Scolopendra alcyona Tsukamoto & Shimano, 2021

Tsukamoto, Sho, Hiruta, Shimpei F., Eguchi, Katsuyuki, Liao, Jhih-Rong & Shimano, Satoshi, 2021, A new amphibious species of the genus Scolopendra Linnaeus, 1758 (Scolopendromorpha, Scolopendridae) from the Ryukyu Archipelago and Taiwan, Zootaxa 4952 (3), pp. 465-494 : 483-489

Scolopendra alcyona Tsukamoto & Shimano , sp. nov.

[New Japanese name for Scolopendra alcyona sp. nov.: Ryûjin-ômukade (琉神大百足); new English name for Scolopendra alcyona sp. nov.: Halcyon giant centipede]

( Figs 3B, C , 4–9 )

Material examined. Holotype: Male (NSMT-My 511, TS-20180914-01), Oku , Kunigami-son , Kunigami-gun, Okinawa-jima Island, Okinawa prefecture, Japan (26°49’04.6”N, 128°16’52.3”E), 14 Sep. 2018, coll. Hutoshi Taira.

Paratypes: sex unknown (NSMT-My 512, TS-20180912-01), Yona , Kunigami-son , Kunigami-gun, Okinawajima Island, Okinawa prefecture, Japan, 12 Sep. 2018, coll. Katsuya Tsukamoto ; sex unknown (RUMF-ZD-02001, TS-20180301-01), Yona , Kunigami-son , Kunigami-gun, Okinawa-jima Island, Okinawa prefecture, Japan, 1 Mar. 2018, coll. Takeshi Sasaki ; 2 sex unknown (NSMT-My 513, TS-20180522-01; NSMT-My 514, TS-20180522-02), Nakachi , Kumejima-cho , Shimajiri-gun, Kume-jima Island, Okinawa prefecture, Japan, 22 May 2018, coll. Humiyasu Sato.

All type specimens except TS-20180301-01 are deposited at the Collection of Myriapoda, Department of Zoology, NSMT, and TS-20180301-01 is deposited at RUMF.

Non-type specimens: sex unknown (NSMT-My 515, TS-2018MMDD-01), Nuha, Ogimi-son, Kunigami-gun , Okinawa-jima Island , Okinawa prefecture, Japan, 2018, coll. Zento Touyama; Female ( NTU TS-19690814-01), Hengchun , Pingtung City, Taiwan, 14 Aug. 1969, coll. Mitsuo Takano. TS-2018MMDD-01 is deposited at the Collection of Myriapoda , Department of Zoology , NSMT . Taiwanese specimen (TS-19690814-01) are deposited at NTU .

Etymology. This epithet “alcyona” derived from the name of a Greek mythological figure, “Alcyone”. In one version of the story, Alcyone was turned into a common kingfisher (halcyon bird) by Zeus ( Gresseth 1964). This epithet is a metaphor for halcyon bird-like jade green legs seen in the Okinawa-jima Island population, and its amphibious behavior.

Diagnosis. 17–20 antennal articles, basal 6 articles glabrous; cephalic plate with small puncta; each tooth-plate with 4–9 teeth; tergites (4, 5) 6–20 with complete paramedian sutures; tergite of ultimate leg-bearing segment without median suture; sternites 2–19 with well-defined, incomplete paramedian suture; coxopleural process with 2 apical spines and 1 subapical spine; ultimate legs long and slender with ratio of width and length of prefemur 1:3, ratio of width and length of femur 1:4 and ratios of lengths of prefemur and femur 1.06:1; femur and tibia 1.13:1; tibia and tarsus 1 1.33:1; tarsus 1 and tarsus 2 2.15:1; dorsally flattened ultimate leg prefemora with 2 VL, 1 M, 2 DM and 1–3 SP; tarsal spurs on legs 1–19; gonopods absent, penis present. Scolopendra alcyona sp. nov. is similar to all other congeners in East and Southeast Asia (see “Morphological comparison among Japanese and Taiwanese Scolopendra ”, and Tables 6 and 7). S. alcyona sp. nov. can be distinguished from S. japonica by the absence gonopods in the male, and incomplete paramedian sutures. S. alcyona sp. nov. can be distinguished from S. multidens by the ratio of the length of femur and tibia, and tibia and tarsus (femur and tibia 1.1:1; tibia and tarsus 1 1.3: 1 in S. alcyona sp. nov.; femur and tibia 1.7:1, tibia and tarsus 1 1.8: 1 in S. multidens ). S. alcyona sp. nov. can be distinguished from S. dawydoffi by the tergite number on which the complete paramedian sutures start (T4–T 6 in S. alcyona sp. nov.; T2 or T 3 in S. dawydoffi ). S. alcyona sp. nov. can be distinguished from S. mutilans and S. subspinipes by the absence gonopods in the male, and the presence of a tarsal spur only on legs 1–19.

