Shikokuobius altaicus, Farzalieva, Gyulli Sh. & Nefediev, Pavel S., 2018

Farzalieva, Gyulli Sh. & Nefediev, Pavel S., 2018, The first record of the anopsobiid genus Shikokuobius Shinohara, 1982 in continental Asia, with the description of a new species from the Altais, southwestern Siberia, Russia (Chilopoda, Lithobiomorpha, Anopsobiidae), ZooKeys 793, pp. 15-28 : 15

Shikokuobius altaicus sp. n. Figs 1-6, 7-13, 14-19, 20-24, 25-29, 30-35, 36-43, 45

Type material.

Holotype ♂ (ZMUM, Rc 7867): Russia, southwestern Siberia, Altai Province, Krasnoshchiokovo District, near Tigirek village, buffer zone of the Tigirek State Nature Reserve, foot of W slope of Mt. Kozyr, 51°09'26.54"N, 83°00'01.59"E, thicket of Padus avium , Lonicera tatarica and Viburnum opulus , 600 m a.s.l., soil sample (30-40 cm deep), 29-30.08.2016, leg. T.M. Krugova, L.Yu. Gruntova, V.V. Zelensky, K.V. Smirnova, A.E. Pupkova, M.N. Terioshkina and R.V. Scherbakova.

Paratypes.

1 ♂ (ZMUM, Rc 7868), 1 ♀ (ZMUM, Rc 7869), together with holotype, soil samples (30-40 cm deep and 0-10 cm deep, respectively); 1 ♀ (PSU-612), Russia, southwestern Siberia, Altai Province, Krasnoshchiokovo District, near Tigirek village, Tigirek State Nature Reserve, Khankhara Site, right bank of Khankhara River, upper part of N slope, 51°11'35.36"N, 82°58'48.26"E, Larix sibirica forest with Betula pendula , 920 m a.s.l., soil sample (20-30 cm deep), 19.08.2016, leg. T.M. Krugova, L.Yu. Gruntova, V.V. Zelensky, K.V. Smirnova, A.E. Pupkova, M.N. Terioshkina and R.V. Scherbakova.

Non-type material.

1 ♂ (PSU-536), [Russia, southwestern Siberia, Republic of Altai, Turochak District], near Lake Teletskoye, environs of Artybash village [51.814745N, 87.278742E, ca 450 m a.s.l.], Betula pendula , Abies sibirica and Pinus sibirica forest, litter, 4-13.07.1982, leg. S.I. Golovatch.

Name.

The specific epithet refers to Altai, the locus typicus.

Diagnosis.

A Shikokuobius species with the body 4-6 mm long, the antennae composed of 15-17 antennomeres, commonly 15; coxosternal teeth large, separated from each other by distances less than width at the base of a tooth; P, F and T of 15 leg relatively short and thick, 15 C with a prominent, acute, mesodistal process; the number of coxal pores varying from 1 to 2 on 12-15 CC (formula 1,1,1,1 in the male and 1,1,1,2 in the female); 15 t and 15 P with bifurcate ventral spines (seldom on legs 13 and 14); at least each leg 15 with a bifurcate spine at the distodorsal end of P; 1-10 tibiae with a distal spinose projection (Figs 7-8, 24); 1-12 tarsi clearly unipartite, claws of 1-14 legs with two accessory spines, claw of legs 15 with a single accessory spine; 1st female gonopodal segment with 2+2 coniform spurs and eight long setae, 2nd with four setae, 3rd with a single seta on the external face; terminal claw simple; male gonopod with four segments including terminal filament.

Distribution

(Fig. 46). Altai Province and Republic of Altai, southwestern Siberia, Russia.

Description.

Holotype ♂. Body ca 4.0 mm long, ca 0.4 mm wide (in 70% alcohol); colour yellow. Tergites: almost smooth, with relatively long and sparse setae, as in Figs 32-33; T 15 indistinct; posterior margin of TT 1, 3, 5, 8, 10, 12 and 14 slightly sinuate; TT 2, 4, 6 7 9 11 and 13 almost straight; intermediate T slightly elongated, as in Fig. 5. Cephalic plate: width/length ratio 0.8 (width 0.4 mm, length 0.5 mm). Antennae short, reaching the middle of T3, composed of 15+15 short moniliform articles (Fig. 13). Ocelli absent; Tömösváry’s organ very large, oval (Fig. 2). The sides of the labrum with poorly-expressed fringes of bristles; a pair of setae projecting across the labral midpiece present (Figs 14-15). Gnathal edge of mandible with 4 pairs of well-developed teeth and 3-4 rather thick aciculae (Fig. 6). First maxillae: edge with 5-6 plumose bristles and simple setae as well (Figs 28, 36). Second maxillary telopodite with simple and plumose bristles on the tip (two plumose bristles on the left and right parts, respectively) (Fig. 20). Forcipulae: dental margin of coxosternite almost straight, with 3+3 teeth and long setiform porodonts, teeth relatively large, separated from each other by distances less than width at the base of a tooth, median diastema V-shaped; shoulders of coxosternite strongly sloping, as in Figs 1, 4; claw as in Figs 18-19.

