Clubiona bicornis, Yu & Li, 2019

Yu, Hao & Li, Shuqiang, 2019, On further species of the spider genus Clubiona Latreille, 1804 (Araneae, Clubionidae) from Xishuangbanna Rainforest, southwestern China, Zootaxa 4679 (2), pp. 201-230 : 221

Clubiona bicornis sp. nov.

Figs 15–16

Type material. Holotype: ♂ ( IZCAS Ar 34716), CHINA: Yunnan: Xishuangbanna, Mengla County, Menglun Town , Menglun Nature Reserve , Primary tropical seasonal rain forest (N21º55.035′, E101º16.500′, 558 m), 22 July 2007, leg. G. Zheng (Fogging-GZI).

Etymology. The species epithet is a Latin adjective and refers to the two-branched retrolateral tibial apophysis.

Diagnosis. Males of Clubiona bicorn is sp. nov. can be easily distinguished from other members of the C. trivialis -group, with the exception of C. cheni Yu & Li, 2019 ( Yu & Li 2019a: 171, figs 13A–E, 14E–F) by the flat body and similar palp. The palpal organ of C. bicorn is sp. nov. resemble those of C. cheni in having similarly shaped prolateral tibial apophysis, and retrolateral tibial apophysis with a long tip extending to mid length of cymbium, but differ by: (1) retrolateral tibial apophysis branched, both ventral and dorsal branch with sharp tip ( Fig. 15B ) (retrolateral tibial apophysis not branched and with blunt tip in C. cheni ); (2) embolic base bearing only dentiform processes ( Figs 15 A–E) (embolic base bearing two processes in C. cheni ); (3) the wide but indistinct distal tegular hump ( Fig. 15D ) (developed more prominent in C. cheni ).

Description. Male (holotype): Total length 2.49; prosoma 1.09 long, 0.85 wide; opisthosoma 1.23 long, 0.70 wide. Prosoma ( Figs 16 A–C), oval in dorsal view, ocular region slightly narrowed, widest between coxae II and III, in profile almost flat; integument smooth, clothed with numerous short fine hairs. Carapace orange, slightly darker in front, with a pair of unobvious short lines running longitudinally from behind AME. Chelicerae protruding and coloured as carapace, with three promarginal and two retromarginal teeth. Labium reddish-brown, endites orange, both longer than wide. Sternum yellowish-orange. Eyes: in dorsal view, both anterior and posterior eye rows recurved, PER wider than AER.AME dark, other eyes light; with black rings. Eye sizes and interdistances:AME 0.05, ALE 0.06, PME 0.06, PLE 0.05, AME–AME 0.02, AME–ALE 0.16, PME–PME 0.29, PME–PLE 0.08, MOQL 0.04, MOQA 0.09, MOQP 0.35. Legs yellowish-white, without distinct color markings. Leg formula: II, IV, I, III; leg measurements: I 2.24 (0.76, 0.95, 0.33, 0.19), II 2.53 (0.82, 0.95, 0.55, 0.21), III 1.69 (0.54, 0.61, 0.36, 0.18), IV 2.26 (0.66, 0.96, 0.41, 0.23). Opisthosoma ( Figs 16 A–C) elongate-oval, dorsally white with two pairs of indistinct muscular depressions; venter and spinnerets light yellow. Palp ( Figs 15 A–E): tibia short, with two apophyses, PTA digitiform, with a bent and blunt tip; RTA well-developed and forked, ventral branch small and with a row of teeth in retrolateral view, dorsal branch horn-shaped, sharp tip extending to mid length of cymbium; genital bulb elongated, with distinctive, sinuate sperm duct; tegular hump indistinct, fusing with conductor; embolic base bearing a dentiform processes; embolus originating from retrolateral side of tegulum, slender and flagelliform, angled across tegular hump, tip terminating at approximately two o’clock position relative to tegulum; conductor area relatively small, with approximately one-fifth the length of tegulum.

Female: Unknown.

Distribution. Presently known only from the type locality.

Figures

FIGURE 15. Clubiona bicornis sp. nov., male holotype: A–B, left palp (A prolateral view; B retrolateral view); C–E, left palpal bulb (C prolateral view; D ventral view; E retrolateral view). Abbreviatures: C, conductor; E, embolus; EB, embolic base; PTA, prolateral tibial apophysis; RTA, retrolateral tibial apophysis; TH, tegular hump. Scale bars: 0.10 mm (A–B, C–E in the same scale).

FIGURE 16. Clubiona bicornis sp. nov., male holotype, habitus: A dorsal view; B ventral view; C lateral view. Scale bars: 1 mm (A–C in the same scale).