Kiusiozonium okai ( Takakuwa & Miyosi, 1949 )

Mikhaljova, Elena V. & Lim, Kil-Young, 2006, New records of the milliped order Polyzoniida from Korean Peninsula, with a redescription of Kiusiozonium okai (Takakuwa & Miyosi, 1949) (Diplopoda), Zootaxa 1256, pp. 59-68 : 61-64

Kiusiozonium okai ( Takakuwa & Miyosi, 1949)

Figs 3–14 .

Saraminozonium okai Takakuwa & Miyosi, 1949: 28 –32, 28–29: fig.1. Saraminozonium okai— Miyosi, 1953: 23.

Kiusiozonium okai— Miyosi, 1959: 55, 223, PL.19: figs 234–234 1111. Kiusiozonium okai— Nishikawa & Murakami, 1991: 293.

Material examined: 8 males, 8 females, 7 juveniles (one male without gonopods, head and telson) (ChNU) from Iksan­shi, Jeollabuk­do, South Korea, collected 2 October1986 by K. ­Y. Lim; 1 male ( IBSS) from Mt. Hakuo­san, 300 m alt., cape Ashizuvi, Tosashimizu­shi, Kochi Prefecture, Shikoku, Japan, collected 3 November 1993 by N. Tsurusaki.

Description. Male. Body 7.5–18 mm in length, 2.7–4.0 mm in width. Body segments varying from 36 to 62 in number. Venter cream­yellowish. Dorsum cream­tannish with two indistinct light­brown longitudinal rows formed by short transverse stripes on the each suture between pro­ and metazonite (specimens from Korea). Or dorsum light tan; each metazonite weakly marbled tan, with thin transverse brown stripe on caudal margin; body perimeter with the exception of telson cream­yellowish (male from Japan). Collum with pair of very light brown marbled subtriangular spots (specimens from Korea) or with brown caudal margin (male from Japan). Eyes black. Legs cream­yellowish. Antennae dark brown. Telson from cream­yellowish to very light brown (specimens from Korea) or brown (male from Japan). Smaller individuals cream­yellowish.

Anterior half of head ( Fig. 3 ) densely setose. Eye patches gently curved, with 4 ocelli. Antennae long, densely setose, in situ reaching to the middle of somite 6. Distodorsal parts of antennomeres 6–7 each with short bacilli (clavate setae) on small knobs ( Fig. 4 ). In addition, tiny bacilli are located in the middle part of antennomere 7. Length ratios of antennomeres 2–7 as 5.0:7.0:4.7:5.7:7.3:1.0, width ratios as 1.1:2.1:2.3:2.3:1.9:1.0, respectively. Collum ellipsoid, much broader than head, overhanging epicranium and at least one pair of ocelli, or not. Body relatively broad, sides not extending laterad. Caudal metatergal margins detached from succeeding tergite, very slightly (large specimens from Korea) ( Fig. 5 ) or sufficiently (male from Japan and small specimens from Korea) ( Fig. 6 ) elevated. In addition, in male from Japan metatergites with tiny setae along caudal margins. Ozopore from somite 6 on set off behind suture dividing pro­ and metazona by a small knob. On somite 5, ozopores located upon suture dividing pro­ and metazona. Ozopores of somite 5 lying at a shorter distance from lateral edge of somite than ozopores of other somites. Telson narrow comprising much less than entire breadth of caudal extremity ( Fig. 7 ). Ventrally, telson with sparse tiny setae and three pairs of more long setae on each pleural bolster.

