Ophichthus zophistius, ibino et al., 2019

Hibino, Yusuke & Mccosker, John E., 2020, Resurrection of Ophichthus zophistius (Actinopterygii: Anguilliformes: Ophichthidae) with a revised diagnosis of O. altipennis, Zootaxa 4801 (2), pp. 328-342 : 332-335

Ophichthus zophistius ( Jordan & Snyder 1901)

(New English name: Temperate Highfin Snake Eel; Japanese standard name: Hotate-umihebi)

( Figs. 3 cd, 5b, 6bc, 7cd, 8–10; Table 2 )

Pisoodonophis zophistius Jordan & Snyder 1901:868, fig. 15 (type locality: outside Bay of Tokyo, near Misaki , Japan) ; Youn 2002:143, 492 (key; Korea).

Pisoödonophis zophistius: Okada & Matsubara 1938:92 (key; near Bay of Tokyo, Mikawa Bay, Misaki, and Kagoshima etc.); Chyung 1977:243 (key; Korea).

Pisodonophis zophistius Jordan et al. 1913:84 (outside Bay of Tokyo); Hatooka 1993 (key; Bay of Tokyo, Osaka Bay, off Hamasaka, Hyogo, Japan) ; Hatooka 2002:224 (key; Bay of Tokyo to Kagoshima, Seto Inland Sea, off Hamasaka, Hyogo, Goto Islands ) .

Ophichthus zophistius: Hibino et al. 2019:302 (key; Japan, Korea, Taiwan and China); Shitamitsu & Sunobe 2020:221, fig. 2 (pelagic area, northwestern Pacific).

Ophichthys intermedius Regan 1905:17 (type locality: Seto Inland Sea , Japan).

Microdonophis intermedius: Okada & Matsubara 1938:93 (key; southern Japan).

Microdonophis fasciatus Chu, Wu & Jin 1981: 21 (type locality: Pingtan Island, Fujian, China); Chen 2003:19, unnumbered fig. (Penghu, Taiwan); Ye et al. 2015:12, fig. 2 (type catalog, Dongyang Island, Fujian Province, China).

Ophichthus altipennis (not of Kaup): Hayashi et al. 1992:18, pl. 1-1 (Izu Peninsula, Shizuoka, Japan); McCosker et al. 2012:7 (key; Japan); Hatooka 2013:269 (key, in part; Bay of Tokyo to Shibushi Bay, Kagoshima, Niigata, off Hamasaka, Oki Island, Yamaguchi, northwestern Kyushu, northeastern East China Sea, Seto Inland Sea, west and south coasts of Korean Peninsula); Ho et al. 2015:171 (list; Taiwan); McCosker & Ho 2015:73 (key; Taiwan); Motomura & Harazaki 2017:8, pl. 1D (Yaku-shima Island, Kagoshima, Japan); Hatooka & Hanazaki 2017:9 (Osaka Bay, Yamaguchi, Iyo-nada Basin, Japan); Kimura et al. 2017:81, unnumbered plate (Kuchierabu-jima Island, Kagoshima, Japan); Koeda et al. 2018:60, unnumbered figures (Uchinoura, Kagoshima, Japan).

Ophichthus fasciatus: Zhang et al. 2010:338 ( Taiwan Strait); Ho et al. 2015:172 (list; Taiwan); Ho & McCosker 2015:72 (key; Taiwan).

Holotype. CAS 106475, 516 mm TL, Bay of Tokyo, near Misaki, Japan.

Other materials. 45 specimens. JAPAN: BMNH 1905.6 .6.49., 917 mm TL, Seto Inland Sea (holotype of O. intermedius ); FRLM 3362, 231 mm TL, Futamiga-ura beach, Futami , Ise , Mie, line-fishing; FRLM 4160 , 77 mm TL, FRLM 5013 , 66 mm TL, FRLM 14438 , 68 mm TL, FRLM 41698 , 80 mm TL, FRLM 41699, 443 mm TL, FRLM 52952, 132 mm TL, FRLM 54572, 553 mm TL, FRLM 54906, 187 mm TL, Zaga-shima Island , Shima , Mie, hand-net; FRLM 6655, 337 mm TL, FRLM 36519, 245 mm TL, FRLM 36624, 243 mm TL, FRLM 36841, 674 mm TL, FRLM 36948, 410 mm TL, FRLM 37276, 584 mm TL, FRLM 41337, 561 mm TL, FRLM 41652, 617 mm TL, FRLM 42426, 724 mm TL, FRLM 43647, 591 mm TL, FRLM 45783, 553 mm TL, FRLM 46313, 549 mm TL, FRLM 46364, 536 mm TL, Goza , Shima , Mie, set-net; FRLM 7090, 263 mm TL, Hamajima , Shima , Mie, seagrass bed, bottom trawl; FRLM 15439, 477 mm TL, East China Sea , hand-net; FRLM 32449, 434 mm TL, Kagoshima Bay , off Kanoya , Kagoshima; FRLM 45500, 826 mm TL, FRLM 45501, 704 mm TL, Katada , Shima , Mie, set-net; FRLM 47470, 755 mm TL, Shiratsuka fishlanding port, Tsu , Mie, line-fishing; FRLM 47802, 715 mm TL, off Kumano-nada basin, hand-net; KAUM–I. 62291, 485 mm TL, KAUM–I. 62426, 475.4 mm TL, Uchinoura Bay , Kimotsuki , Kimotsuki-gun, Kagoshima, set-net ; KPM-NI 44112 (donated from UMNB-I 3740 ), 316 mm TL, Kadogawa Bay , Kadogawa, Miyazaki ; KSHS 23354, 765 mm TL, Kuchierabu-jima Island , Osumi Group, southern Kagoshima ; MUFS 25988, 335 mm TL, MUFS 26505, 304 mm TL, MUFS 27461, 338 mm TL, MUFS 30457, 532 mm TL, MUFS 31100, 287 mm TL, MUFS 32210, 363 mm TL, Iorigawa , Kagodawa, Miyazaki, set-net ; SNFR 15295, 510 mm TL, off Goto Islands , East China Sea; UMNB-I 1431, 333 mm TL, Urakami-gawa River , Totoro , Nobeoka, Miyazaki. TAIWAN : NTUM 1793, 312 mm TL, Kinmen, Fujian Province, Taiwan (formerly identified as O. stenopterus ) (not examined in detail) ; NTUM 50567, 422 mm TL, northeastern Taiwan (not examined in detail) . CHINA : ASIZB (formerly NZMC) 70407, 611 mm TL, Dongyang Island , Pingtan Country, Fujian Province, China (holotype of M. fasciatus ; data provided by Hsuan-Ching Ho ) .

