Eurypauropus japonicus Hagino & Scheller, 1985, new record to China

Gao, Yan & Bu, Yun, 2023, Two new species of the genus Samarangopus and the first record of Eurypauropus japonicus (Arthropoda, Myriapoda, Pauropoda, Eurypauropodidae) from China, ZooKeys 1165, pp. 137-154 : 137

Eurypauropus japonicus Hagino & Scheller, 1985, new record to China

Fig. 8

Material examined.

1 female adult with 9 pairs of legs (slide no. ZJ-GTS-PA2012023), China, Zhejiang Province, Gutian Mountain , extracted from soil samples in broad-leaved forest, alt. 1000 m, 29°16'N, 118°06'E, 27-III-2013, coll. Y. Bu.

Diagnosis.

Eurypauropus japonicus is characterized by the shape of the anal plate with one pair of small, pointed lateral appendages, subcylindrical setae b 2 on the sternum of the pygidium, tergites with large, curved, ciliated spines and small, nipple-shaped tubercles with conical bases.

Description of new material.

Length 1.28 mm, light brown (Fig. 8A ). Head covered by tergite I and chaetotaxy not observed in detail.

Antennae (Fig. 8B, D ). Chaetotaxy of segments 1-4: 2/2/4/5. Setae cylindrical, annulate. Length of setae on segment 4: p = 40 μm, p ' = 26 μm, p ″ = 25 μm; p ‴ = 21; r = 15 μm, u absent. Tergal branch t fusiform, 3.3 times as wide as greatest diameter and 0.8 times as long as sternal branch. Sternal branch s with distinct anterior indentation at level of F 2, 2.6 times as long as greatest diameter. Seta q similar to setae of segment IV, 40 μm, 0.8 times the length of s. Globulus g with long, cylindrical stalk, length of g (27 μm) 3.8 times as long as greatest diameter; the latter 0.2 times of greatest diameter of t; 10 bracts, capsule spherical, diameter = 5 μm; stalk length 20 μm. Globulus g 2 on third antennal segment with short, pubescent stalk, 6 μm in length, 2.2 times as long as greatest diameter, capsule tiny, diameter = 2.5 μm, stalk length 4 μm. Relative lengths of flagella (base segments included): F 1 = 100, F 2 = 69, F 3 = 88. Lengths of base segments: bs 1 = 12 μm, bs 2 = 11 μm, bs 3 = 13 μm. F 1 3.3 times as long as t, F 2 and F 3 1.9 and 2.4 times as long as sternal branch s, respectively. Calyces of F 1 largest, conical, those of F 2 and F 3 smaller, subhemispherical.

Trunk. Setae of collum segment not clearly seen. Tergites densely covered with two types of protuberances: large, curved, evenly distributed, spiniform protuberances and small, nipple-shaped tubercles with conical bases (Fig. 8 F-L ). The former distinct and long on marginal parts of tergites (Fig. 8K, L ) but absent on anterior parts of tergites II-VI (Fig. 8G-J ). Tergite I-V each with six open fields without protuberances but with circular tubercles of medium size. Posterior margin of tergites II-V with one regular row of protuberances (Fig. 8A, E, G-J ). One large spine (40 μm) present on the posterior corner of tergite VI (Fig. 8C ). Pattern of marginal protuberances: tergite I: 40; tergite II: T 1-19; tergite III: 7- T 2-l2; tergite IV: 8- T 3-l0; tergite V: (8-10)- T 4-(6-8); tergite VI: 1 spine- T 5-2. Length/width ratio of tergites: I = 0.62, II = 0.35, III = 0.39, IV = 0.41, V = 0.56, VI = 0.32.

Bothriotricha . T 1 and T 2 with thin axes and glabrous proximal parts, medial part with erect, short pubescence, and distal 4/5 with branched hairs arranged in whorls. T 3 shorter than others, club-like, and glabrous (Fig. 8K ). T 4 and T 5 with thin axes and glabrous. Relative lengths of bothriotricha: T 1 = 100, T 2 = 107, T 3 = 50, T 4 = 93, T 5 = 83.

