Levizonus circularis Takakuwa, 1942

Mikhaljova, Elena V., 2021, Review of the millipede genus Levizonus Attems, 1898, with description of a new species from the Far East of Russia (Diplopoda, Polydesmida, Xystodesmidae), European Journal of Taxonomy 751, pp. 159-184 : 163-167

Levizonus circularis Takakuwa, 1942

Figs 1–3 , 13

Levizonus circularis Takakuwa, 1942: 43–44 , 44, fig. 8 (holotype or lectotype not designated; number of specimens in the type series unclear; location of types is unknown; type locality: Sangnam-ri, North Korea).

Levizonus variabilis Lokschina & Golovatch, 1977: 76–77 , fig. 3 (holotype ♂, from Olenevod, Lazovskiy District, Primorskiy krai, Russia, in ZMUM). Syn. nov.

Levizonus circularis – Takakuwa 1954: 74–75, 74, fig. 79. — Paik 1958: 362. — Golovatch 1979: 17. — Mikhaljova et al. 2000: 117. — Marek et al. 2014: 72.

Levizonus variabilis – Lokšina & Golovatch 1979: 385. — Kurcheva & Mikhaljova 1980: 120. — Mikhaljova 1981a: 64, figs 2, 4, map (fig. 5); 1981b: 87; 1983: 81; 1990: 136; 1993: 34; 1998: 55, figs 218–223, map 12; 2004: 251, figs 638–650, map 32; 2009a: 5; 2009b: 394; 2017: 301, figs 685–697, map 43. — Mikhaljova & Petukhova 1983: 53. — Ganin 1997: 124; 2009: 153; 2011: 341. — Tanabe 1994: 108; 2002: 2178.

Diagnosis

The main distinguishing characters of the species are as follows: apex of gonopod telopodite ( Fig. 2C ) not like two plates placed perpendicular to each other as in L. malewitschi ; gonopod SL, more or less strongly curved mesad (vs not strongly curved mesad in other congeners); the central edge of the gonopod telopodite apex with outgrowths and spinules ( Fig. 3A–D ) (vs without outgrowths and spinules in other congeners excluding L. thaumasius , L. nakhodka sp. nov. and L. malewitschi ); metaterga with low bosses either everywhere ( Fig. 1 ) or only laterally (vs smooth in other congeners).

Material examined

RUSSIA • 1♂ (holotype of Levizonus variabilis ;unfortunately,the holotype is devoid of gonopods); Primorskiy krai, Lazovskiy District, Olenevod ; 14 Sep. 1968; L.S. Shvetsova leg.; ZMUM 1912 • 1 ♀; Primorskiy krai, Lazovskiy State Nature Reserve, Zvyozdochka Cordon ; 8 Jun. 1979; E.V. Mikhaljova leg.; valley of stream, litter; FSCB 11979 • 3 ♂♂, 3 ♀♀; same locality as for preceding but Quercus forest on the coast near Petrova Island; 9 Jun. 1979; E.V. Mikhaljova leg.; litter; FSCB 21979 • 2 ♂♂, 1 ♀; same locality as for preceding but Sokolovka Cordon ; 11 Jun. 1979; E.V. Mikhaljova leg.; forest, litter; FSCB 41979 • 1 ♂, 3 ♀♀; same locality as for preceding but Amerika Cordon ; 17 Jun. 1979; E.V. Mikhaljova leg.; valley forest, litter; FSCB 71979 • 1 ♂; same locality as for preceding but Pinus koraiensis forest ; 20 Jun. 1979, E.V. Mikhaljova leg.; litter; FSCB 141979 • 1 ♂; same locality as for preceding but in a glade ; 4–5 Sep. 2005; S.Yu. Storozhenko, V.S. Sidorenko, S.K. Kholin and Yu.N. Sundukov leg.; pitfall traps; FSCB 162005 • 2 ♂♂; same locality as for preceding but Korpad Cordon ; 2 Sep. 2005; S.Yu. Storozhenko, V.S. Sidorenko, S.K. Kholin and Yu.N. Sundukov leg.; grass meadow, pitfall traps; FSCB 142005 • 1 ♂; Primorskiy krai, Chuguevskiy District, Verchneussuriiskiy Research Station ; 13 Aug. 1973; G.F. Kurcheva leg.; forest; FSCB 11973 • 2 ♂♂; same locality as for preceding; 21–25 May 2008; S.A. Shabalin leg.; forest; FSCB 212008 • 1 ♂; same locality as for preceding; 27–30 Jun. 2008; S.A. Shabalin leg.; forest; FSCB 222008 • 1 ♂; same locality as for preceding; 21–24 Aug. 2008; S.A. Shabalin leg.; forest; FSCB 232008 • 1 ♂; Primorskiy krai, Lazovskiy mountain range, Shpilka pass, near 1000 m a.s.l.; Aug. 2012; G.N. Ganin leg.; dark coniferous forest; FSCB 292012 .

NORTH-EAST CHINA – Jilin Province • 1 ♂; environs of Baishan town; 30 Aug. 2019; L.A. Prozorova and Guoyi Zhang leg.; FSCB 12019Ch .

Material re-examined (specimen published by Mikhaljova et al. 2000)

NORTH KOREA – Hamgjŏng-namdo Province • 1 ♂; Lake Čangdžin-ho ; 9 Jun. 1965; M. Mroczkowski and A. Riedel leg.; FSCB 11965K .

Description

Male

SIZE. Body 25–30 mm long, 3.3–3.8 mm wide.