Diagnosis based on larger specimens (> 150 mm TL). A species of Ophichthus with the following combination of characters: HL 8.8–10.9% TL; tail length 59.3–64.4% TL, relatively broad and tapering slowly; snout relatively acute, its length 17.3–21.0% HL; three preopercular pores; teeth on upper jaw uniserial, teeth on vomer generally uniserial; dorsal-fin origin usually just above or posterior to a vertical through pectoral-fin insertion; anterior dorsal-fin membrane with a distinct dark blotch; cephalic sensory pores margined dark brown, with additional black pit rows on snout, cheek and lower jaw; body with obscure distorted bars (both in life and preservation) but sometime faded (less in young specimens); 10–14 predorsal and 59–64 preanal lateral-line pores; 14–16 pectoral-fin rays; 11–13 predorsal, 61–63 preanal and 177–184 total vertebrae; mean vertebral formula 12-62-181.

Description. Body elongate and cylindrical, tail relatively broad, slowly tapered posteriorly and becoming laterally compressed in posterior portion. Head and body with numerous longitudinal grooves.

Head relatively small, branchial basket moderately convex; snout relatively acute but swollen, dorsal contour of anterior snout around second supraorbital pore weakly convex; anterior nostril a prominent anteriorly directed tube; posterior nostril opening inner margin of upper lip, covered with a dermal flap; eye large, 1.7–2.2 in snout length in larger specimens, 1.1–1.4 in smaller specimens (<150 mm TL); mouth inferior, tip of lower jaw just below or slightly beyond posterior base of anterior nostril tube; lips without small sensory papillae or cirri; two prominent short thorn-shaped barbels along upper lip, the first between anterior and posterior nostrils, the second below anterior margin of eye.

Sensory pores developed; one + four on supraorbital; four + two on infraorbital; five (rarely six on one side) on mandible and three on preopercle; three supratemporal pores, midtemporal and interorbital pores present; prominent rows of minute sensory pits on snout, lower jaw, cheek, branchial basket and occipital region. Lateral-line pores almost complete.

All teeth conical, pointed, not robust; teeth on upper jaw uniserial, dentary biserial anteriorly (restricted at synapse, less than five pairs) and uniserial posteriorly, vomerine teeth irregularly biserial anteriorly and uniserial posteriorly.

Dorsal fin well-elevated, its highest point 3/5 to 2/3 body depth; dorsal-fin origin normally just above or posteri- or to a vertical through pectoral-fin insertion (including holotype), rarely one or two rays anterior to the origin; anal fin relatively elevated; dorsal and anal fins becoming lower gradually but relatively high before tail tip, sagittal in shape, the last rays anterior to tail tip by 1/3 head length; pectoral fin oblong-shaped, tip rounded, not lanceolate.

Coloration in life. Head and body pale brown to purplish dark gray, generally with distorted-shaped bars dorsally, but rarely faded, the pattern absent or very pale in young specimens; belly yellowish white to dark brown; snout with a pale blotch; sensory pores on head and body darkly margined, minute sensory pits on head also dark; anterior-nostril tube, posterior nostril cover, third supraorbital pore and barbels along upper lip lighter than others; eyes goldish brown; fins semi-transparent, dorsal fin with a distinct dark to black blotch anteriorly (generally anterior to 15th to 21th ray in larger specimens), pale irregular bars throughout, with a narrow dark margin, posterior tip darker; anal fin with or without a narrow-dark margin, dusky posteriorly; pectoral fin yellowish pale brown to black.

Size. Maximum size 1148 mm TL, estimated to be a mature female from photograph ( Chen 2003). One mature female (902 mm TL) with 0.9–1.2 mm eggs was reported by Shitamitsu & Sunobe (2020).

Distribution. Widespread in the western Pacific from Tokyo to Kuchinoerabu-jima Island, Osumi Islands, Kagoshima along Pacific coast and Niigata to Nagasaki along Sea of Japan and East China Sea (not found in Ryukyu Islands at present), southern Korea, northern Taiwan, Taiwan Strait of Fujin, China (holotype of M. fasciatus ). One specimen was collected from pelagic area of the northwestern Pacific by Shitamitsu & Sunobe (2020). Common in Japan but rarely found from Taiwan and China.

Figures

FIGURE 3. Teeth of Ophichthus altipennis (a, b) and O. zophistius (c, d). a, b, Ophichthus altipennis, KPM-NI 34558, 903 mm TL, Tokashiki-jima Island, Ryukyu Islands, Japan. c, d, O. zophistius, FRLM 45500, 826 mm TL, Katada, Shima, Mie, Japan. north to Ryukyu Islands, Japan. Many images taken by divers from Indonesia, the Philippines and Malaysia. Al-