Holotype description (variation of paratypes is given in parenthesis). Body length in 100% Ethanol 130 mm rounding off (TS-20180301-01: 190 mm, TS-20180912-01: 180 mm, TS-20180522-01: 140 mm, TS-20180522-02: 130 mm).

Antenna ( Figs 4A , 7A , 9A, C ) with 18 articles (17–20 article in paratypes); basal 6 articles glabrous.

Cephalic plate ( Figs 4A , 7A , 9C ) with small puncta entirely; short anterior median sulcus; paramedian suture absent.

Article 2 of second maxillary telopodite with spur. Second maxillary pretarsus 0.36 times as long as article 3 of second maxillary telopodite, rounded at the tip, with dorsal and ventral spurs.

Coxosternite ( Figs 4B–D , 7B–D ) surface smooth, without median suture; tooth-plates longer than wide, with 7 + 7 teeth in two groups (8 + 7 in TS-20180301-01, 9 + 8 in TS-20180912-01, 5 + 4 in TS-20180522-01 and 5 + 7 in TS-20180522-02) and with transverse basal sulci. Forcipule ( Figs 4B–D , 7B ) surface smooth; process of trochanteroprefemur with teeth in two groups, 1 apical tooth and 1(3) inner teeth.

Tergite ( Figs 4E , 7E ) surface smooth. Anterior margin of T1 overlapped by cephalic plate. Complete paramedian sutures on TT6–20 (paramedian sutures starting on TT 4–6 in paratypes); margination on TT6–20 (margination starting on TT 6–11 in paratypes). Tergite of ultimate leg-bearing segment ( Figs 5A , 8A ) without median suture or depression; posterior margin of tergite of ultimate leg-bearing segment curved posteriorly; ratio of width and length of tergite of ultimate leg-bearing segment 1:1.

Sternite ( Figs 4F , 7F ) surface smooth; SS2–19 with paramedian sutures, posteriorly incomplete, extending to approximately 65–76% length of sternite. Sternite of ultimate leg-bearing segment ( Figs 5B , 8B ) with lateral margins converging posteriorly and posterior margin convex posteriorly; surface with shallow median longitudinal depression.

Coxopleuron ( Figs 5B, C , 8B, C ) with numerous pores, pore-field extending into coxopleural process covering most of its surface, except for a narrow pore-free area, dorsal margin of pore-field gradually elevated anteriorly. Coxopleural process moderately long, with 2 apical spines and 1 subapical spine (0–2 apical and 0–2 subapical spines in paratypes), without lateral spine; pore-free area of coxopleural process extending ventrally 79–93% length from distal part of coxopleural process to posterior margin of sternite of ultimate leg-bearing segment (73–100% in paratypes).

All legs without setae and tibial spur. One ventrodistal tarsal spur on tarsus 1 of legs 1–19. Ultimate legs ( Figs 6 , 8A, B , 9D ) long and slender with ratio of width and length of prefemur 1:3, ratio of width and length of femur 1:4 and ratios of lengths of prefemur and femur 1.06:1; femur and tibia 1.13:1; tibia and tarsus 1 1.33:1; tarsus 1 and tarsus 2 2.15:1. Prefemur of ultimate leg flattened dorsally with acute blackish spines row as below: 2 VL, 1 M, 2 DM and 2–3 SP (1–3 SP in paratypes).