Legs. Legs 1 and 9 both 5-segmented, others 6-segmented. Setae on coxa and trochanter of leg 9 similar to each other, bifurcate, densely annulated, length of secondary branch subequal to primary one. Tarsus of leg 9 thick, tapering, 1.6 times as long as greatest diameter; 2 tergal setae and 1 sternal setae pointed, glabrous; proximal seta length 23 μm, 0.4 times of the length of tarsus (52 μm) and 1.9 times as long as distal seta (13 μm). Main claw 27 μm, 0.5 times as long as tarsus, anterior accessory claw tapering (17 μm). Cuticle of tarsus with minute granules. Tarsus of leg 1 with 1 tergal seta (13 μm) and 1 sternal seta (15 μm), both glabrous and pointed, main claw 27 μm and accessory claw 10 μm.

Pygidium. Tergum. Posterior margin round. Seta a 1 short, cylindrical, pubescent; a 2 and a 3 spiniform, glabrous; a 3 sharply pointed (Fig. 8C ). Lengths of setae: a 1 = 13 μm, a 2 = 17 μm, a 3 = 36 μm. Distance a 1- a 1 = 23 μm, a 1- a 2 = 15 μm, a 2- a 3 = 12 μm.

Sternum (Fig. 8C ). Posterior margin between b 1 with two low, median, rounded lobes. All setae cylindrical, blunt, and pubescent, b 1 with broad base and distal weak swelling, b 2 and b 3 short. Lengths of setae: b 1 = 40 μm, b 2 = 20 μm, b 3 = 20 μm. Distances b 1- b 1 = 32 μm, b 2- b 2 = 60 μm, b 1- b 2 = 28 μm, b 3- b 3 = 10 μm. b 1 1.2 times as long as interdistance, b 2 0.7 of distance b 1 - b 2, b 3 2.0 of interdistance. Styli st slender, cylindrical, pubescent, and curved, 20 μm, st - st = 30 μm.

Anal plate. 1.1 times as long as broad; narrow at base; distal part of plate cleft by narrow, V-shaped incision, depth about half of plate length, incision forming two posterior branches, each carrying two pairs of appendages: submedian pair leaf-shaped, about half length of plate, 2.1 times as long and wide; lateral ones short, pointed and pubescent. Plate glabrous, distal appendages pubescent (Fig. 8C ).

Distribution.

China (Zhejiang), Japan (Honshu, Kyushu).

Remarks.

Eurypauropus japonicus was originally described and known from Honshu and Kyushu, Japan ( Hagino and Scheller 1985; Hagino 1992). The antenna, protuberances, and bothriotricha on tergites, the setae on legs and pygidium, and the shape of the anal plate of Chinese specimens are very similar to E. japonicus , which corroborates the species identity. The main difference observed are: (1) the protuberances on the lateral margin of tergites which are thin and pointed (thick and blunt in types); (2) tergites I-V each with 6 open fields have circular tubercles (eight in types); (3) the bothriotricha T 1 and T 2 are medially with erect, short pubescence and the distal 4/5 have distinct, branched hairs arranged in whorls (distal 1/3 with short pubescence in types). Other minor differences are body size, lengths of setae, bothriotricha, and flagella, which might be due to the variation between populations. In addition, one pair of large spines located on the posterior corner of tergite VI observed in Chinese specimens was not mentioned in the original description of type materials.

Figures

Figure 8. Eurypauropus japonicus Hagino & Scheller, 1985 (Chinese specimen) A habitus, tergal view, on slide B right antenna, tergal view C posterior corner of tergite VI, pygidium and anal plate (arrow indicates the big spine), sternal view D antennal segment III, showing globulus g 2 E Tergite II-IV F tergites I G tergite II, middle part H tergite III, middle part I tergite IV, middle part J tergite V K tergite IV, left side, showing the marginal protuberances and T 3 L tergite V, left side, showing marginal protuberances. Scale bars: 100 μm (A); 20 μm (B-L).