Clubiona japonica
Creators: name: Dankittipakul, Pakawin
name: Singtripop, Tippawan
Publisher: name: Zenodo
Year: 2008
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Clubionidae
Clubiona
Clubiona japonica

description: The japonica -group
Diagnosis. Infrageneric classification as proposed by Mikhailov (1995) was defined on the base of the Palaearctic fauna. Deeleman-Reinhold (2001) provided a further discussion of species-group limits and relationships on a regional scale, with focus on the Oriental species. Representatives of the japonica -group are easily recognized by general appearance in which carapace and dorsum of opisthosoma are marked with a dark color pattern (Figs 1, 5, 8, 34, 41, 48, 55). For the Thai species treated below there are three teeth situated on promarginal margin of cheliceral fang grooves, middle one largest, and two separated small teeth on retromargin. Male palp is provided with unbranched tibial apophysis (Figs 7, 10, 12, 16); tegulum distinctly with sinuate sperm duct (Figs 6, 9, 11, 15, 20, 22); and the conductor sclerotized (Figs 9, 22). Females are recognized by epigynal atrium situated anteriorly (Figs 13, 17, 24); genital orifices located in a rebordered groove (Figs 2, 39); and membranous bursae being slightly larger than anterior spermathecae (Figs 4, 18, 25).
Taxonomic remarks. Based on examination of the Southeast Asian fauna, the japonica -group can be further divided into two different lineages. Members of a complex including C. melanosticta Thorell, C. melanothele Thorell, 1895, C. suthepica sp. n., C. charleneae Barrion & Litsinger, 1995, and C. scandens Deeleman-Reinhold, 2001 seem to form a monophyletic linage based on the possession of a beak-shaped conductor that is transversely aligned at the apical portion of the bulb (Figs 9, 22). A somewhat similar character has evolved independently in C. picturata Deeleman-Reinhold, 2001 and related species i.e., C. filicata O. P.- Cambridge, 1874, C. biembolata Deeleman-Reinhold, 2001, C. campylacantha sp. n., C. octoginta sp. n., C. submaculata (Thorell, 1891). The monophyly of this group is supported by the possession of a conspicuous apical appendage on the tegulum which is considered as a transformation of the very long, filiform conductor that fuses with the reduced embolus (Figs 6–7, 11–12, 15–16, 20–21, 30–32).
The rather strange vulvae of the japonica -group form one of the most striking features of the taxon. However, the female genitalia of the included species are all very similar, to the extent that species identification on female genitalia alone may well be impossible. The epigyne is characterized by the atrium and atrial margin. In the Thai species described below, the atrium is situated anteriorly on the epigynal plate. The anterior and lateral atrial margins are often rebordered (Figs 13, 17, 24). The genital orifices are near the middle part of the epigyne, situated close to the base of rebordered basolateral atrial margin (Fig. 2) and lead to the short insemination ducts of the vulva (Figs 2–3). The insemination ducts are membranous and almost indistinct; they connect to the anterior portion of the membranous bursae situated posteriorly (Fig. 3). The spermathecae are strongly elongated and highly convoluted (Fig. 4). The spermathecae comprise three distinct parts: spermathecal heads (= an additional appendix of insemination ducts according to Deeleman-Reinhold 2001), stalks and bases (Fig. 4). Spermathecal heads are elongate extensions of the spermathecae that connect to the anterior part of the spermathecal stalks; they expand laterally, gradually narrowing towards terminal ends which are dilated and covered with numerous apical pores (Figs 14, 19, 27). Spermathecal stalks are elongated, often parallel tubular structures. The spermathecal bases are indistinguishable from the stalks and encircle around the fertilization ducts. The fertilization ducts are relatively small and arise from the posteriolateral end of the spermathecae. It seems that obliquely directed tubular spermathecal heads with distally dilated portions, spermathecal bases encircling fertilization ducts and posteriorly situated membranous bursae are plesiomorphic within the japonica -group. The insemination ducts referred by Deeleman-Reinhold (2001) are here considered part of spermathecae. The insemination ducts of the Thai species described below are distinctly short, entirely membranous (Fig. 3) and lead to posterior bursae that open directly to the anterior spermathecae.
description: Published as part of Dankittipakul, Pakawin & Singtripop, Tippawan, 2008, Five new species of the spider genus Clubiona Latreille (Araneae: Clubionidae) from Thailand, pp. 34-60 in Zootaxa 1747 on page 36, DOI: 10.5281/zenodo.181670