In the male holotype, and a female non-type specimen (TS-19690814-01), genital segments ( Figs 5D, E ) everted and projected beyond distal part of coxopleural process. Sternite of genital segment 1 round and convex posteriorly. Gonopods absent. Sternite of genital segment 2 well developed in male. Tergite of genital segment small, horseshoeshaped and lacking setae. Lamina subanalis between genitalia and anal valves; lamina adanalis between anal valves and tergite of genital segment. Penis present.

Coloration in living condition as in Figs 9A–D . Brownish black on cephalic plate and T1; greenish black on remaining tergites; bluish black on antenna; light brown on coxosternite and forcipule (but forcipular tarsungulum blackish); pale green on all sternites; bluish black on eupleuria, with greenish black integuments; orange on coxopleura; basal part of legs 1–20 yellow, distal part of legs 1–20 and ultimate legs greenish blue (all legs yellow in Kume-jima Island specimens); pale blue on intermediate sternite.

Distribution: Ryukyu Archipelago (Okinawa-jima Island, Kume-jima Island) and Taiwan. S. alcyona sp. nov. specimens examined in this study were collected in Okinawa-jima Island, Kume-jima Island, and Taiwan, but S. alcyona sp. nov. could be also distributed in Tokashiki-jima Island, Ishigaki-jima Island, and Iriomote-jima Island (Masashi Sugimoto and Taku Shimada, personal communication).

Habitat: Scolopendra alcyona sp. nov. lives along streams that flow through the forest. It is often found under stones nearby the streams.

Figures

FIGURE 3. A, Habitat of Scolopendra alcyona Tsukamoto & Shimano, sp. nov. in Kume-jima Island; B, C, S. alcyona Tsukamoto & Shimano, sp. nov., found underwater at the upper reach of Shirase River, Kume-jima Island (by Mr. H. Sato; specimen not collected).

FIGURE 4. Scolopendra alcyona Tsukamoto & Shimano, sp. nov., A, B, E, F: holotype TS-20180914-01, C: paratype TS- 20180301-01, D: paratype TS-20180522-02: A, cephalic plate, dorsal; B–D, variation of forcipular segment, ventral; E, tergites 14 and 15; F, sternites 14 and 15. Scale bars: 5 mm.

FIGURE 5. Scolopendra alcyona Tsukamoto & Shimano, sp. nov., holotype TS-20180914-01: A, posterior part of tergite 20, and tergite 21; B, ultimate leg-bearing segment, ventral; C, left coxopleuron, lateral; D, male genital segments, ventral; E, male genital segments, lateral. Legends: triangles = genital sternite 1; arrows = genital sternite 2; arrowheads = tergite of genital segment. Scale bars: 5 mm (A–C), 2.5 mm (D, E).

FIGURE 6. Scolopendra alcyona Tsukamoto & Shimano, sp. nov., holotype TS-20180914-01: A, prefemora and femora of ultimate legs, dorsal; B, prefemora and femora of ultimate legs, ventral; C, tibiae, tarsi 1, tarsi 2, and pretarsi of ultimate legs, dorsal; D, tibiae tarsi 1, tarsi 2, and pretarsi of ultimate legs, ventral. Scale bars: 5 mm.

FIGURE 7. Scolopendra alcyona Tsukamoto & Shimano, sp. nov., A–C, E, F: paratype TS-20180301-01, D: holotype TS- 20180914-01: A, cephalic plate, basal antennal articles and tergite 1, dorsal; B, forcipular segment, ventral; C, D, variation of teeth on tooth-plates; E, tergites 9–11; F, sternites 9–11. Scale bars: 5 mm (A, B, E, F); 1 mm (C, D).

FIGURE 8. Scolopendra alcyona Tsukamoto & Shimano, sp. nov., paratype TS-20180301-01: A, tergite 21 and prefemur of ultimate leg, dorsal; B, ultimate leg-bearing segment and prefemur of ultimate leg, ventral; C, left coxopleuron, lateral. Scale bars: 5 mm.

FIGURE 9. Habitus and color variation of Scolopendra alcyona Tsukamoto & Shimano, sp. nov.: A, paratype TS-20180301- 01, habitus Okinawa-jima Island; B, paratype TS-20180522-02, Kume-jima Island; C, paratype TS-20180301-01, head and antennae; D, paratype TS-20180301-01, prefemur of ultimate legs, dorsal view (A, C, D by Mr. K. Tsukamoto).