate; their lengths 0.57 and 0.26 times the tarsal length, respectively. Cuticle of tarsus glabrous.

Posterior margin of pygidial tergum (Fig. 1B) between st straight. Relative lengths of setae: a 1 = 100, a 2 = 107.4 (106‒108), a 3 = 203.7 (198.4–201.8), st = 107.4 (108‒110). All setae blunt, subcylindrical, striate; st blunt, subcylindrical, striate, convergent; Distance a 1– a 1 2.4 times length of a 1; distance a 1– a 2 2.0 (1.9‒2.0) times length of a 2– a 3; distance st–st 2.1 (1.9‒2.0) times length of st and 1.5 times length of distance a 1– a 1. Pygidial sternum posterior margin with shallow indentation between b 1. Relative lengths of setae (a 1 =100): b 1 = 692.6.4 (690‒701), b 2 = 226 (228‒231). All setae subcylindrical, blunt, striate. Distance b 1– b 1 0.84 (0.8‒1.0) times length of b 1; distance b 1– b 2 1.2 (1.3‒1.4) times length of b 2.

Anal plate heart-shaped, length and width equal, posterior edge rounded with a shallow incision; two annulate, finely pubescent appendages protruding backwards and outwards from the submedian of the plate, length of appendages 0.92 times that of the plate; posterior margins glabrous.

Diagnosis. Decapauropus annulicordatus sp. n. is similar to D. asperosus Scheller, 1983 ( Canada) , D. thailandensis Scheller, 1995 ( Thailand) and D. terrestris Scheller, 2009 (Tasmania) . All four species are similar in the general shape of the antennae and the pygidium with its setae. In D. annulicordatus sp. n. the anal plate is heart-shaped, glabrous, and possesses appendages nearly as long as the plate itself. In D. asperosus the plate is subrectangular, while in D. thailandensis the anal plate and appendages have a short pubescence. On D. terrestris the incision is deeper and the plate has very short appendages with short pubescence.