Legs slender. Leg pair 1 and 2 somewhat reduced in size. Penes short and subconical, located caudoventrad on male coxa 2, extending caudad barely beyond level of leg pair 3, sufficiently segregated ( Fig. 8 ). Tarsal claws of leg pair 1 ( Fig. 9 ) and 2 short and stout. Gonopods small. Anterior gonopods 5­segmented ( Figs 10–11 ). Coxite narrow. Podomere 2 broader. Coxal process simple, entire, and slender with apical setae. Base of the coxal process closely adjacent to telopodite. Podomere 3 of anterior gonopod somewhat broader and longer than other podomeres, with a small setigerous prominence caudally. Podomeres 2–4 setose laterally. The middle part of distal podomere with prominence carrying 2 setae caudally and 1 seta mesally or with more than three such setae. Telopodite apex entire, unciformed, with styloid projections ( Fig. 12 ). Seminal groove opening subterminally. Distal podomere of anterior gonopod extending ventrad, subperpendicular to rest of telopodite. Anterior gonopod sternite broad with sublateral large flat setigerous lobes ( Fig. 13 ). Posterior gonopod terminal podomere long, flagelliform, with an apical deep fovea ( Fig. 14 ).

Female. Body 9.0–23.0 mm in length, 2.9–4.0 mm in width. Telson cream­yellowish. Metatergites without setae along caudal margins; elevations of caudal metatergal margins as in males from Korea.

Remarks. This species, originally described as Saraminozonium okai from the mountain Saraga­Mine, Ehime­ken, Japan ( Takakuwa & Miyosi, 1949) has since been transferred to Kiusiozonium ( Miyosi, 1959) . Miyosi, in the literature review of his publication concerning Japanese Platydesmidae , referred to the original name of this species ( Miyosi, 1953). It is surprising that the review of the millipede fauna of Japan by Takakuwa (1954) did not mention this species. Nishikawa & Murakami (1991), writing on the distribution of Japanese millipedes, refer to this species. The genus Kiusiozonium and the species K. okai are here recorded in the fauna of Korea for the first time.

Hitherto Orsiboe sp., as a member of the family Polyzoniidae or the family Hirudisomatidae , has been recorded in the Mt. Jiri ( Paik, 1960) and Mt. Sokkri ( Paik, 1963), South Korea. However, this species might well be the representative of Kiusiozonium . At least the second author's numerous samples from South Korea do not contain any species of Orsiboe . The true identity of this diplopod is to be ascertained only upon examination of Paik’s samples or fresh material from those territories. It is to be noted that according to the classification by Hoffman (1980), Orsiboe is the member of the family Hirudisomatidae . However, its taxonomic status requires confirmation. The identity of the localities as well as the illustrations and the description proves that Lim (1988) misidentified Kiusiozonium okai specimens from the Iksan­shi, Buan­gun and Dejeon­shi, South Korea as belonging to Orsiboe sp.

The species appears to be rather variable as regards body size, sculpture and coloration of dorsum as well as pilosity of the middle part of the distal podomere of the anterior gonopod. Variations have even been revealed in one individual. Thus, the middle part of left anterior gonopod distal podomere of a Japanese male carries 7 setae while the right one has only 3 such setae. In addition, the left coxal process of the anterior gonopod is smaller than the right one in a Japanese male. Extent of the elevation of caudal metatergal margins varies not only between Korean and Japanese males, but also among specimens from Korea. Metatergites have tiny setae along the caudal margins in the male from Japan only.

Distribution. Japan, South Korea.

Figures

FIGURES 3 – 14. Kiusiozonium okai (Takakuwa & Miyosi, 1949), male. 3, head, anterior view, pigmentation omitted, right part broken; 4, distal part of antenna; 5, midbody segments, male from Korea, lateral view of the dorsum, left side, pigmentation omitted; 6, midbody segments, male from Japan, lateral view of the dorsum, left side, pigmentation omitted; 7, telson and caudal tergites, dorsal view; 8, penes and leg pair 2, caudal view; 9, leg pair 1, caudal view; 10, gonopods, caudal view; 11, gonopods, caudal view, a bit skewed frontally; 12, apex of distal podomere of anterior gonopod; 13, gonopods, anterior view; 14, apex of posterior gonopod terminal podomere (enlarged not to scale); st, anterior gonopod sternite. Scales in mm, Mikhaljova del.