Leiobunum hiraiwai ( Sato & Suzuki, 1939 )

Tsurusaki, Nobuo, 2006, Geographic variation of chromosomes and somatic morphology in the Japanese polymorphic species Leiobunum hiraiwai (Arachnida: Opiliones: Sclerosomatidae), Zootaxa 1325, pp. 157-190 : 160-163

publication ID	https://doi.org/ 10.5281/zenodo.174045
DOI	https://doi.org/10.5281/zenodo.5679671
persistent identifier	https://treatment.plazi.org/id/03B39772-854C-FFA2-E60C-FE5B3B72FE45
treatment provided by	Plazi
scientific name	Leiobunum hiraiwai ( Sato & Suzuki, 1939 )
status

Treatment

Leiobunum hiraiwai ( Sato & Suzuki, 1939) View in CoL

Figs 1–18 View FIGURES 1 A – L View FIGURES 2 A – Q View FIGURES 3 A – I View FIGURES 5 A – E View FIGURES 6 A – E View FIGURE 7 View FIGURES 8 A – E View FIGURES 9 A – E View FIGURES 10 A – E View FIGURES 11 A – F View FIGURES 12 A – F View FIGURES 13 A – G View FIGURES 14 A – F View FIGURES 15 A – G View FIGURE 16 View FIGURE 18

Nelima hiraiwai Sato & Suzuki, 1939: 38 , figs 3–4. (Type locality: Mt Hikosan, Kyushu, Japan).

Liobunum hiraiwai: Suzuki 1953 , figs 4–5; 1957: 109, figs 9–12, 15, 18, 21.

Leiobunum hiraiwai: Suzuki 1966: 160 View in CoL , figs 2F, H: 3F; Tsurusaki & Sasaji 1991: 16, fig. 7C; Tsurusaki 1993: 214; Tsurusaki & Okada 2000: 73, fig. IV11 (left); Tsurusaki 2002a: 92.

Leiobunum hiraiwai hiraiwai: Suzuki 1976: 237 View in CoL , figs 48–50, 110–111, 252–254, 269, 345–347.

Leiobunum hiraiwai izuense Suzuki, 1976: 239 View in CoL , figs 51–52, 112, 256–257, 270–274, 348–350. (Type locality: Mt Yahazuyama, Shizuoka Pref.)

Leiobunum hiraiwai fuji Suzuki, 1976: 241 View in CoL , figs 5358, 113115, 277280, 351352. (Type locality: Lake Yamanaka, Yamanashi Pref.).

Leiobunum hiraiwai shiranense Suzuki, 1976: 244 View in CoL , figs 59–60, 116, 255, 275–276. (Type: ď holotype and 1φ paratype, Shiranesanzan, from Mt Ainodake to Mt Nôtoridake, Yamanashi Pref., Z. Ôshimo leg., 27. August 1953, in ZLHU, examined).

Leiobunum hiraiwai longum Suzuki, 1976: 244 View in CoL , figs 61–64, 117, 261–263, 281–284, 353–355. (Type locality: Mt Hyônosen, Tottori Pref.).

Liobunum tamanum Suzuki, 1957: 113 , figs 1–3, 5–8, 16, 19, 22, 24–25. (Type locality: Mt Bushû Mitake, Tokyo Pref.). NEW SYNONYMY.

Leiobunum tamanum: Suzuki 1976: 232 View in CoL , figs 72–73, 124, 239–244, 340–341; Tsurusaki & Hayashi 1985: 509.

Leiobunum tsushimense Suzuki, 1976: 234 View in CoL , figs 65–66, 245–251, 342–344. (Type: ♂ holotype from Mt Ariakeyama, Tsushima Is., Nagasaki Pref., 7. July 1973, S. Suzuki leg., in ZLHU, examined). NEW SYNONYMY.

Diagnosis. Characterized by the unique shape of the penis shaft with laterally expanded projections (winglets); winglets often barbed (Nos 2–9 in Fig. 16 View FIGURE 16 ). Palps of both males and females often darkened (This character state is only shared by L. curvipalpe Roewer, 1910 ; see Tsurusaki 1990).

Description. Male. With medium to largesized body (3.3–5.9 mm long). Genital operculum as shown in Figs 1C–D View FIGURES 1 A – L , boundary between operculum and 3rd sternite somewhat obscure. Labrum as in Fig. 2 View FIGURES 2 A – Q , clubshaped, laterally with numerous dark tubercles. Chelicera as in Figs 1I –K View FIGURES 1 A – L , second segment with a few black teeth on its distomesal surface. Palp as shown in Fig. 3 View FIGURES 3 A – I ; femur moderately curved ventrad, distolaterally with a few teeth; patella distally widened, with a small but distinct apophysis on mesal distal margin; tibia proximally swollen, ventromesally with numerous dark teeth in distal third; tarsus with a distinct ventromesal row of teeth. Palps often completely ( Figs 3C–F View FIGURES 3 A – I ) or partially ( Fig. 3B View FIGURES 3 A – I ) darkened; degree of the melanism varying geographically (Fig. 4).

Penis as in Figs 8–16 View FIGURES 8 A – E View FIGURES 9 A – E View FIGURES 10 A – E View FIGURES 11 A – F View FIGURES 12 A – F View FIGURES 13 A – G View FIGURES 14 A – F View FIGURES 15 A – G View FIGURE 16 ; shape and size variable among populations; shaft widest at base and gradually narrowing toward apex but expanded distally; lateral projections at distal end of shaft ventrally forming a pair of pouches.

Female. Labrum as shown in Figs 1G–H View FIGURES 1 A – L , gradually tapering. Genital operculum ( Figs 1E–F View FIGURES 1 A – L ) with posterior margin weakly delimited and sharply rounded.

Frequencies of darkcolored and lightcolored palps in males of Leiobunum hiraiwai . The upper left box shows different grades of melanism for palpal patella (Pa) and tibia (Ti) in lateral view, which corresponds to the shading of the circles. 1. Light colored. 2–3. Intermediate condition (corresponding to stippled section of circles). 4–5. Dark colored.

Karyotypes ( Figs 5–6 View FIGURES 5 A – E View FIGURES 6 A – E ). Suzuki (1980) briefly reported the existence of three different karyotypes in “ L. hiraiwai ”, which were easily separable by the number of chromosomes (2n = 18, 20 and 22, respectively). To ascertain this, a total of 99 individuals collected from 19 populations were karyologically analyzed by two methods (squash and airdrying). Provenance of material and the results obtained are synoptically presented in Table 1 View TABLE 1 .

Chromosomes were found to vary in number and in morphology among the populations examined. This phenomenon was already reported by Suzuki (1980). Interestingly, an obvious eastward increase in the number of chromosomes from 2n = 18 (Mt Hikosan population) to 2n = 22 (Mt Bushû–Mitake, Mt Amagi and Mt Kiyosumi populations) was observed (see Figs 7 View FIGURE 7 , 17). Of diploid complement, the X and Y chromosomes were usually the largest or the smallest chromosomes, respectively, although some variants were found. Characteristics of these karyotypes are mentioned in the descriptions of races below.