Pseudoleiobunum, Suzuki & Ohrui, 1972

Tan, Desmond Kai Teck, Tsurusaki, Nobuo, Fong, Jonathan J. & Zhang, Chao, 2025, Reinstatement of the genus Pseudoleiobunum Müller, 1914 with the inclusion of a new species from Hong Kong and reallocation of the Leiobunum maximum species complex (Arachnida: Opiliones: Eupnoi: Sclerosomatidae), Zootaxa 5646 (3), pp. 301-343 : 315-317

Pseudoleiobunum (superspecies maximum ) japanense japonicum Roewer, 1957

Pseudoleiobunum japonicum Suzuki, 1940: 95 .

Leiobunum suzukii Roewer, 1957: 343 , Figures 12 –13 in Tafel 26 (Type: 2♀ from Yokohama).

Leiobunum bifrons Roewer, 1957: 343 , Figure 14 in Tafel 26 (Type 1♀ from Nagasaki).

Metaliobunum japonicum Suzuki, 1940: 276–279 ; 1960: 22; 1965: 353.

Leiobunum japanense japonicum Suzuki, 1976: 202–204 , Figures 17–22, 96, 147–160; Tsurusaki & Sasaji, 1991: 11, Figure 5B ; Suzuki, 1986:26, Figures 30–31; Kato et al., 2023: 63.

Leiobunum japanense Tsurusaki, 2006: 163 , Figure 8B .

Leiobunum japanense suzukii Crawford, 1992: 30 .

