Samarangopus zhongi, Bu, 2020

Bu, Yun, 2020, Study on the Pauropoda (Myriapoda) from Tibet, China - Part II: New species and new record of the genus Samarangopus, ZooKeys 927, pp. 53-64 : 53

Samarangopus zhongi sp. nov. Figures 1 , 2 , 3

Material examined.

Holotype, male adult with 9 pairs of legs (slide no. XZ-PA2015004) (SNHM), China, Tibet, Motuo county, Dexing town, extracted from soil samples in a broad-leaf forest, alt. 1100 m, 29°40'N, 95°26'E, 3-XI-2015, coll. Y. Bu. Paratypes, 5 male adults with 9 pairs of legs (slides no. XZ-PA2015001, XZ-PA2015006, XZ-PA2015052, XZ-PA2015056, XZ-PA2015057) (SNHM), 3 female adults, with 9 pairs of legs (slides no. XZ-PA2015005, XZ-PA2015024, XZ-PA2015054) (SNHM), same data as holotype. Other material, 1 juvenile, with 6 pairs of legs (slides no. XZ-PA2015051) (SNHM), same data as holotype.

Diagnosis.

Samarangopus zhongi sp. nov. is characterized by one pair of spiniform appendage on sternum of last trunk segment, 28-34 marginal protuberances on tergite I, the distal quarter of bothriotricha T 3 golf-club-shaped, and the leaf-shaped seta st on tergum of pygidium.

Description.

Adult body length (0.62-) 0.69 (-0.75) mm (n = 9); body yellow to brown (Figs 1A , 3A ).

Head (Figs 1D , 3E ) setae strongly reduced, dorsally with first row setae a 1 and 1 pair of lateral setae, other setae absent. Temporal organs rectangular in tergal view, length 0.9 of shortest interdistance, glabrous. Tiny pistils present laterally.

Antennae (Figs 1E , 3C ). Chaetotaxy of segments 1-4: 2/2/2( g’)/3. Setae thin, cylindrical, striate, length of seate on segment 4: p =14 (-15) μm, p ' =14 (-17) μm, p' ’’ =12 (-15) μm; u and r absent. Tergal branch t cylindrical, (2.1-) 2.6 times as wide as greatest diameter and 1.0 (-1.1) times as long as sternal branch. Sternal branch s with distinct anterior indentation at level of F2, 1.9 (-2.3) times as long as greatest diameter, anterodistal corner distinctly truncate. Seta q similar to setae of segment 4, 15 (-17) μm, (0.9 of-) 1.1 times as long as the length of s. Globulus g with conical stalk, length of g (8-10 μm) 1.7 (-1.8) times as long as its greatest diameter; the latter 0.3 (-0.4) of greatest diameter of t; 10 bracts, capsule spherical, diameter = 4-5 μm; stalk length 4-5 μm. Relative lengths of flagella (base segments included): F 1 = 100, F 2 = 48 (-55), F 3 = (78-) 84 (-89). Lengths of base segments: bs 1 = (10-) 12, bs 2 = 5 (-7), bs 3 = 10 (-11) μm. F 1 (4.1-) 4.4 times as long as t, F 2 and F 3 (1.9-) 2.3 and (3.2-) 3.7 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 similar, furcate, branches tapering, pointed; main branch striate; secondary branch rudimentary, glabrous; both setae length 10 (-11) μm (Fig. 2A ). Appendages barrel-shaped; caps flat (Fig. 2A ). Sternite process broad and low, with anterior V-shaped incision. Tergites densely covered with protuberances (Figs 1A-C , 3D, L ). Three main types of protuberances observed: large and stalked protuberances present on anterior margin of tergite I and lateral margins of I-VI; smaller fungiform protuberances with transparent hat and subcylindrical foot; small cylindrical cuticular structures with distal candle flame-like vesicle surrounded by circular collar. Cuticles between these structures coarse. Number of marginal protuberances: I, (28-) 34; II, 1 small- T 1-1 small-(9-10); III, 1 small-7- T 2-l small-7; IV, 1 small-(7-8)- T 3-l small-5; V, 1 small-(7-9)- T 4-1small-3; VI, (6-8)- T 5-l. Length/width ratio of tergites: I=0.56 (-0.6), II=0.35 (-0.37), III and IV = 0.38 (-0.43), V = 0.45 (-0.48), V = (0.54-) 0.57 (Fig. 1A ). Sternum of last trunk segment with one pair of blunt, spiniform, pubescent posterior appendages (Figs 2B , 3I ), 23 (-26) μm in length.

Bothriotricha . All with thin axes and short almost erect pubescence, T 1, T 2, T 4, and T 5 with distal part curled (Fig. 1G ), T 3 shorter than others, with thicker axis and distal quarter flat, golf-club-shaped, densely pubescent (Figs 1F , 3L ). Relative lengths of bothriotricha: T 1 = 100, T 2 = (91-) 94, T 3 = (45-) 53, T 4 = (100-) 106, T 5 = 112 (-115).

Legs. All legs 5-segmented. Setae on coxa and trochanter of leg 9 similar to each other, thin, furcate, striate, with glabrous base, length of secondary branch 0.7 (-0.8) of primary one (Figs 1H , 3J ). On more anterior legs these setae similar to those of collum segment (Fig. 3G ); Tarsi tapering, those of leg 9 (1.9-) 2.5 times as long as greatest diameter; proximal seta striate 11 μm, (0.4-) 0.5 of the length of tarsus (22-28 μm) and (1.7-) 2.0 times as long as distal glabrous seta (5-6 μm) (Figs 2F , 3H ). Cuticle of tarsus glabrous (Fig. 3F-H ). Tarsus of leg 1 with only glabrous distal seta (Fig. 2E ). All legs with large main claw and small setose anterior secondary claw, the former on those of leg 9 0.5 of tarsi. On anterior side of femur of leg 1 with 1 blunt granulated appendage (Figs 2G , 3F ).

