Otostigmus aculeatus Haase, 1887

Vu, Ha T., Nguyen, Hung D., Le, Son X., Eguchi, Katsuyuki, Nguyen, Anh D. & Tran, Binh T. T., 2020, A review and notes on the phylogenetic relationship of the centipede genus Otostigmus Porat, 1876 (Chilopoda: Scolopendromorpha: Scolopendridae) from Vietnam, Zootaxa 4808 (3), pp. 401-438 : 405-408

Otostigmus aculeatus Haase, 1887

( Figs. 2–7 )

Otostigmus (O.) aculeatus Haase, 1887: 71 ; Attems 1938: 337; Attems 1953: 138; Schileyko 1992: 7; Schileyko 1995: 83, fig. 11; Schileyko 1998: 268; Schileyko 2001: 430; Lewis 2001: 28, figs 53–58; Chao & Chang 2003: 2; Schileyko 2007: 76, fig. 2.

Otostigmus (O.) ziesel Schileyko, 1992: 10 , figs 2b–d; Schileyko 1995: 85, fig. 13; Schileyko 1998: 268; Schileyko 2001: 431; synonymised by Schileyko (2007).

Material examined. DIEN BIEN Province: 1 specimen (IEBR-Chi 074) Muong Nhe Natural Reserve , bamboo forests, 20.7091N– 104.6869”E, 14 June 2018, coll. Nguyen D. Hung & Le X. Son ; 1 specimen (IEBR-Chi 076) same locality, but mixed forests, 20.7108N– 104.6869E, elevation of 673 m, 14 May 2018, coll. Nguyen D. Hung & Le X. Son ; 1 specimen (IEBR-Chi 179) same locality, residential area, pitfall trapping, 11 January 2017, coll. Nguyen D. Hung & Le X. Son ; SON LA Province: 6 specimens (IEBR-Chi 061, 063-067) Ta Xua Natural Reserve , natural forests, 20.7108N– 20.7108E, elevation of 400 m, 9 February 2017, coll. Ha Kieu Loan & Le X. Son ; 1 specimen (IEBR-Chi 070) same locality, but bamboo forests, 21.3491N– 104.6947E, elevation of 810 m, 11 November 2017, coll. Ha Kieu Loan & Le X. Son ; 1 specimen (IEBR-Chi 072) same data, but 20.3437N– 104.6802E, elevation of 515 m, 13 November 2017 ; HOA BINH Province: 3 specimens (IEBR-Chi 049, 222, 229) Thuong Tien Natural Reserve , natural forest, 21.6357N– 105.4490E, elevation of 443 m, 31 January 2018, coll. Hoang N. Anh & Nguyen D. Hung ; 1 specimen (IEBR-Chi 050) same data, but 20.6346N– 105.4500E, elevation of 515 m ; 2 specimens (IEBR-Chi 227, IEBR-Chi 228) but 20.6287N– 105.4340E, elevation of 509 m, 30 January 2018, coll. Tran T. T. Binh & Nguyen D. Hung ; 5 specimens (IEBR-Chi 051, IEBR-Chi 231, IEBR-Chi 235, IEBR-Chi 233, IEBR-Chi 234) same data, but 20.6400N– 105.4440E, elevation of 295 m, 12 May 2017, coll. Tran T. T. Binh & Nguyen D. Hung ; 1 specimen (IEBR-Chi 232) same data, but 20.6378N– 105.4467E, elevation of 357 m, 14 May 2017, coll. Tran T. T. Binh & Nguyen D. Hung ; 1 specimen (IEBR-Chi 060) same data, but 20.6231N– 105.4298E, elevation of 586 m, 30 May 2017, coll. Tran T. T. Binh & Nguyen D. Hung ; VINH PHUC Province: 2 specimens (IEBR-Chi 129, IEBR-Chi 130), Me Linh station for biodiversity, regenerated forests, 21.3973N– 105.7130E, 9 September 2018, coll. Vu T. Ha ; 2 specimens (IEBR-Chi 250, IEBR-Chi 253) same locality, Eucalyptus forests, 21.3833N– 105.7126E, 2 December 2018, coll. Vu T. Ha ; 1 specimen (IEBR-Chi 254), Me Linh station for Biodiversity , regenerated forests, 21.3885N– 105.7193E, 2-3 December 2018, coll. Vu T. Ha ; 1 specimen (IEBR-Chi 035) same locality, mixed forests, 21.3992N– 105.7241E, 9 July 2018, coll. Nguyen D. Anh ; 4 specimens (IEBR- Chi 011, 099, 103, 118) same locality, regenerated forests, 10–17 September 2016, coll. Nguyen D. Anh ; 1 specimen (IEBR-Chi 094) same data, but 8–18 April 2014, pitfall trapping, coll. Nguyen D. Anh ; QUANG NINH Province: 1 specimen (IEBR-Chi 239) Bai Tu Long National Park, Sau Nam Island (21.1784N– 107.6646E), natural forests, 22 February 2012, coll. Nguyen D. Anh ; BAC GIANG Province: 1 specimen (IEBR-Chi 012) Son Dong District, Tay Yen Tu Natural Reserve, Khe Ro station (21.3436N- 106.9698E )), natural forests, 17–18 May 2013, coll. Phung T.H. Luong ; HAI PHONG Province: 8 specimens (IEBR-Chi 242, 244, 021, 022, 009, 183, 194, 245) Cat Ba National Park , natural forests, 20.7984N– 106.9994E, 18 March 2012, coll. Nguyen D. Anh ; NINH BINH Province: 4 specimens (IEBR-Chi 020, 088, 089, 090) Cuc Phuong National Park , natural forests, “Nguoi Xua Cave, 21–22 September 2016, coll. Nguyen D. Anh; 1 specimen (IEBR-Chi 093) same locality, but 20.3217N– 109.6081”E, 28 July–2 August 2017, coll. Nguyen D. Anh ; NGHE AN Province: 1 specimen (IEBR-Chi 240) Pu Mat National Park , natural forests, 19.0799N– 104.6371E, 4–10 April 2011, coll. Nguyen D. Anh ; QUANG BINH Province: 1 specimen (IEBR-Chi 237) Son Trach District, Cha Noi Commune , limestone forests, 17.6432N– 106.1019E, 16–19 February 2012, coll. Pham H. Phong ; QUANG NGAI Province: 1 specimen (IEBR-Chi 193) Ly Son island, An Binh commune (15.4289N- 109.0811E), natural forests, 8 August 2017, coll. Dang T. Hoa ; QUANG NAM Province: 1 specimen (IEBR-Chi 255) Song Thanh Natural Reserve (15.6700N– 107.7188E), natural forests, elevation of 1,000 m, 11 January 2019, coll. Le X. Son ; DAK LAK Province: 1 specimen (IEBR-Chi 172) Kon Ka Kinh National Park (14.2589N– 108.3794E), natural forests, elevation of 920–1,200 m, 12 May 2016, coll. Le X. Son ; DONG NAI Province: 1 specimen (IEBR-Chi 156) Cat Tien National Park, natural forests, on the way to Bau Sau , 11.4533N– 107.3658E, elevation of 180 m, 10–11 July 2018, coll. Nguyen D. Anh.

