Schizotergitius altajicus Loksa, 1978

Dyachkov, Yu. V., Farzalieva, G. Sh. & Dányi, L., 2021, On the centipede genus Schizotergitius Verhoeff, 1930, with a redescription of Schizotergitius altajicus Loksa, 1978 and a key to the genera of the family Lithobiidae in Central Asia (Chilopoda: Lithobiomorpha), Russian Entomological Journal 30 (3), pp. 361-371 : 364-371

publication ID

https://doi.org/ 10.15298/rusentj.30.3.16

persistent identifier

https://treatment.plazi.org/id/B3548B73-1857-2C41-FEC8-FEB07845FB4C

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Felipe

scientific name

Schizotergitius altajicus Loksa, 1978
status

 

Schizotergitius altajicus Loksa, 1978 View in CoL

Figs 1–53 View Fig View Figs 2–8 View Figs 9–18 View Figs 19–29 View Figs 41–49 View Figs 50–57 .

Schizotergitius altajicus Loksa, 1978: 116–118 View in CoL , figs 10–19.

Schizotergitius altajicus View in CoL forma gracile (sic!) Loksa, 1978: 118.

Schizotergitius altajicus View in CoL — Eason, 1986a: 190.

Schizotergitius altajicus View in CoL — Dyachkov, 2017: 35 View Cited Treatment .

Schizotergitius View in CoL — Farzalieva et al., 2017: 124, table 1.

DIAGNOSIS. The species differs from S. longiventris by the smaller size (12–21 mm vs. 22.5– 25 mm in S. longiventris ), body colouration (yellow or brownish yellow vs. a greybrown body with a darker head in S. longiventris ), the presence of DCa on 15 legs (vs. absent in S. longiventris ), as well as the number of dorsal spines on 13P (three dorsal spines vs. a single dorsal spine on 13P in S. longiventris ).

BRIEF DESCRIPTION. A medium-sized (12–21 mm) Lithobiinae with 5–6 ocelli in a single broken row, Tömösváry´s organ smaller than the nearest ocelli; usually 20 antennal articles (rarely 17–22); forcipular coxosternite with 2+2 acute teeth and setiform porodonts; TT 3, 5, 8, 10, 12 with posterior median notches, SS elongated (excluding genital S); legs 1–13 with functionally biarticulate tarsi; legs 15 without accessory spines; DCa present on legs (11)12–15; number of coxal pores, 2–4 on legs 12–15; ♂ 15F (sometimes 15P) showing more or less evident, indistinct, wide, dorsal and/or dorsolateral sulci, 15Ti with a dorsal or dorsolateral sulcus and a dark blot in distodorsal part covered with numerous setae; ♂ gonopod 1-segmented with 2–4 setae; ♀ gonopod with 2+2 gonopodal spurs and a simple, curved and pointed claw, 1 st segment without dorsal setae (rarely with 1), 2 nd segment with a small, translucent, distodorsal outgrowth shifted mesad ( Figs 28 View Figs 19–29 –30) and 4–6 dorsal setae, 3 rd segment with 2–4 dorsal setae (Figs 31–33, 36–37).

MATERIAL. Type material: paratypes: 12 ♂♂, 10 ♀♀ [vs. 11 ♂♂, 11 ♀♀, 4 juv. in the original description] ( HNHM chilo-7558) (one ♂ with postpedal segments, forcipules, the left ocellar field, T7 , left 1 st and right 14–15 th legs missing, probably removed and mounted on slides which could have served for Loksa´s [1978] illustrations, but no such slides could be relocated], [ Mongolia, Govi-Altai Aimag, Mt. Range, 10 km S Somon Cogt, ca. N45°20´, E96°38´] “ Gobi Altaj Gebirge, 10 km S. von Somon Cogt, am Pass, 2500 m, 27.VI.1966 (Nr. 589)”; Schizotergitius altajicus f. gracile Loksa, 1978, types: 3 ♀♀ [♀ holotype, 1 ♂ and 1 ♀ paratype, according to the original description, but no holotype selected and labeled in the material] ( HNHM chilo-7559), [ Mongolia, Govi-Altai Aimag, between Lake Beger-Nuur and Somon Beger, ca. N45°44´, E97°09´] “zwischen dem See Beger Nuur und Somon Beger , 1400 m, 25–26.VI.1966 (Nr.579)”. GoogleMaps

