Paracortina zhangi Liu & Tian

Liu, Weixin & Tian, Mingyi, 2015, Two new cave-dwelling species of the millipede genus Paracortina Wang & Zhang, 1993 from southern China (Diplopoda, Callipodida, Paracortinidae), ZooKeys 517, pp. 123-140 : 125-128

Taxon classification Animalia Callipodida Paracortinidae

Paracortina zhangi Liu & Tian sp. n. Figs 1-6, 7, 8-10, 11-14, 15-18, 19-22

Material examined.

Holotype: adult male (SCAU), China, Guizhou, Qianxinan Zizhizhou, Ceheng County, Rongdu Village, Cave Qiaoxia Dong, 24° 03.008N, 105° 43.147E, 964 m, 26.XII.2012, leg. Mingyi Tian, Weixin Liu, Feifei Sun & Haomin Yin. Paratypes. 1 male, 3 females, 10 juveniles (SCAU), same locality, together with holotype.

Description.

Length of adults of both sexes 46-55 mm, width of midbody segments 2.6-3.0 mm, body with 55-58 pleurotergites + telson. Holotype 46 mm long, 2.6 mm wide on midbody segment, maximum width on 6th pleurotergite 3.5 mm, body with 57 pleurotergites + telson. Body coloration light yellow-brownish, anterior part of body slightly lighter. Metazonae slightly darker than prozonae, posterior margin of pleurotergites brownish to dark brown, more infuscate on anterior pleurotergites (Figs 1-7). Head yellowish, epicranial suture distinct, with a large, median, beak-shaped process located between antennae in males, below it densely and finely setose and granulate (Figs 1-2). Edges of genae, posterior margin of the head, and bases of antennae marbled light brown-yellowish. Labrum dark brown. Ocellaria composed of ca. 16-23, dark grey ocelli arranged in four irregular longitudinal rows (Fig. 2). Tömösváry’s organs about 2-3 times larger than an ocellus, placed between ocellaria and base of antenna. Antennae light yellow, rather long and slender, extending behind posterior edge of pleurotergite 6 in males or pleurotergite 3(4) in females when stretched backwards; antennomere length ratios: 2=3>4=5>6>1>7, antennomeres 5 and 6 with a small distodorsal field of fine setae (Fig. 16). Legs light yellow to yellow-brownish, tarsi much darker (Figs 1-7).

Collum much narrower than head, pleurotergite 6 in males strongly enlarged (Fig. 2). Prozonae delicately alveolate-areolate; fine longitudinal striations in front of stricture between prozonae and metazonae. Crests on collum normal, extended forwards from about midlength (Figs 1-2). All crests on the metazonae well-developed, forming 5+5 primary crests, 5+5 secondary crests, and 12-18 lower crests down to ventral pleurotergal edge (Figs 4, 6). 3rd primary crest strongly enlarged. Ozopores starting with pleurotergite 6, present until penultimate pleurotergite, placed on tip of 3rd primary crest (Figs 2, 4, 7). 2+2 primary and 3+3 secondary crests between poriferous crests. Pleurotergal setae 5+5, located at edges of primary crests; setal pattern as in Table 1. Axial line rather distinct (Figs 4, 6).

Male leg-pairs 1 and 2 much shorter, leg-pair 3 slightly shorter than following legs (Figs 1-2). Midbody legs about 4 (male) or 3 times (female) as long as pleurotergite height. Prefemora to a lesser extent, postfemora and tibiae more strongly, but still finely micropapillate ventrally (Fig. 15). Tarsi 1-3 only 1-segmented, from leg 4 to ultimate pair 2-segmented in both sexes; male tarsal pads visible from leg-pairs 3 to 23. All legs ending with a rather slender, long and curved claw (Figs 1, 2, 15). Coxal sacs present from leg 3 to 23. Male coxa 2 with a small anterior process and a posterior gonopore, the latter placed on a small cone. Coxa 7 with a long, subfalcate and apically pointed posterior (f), and a rather strong, pear-shaped anterior process (t) (Fig. 8); f in situ protruding between the gonopods. Coxae of remaining legs normal. Epiproct simple, with about 10 tuberculations in irregular rows (Fig. 6). Hypoproct tripartite, medial sclerite largest, subrectangular, bearing two paramedian macrosetae; each lateral sclerite with a single macroseta. Anal valves smooth, each divided into a small triangle and a large sclerite, both with a pair of macrosetae. Spinnerets comparatively thin and long, ending with a long macroseta (Fig. 5).

Gonopods (Figs 9-10, 17-18) yellow-brown to brown basally, seminal groove and telopodite black brown. Coxa with a large, curved, arch-shaped, anterior process (a) and a rather slender process (b), the latter a little more than half the length of telopodite. Prefemur with a large, clavate process (c) densely covered with long macrosetae. Femoroidal stem long, slender, rather clearly curved, directed cephalad. Telopodite’s terminal part twisted, with a large median (l), and a small lateral lobe (h). Solenomere (s) bifid, parasolenomere (ps) much shorter; seminal groove ending on the longer branch.

Female. Pleurotergites 2 and 3 greatly enlarged. Leg-pairs 1 and 3 with tarsal pads (Figs 11-12). Coxa 3 with a rather small process (m). Prefemora 3 and 4 relatively stout and clearly enlarged (Fig. 12). Leg-pair 2 (Fig. 13) rather strongly reduced down to a pairs of stout, apically shallowly biramous remnants in adult female (Fig. 7), normal in younger ones. Cyphopods small, densely setose, hidden in membranous sacs, divided laterally in the middle (Fig. 14). Coxae 7 normal, without processes.

Etymology.

The species is dedicated to the memory of Mr. Chongzhou Zhang for his contribution to the systematics of Diplopoda in China.

Remarks.

This species is distinguished from its congeners by the presence of 5+5 primary crests, 5+5 secondary crests on the metazonae, two processes on coxa 7 in males, and in certain specific characters of the male gonopods, as well as in the small process on coxa 3, and reduced leg-pair 2 in females.

Distribution.

China: Guizhou (Fig. 46).

The entrance of cave Qiaoxia Dong (Figs 19-22) is located under a bridge in the village of Rongdu. The cave is about 200 meters long, 10 meters wide and 5 meters high. It is rather polluted from sewage water and rubbish. Other animals living in this cave are the ubiquitous diplopod, Oxidus gracilis C. L. Koch, 1847 ( Polydesmida , Paradoxosomatidae ), some ground beetles, crickets (Fig. 19), glowworms (Fig. 20), and spiders, etc.