Bucliona Benoit, 1977

Zhang, Jianshuang, Marusik, Yuri M., Oketch, Ambata D., Kioko, Esther N., Yu, Hao & Li, Shuqiang, 2021, Resurrection of the spider genus Bucliona Benoit, 1977, with a description of a new species from Kenya (Araneae, Clubionidae), Zootaxa 5006 (1), pp. 195-207 : 196-197

Genus Bucliona Benoit, 1977 , status revalidated

Bucliona Benoit, 1977: 68 .

Bicluona Mikhailov, 1994: 52 (described as a subgenus of Clubiona , type Liocranum jucundum Karsch, 1879 ).

Bucliona : Mikhailov 1997: 95 (downgraded to subgenus of Clubiona and synonymized with Bicluona ).

Type species. Clubiona dubia O. Pickard-Cambridge, 1870 from Saint Helena Island, by monotypy .

Diagnosis. Bucliona differs from Clubiona sensu stricto (type species Araneus pallidulus Clerck, 1757 ) by: having a distinct mesal ridge on the male chelicerae ( Fig. 2A, C ) (vs. lacking in Clubiona ); the presence of a dorsal abdominal scutum in males ( Figs 4E, F , 6A, C ) (vs. absent); the undivided, short tibial apophysis of the male palp ( Figs 3B , 5B , 7B–D ) (vs. divided in many species); the presence of a tegular (= median) apophysis and the lack of a meandering sperm duct ( Figs 3B–E , 5A–E ) (vs. lack of a tegular apophysis and presence of a meandering sperm duct); the subtegulum with a prolateral extension ( Fig. 8A ) (vs. without, Figs 8B–F ); the tip of the embolus directed anteriorly or antero-mesally ( Figs 3D , 5D , 7A, B ) (vs. retrolaterally or posteriorly). Females of Bucliona differ from those of Clubiona sensu stricto in having an epigyne with a distinct, undivided epigynal fovea with an anterior hood and a pair of posterior hoods ( Figs 1C, D , 4A, C ) (vs. fovea and hoods lacking) and longer copulatory ducts ( Fig. 4D ). Both the males and females of Bucliona can be recognized by the anterior tibiae with a prolateral “scopula”, which is reduced to a single row ( Fig. 2D–F ) (vs. dense scopula ventrally on the anterior tibiae).

Description. Medium to large size, with the body length of males 4.90–7.75 and of females 6.50–9.50.

Male. Body yellow-brown, legs uniformly coloured as carapace ( Figs 4E, F , 6A–C ). Carapace ( Figs 4E, F , 6A, C ): elongate-oval, widest at midpoint, pars cephalica slightly elevated above thorax, pars thoracica distinctly wider and slightly higher than pars cephalica; integument smooth; distinctly darker in ocular region, without distinct pattern; cervical groove and radial grooves distinct; fovea a short slit on posterior half of carapace, longitudinal and reddish. Clypeus height distinctly narrower than AME ( Figs 2A, C ). Chelicerae ( Figs 2A, C , 4E, F , 6A–C ): robust and red brownish, consisting of a coniform paturon and claw-shaped fang; cheliceral paturon with distinct mesal ridge, distally with several setae; fang furrow with 3 promarginal and 2 retromarginal teeth. Both endites and labium longer than wide; endites depressed posteriorly, slightly convergent anteriorly, with dense scopulae on inner margin; labium nearly trapezoidal and depressed laterally ( Fig. 6B ). Sternum ( Fig. 6B ): shield shaped and brown, longer than wide, anteriorly straight; posterior region protruding strongly between coxae IV. Eyes: in dorsal view, AER slightly recurved, PER almost straight ( Figs 4E , 6A ); in anterior view, AER almost straight, PER slightly recurved ( Figs 2A, C ); AME very slightly smaller than ALE, or equal in diameter, AME closer to ALE than to each other; in dorsal view, PME and PLE nearly equal in diameter, well-separated, PME located about 2–3 diameters apart, PME–PLE distance ca. 2/3 PME–PME distance. Legs: leg formula 4213; anterior legs with conspicuous scopulae disto-prolaterally on tibiae, and entire metatarsi and tarsi ( Figs 2D, F ); anterior femora with 3‒5 dorsal spines, posterior femora with 5‒7 dorsal spines; all patellae with 0‒1 dorsal or retrolateral spine; tibiae I‒II with 2 or 3 pairs of ventral spines, 1 retrolateral, and 1 prolateral spine; metatarsi I‒II with 1 or 2 pair of spines, 1 retrolateral, and 1 prolateral spine; tibiae and metatarsi of posterior legs with more spines than anterior legs but spination varies among different individuals. Abdomen ( Figs 4E, F 6A–C ): elongate-oval, tapering posteriorly, dorsal scutum over 3/4 of length of abdomen; without distinct colour patterns in the type species and B. jucunda (with median band and chevrons in B. kirilli sp. n., see description below).