Tarsal articulation of legs 1-12 indistinct, tarsi distinctly longer than tibiae. 1-10 tibiae with a distal spinose projection, as in Figs 7-8, 24. 1-14 legs with two accessory spines. 14 and 15 legs not incrassate, with long setae (Figs 11-12). 15 leg: P, F and T relatively short and thick (Fig. 11); C ventrally with a long process (Fig. 26); t and P ventrally with bifurcate spines (Figs 11, 21-22); tarsus 2 with a small distodorsal projection (Fig. 11, shown by arrow). 14-13 legs with the same, but less strongly expressed distodorsal projections. Accessory spines on 15 leg small, poorly-developed (Figs 16-17). At least 13-15 legs dorsally with trace of a broken spine or process (Figs 9, 11-12). A single coxal pore on each of 12-15 legs small and rounded (Fig. 3). Gonopods 4-segmented including terminal filament; 1st segment with three, 2nd segment with four long setae on the external face (Fig. 25).

Paratype ♂. Length 4.0 mm, width 0.4 mm. All other characters as in holotype, but coxal process on leg 15 broken off on both legs.

Non-type material ♂. Length 4.9 mm, width 0.5 mm. All other characters as in holotype (Figs 39-40, 42), but antennae with 17+17 articles, first maxillae with at least six plumose bristles (Fig. 37); second maxillae with four plumose bristles; 14 C ventrally with a tiny denticle, as in Fig. 38; 15 P with a bifurcate spine at distodorsal end (Figs 41, 43); 15 leg with a single well-developed accessory spine; 3rd gonopodal segment with two long setae on the external face.

Paratype ♀♀. All characters as in ♂♂. The number of antennomeres in females unknown: one ♀ with antennae completely broken off, while another ♀ with damaged antennae, having 12+7 antennal articles. Coxal pores as in holotype, formula 1,1,1,2 (Figs 34-35). The number of accessory spines unknown: both females had no 15 leg-pairs. Gonopods without setae on internal face, with 2+2 conical spurs and simple claw (Fig. 27). All segments of gonopods with long setae (broken off as in Fig. 27): 1st segment with eight setae, 2nd with four ones, while 3rd with a single seta on the external face of gonopod.

Habitats.

The new species was collected in the lowland Altais in small-leaved and mixed taiga forests at 450 to 920 m a.s.l. (Fig. 45), mainly in soil samples, frequently in deep layers down to 40 cm.

Remarks.

The new species belongs to the genus Shikokuobius Shinohara, 1982 that shows the following synapomorphies: antenna with up to 18 articles, 3+3 coxosternal teeth; spiracles on leg-bearing segments 3, 5, 8, 10, 12 and 14; coxal pores on 12-15 legs; 15 C with a prominent, acute, mesodistal process; 15 t and 15 P with spines, ventrally bifurcated at their tips; at least 15 P with a bifurcate spine at distodorsal end (as some specimens with spines apparently broken off, so these are not visible).

S. altaicus sp. n. is similar to S. japonicus (Murakami, 1967), so far the single species in the genus Shikokuobius , with the above characters. The main differences between them are given in Table 1. Besides this, the new species differs from S. japonicus by: (1) a small distodorsal process on tarsus 2 of legs 13-15 (absent from S. japonicus ); (2) the number of coxal pores (1,1,1,1(2) in S. altaicus sp. n. vs. 2(1),2,2,2 sensu Murakami 1967 and 2,2,2,2(3) sensu Shinohara 1982 in S. japonicus ).

Finally, S. altaicus sp. n. is also rather similar to Ghilaroviella valiachmedovi Zalesskaja, 1975, from the Tajikistan in showing the same body length, simple and plumose bristles on the second maxillae; the number of antennomeres, 1-2 coxal pores, 2+2 spurs and a simple ♀ gonopodal claw. However, S. altaicus sp. n. is well-distinguished from the latter species by: (1) 3+3 coxosternal teeth (vs. 2+2 in G. valiachmedovi ); (2) coxal process well-developed only on leg 15 (vs. on legs 14 and 15 in G. valiachmedovi ) and (3) the absence of small warts at the base of the ♀ gonopodal claw (vs. 2 small warts in G. valiachmedovi ).