Diagnosis. Body with 21 leg-bearing segments. Spiracles oval-shaped ( Fig. 2D ). Antennae with 17 antennomeres including 3 basal smoothly glabrous ones ( Fig. 2 A–B). Coxosternal plate with 4+4 teeth ( Fig. 2B ). Paramedian grooves distinct on both tergites and sternites ( Fig. 3 A–B). Coxopleural process long, conical, with 5–7 apical spines ( Figs 3 C–D, 5A–B, 6A–B). Prefemur of the ultimate legs with numerous spines arranged in rows ( Figs 4 A–B, 5C, 6C).

Previous records from Vietnam. QUANG NINH (Hon Gai, Ha Long); HAI PHONG (Cat Ba NP); HA NOI (Ba Vi NP); HOA BINH (Mai Chau District); VINH PHUC (Tam Dao NP); NINH BINH (Cuc Phuong NP); QUANG NAM (Cu Lao Cham Island); KON TUM (Buon Luoi); GIA LAI (An Khe District); DONG NAI (Ma Da; Cat Tien NP); Tho Chu Island; ( Attems, 1938, 1953; Schileyko, 1992, 1995, 2007).

Distribution. Also known from Laos, Indonesia (Java), Taiwan, Hong Kong, and China ( Chao & Chang 2003; Schileyko 2007).

Remarks. The species is widely distributed in Vietnam ( Fig. 7 ). Otostigmus aculeatus varies remarkably in shape and chaetotaxic pattern of prefemoral spines of the ultimate leg. Based on the number of spines on coxopleural process and on prefemur of the ultimate leg, it can be divided into three morphological types.

The first type has coxopleural process with 4 apical, 3 subapical and 1 dorsal spine, no lateral ones ( Fig. 5 A–B). Prefemur of the ultimate leg has 1 corner, 3–4 dorsomedial, 6–8 medial, 8–9 ventromedial, and 5 ventrolateral spines—all spines are arranged in lines, but the dorsomedial and ventrolateral spines are big whereas medial and ventromedial ones are small ( Fig. 5C ). The second type has coxopleural process with 4 apical, 2–3 subapical, 1 lateral and 1 dorsal spine ( Fig. 6 A–B). Prefemur of the ultimate leg has numerous small spines which are not arranged in lines ( Fig. 6C ). The last type has coxopleural process with 5–6 apical, 1 subapical, 1 dorsal spine, no lateral ones ( Fig. 3 C–D). Prefemur of the ultimate leg has 1 corner, 3–4 dorsomedial, 5–8 medial, 7–8 ventromedial and 4–5 ventrolateral spines. These spines are big and arranged in lines ( Fig. 4 ).

These types were sometimes found in the same locality, e.g. Me Linh or Thuong Tien. The three types also formed different lineages in the phylogenetic tree ( Fig. 40 ). The differences may suggest that different species may be separated from O. aculeatus .

Figures

FIGURE 2. Otostigmus aculeatus Haase, 1887 (IEBR-Chi 020). Head and antennae, dorsal view (A), ventral view (B). Ocelli, lateral view (C). Spiracle 9th (D).

FIGURE 3. Otostigmus aculeatus Haase, 1887 (IEBR-Chi 020). Tergite 9 (A). Sternite 9–10 (B). Coxopleural process, ventral view (C), lateral view (D).

FIGURE 4. Otostigmus aculeatus Haase, 1887 (IEBR-Chi 020). Right ultimate leg, mesal view (A). Prefemur of the ultimate leg, ventral view (B).

FIGURE 5. Otostigmus aculeatus Haase, 1887 (IEBR-Chi 011). Coxopleural process, ventral view (A), lateral view (B). Prefemur of the ultimate leg, ventral view (C).

FIGURE 6. Otostigmus aculeatus Haase, 1887 (IEBR-Chi 051). Coxopleural process, ventral view (A), lateral view (B). Prefemur of the ultimate leg, ventral view (C).

FIGURE 7. Distribution of Otostigmus aculeatus Haase, 1887 in Vietnam

FIGURE 40. The phylogenetic tree revealed from the COI dataset using Bayesian Inference (A) and Maximum Likelihood (B) analyses.