Other material: Mongolia: 4 ♀♀ ( ASU No. 295), Bayan-Ölgii Aimag, Buratyn-Davaa Pass , N48°28´, E90°27´, mountain stony steppe, 2600 m, 24. VI.2015, coll. AF, OB, DN GoogleMaps ; 8 ♂♂ ( ASU No. 320), 24. VI 2015, coll. AF, OB, DN ; 1 ♂, 1 ♀ ( ASU No. 41), Khovd Aimag, Sutai-Uul Mt. Range, Mt Zamlyn-Bogt , scree, N46°39´, E93°42´, 3810–3860 m, coll. AF GoogleMaps ; 2 ♂♂, 1 ♀ ( ASU No. 42), Bumbat- Khayrhan-Bogt Mt. Range, Mt Degnuul , stony alpine meadow, N47°12´, E93°08´, 3000–3200 m a.s.l., 24. VI.2017, coll. AF GoogleMaps ; 1 ♂, 2 ♀♀ ( ASU No. 296), Baitag-Bogd-Uul Mt. Range, Gushoot-Shyneetiyn-Gol River Valley , N45°16´, E91°04´, 1900 m, 23. V.2015, coll. VD, AK GoogleMaps ; 2 ♂♂, 1 ♀ ( PSU No. 685), N45°15´, E91°03´, 1900 m a.s.l., 24. V.2015, coll. RY GoogleMaps ; 2 ♂♂ ( ASU No. 293), Dzhargalant-Khairkhan Mt. Range, near source of Ar-Shaatyn-Gol River , mountain stony tundra, N47°43´, E92°29´, 3300–3500 m a.s.l., 25. VI.2015, coll. AF GoogleMaps ; 1 ♂ ( ASU No. 294), Ikh-Khavtag-Uul Mt. Range, near Zhugentiyn Spring , N45°04´, E92°13´, mountain stony steppe with rocks, 2050– 2300 m a.s.l., 30. VI –2.VII.2015, coll. AF GoogleMaps ; 1 ♂ ( PSU No. 668), Ikh-Khavtag-Uul Mt. Range, near Yargaytiyn-Sayr Ravine , mountain stony steppe with rocks, N45°04´, E92°13´, 1900–2150 m a.s.l., 30– 31. V.2015, coll. AF GoogleMaps ; 4 ♂♂, 1 ♀ ( HNHM chilo-7686), Govi-Altai Aimag, Cakhir-Khaalgyn-Nuruu Mt. Range , 2–5 km SSE Dotiyn-Davaa Pass, mountain stony tundra with rocks and scree, N45°25´, E97°05´— N45°24´, E97°07´, 3300–3660 m a.s.l., 04.VII.2017, coll. AF GoogleMaps ; 1 ♂ ( HNHM chilo-7688), 04.VII.2017, coll. AF ; 1 ♀ ( HNHM chilo-7687), foothill of Cakhir-Khaalgyn-Nuruu Mt. Range, near Mt Dotiyn-Davaa , pass, stony alpine meadow, N45°25´, E97°05´, 2900– 3000 m a.s.l., 04–05.VII.2017, coll. AF GoogleMaps ; 4 ♂♂, 2 ♀♀ ( ZMMU Rc 7892), Khasagtiyn-Nuruu Mt. Range, vicinity of Mt Khoit-Bogd- Uul , mountain stony tundra with rocks and scree, N46°47´, E95°50´, 3400–3500 m a.s.l., 08.VII.2017, coll. AF GoogleMaps .

