Clubiona jiandan, 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 : 226-229

Clubiona jiandan sp. nov.

Figs 19–20

Type material. Holotype: ♂ ( IZCAS Ar 34720), CHINA: Yunnan: Xishuangbanna, Mengla County, Menglun Town , Menglun Nature Reserve , Secondary tropical montane evergreen broad-leaved forest (N21º57.784', E101º11.947', 895 m), 6 August 2007, leg. G. Zheng (Fogging-CBI) . Paratypes: CHINA: Yunnan: Xishuangbanna, Mengla County, Menglun Town , Menglun Nature Reserve : 1♂, 1♀ ( IZCAS Ar 34721–34722), Secondary tropical montane ever- green broad-leaved forest (N21º57.809', E101º12.173', 888 m), 4 August 2007, leg. G. Zheng (Fogging-CBIII) ; 1♀ ( IZCAS Ar 34723), Secondary tropical montane evergreen broad-leaved forest (N21º57.767', E101º12.431', 880 m), 6 August 2007, leg. G. Zheng (Fogging-CBII) .

Etymology. The specific name is derived from the Chinese pinyin 'jian dan', which means 'simple', referring to the simple genital bulb and the weakly developed tibial apophysis; adjective.

Diagnosis. Males of Clubiona jiandan sp. nov. resembles those of C. yaoi Yu & Li, 2019 ( Yu & Li 2019a: 152, figs 1A–E; 2A–H) in having a simple palpal bulb with U-shaped sperm duct, transparent, lamelliform conductor, and short embolus ( Figs 19 C–E), but differ by: (1) tibia only with retrolateral apophysis ( Fig. 19B) (with three apophyses in C. yaoi ); (2) retrolateral tibial apophysis unbranched, small and weakly developed ( Fig. 19B) (retrolateral tibial apophysis distally forked and well developed in C. yaoi ); (3) dorsal cymbial apophysis absent ( Figs 19 A–B); (4) embolus cone-shaped and partly membranous ( Figs 19 C–E) (embolus spiniform in C. yaoi ). Females also resemble those of C. yaoi by the general shape of vulva but can be recognized by the oval spermathecae ( Figs 20 B–D) (globular in C. yaoi ), and by the globular bursae ( Figs 20 B–D) (oblong in C. yaoi ).

Taxonomic remarks. Clubiona jiandan sp. nov. possesses several characters associated with the apiculata - group and resembles C. yaoi (the only apiculata -group species recorded from China) for their characteristic genital organs (for a detailed diagnosis, see above). The males of the apiculata -group (known for C. yaoi and four apiculata group species from Borneo reported by Dankittipakul & Singtripop 2014) share the following distinctive suite of characters, here contrasted with the corresponding condition in this new species: (1) the presence of the tubercle at dorsal cymbium ( C. jiandan sp. nov.: dorsal cymbial apophysis absent, Figs 19 A–B); (2) males with at least two palpal tibial apophyses, the retrolateral one usually well-developed ( C. jiandan sp. nov.: tibia only with retrolateral apophysis, RTA small, simple and weakly developed, Fig. 19B). Female closely resembles those of the apiculata - group, in possessing a vulva with ascending copulatory ducts connected to bursae at mid length between copulatory openings and spermathecae, and a pair copulatory ducts lacking convolution. In addition, this new species can be separated from existing members of the apiculata -group by number of ventral spines in tibia I and II, namely two pairs in C. jiandan sp. nov., but three pairs in known apiculata -group species. Nevertheless, considerable uncertainty about placing this new species in the apiculata -group remains. Despite the fact that the general shape of palpal bulb and vulva of Clubiona jiandan sp. nov. is fairly typical of a member of the apiculata -group, it is currently impossible to discern any obvious derived features (i.e., well-developed RTA) that could indicate a close relationship to the apiculata -group.

Description. Male (holotype): Total length 3.55; prosoma 1.74 long, 1.17 wide; opisthosoma 1.76 long, 0.96 wide. Prosoma ( Figs 20 E–F), oval, pars cephalica slightly narrowed, widest between coxae II and III, in profile slightly higher just behind longitudinal fovea, gradually sloping towards pars cephalica; integument smooth, clothed with numerous short fine hairs. Carapace yellowish-orange, without distinct color pattern; fovea reddish. Chelicerae protruding and orange, with five promarginal and three retromarginal teeth. Labium and endites yellowish-orange, longer than wide. Sternum yellowish. Eyes: both AER and PER straight in dorsal view. AME dark, other eyes light; with black rings. Eye sizes and interdistances: AME 0.11, ALE 0.11, PME 0.14, PLE 0.11, AME–AME 0.04, AME–ALE 0.02, PME–PME 0.02, PME–PLE 0.08, MOQL 0.14, MOQA 0.16, MOQP 0.32. Legs yellowish-white, without distinct color markings. Leg formula: IV, I, II, III; leg measurements: I 4.23 (1.27, 1.75, 0.76, 0.44), II 3.51 (0.99, 1.49, 0.66, 0.37), III 2.94 (0.88, 1.03, 0.75, 0.28), IV 4.52 (1.36, 1.55, 1.22, 0.38). Opisthosoma ( Figs 20 E–F) elongate-oval, yellowish-white, dorsum without color marking; venter white; all spinnerets without distinct color marking. Palp ( Figs 19 A–E): Tibia short, with single retrolateral apophysis; RTA small and flat, triangular; genital bulb elongated, with a relatively flat tegulum, sperm duct distinct, U-shaped; embolus, a small cone, originating from apical, prolateral side of tegulum, apex points ventrally; conductor represented by a transparent lamina, originating on apical, retrolateral area of tegulum.

Female (paratype IZCAS Ar 34723): Total length 4.08; prosoma 1.45 long, 1.16 wide; opisthosoma 2.55 long, 1.38 wide. Not strikingly different from males but slightly darker in color ( Figs 20 G–H). Eye sizes and interdistances: AME 0.13, ALE 0.09, PME 0.11, PLE 0.09, AME–AME 0.03, AME–ALE 0.03, PME–PME 0.19, PME–PLE 0.05, MOQL 0.13, MOQA 0.13, MOQP 0.31. Legs yellowish-white, without distinct color markings. Leg formula: IV, II, I, III; leg measurements: I 2.84 (0.72, 1.28, 0.48, 0.37), II 2.97 (0.93, 1.13, 0.57, 0.33), III 2.74 (0.82, 0.92, 0.68, 0.32), IV 3.88 (1.17, 1.32, 1.08, 0.32). Epigyne ( Figs 20 A–D): Epigynal plate longer than wide, posterior margin concaved in the middle; atrium absent; spermathecae, bursae and copulatory ducts prominently visible through epigynal plate in ventral view; two copulatory openings distinctive and large, located at postero-lateral portion of epigynal plate; copulatory ducts ascending anteriorly, connect with spermathecae; spermathecae oval, basolaterally with digitiform head; bursae globular, connected to copulatory ducts at mid length between copulatory openings and spermathecae; fertilization ducts acicular, membranous, located on dorsal-lateral surface of spermathecae.

Distribution. Presently known only from the type locality.