Materials examined. (NT. = N. Tsurusaki). JAPAN, MIE PREF.: Owase City: Yanokawa, Mt. Takamine , 400 m, 2 juv., 25 March 1989, Y. Nishikawa; NE of Yanokawa Pass, 310–380 m, 3 juv., 26 March 1989, Y. Nishikawa — JAPAN, SHIGA PREF.: Otsu City , Katsuragawa-Sakashita-cho, 450 m, 1 juv., 3 October 2011, N. Nunomura; Koka City , Tsuchiyama-cho , Left Bank of Nosugawa Dam , 410 m, 1♀, 27 May, 2012, NT.; Maibara City , Kozuwara , Oku-Ibuki Skiing ground [N35°31.078', E136°22.5867'], 635 m, 1♂, 9 June 2017, NT.— JAPAN, KYOTO PREF.: Fukuchiyama City , Yakuno-cho , Oku-Mizusawa , 1♂ 2♀, 13 July 2002, M. Sasakawa — JAPAN, OSAWA PREF.: Kishiwada City, Mt. Izumi-Katsuragi , 850 m, 2 juv., 28 March 1997, NT.; Ibaraki City, Shobo, Left Bank of R. Ai, 80 m, 10♂ 24♀, 2 June 1994, Y. Nishikawa; Mino-o City: Todoromi, 9 juv., 7 May 2010, H. Anaze et al.; Mino-o Park, Sasagare-no-komichi, ca. 370 m, 3 juv., 26 March 1977, Y. Nishikawa; Higashi-Osaka City, Yamate-cho, Hiraoka Shrine, 1♂ 1♀, 29 May 2005, H. Tanaka — JAPAN, HYOGO PREF.: Shiso City, Haga-cho, Hitsujigadakiguchi, 1♀, 10 June 1990, K. Yamamoto; Shiso City, Oya-cho, Yokoiki-oku, 1♀, 2 August 1990, K. Yamamoto; 1 juv., 3 November 1990, K. Yamamoto — JAPAN, NARA PREF: Gojo City, Nishi-Yoshino-cho, Tentsuji Pass to Mt. Norikura [N34°14.051' E135°44.4341'], 850 m, 1 juv., 19 October 2015, NT.; Yoshino-gun, Totsukawa-mura, Mt. Shaka-ga-dake, Fudo-Kiyadani [N34°6.3368' E135°52.3868'], 1090 m, 3 juv., 20 October 2015, NT.; Kamikitayamamura, Mt. Oda-ga-hara, 1 juv., 26 May 1973, H. Minato; Tanabe City: Mt. Jogamori , 1♂ 2 juv., 4 June 2018, I. Matoba; Ryujin-mura, Mt.Gomadan , 1♂, 15 July2018, I. Matoba;Hongu-cho, Hatenashi Mountains , Higashinokawa- Oku, 1100 m, 1♀, 26 July 1978, H. Minato; Arida-gun, Aridagawa-cho, Mt. Higashidani , 1♂, 24 June 2017, I. Matoba; Mt. Toishi , 1♂, 4 July 2019, I. Matoba; Mt. Shirama , 1♂, 16 May 2019, I. Matoba; Kaiso-gun, Kiminocho: Ta, 250 m, 4♀, 28 February 1994, K. Katsura; Machida, Seminar House, 270 m, 1♂ 1♀, 19 May 2012, R. Yuasa; Nishi-Muro-gun, Ohto-mura, Hyakken Gorge, 3 juv., 2 May 1999, H. Minato; Higashi-Muro-gun, Kozakawacho, Hirai, 1♀, 9 August 1980, H. Minato; Nachi-Katsu-ura-cho, Seigantoji Temple, 340 m, 1♀, 28 July 1983, NT.; Iwade City, Negoro, Genki-no-mori, [N34°17.7167', E135°19.8347'], 1♀, 23 May 2021, Y. Yamamoto — JAPAN, TOTTORI PREF.: Tottori City, Kokufu-cho, Amedaki Falls , 460 m, 1♀, 1 June 1989, NT.; M. Murakami, K. Shimokawa, 440 m, 1 juv., 15 November 2007, NT.; Tottori City, Kawahara-cho, Gobara, 1 juv., 29 October 2010, Yachiyo Enginering; Ochidani, 50 m, 1♀, 27 May 1988, NT.; Mitaki Gorge, 560 m, 1♂, 24 May 1992, M. Murakam; Kitamura, along Midori-shigen Forest Road [N35°23.4038', E134°5.216'], 440 m, 1 juv., 27 March 2017, NT.; Tottori City, Saji-cho, Sanno-daki, Falls, 430 m, 1♂ 2♀, 3 June 2001, NT.; T. Adachi & S. Okada; KItadani, 830– 1200 m, 1♀, 1 June 2002, NT.; Tottori City, Shikano-cho, Mt. Jubo , Kochi to Azogoe, 370 m, 1♂, 14 June 1992, H. Kunimoto.; Tottori City, Shikano-cho, Mt. Jubo , Obata Forest Road, 230 m, 1 juv., 2 May 1992, NT.; 