REDESCRIPTION. ♂ paratypes. Body 12–17 mm long, colouration in alcohol yellow ( Fig. 2 View Figs 2–8 ), cephalic plate slightly brighter; head and body slightly punctate. Head a little broad- er than T1 ( Fig. 41 View Figs 41–49 ) (ca. 1:0.95).

Antennae with 20 articles (1 ♂ with 18+20 ones, 2 ♂♂ with 19+20), covered with dense, short, dark and erect sensilla. Length to breadth ratio of terminal article, 1:0.4 ( Fig. 44 View Figs 41–49 ). Antennae extending back to ca. T4.

Ocelli: 5–6 on each side arranged in a single broken row inside a contoured area ( Figs 13, 14 View Figs 9–18 ). Tömösváry´s organ smaller than nearest ocelli, rounded.

Coxosternum with 2+2 acute teeth and setiform porodonts, median diastema V-shaped. Shoulders very gently sloping behind porodonts.

Tergites: almost smooth, with short and sparse setae, without posterior triangular projections. TT 3, 5, 8, 10, and 12 elongated (Table 3); posterior median notch developed on TT 3, 5, 8, 10 and 12 (caudal part of each of these TT with a well-developed, light, short suture dividing it into two lobes) ( Figs 4–8 View Figs 2–8 , 51 View Figs 50–57 ); T15 indistinct. T1 breadth ca. 1.2 mm, T8 breadth ca. 1.45 mm. All microtergites (TT 2, 4, 6, 9, 11, 13) and T7 with one median and two paramedian, short, translucent sutures at posterior margin ( Fig. 50 View Figs 50–57 ). Caudal margin of Tim slightly sinuate, length to breadth ratio, 1:0.94 ( Fig. 42 View Figs 41–49 ). Caudal part of 14–15 th sternites and coxae densely covered with short setae ( Fig. 45 View Figs 41–49 ).

Sternites elongate (except for genital S); posterior margin of SS 1–14 with short sutures (best expressed on SS 2–12).

All Tsi functionally biarticulate, with Ts1 about 2 times longer than Ts2. Tsi 1–13 each with a ventral row of dark setae especially well-developed on midbody legs. Legs 1–14 each with a posterior accessory spine, legs 1–13 each with a large, pretarsal, anteroventral spine (Fig. 35). Legs 15 without accessory spines ( Fig. 21 View Figs 19–29 ), but with a very small anteroventral spine (interpreted as an accessory spine in the original description). P, F, Ti of legs 15 slightly incrassate and flattened dorsally ( Figs 19–20 View Figs 19–29 ). Legs 14 without visible secondary sexual characters.

15F covered with sparse minute setae and several small, oval, dark pores ( Figs 26, 27 View Figs 19–29 ). Distodorsal part of 15Ti flattened and with a long, median, dark blot formed by numerous small pores, as well as with numerous dense setae located on and around the dark blot ( Figs 22, 23, 25 View Figs 19–29 ); 15F and 15Ti with more or less evident, shallow, wide, indistinct dorsal and/or dorsolateral sulci ( Figs 20, 26 View Figs 19–29 ). Leg plectrotaxy as in Table 1.

DCa developed starting with legs (11)12. Coxal pores small, rounded, separated from one another by a distance about 2–4 times greater than their own diameter, formula 3,2(3),2(3),2(3) ( Fig. 45 View Figs 41–49 ). Gonopod ( Fig. 24 View Figs 19–29 ) 1-segmented, with 3–4 very thin and light setae placed at gonopodal middle.

♂ variations (non-type material).