COLOUR. Shining whitish.Tergites often patterned with lateral marbled brown spots and transverse brown stripes.

HEAD. Epicranial suture not quite reaching the level of antennal sockets. Lateral excavation of head relatively deep for accommodation of antennae. Antennae rather slender, varying from short (reaching to front edge of ring 2) to long (reaching to front edge of ring 4).

BODY. Metaterga with bosses ( Fig. 1 ) increasingly evident from ring 5 posteriorly, especially so in males in contrast to females and juveniles. The number and location of the bosses varies from a few (or one) only in lateral parts above peritremata to relatively numerous as transverse rows throughout each metatergite ( Fig. 1B ). Paraterga rounded laterally; starting from ring 12–13, they have rounded, though never clear-cut, caudal corners.

TELSON. Caudal dorsal projection with long sparse setae, blunt apically.

LEGS. Each coxa and prefemur of postgonopodal legs distoventrally with a short conical knob becoming spineshaped in coxa toward telson. Coxa of leg 2 with a large setigerous process curved forward and terminating with gonopore.

GONOPODS. Distal part of coxite with three strong setae laterally (two) ( Fig. 2A ) and mesally (one) ( Fig. 2E ). Telopodite laterally with longitudinal striae along almost its entire length. Distal part of telopodite with an external dentiform process (= SL) of different length. SL more ( Figs 2F , 3A–I ) or less ( Figs 2B , 3J ) strongly curved mesad and located lower or higher. Central edge of telopodite apex with outgrowths and spinules of varying shape and size ( Figs 2C , 3 A–J ).

Female

SIZE. Body 25–32 mm long, 3.0–5.0 mm wide, often stouter than in male.

BODY. Metatergal bosses either relatively well developed or traceable, same as in juvenile.

LEGS. Coxa 2 with a small, pointed, setigerous process.

VULVAE. As in Fig. 2G .

Distribution

Russia: Far East (Primorskiy krai); North Korea; North-East China.

Remarks

This species was originally described by Takakuwa (1942) from Zyônanri (modern names: village: Sangnam-ri; county: Yeonweon-gun; province: Pyeongannam-do; North Korea). However the original description is far too fragmentary. That L. circularis might prove to be a senior synonym of L. variabilis has long been suspected ( Golovatch 1979; Mikhaljova et al. 2000). So, the above male from North Korea, kept at FSCB, can be considered as near topotypic, because both localities are only a few airkm away from one another. Unfortunately, information about the holotype of L. circularis could not be found; the holotype is probably lost. Maybe it was deposited in the private collection of Y. Miyosi as Takakuwa’s other xystodesmid samples and was destroyed (see Tanabe 1994). Originally described from Lazovskiy (old name: Sudzukhinskiy) and Kavalerovskiy districts, Primorskiy krai, Russia ( Lokschina & Golovatch 1977), L. variabilis appears to be widespread in and confined to the south-eastern and eastern parts of the Primorskiy krai ( Mikhaljova 2017). The gonopods of L. variabilis are variable ( Mikhaljova 1981a; Mikhaljova et al. 2000). The telopodite apex carries outgrowths and spinules of varying shape and size ( Fig. 3A–D ). The SL is located somewhat lower and less strongly curved mesad in specimens from North Korea ( Fig. 3J ) and North-East China ( Fig. 2A–B ) as compared to that of Russian samples.

Supported by the geographical evidence and the morphological variability of the gonopods of L. variabilis , the following new formal synonym is proposed: Levizonus circularis Takakuwa, 1942 = Levizonus variabilis Lokschina & Golovatch 1977 syn. nov., the valid name being the first.

Levizonus circularis and accordingly its junior synonym L. variabilis have never been recorded from China. The species is new for the Chinese fauna.

Figures

Fig. 1. Levizonus circularis Takakuwa, 1942, ♂, from Russia (FSCB 142005). A. Habitus, dorsal view. B. Midbody rings, dorsal view. Scale bars: A = 2 mm; B = 1 mm.

Fig. 2. Levizonus circularis Takakuwa, 1942, ♂♂, ♀, from China (FSCB 12019Ch) (A–B) and Russia (FSCB 232008, 212008) (C–G). A. Gonopod, lateral view, longitudinal striae are not visible. B. Gonopod apex, lateral view. C, F. Gonopod apex, ventral view. D. Gonopod, lateral view, coxite partially destroyed. E. Middle part of gonopod, mesal view. G. Vulva, mesal view. Scale bars: A, E = 200 μm; D, G = 100 μm; B–C, F = 20 μm.

Fig. 3. Levizonus circularis Takakuwa, 1942, ♂♂, from Russia (A–I) and North Korea(J). A–D. Variations in shape of distal part of gonopod telopodite, ventral view. E–J. Variations in shape of distal part of gonopod telopodite, lateral view. Scale bars: A–D, J = 0.25 mm; E–G = 0.2 mm; H–I = 0.1 mm. A–H: after Mikhaljova 1981a; I: after Lokschina & Golovatch 1977; J: after Mikhaljova et al. 2000.

Fig. 13. Distribution of species of the genus Levizonus Attems, 1898. Filled square: L. circularis Takakuwa, 1942. Filled circle: L. distinctus Mikhaljova, 1990. Open square: L. laqueatus Mikhaljova, 1981. Open triangle: L. nakhodka Mikhaljova sp. nov. Filled triangle: L. malewitschi Lokschina & Golovatch, 1977. Filled diamond: L. thaumasius Attems, 1898. Heart: L. takakuwai (Verhoeff, 1941). Oval: L. montanus (Takakuwa, 1941).