230 m, 1 juv., 18 May 1992, NT.; 230 m, 1♀, 16 June 1992, NT.; Iwami-gun, Iwami-cho, Nagatani, 200 m, 1♀, 18 May 2004, NT. et al.; Kugami, Higashihama, Kanro Shrine [N35°35.9478', E134°21.6338'], 10 m, 1 juv., 28 March 2017, NT.; Yazu-gun, Wakasa-cho, Mt. Hyonosen , Hibiki-no-mori, 850 m, 1♀, 3 August 2003, T. Okada; Yazu-gun, Chizu-cho, Ashizu-kei, Mitaki Dam [N35°16.54', E134°20.4293'], 820 m, 1♂, 3 June 2003, NT.; Ute Pass, 600 m, 1 juv., 9 August 2005, NT.; Mitaki Dam, 720–740 m, 1 juv., 26 November 1989, NT.— JAPAN, SHIMANE PREF.: Izumo City, Tachikue-kyo, 40 m, 1♀, 15 July 1988, NT.— JAPAN, OAKYAMA PREF.: Mimasaka City, Shiramizu, 225 m, 2♀, 22 June 2015, M. Yamada — JAPAN, HIROSHIMA PREF.: Shobara City, Takano-cho, Oka-Ouchi, 1♀, 22 June 2001, S. Okada; Saijo-cho, Misaka, 5 juv., 8 September 2005, S. Nakamura; Oi Pass, Oi Pass Shrine, 640 m, 1♂, 6 August 1990, NT.; Hiroshima City, Asa-kita-ku, Uga-kyo, 2♀, 30 May 1976, NT.; Kure City, Niko-kyo, 50m, 1♂, 17 July 1990, NT.; Hatsukaichi City, Mt. Gokurakuji , 1♀, 25 May 1975, NT.; Yamagata-gun, Aki-Ota-cho, Sandankyo Gorge, 1♂ 1♀, 3 July 1977, NT. & H. Komatsu — JAPAN, TOKUSHIMA PREF.: Tokushima City, Hachimancho, Bunka-no-mori, 1 juv., 25 November 1990, T. Tanabe; Myozai-gun, Kamiyama-cho, Mt. Kumosozan [N33°5 4.7095 ', E134°17.3679'], 1120–1140 m, 2♂, 1 August 1997, NT.; Oe-gun, Kamikawa-ho, Mt. Kotsuzan , 1080–1100 m, 1♂ 1♀ 1 juv., 18 May 1998, NT.; Miyoshi City, Ochiai Pass, 1320 m, 1 juv., 13 October 1994, T. Tanabe; Higashi- Iya, Sano, 1180m, 1♀, 13 July 1991, M. Kamata — JAPAN, KAGAWA PREF.: Zentsuji City, Oasa-cho, Mt. Oasa , ca. 450 m, 1 juv., 14 November 2006, S. Mitani; Kan-nonji City, Mt. Umpenji , 850 m, 1 juv., 16 May 2019, S. Mitani; Sanuki City, Okuboji Temple, 450 m, 1♀, 15 June 2007, NT. & M. Takeuchi; Takamatsu City, Shionoe-cho, Mt. Otaki , 1♂ 1♀, 27 July 2003, S. Mitani; Nakatado-gun, Kotonan-cho, Hirakawa, 1♀, 2 July 2001, S. Mitani; Kotoshira-cho, Mt. Kotohira , 1♂ 1♀, 15 September, 2002, S. Mitani; Chunan-cho, Mt. Onoseyama , 1♂, 14 July 2003, S. Mitani — JAPAN, EHIME PREF.: Matsuyama City, Mt. Takanawa , 1 juv., 5 May 1972, NT.; 1♂, 17 July 2010, R. Ogawa; 960 m, 1 juv., 3 May 1993, NT.; 920 m, 1 juv., 4 April 1994, NT.; Matsuyama City, Mt. Hikijiyama , 900 m, 1♂, 11 August 2001, NT.; Mt. Sugitate , under Sugitate Bridge, 1 juv., 5 May 1970, NT.; Yuyama- Aonami, 2♂, 3 June 1973, H. Tsutsumi; Shuso-gun, Tambara-cho, Kurase, Iwane Shrine, 110 m, 1 juv., 23 April 2000, NT.; To-on City, Mt. Saragamine , Kambayashi, 1♂, 21 July 1972, NT. et al.; Kambayashi, Kambayashi Route, 1 juv., 3 May 1972, NT.; Kami-Ukena-gun, Kuma-kogen-cho, Mt. Saragamine , 1 juv., 23 April 1972, NT.; 3 juv., 29 April 1972, NT., Y. Yaeshima, A. Wake; 3 juv., 14 May 1972, NT & H. Yamashita; 1♂, 4 June 1972, NT. et al.; 950 m, 1 juv., 5 November 1974, NT.; 1♀, 21 May 1986, T. Tanabe; Kuma-kogen-cho, Teppoishigawa, 1♀, 13 August 2000, H. Ishikawa; Bansho-dani, 1♂, 20 August 2000, H. Ishikawa; Kuma-kogen-cho, Mt. Ishizuchi , Tchichigoya to Mt. Iwaguro , 1600 m, 1♂, 5 August 1982, NT.; Mt. Omogo , 