Most characteristics as in paratypes, except as follows. Body length 13–21 mm, colouration in alcohol always brownish yellow ( Fig. 3 View Figs 2–8 ). Antennae with 20–22 segments

Table 1. Plectrotaxy of Schizotergitius altajicus Loksa, 1978 (paratypes). Brackets indicate variable spines. Таблица 1. Распределение Шипов на ногах у Schizotergitius altajicus Loksa, 1978 (паратипы). Скобки обоЗначают вариабельные Шипы. <

Figs 30–40. Schizotergitius altajicus Loksa, 1978 (♀♀ paratypes: 30–33, 35; ♀ non-type: 34, 36–40 — ASU No. 295): 30, 31 — gonopods, ventral and ventrolateral views, respectively; 32 — right gonopod, dorsolateral view; 33, 34 — left gonopod, dorsal and lateral views, respectively; 35 — pretarsus of leg 14; 36 — fragment of right gonopod, ventrolateral view; 37 — left gonopod, dorsolateral view; 38 — right gonopod segments 2 and 3, lateral view; 39, 40 — right gonopod, distal and distodorsal views, respectively. Abbreviations: as — posterior accessory spine; do — distodorsal outgrowth, s — anteroventral spine. Scale: 0.2 mm (30, 31), 0.1 mm (32–40).

Рис. 30–40. Schizotergitius altajicus Loksa, 1978 (паратипы ♀♀: 30–33, 35; нетиповаЯ ♀: 34, 36–40 — ASU No. 295): 30, 31 — гоноподы, соответственно сниЗу и одновременно сниЗу и сбоку; 32 — правый гонопод, одновременно сверху и сбоку; 33, 34 — левый гонопод, соответственно сверху и сбоку; 35 — коготь ноги 14; 36 — фрагмент правого гонопода, одновременно сниЗу и сбоку; 37 — левый гонопод, одновременно сверху и сбоку; 38 — сегменты 2 и 3 правого гонопода, сбоку; 39, 40 — правый гонопод дистально и дистодорсально. ОбоЗначениЯ: as — дополнительный коготок; do — дистальный верхний вырост, s — передне- нижнЯЯ Щетинка. МасШтаб: 0,2 мм (30, 31), 0,1 мм (32–40).

(19+ 20 in 1 specimen), terminal segment of antennae as in Fig. 43 View Figs 41–49 .

Dental margin of forcipular coxosternite as in Fig. 47 View Figs 41–49 .

Sides of labrum with well-expressed fringes of numerous thin bristles; a pair of setae projecting across labral midpiece ( Fig. 15 View Figs 9–18 ). Gnathal edge of mandible with numerous pulvilli, 4 pairs of well-developed teeth and 10–12 rather thick and serrate aciculae ( Figs 9–10 View Figs 9–18 ). First maxillae: edge with more than 20 plumose bristles and simple setae as well ( Figs 16– 18 View Figs 9–18 ). Second maxillary telopodite ( Figs 11, 12 View Figs 9–18 ) with bristles, both simple and plumose, at tip (more than 25 plumose bristles on internal side).

Hind margin of Tim strongly sinuate, and posterior margins of lobes slightly deflexed down.

15P rarely with indistinct dorsal and/or dorsolateral sulci; 15F dorsally with 3–7 oval pores ( Figs 48, 49 View Figs 41–49 ). Dark blot on 15Ti consisting of numerous, densely located, small pores ( Figs 28, 29 View Figs 19–29 ). Leg plectrotaxy as in Table 2.

SS 14 and 15, coxae 13–15 ( Fig. 45 View Figs 41–49 ), as well as ventral sides of P, F and Ti 12 and 13 covered with very small and dense setae in rear parts and, in some cases, even all along the articles ( Fig. 54 View Figs 50–57 ). Genital sternite short and broad, covered with long setae.

Each gonopod with 3 (rarely 2) setae.

♀ paratypes. Most characteristics as in ♂ paratypes, but body (11–16 mm) and TT shorter than in ♂ (Table 3). T1 breadth ca. 1.01 mm, T8 breadth ca. 1.29 mm. Coxosternum usually with 2+2 acute teeth (1 specimen with 2+1, another one with 2+3 ones). Formula of coxal pores, 3,3,3,3.