Genital papillae (Figs 2H , 3K ). Base segments cylindrical. Length of papillae = 25 (-28) μm, greatest diameter =15 (-16) μm, length of seta= 9 (-11) μm. Proximal part of genital papillae subcylindrical, distal part conical, seta 0.4 (-0.5) of length of papilla. Cuticle glabrous. Coxal seta of leg 2 same as on leg 1 (Fig. 3G, K ).

Pygidium. Tergum (Fig. 2C ). Posterior margin with 2 lateral triangular appendages between a 2 and a 3. Setae annulated, a 1 and a 2 somewhat clavate, the former curved inwards and the latter almost straight; a 3 straight, cylindrical, somewhat tapering, diverging; st leaf-shaped, glabrous. Lengths of setae: a 1= a 2 =5 μm, a 3 = 10 (-12) μm, st = 8 (-9) μm. Distances a 1- a 1=6 (-8) μm, a 1- a 2=5 (-6) μm, a 2- a 3=(4-) 5 μm, st - st =(8-) 10 μm.

Sternum (Fig. 2D ). Posterior margin between b 1 straight. Setae thin, tapering, distally striate, pointed. Lengths of setae: b 1= (25-) 28 (-30) μm, b 2=17 (-20) μm, b 3= (11-) 13 μm. Distance b 1- b 1= (26-) 27 μm, b 2- b 2= 45 (-47) μm, b 1- b 2=15 (-16) μm, b 3- b 3= (18-) 20 μm. b 1 1.0 (-1.3) times as long as interdistance, b 2 (0.9 of-) 1.1 times as long as distance b 1 - b 2, b 3 (0.6-) 0.7 of interdistance.

Anal plate (Figs 2D , 3B ) (2.1-) 2.2 times as long as broad, tapering posteriorly; lateral margins with a pair of thin, diverging, cylindrical, distal part faintly inflated, pubescent branches which are (0.3-) 0.4 of the length of plate; posterior 2/5 of plate divided into 2 tapering branches by a narrow V-shaped incision, each branch with 2 appendages: a submedian short, straight, tapering, glabrous one and a stalked bladder of triangular shape in sternal view. Bladder-shaped appendages (0.6-) 0.7 of length of plate. Plate glabrous, bladder-shaped appendages with short erect pubescence.

Etymology.

The new species is dedicated in honor of the late Professor Zhong Yang (1964-2017) who was an eminent botanist from Fudan University and Tibet University, for his great contribution to the knowledge of flora and biodiversity of Tibet. This study is also to express my great gratitude to his help.

Distribution.

Known only from the type locality.

Remarks.

Samarangopus zhongi sp. nov. can be easily distinguished from all other congeners by the presence of the one pair of spiniform appendages on the sternal side of last trunk segment. It is most similar to S. campanulatus Scheller, 2004 from Vietnam in the shape of anal plate, the chaetotaxy of pygidium and the protuberances on the body. It can be distinguished from S. campanulatus by: the spiniform appendages on the sternum of last trunk segment (present in S. zhongi sp. nov. vs absent in S. campanulatus ), shape of bothriotricha T 3 (distal quarter golf-club-shaped, densely pubescent in S. zhongi sp. nov. vs distal 2/5 part clavate, end-swelling in S. campanulatus ), shape of seta st on tergum of pygidium (leaf-shaped in S. zhongi sp. nov. vs lanceolate in S. campanulatus ), the shape of proximal seta on tarsus 9 (striated in S. zhongi sp. nov. vs glabrous in S. campanulatus ), and the shape of appendage on the femur of leg 1 (broad triangular in S. zhongi sp. nov. vs blunt cylindrical in S. campanulatus ). The shape of posterior appendage on anal plate of the new species is also similar to S. tuberosus Scheller, 2007 from Singapore and S. cylindratus Scheller, 2009 from Indonesia. The new species differs from S. tuberosus in the shape of setae b 2 on pygidium (slender and pointed in S. zhongi sp. nov. vs large and lanceolate in S. tuberosus ). It differs from S. cylindratus in the shape of appendages of the collum segment (barrel-shaped in S. zhongi sp. nov. vs cylindrical and large in S. cylindratus ).

Figures

Figure 1. Samarangopus zhongi sp. nov. (holotype) A body, tergal view B tergite I, right side C protuberances on posterolateral corner of tergite I, right side D head, anteriodorsal view E left antenna, tergal view F T 3 G T 5 H setae on coxa (left) and trochanter (right) of leg 9. Scale bars: 20 μm.

Figure 2. Samarangopus zhongi sp. nov. (holotype) A collum segment, sternal view B sternum of the last trunk segment, show spiniform appendages C tergum of pygidum D sternum of pygidum and anal plate E tarsus of leg 1 F tarsus of leg 9 G femur of leg 1 with appendage H male genital papillae. Scale bars: 20 μm.

Figure 3. Samarangopus zhongi sp. nov. (holotype) A habitus, sternal view B anal plate C right antenna, sternal view D anterior margin of tergite I E head, tergal view F leg 1, arrow shows appendage on femur G setae on coxa and trochanter of leg 1 H tarsus of leg 9 I last trunk segment, arrows show one pair of appendages, sternal view J setae on coxa and trochanter of leg 9 K male genital papillae and coxa of leg 2 L right side margin of tergite IV and T 3. Scale bars: 100 μm (A); 20 μm (B-L).