Sphaeropauropus exilis, Scheller, Ulf, 2014

Scheller, Ulf, 2014, New records of Pauropoda (Myriapoda) with descriptions of new taxa, Zootaxa 3866 (3), pp. 301-332 : 327-329

Sphaeropauropus exilis n. sp.

Figs 71–79

Type specimen. Holotype, ad. 9(♀), Papua New Guinea, Morobe Prov., Mt Kaindi, 2360 m a.s.l., in moss forest, October–November, 1980, A. Allison leg. Type specimen deposited in the Zoological Museum, University of Lund, Sweden.

Diagnosis. Because of the high variability in the descriptive characters and the poor knowledge of the genus in general the relationships to other species are difficult to trace. It may be closest to S. reunionensis Scheller (2003) from Réunion and S. breviglobulatus Scheller (2000) from Nepal because of similarities in the antennae, the bothriotricha T 3 and the cuticular structures of the tergites.

Derivation of name. From the Latin exilis = thin, slender, referring to the shape of the posterior branches of the anal plate.

Description. Length. 1.05 mm.

FIGURES 71–79. Sphaeropauropus exilis n. sp., holotype ad. 9(♀). 71. Left temporal organ. 72. Left antenna, sternal view. 73. Setae and cuticular structure of inner part of tergite I. 74. Posteriomedian part of tergite VI. 75. Setae of left lateral part of tergite II. 76. T3. 77. Seta on coxa of leg 9. 78 Tarsus of leg 9. 79. Pygidium, median part, sternal view..Scale a: 71, 76: b: 72, 77, 78; c: 73–75, 79.

Head (Fig. 71). Temporal organs with marginal pistil as shown in figure.

Antennae (Fig. 72). Chaetotaxy of segments 1–4: 2/2/2 + g´/ 3. Setae of segment 4 of different shape, p thin, in distal half very thin, pointed, p´ and p´´cylindrical, annulated, their relative lengths: p = 100, p´ = 64 and p´´= 42. Tergal branch t somewhat narrower distally than at base, 4.0 times wider than greatest diameter, 1.1 times as long as sternal branch s. That branch 2.6 times as long as greatest diameter, anterodistal corner distinctly truncated, Seta q similar to setae p´ and p´´of 4th segment, only more densely annulated, 0.6 of the length of s, insertion point of q just above the middle of s. Relative lengths of flagella (base segments included) and base segments: F 1 = 100, bs 1 = 27, F 2 = 58, bs 2 = 21, F 3 = 86, bs3 = 18, F 1 2.8 times as long as tergal branch t, F 2 and F 3 1.9 and 2.8 times as long as sternal branch s respectively. Calyces helmet-shaped. Globulus g with distinctly thickened stalk, length of g 2.0 times longer than greatest diameter of g, width as greatest diameter of t, ≈15 bracts, capsule with somewhat flattened bottom.

Trunk (Figs 73–75). Most setae on tergites short, clavate, shortly pubescent, on lateral margins often more longish, subcylindrical (Figs 73–75). Cuticle between setae with short pubescence, on anterior tergites also with small knobs surrounded by dense whorl of pubescence (Fig. 73)

Bothriotricha (Fig. 76). All with simple, thin, axes, T 3 (Fig. 76) thickest, clavate, distally.

thickened part 3.5 times as long as wide and its length reaching about ¼ of the length of the bothriothrix. Relative lengths: T 1 =100, T 2 = 96, T 3 = 79, T 4 = 109, T 5 = 54.

Legs (Figs 77, 78). All legs 5-segmented. Seta on coxa (Fig. 77) and trochanter of leg 9 simple, thin, annulated. Tarsi slender, tapering, those of leg 9 (Fig. 78) distinctly curved, 3.8 times as long as greatest diameter, tergal setae thin, pointed, glabrous, proximal seta 0.3 of the length of tarsus and 2.3 times as long as distal seta. All legs with long, straight main claw, those of leg 9 0.3 of the length of tarsus.

Pygidium (Fig. 79). Tergum: Posterior margin evenly rounded, a -setae and st blunt – slightly pointed, a 2 with short pubescence. All setae on tergum curved inwards, a 2 and a 3 also converging. Relative lengths of setae: a 1 = 10, a 2 = a 3 = 8, st = 11. Tergum glabrous.

Sternum. Posterior margin below anal plate almost straight. Setae tapering, pointed. b 3 annulated, most distal part of b with short pubescence, b 1 an d b 2 curved inwards; relative lengths of setae (pygidial a 1=10): b 1=44, b 2=14, b 3=11; b 1 1.1 times as long as interdistance, b 2 1.2 times as long as distance b 1– b 2, b 3 0.5 of interdistance.

Anal plate discoid with two posteriorly directed tapering submedian branches separated by narrowly V-shaped incision, depth 0.5 of the length of the plate, branches cut obliquely, each branch with narrow inner tooth and clavate appendage, the latter distinctly pubescent, length 0.2 of the length of plate.