Cybaeus melanoparvus Kobayashi, 2006

Sugawara, Yusuke, Ihara, Yoh & Nakano, Takafumi, 2021, A new species of Cybaeus L. Koch, 1868 (Araneae, Cybaeidae) with simple genitalia from central Japan is the sister species of C. melanoparvus Kobayashi, 2006 with elongated genitalia, Zoosystematics and Evolution 97 (1), pp. 223-233 : 223

Cybaeus melanoparvus Kobayashi, 2006 Figures 8 , 9

Cybaeus melanoparvus Kobayashi, 2006: 41-42, figs 53-57; Ihara 2009a: 167, figs 2-2-30-228-230.

Material examined.

Japan • 1 ♂, 1 ♀; Gifu Prefecture, Ibi-gun, Ibigawa Town, Sakauchihirose ; 35°36.77'N, 136°25.16'E; 27 Oct. 2012; N. Koike leg.; KUZ Z3764 • 2 ♂♂, 2 ♀♀; Shiga Prefecture, Maibara City, Mt. Bungen ; 35°30.51'N, 136°23.42'E; 26 Oct. 2012; N. Koike leg.; KUZ Z3765 .

Supplementary description of female spermathecae

(Figs 8F , 9 ). CD, SH, and SS continuous tubular, and similar in diameter from CP through to SB; this duct starting from CP running on ventral side anteriorly, then bending posteromedially and coiling once toward anterior tip; this duct then turning at anterior tip, coiling 2.5 times in the opposite direction, undulating twice on ventral side, and then a half coil to SB; PP located on dorsal side, 1 coil before turning point at anterior tip; SB globular, extending anterolaterally, and expanded at connection with SS; BG well-developed, located dorsally at connection between SS and SB; each FD not running from basal part of SB, but extending from small atrium located beneath SB.

Remarks.

The present specimens were unquestionably identified as C. melanoparvus by features of the male palp and female genitalia; that is, the remarkably developed conductor and complicated tubular spermathecae.

The present study could successfully document the positions of PP and BG in the spermathecae of this species for the first time. Because PPs were located at the dorsal surface of the duct near its anterior tip, this tubular structure, which was referred to as an 'anterior duct’ by Kobayashi (2006), must comprise CD, and also SH and SS.

Figures

Figure 8. Cybaeus melanoparvus Kobayashi, from Mt. Bungen, Shiga Prefecture (KUZ Z 3765), male (A-D) and females (E, F). A. Cymbium of left palp, dorsal view; B. Bulb of left palp, ventral view; PCO, proximal arm of conductor; C. Bulb of left palp, prolateral view; EM, embolus; D. Left palp, retrolateral view; PCO, proximal arm of conductor; RTA, retrolateral tibial apophysis; E. Epigyne, ventral view; PME, posterior margin of epigynal plate; F. Spermathecae, dorsal view; BG, Bennett's gland; FD, fertilization duct; PP, primary pore; SB, spermathecal base; SH, spermathecal head; SS, spermathecal stalk. Scale bars: 500 µm (A-D.); 100 µm (E, F.).

Figure 9. Cybaeus melanoparvus Kobayashi, schematic drawing of epigyne and spermathecae, based on female specimen (KUZ Z 3765). A. Ventral view; CD, copulatory duct; CP, copulatory pore; FD, fertilization duct; PME, posterior margin of epigynal plate; SB, spermathecal base; SH, spermathecal head; B. Dorsal view; BG, Bennett's gland; FD, fertilization duct; PP, primary pore; SB, spermathecal base; SS, spermathecal stalk; SS, spermathecal stalk. Duct from CP to before PP colored in red; duct from PP to before SB colored in blue; SB colored in green. Scale bar: 50 µm.