1360–1500 m, 3♂ 2♀, 3 August 1982, Y. Sugino; Mt. Okawamine , 1250 m, 1 juv., 5 November 1993, NT.; 1400m, 1 juv., 5 November 1993, NT.; Kita-gun, Uchiko-cho, Oda-Miyama, 800 m, 3 juv., 6 October 1992, E. Yamamoto; 2 juv., 4 May 1994, E. Yamamoto; 800 m, 2 juv., 25 May 1993, E. Yamamoto; Koyayama, ca. 1200–1300 m, 3♂ 4♀, 12 June 1988, E. Yamamoto; Koyayama, 1♀, 2 August 1995, E. Yamamoto; Koyayama, 1♀, 5 August 1995, E. Yamamoto; Namakusa-dani, 8 juv., 1 May 1994, E. Yamamoto; Nakakusa-dani, 2♀, 25 June 1994, E. Yamamoto; Namakusa-dani, 1♀, 20 July 1994, E. Yamamoto; Nakmakusa-dani, 3 juv., 18 October 1994, E. Yamamoto; 1♂ 1♀, 10 June 1994, E. Yamamoto; Namakusa-dani, 1220 m, 4♀, 1 May 1994, NT. & C. Tsurusaki; Natural Forest , 800–900 m, 1 juv., 7 June 1988, E. Yamamoto; Shishigoe, 980 m, 1♀, 23 August 1994, E. Yamamoto; Namakusadani, 3♂ 8♀, 7 August 1995, E. Yamamoto; Namakusa-dani, 3♂ 1♀, 10 August 1995, E. Yamamoto; Masa-goya, 800m, 2 juv., 2 May 1994, NT.; 3♂ 4♀, 5August 1991, E.Yamamoto; 1♂ 1♀, 11August 1995, E. Yamamoto; Kita-gun, Uchiko-cho, Oda: Miyanotani, 400 m, 1 juv., 2 January 1995, E. Yamamoto; 1 juv., 1 April 1992, E. Yamamoto; 400 m, 1♂ 4♀, 10 August 1992, E. Yamamoto; Kita-gun, Hijikawa-cho, Yamatosaka, 1♂ 2♀, 22 June 2004, K. Uyeno; Kita-Uwa-gun, Kihoku-cho, Ogura, Odaru-Medaru Falls , 255 m, 2♂, 28 May 2013, NT.— JAPAN, KOCHI PREF.: Nagaoka-gun, Otoyo-cho, S. Ugi, Yasaka Shrine, 1 juv., 6 April 1994, Y. Murakami; Agawa-gun, Ino-cho, Nanokawagoe, 1♂, 22 June 2011, H. Ishikawa — JAPAN, FUKUOKA PREF.: Tagawa-gun, Soeda-cho, Mt. Hikosan [N33°29.1069', E130°55.8407'], 800 m, 2♂ 1♀, 17 June 2022, NT.; 1100–1199.5 m, 1♀, 30 July 1982, NT.; Asakura City, Mt. Koshozan [N33°29.0169', E130°43.5336'], 850 m, 1♂, 17 June 2022, NT.— JAPAN, NAGASAKI PREF. :: Iki-gun, Ishida-cho, Kuki, 2♀, 3 June 1990, M. Yamashita; Kuki, 1♂, 2 May 1991, M. Yamashita; Kuki, 3♂ 2♀, 25 May 1991, M. Yamashita; Kukishoku, 3 juv., 4 April 1994, M. Yamashita; Kukishoku, 3♂ 11♀, 18 May 1991, M. Yamashita; Kukishoku, 1♀, 8 May 1992, M. Yamashita; Kukishoku, 3♀, 10 May 1992, M. Yamashita; Unzen City, Unzen, Mt. Yadake , Hobaru, 730 m, 1 juv., 29 November 1993, NT. & C. Tusrusaki; Goto City, Is. Wakamatsu, Mt. Ryukan , 120 m, 1 juv., 7 February 2008, K. Okumura; Is. Fukue, Mt. Outou , 80 m, 1♂ 2♀, 9 May 2009, K. Okumura; Is. Fukue, Mt. Chichigadake , 150 m, 2 juv., 14 February 2009, K. Okumura; Is. Fukue, Mt. Chichigadake , 150 m, 5 juv., 2 March 2009, K. Okumura; Matsuura-gun, Shin-Kamigoto-cho, Is. Nakadori, Hifumi-daki Falls , 1 juv., 8 February 2009, K. Okumura — JAPAN, KUMAMOTO PREF: Kikuchi City, Kikuchi-keikoku, 1♂, 29 July 1970, M. Yoshikura — JAPAN, MIYAZAKI PREF.: Mito-gun, Nango-mura, Sasanotoge Pass, 1200 m, 1 juv., 15 November 2012, K. Nishi. Kobayashi City, Suki, along Ayaminami Forest Road, 400 m, 1 juv., 25 July 2012, K. Nishi; 1 juv., 25 December 2012, K. Nishi; Higashi-usuki-gun, Shiiba-son, Mt. Eboshi , 1470 m, 1♀, 16 June 2013, K. Nishi — JAPAN, KAGOSHIMA PREF.: Is. Yakushima, Arakawa, Collision trap, 1200 m, 1 juv., 30 October 2007, T. Yamauchi .