Gonopod with 2+2 acute spurs (Figs 30, 31) and a simple, pointed and curved claw; 1 st segment without dorsal setae, but with 1–3 short and 3 longer medial setae, 2 nd segment with a small, translucent, distodorsal outgrowth shifted mesad and 4–6 dorsal setae (vs. 7 in the holotype in the original description, but, according to the illustrations [ Loksa, 1978: figs 17, 19], a lateral seta similar in appearance was also counted), 3 rd segment with 2–3 dorsal setae (Figs 32, 33).

♀ variations (non-type material).

Body 12–20 mm long, antennae usually with 20 antennomeres (1 ♀ with 17+19).

Table 2. Plectrotaxy of Schizotergitius altajicus Loksa, 1978 (non-types). Brackets indicate variable spines. Таблица 2. Распределение Шипов на ногах у Schizotergitius altajicus Loksa, 1978 (нетиповой материал). Скобки обоЗначают вариабельные Шипы. Table 3. Average lengths and breadths of tergites of ♂♂ and ♀♀ in Schizotergitius altajicus Loksa, 1978 (paratypes).

Таблица 3. Средние ЗначениЯ длины и Ширины тергитов у самок и самцов Schizotergitius altajicus Loksa, 1978 (паратипы).

Forcipular coxosternum as in Fig. 46 View Figs 41–49 .

Posterior margin of SS 1–14 with short sutures ( Figs 52, 53 View Figs 50–57 ). Formula of coxal pores, 3(4),3,3,2(4).

Gonopods: each with 2+2 acute spurs (Fig. 34) and a simple, pointed and curved claw (Figs 36–40) with irregular edges (often broken off); 1 st segment mostly without dorsal setae (1 dorsal seta on one or both gonopods presents (Fig. 37) in 3 of 4 ♀♀ from Bayan-Ölgii Aimag (ASU No. 295)), with up to 6 medial setae, 2 nd with 4–6, 3 rd with 3–4 dorsal setae in a single row; 2 nd segment with a small, distodorsal and transparent outgrowth shifted mesad.

DISTRIBUTION. Western Mongolia: Bayan-Ölgii, Khovd and Govi-Altai Aimags [ Loksa, 1978; Dyachkov, 2017], summarized in Fig. 1 View Fig .

REMARKS. Three specimens of S. altajicus f. gracile (recte: gracilis ) are labeled as 1 ♂ and 2 ♀♀ in the original description [♀ holotype, 1 ♂ and 1 ♀ paratype], but actually all three are ♀♀: one ♀ has postpedal segments damaged, and legs 15 are devoid of the secondary sexual characters of the ♂. No holotype is labeled as such in the vial.

An important feature of S. altajicus is its remarkable sexual dimorphism. ♂♂ show the body and macrotergites more strongly elongated than ♀♀ do, but this character is not unique, as the same pattern is observed in the Asiatic Lithobius giganteus Sseliwanoff, 1881 [ Eason, 1986a]. This similarity between S. altajicus and L. giganteus was noted by Eason [1986a] who mentioned tergal modifications in some specimens of L. giganteus ( Figs 55–57 View Figs 50–57 ), as well as “tergite 12 in the fragmented female of [ Lithobius ] mongolicus [now L. giganteus ] is exactly the same as that of tergite 5 in S. altajicus ”. However, S. altajicus differs from L. giganteus in the shorter body, as well as the presence of the well-developed secondary sexual modifications of ♂ legs 15: 15F has a row of 3–7 oval and dark pores, 15Ti shows a dark, distodorsal, elongate blot (consisting of numerous pores) covered with dense and short setae. Similarly dense setae are also present in another Asiatic genus, Disphaerobius Attems, 1926 , but these are located on a rounded outgrowth of Ti, while a blot is absent [ Farzalieva et al., 2017: fig. 5].