Palp: femur and patella unmodified, tibia cylindrical with single, unbranched retrolateral apophysis (RTA), apophysis shorter than diameter of tibia; cymbium unmodified, lacking spines; bulb elongate-oval; subtegulum (ST) with characteristic prolateral extension ( Figs 3A, C , 5A, C , 8A ); sperm duct not meandering, U-shaped in ventral view of tegulum; tegulum with well-developed hook-shaped distal apophysis (TA); embolus helical, originating prolatero-distally, either filamentous and wrapping around dorsal side of tegulum ( B. kirilli sp. n.) or shorter, tip directed either anteriorly ( B. dubia ) or antero-mesally ( B. jucunda ).

Female. General characters as in males, from which the females differ by (1) the cheliceral base without a mesal ridge ( Fig. 2B ); (2) the abdomen without a scutum ( Figs 1A , 4G ); and (3) a denser “scopula” on anterior legs ( Fig. 2E ). Epigyne: epigynal plate with large fovea, located posteriorly, with 1 anterior (AH) and 2 posterior hoods ( PH); copulatory openings (CO) small and indistinct, located in central portion of fovea; copulatory ducts (CD) hyaline, strongly convoluted; receptacles (R) small and located posteriorly; bursae (BS) situated anteriorly, balloon shaped, larger than receptacles.

Composition. Bucliona dubia ( Saint Helena Island), B. kirilli sp. n. ( Kenya), and B. jucunda (Far East Russia, China, Korea, Japan).

Figures

FIGURE 1. Bucliona dubia, holotype female: A–B habitus, dorsal and ventral; C–D epigyne, ventral. Abbreviations: AH, anterior hood; PH, posterior hood; Scale bars: A–B 1 mm; C–D 0.25 mm.

FIGURE 2. Somatic characters of Bucliona jucunda (A, B, D, E) and B. kirilli sp. n. (C, F): A, C male prosoma, frontal; B female prosoma, frontal; D male leg I, prolateral; E–F female leg I, prolateral. Arrows (A, C) point at mesal ridge of male chelicera; Arrows (D–F) point at scopula on the distal part of the tibia. Scale bars: 1 mm.

FIGURE 3. Left male palp of Bucliona jucunda. A–B prolateral and retrolateral; C–E bulb, prolateral, ventral, and retrolateral. Abbreviations: E, embolus; EB, embolic base; RTA, retrolateral tibial apophysis; ST, subtegulum; TA, tegular apophysis. Scale bars: 0.2 mm.

FIGURE 4. Epigyne (A–D) and somatic characters of Bucliona jucunda. A–B macerated epigyne, ventral and dorsal; C–D epigyne, macerated and embedded inArabic gum, ventral and dorsal; E–F male habitus, dorsal and lateral, arrows point to dorsal abdominal scutum; G–H female habitus, dorsal and ventral. Abbreviations: AH, anterior hood; BS, bursa; CD, copulatory duct (dashed line in D showing schematic course of copulatory duct, dorsal); CO, copulatory opening; FD, fertilisation duct; PH, posterior hood; R, receptacle. Scale bars: A–D 0.2 mm; E–H 2 mm.

FIGURE 5. Male palp of Bucliona kirilli sp. n. holotype: A–B prolateral and retrolateral; C–E bulb, prolateral, ventral, and retrolateral. Abbreviations: E, embolus; EB, embolic base; RTA, retrolateral tibial apophysis; ST, subtegulum; TA, tegular apophysis. Scale bars: 0.2 mm.

FIGURE 6. Habitus of the holotype of Bucliona kirilli sp. n. A dorsal; B ventral; C lateral.Arrows indicate the dorsal abdominal scutum. Scale bar: 2 mm.

FIGURE 7. Comparison of the male palp of Bucliona kirilli sp. n. (A, C) and B. jucunda (B, D). A–B ventral; C–D RTA, dorsoretrolateral. Abbreviations: E, embolus; RTA, retrolateral tibial apophysis; ST, subtegulum; TA, tegular apophysis. Scale bars: 0.2 mm.

FIGURE 8. Bulb of Clubionidae spp. in prolateral view, showing subtegulum (ST) in Bucliona and in different Clubiona species groups.A Bucliona kirilli sp. n., arrow points to extension of the subtegulum (ST); B Clubiona theoblicki, C. hatamensis group; C C. subasrevida, C. trivialis group; D C. moralis, C. corticalis group; E C. filicata, C. filicata group; F C. yaoi, C. milingae group. Scale bars: A, B, D, E 0.2 mm, C, F 0.1 mm.