Diagnosis. ( Fig. 2A ) General morphology similar to type species P. japanense japanense but differs in the shape of leg trochanters, the former being unarmed and generally oval in appearance while the latter has two dorsolateral and anterior tubercles on the trochanters ( Suzuki 1976: 202–204, figs 142, 152–155). This species also possesses relatively smaller pedipalpal patellar and tibial apophyses when compared to other species of the Pseudoleiobunum genus ( Suzuki 1976).

Habitat. This subspecies is univoltine and overwinters as juveniles. Adults can be found from May to August. They can be found under logs or stones on well-moistened forest ground or on the wall of wet cliffs along mountain streams, rarely on tree trunks.

Distribution. Widespread in western Japan (Kyushu, Shikoku, Chugoku, Kinki District, West Chubu District) ( Fig. 12).

Notes. Pseudoleiobunum japonicum was first described by Suzuki (1940) as Metaliobunum japonicum based on a male collected from Mt. Ishizuchi, Shikoku as the holotype. Suzuki considered this species and P. japanense japanense Müller, 1914 to be conspecific and redescribed the former as Leiobunum japanense japonicum ( Suzuki 1976) . Crawford (1992) considered the name Leiobunum japanense japonicum a junior homonym of Leiobunum japonicum Müller, 1914 and proposed the replacement name Leiobunum japanense suzukii Roewer, 1957 .

However, upon phylogenetic analysis conducted by Hedin et al. (2012), L. japonicum was found to form a clade with Pseudogagrella amamiana Nakatsudi, 1942 . Therefore, L. japonicum likely should be transferred to Gagrellinae in the future.

By transferring L. japanense japonicum to Pseudoleiobunum , the homonym problem is resolved. Thus, we use P. japanense japonicum , instead of Crawford (1972)’s replacement name L. japanense suzukii , for this subspecies.

Figures

FIGURE 2. Comparisons between Pseudoleiobunum specimens. A–C Comparison of female dorsal bodies between three Pseudoleiobunum species, highlighting features of the genus, yellow rectangle highlighting the small central, dorsal hump on the dorsal scutum; yellow circles highlighting the elevated lateral-posterior edges of the dorsal scute, resembling a pair of tubercles. D–E Comparison of general body size between male and female. F–G Comparison of male and female cheliceral size. A P. maximum distinctum, female. B P. japanense japonicus, female. C P. lutulentum sp. nov, LINGU-INV117, female. D Dorsal view of the female body, LINGU-INV117. E Dorsal view of the male body, LINGU-INV118. F Full lateral view of male chelicera, LINGU-INV72. G Full lateral view of female chelicera, LINGU-INV146. Scale bars: 1 mm.

FIGURE 5. Pseudoleiobunum lutulentum sp. nov., close-up comparisons of femora II under light microscope and scanning electron microscope of leg surface, revealing the granules that are present in the legs of P. lutulentum sp. nov. A Light microscopy of leg II femur, LINGU-INV72. B Light microscopy of leg II femur, LINGU-INV106. C Scanning electron microscopy of the surface of leg II femur, LINGU-INV115. D Close-up of the granules on leg surface, LINGU-INV116. Scale bars: 100 μm for C; 20 μm for D.

FIGURE 8. 28S alignment maximum-likelihood phylogram. Tree rooted using Odiellus pictus OP1063 as outgroup shown.