The following eight genera of Lithobiidae are presently known to occur in Central Asia: Bothropolys Wood, 1862 (Ethopolyinae Chamberlin, 1915), Australobius Chamberlin, 1920 , Disphaerobius Attems, 1926 , Hessebius Verhoeff, 1941 , Lithobius Leach, 1814 , Schizotergitius Verhoeff, 1930 , and Validifemur Ma, Song & Zhu, 2007 ( Lithobiinae Verhoeff, 1907) [ Loksa, 1978; Zalesskaja, 1978; Eason, 1997; Ma et al., 2007, 2014; Farzalieva et al., 2017; Ganske et al., 2020]. Now that the identity of Schizotergitius has become clarified, we can propose the following key for their separation.

A KEY TO THE GENERA OF LITHOBIIDAE REPORTED FROM CENTRAL ASIA

1 Coxal pores scattered ................................. Bothropolys View in CoL

— Coxal pores arranged in a single row ( Fig. 45 View Figs 41–49 ) ........... 2

2 Tömösváry´s organ located below interior row of ocelli ................................................................... Australobius View in CoL

— Tömösváry´s organ located level with interior row of ocelli ( Figs 13, 14 View Figs 9–18 ) ....................................................... 3

3 Tergites 3, 5, 8, 10, 12 with posterior median notches ( Figs 4–8 View Figs 2–8 , 51 View Figs 50–57 ) ......................................... Schizotergitius View in CoL

— Tergites without median notches ................................. 4

4 ♂ .................................................................................. 5

— ♀ .................................................................................... 7

5 Tergites 12–14 (or some of them) modified: serrate and sometimes broadened ............................ Disphaerobius

— Tergites neither serrate nor broadened ........................ 6

6 Leg-pair 15 without falciform spines ............................. ................................................ Hessebius View in CoL and Lithobius View in CoL

— Leg-pair 15 with strong falciform spines ... Validifemur

7 Second ♀ gonopodal article with neither a distodorsal protuberance nor an outgrowth ................................... 8

— Second ♀ gonopodal article with a distodorsal protuberance or outgrowth ........................................................ 9

8 Tarsus of legs 1–13 without any marking on dorsal side, but with a trace of bipartite division on ventral side ..... ..................................................................... Validifemur

— Tarsus of legs 1–13 with or without a bipartite division ......................................................................... Lithobius View in CoL

9 Second ♀ gonopodal article with a more or less developed protuberance, often with setae or spines ....... Hessebius View in CoL

— Second ♀ gonopodal article without such protuberance, but with a small, oval, distodorsal outgrowth directed mesad, always with neither setae nor spines ........ Disphaerobius

Acknowledgements. We are most grateful to S.I. Golovatch (Moscow) who kindly checked the English of an advanced draft. We are highly obliged to A.A. Fomichev who donated us his material for study. The first author is grateful to R.V. Yakovlev who organized his trip to Budapest, and to O.V. Fast, L.A. Khvorova, and A.V. Vaganov (all Barnaul, Russia) who kindly provided FAST software for taking the measurements.

Competing interests. The authors declare no competing interests.

HNHM

Hungarian Natural History Museum (Termeszettudomanyi Muzeum)

ASU

Arizona State University

VI

Mykotektet, National Veterinary Institute

V

Royal British Columbia Museum - Herbarium

PSU

Portland State University, Vertebrate Biology Museum

ZMMU

Zoological Museum, Moscow Lomonosov State University

Kingdom

Animalia

Phylum

Arthropoda

Class

Chilopoda

Order

Lithobiomorpha

Family

Lithobiidae

Genus

Schizotergitius

Loc

Schizotergitius altajicus Loksa, 1978

Dyachkov, Yu. V., Farzalieva, G. Sh. & Dányi, L. 2021
2021
Loc

Schizotergitius altajicus

Dyachkov Yu. V. 2017: 35
2017
Loc

Schizotergitius

Farzalieva G. Sh. & Nefediev P. S. & Tuf I. H. 2017: 124
2017
Loc

Schizotergitius altajicus

Eason E. H. 1986: 190
1986
Loc

Schizotergitius altajicus

Loksa I. 1978: 118
1978
Loc

Schizotergitius altajicus

Loksa I. 1978: 118
1978
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