Cypselurus starksi Abe, 1953

Shakhovskoy, Ilia B. & Parin, Nikolay V., 2022, A review of the flying fish genus Cypselurus (Beloniformes: Exocoetidae). Part 2. Revision of the subgenus Poecilocypselurus Bruun, 1935 with descriptions of three new species and five new subspecies and reinstatement of Exocoetus apus Valenciennes and E. neglectus Bleeker, Zootaxa 5117 (1), pp. 1-109 : 11-13

Cypselurus starksi Abe, 1953

Synonymy and bibliography.

Cypsilurus agoo (non Temminck & Schlegel). Jordan & Starks 1903: 541–542, fig. 3 (description, distribution; waters of Japan; in part?).

Cypselurus starksi Abe, 1953: 969–974 , Pl. 192, figs. 525–526 (original description; Japan). Matsubara 1955: 400 (in key). Tomiyama et al. 1958: 244 (short description, figure; Japan). Imai 1958a: 41, Pl. 39 figs. 1–2 (early life history stages; Japan; in part). Parin 1958: 121 (distribution). Imai 1959: 75–81, Pls. 36–37, 38a, c–d (description, distribution, early life history stages; Japan; in part). Tsukahara 1959: 181–183, figs. 37–41 (description, early life history stages; Amakusa Is.). Abe 1960: 149 (listed; Japan: Kuroshio Current). Parin 1960a: 223, 255, 279 (description (after Abe 1953); Japan). Parin 1960b: 156 (distribution; Japan). Parin 1961b: 118, 129, 167 (morphology, systematics). Parin 1962: 224–229 (distribution; Sea of Japan and adjacent waters). Honma 1963: 17 (listed; Sado I., Japan). Shojima & Ueki 1964: 252 (listed as associated with drifting algae; Tsuyazaki, Japan). Lindberg & Legeza 1965: 222, 228–230, fig. 216 (short description (after Abe 1953), distribution; Japan and Yellow seas). Nishimura 1965: 66 (listed; Sea of Japan). Parin 1967: 47, 50–52, 54 (distribution, biology). Shiokawa 1967: 4 (experimental fishery; Japan). Chen 1978: 298–299 (distribution, identification key; Taiwan). Kovalevskaya 1980: 224 (listed). Fedoryako 1982: 111 (juveniles listed as associated with drifting objects; Pacific Ocean). Chen 1987: 15, 18, 23, 25, 52–53, 151, Figs. 3-21, 4-7, 6-9, 6-20 , Tabs. 2-1, 3-1, 4-7 (description, distribution, early life history stages; North-West Pacific). Chen 1988: 284–285, 1028 (early life history stages, figures, distribution; Japan). Senou et al. 2006: 431 (listed; Sagami Sea). Ichimaru 2007: 39 (listed; Goto Is., Japan). Nishida et al. 2008: 287, 290 (listed as associated with drifting seaweeds; Northern Kyushu, Japan). Fujiwara et al. 2017: 85–86 (meristic characters; Japan). Iwatsuki et al. 2017: 34 (listed; Hyuga Nada, Southwestern Japan). Fujiwara et al. 2018: 52, 65, 69, 73, fig. 5N (short description; Mi-shima I., Japan). Hata 2020: 160–161 (short description, photos, fishery; Osumi, Japan; in part?). Sonoyama et al. 2020: 40 ( Japan (Yamaguchi Pref. )).

Cypselurus poecilopterus (non Valenciennes). Chyung 1977: Pl. 169 (1) ( Korea, in part).

Prognichthys agoo (non Temminck & Schlegel). Chyung 1977: Pl. 170 (3) ( Korea; in part).

Cypselurus spilonotopterus (non Bleeker). Hata & Motomura 2014: 25–28, fig.1 (description; Kagoshima, Japan; in part: only specimen 89.3 mm SL).

Material examined. Twenty-seven specimens 65–200 mm SL.

Full morphological study. IORAS 03962 (158 mm SL), probably Vietnam (Danang?), 18.04.1980 . IORAS 03963 (179 mm SL), China, Yentai , 30.06.1958 . IORAS 03964 (172 mm SL), China . IORAS 03965 (168 mm SL), China . IORAS 03966 (155 mm SL), China . CAS 17790 (1, 189 mm SL), Hong Kong, 14.06.1971 . NSMT P.19431* (1, 130 mm SL), 34°55’N 139°07’E, 10.10.1980 .

Partial morphological study. AMS I.27404.001* (1, 171 mm SL), no data. CAS 107329 * (1, 179 mm SL), Honshu I.: Tokyo Bay . CAS 107892 (SU 7892)* (paratypes), (2, 182– 199 mm SL), Kyushu I., Nagasaki . FRSKU 102256 * (1, 176 mm SL), Kanongi, Kagama Pref. , 8.07.1970 . FRSKU W487 * (5, 65– 120 mm SL), Maizuru Fish Market , 8.09.1978 . FRSKU W556 * (3, 126– 142 mm SL), same place, 22.09.1978 . FRSKU W564 * (3, 102– 111.5 mm SL), same place, 20.09.1978 . FRSKU W840 * (1, 133 mm SL), same place, 17.10.1977 . FRSKU W841 * (1, 134 mm SL), same place, 17.10.1977 . HUMZ 37296 * (1, 131 mm SL), no data . NSMT P35790* (1, 200 mm SL), 35°38’N 134°46’E, 30.06.1991 .

Holotype. The holotype of C. starksi ( ZUMT 47821, according to Fricke et al. 2021) was not studied by us. However, Abe (1953) provided a detailed description of the holotype.

Paratypes. Paratypes of C. starksi ( CAS 107892 , 2 specimens) were studied by the second author. Their characters are given below (also included in Tables 1–6 and 10 ) .

Length 199 mm SL, D 13, A 8, P I 15, Spred 32, Str 8½. Measurements (in % SL): cV 1 33.9, pV 41.9, Dc 29.1, c 25.1, H 18.3.

Length 182 mm SL, D 13, A 9, P I 15, Spred 32, Str 8. Measurements (in % SL): cV 1 34.0, pV 40.3, Dc 28.2, c 23.0.

Description. Meristic and morphometric characters are given in Tables 1–6 and 10. D 12–14, A (7)8–9, P I 13–16 (usually I 15), Spred 26–33 (usually 28–29), Str 8–10 (usually 9–9½), Sp.br 20–26 (5–8 + 15–19), Vert 42–44 (27–29 + 14–16). Snout short and blunt, upper jaw not pointed anteriorly ( Fig. 2a ). With mouth closed lower jaw usually shorter than upper jaw or of equal size. Jaw teeth rather large (usually plainly visible with a naked eye), tricuspid, rarely with additional cusps; arranged in 2–5 rows. Palatine teeth always present, numerous.

In fish 130–200 mm SL body elongate to rather deep. Greatest body depth fits 4.9–5.7 times in SL, greatest head depth 5.3–5.7 in SL. Body width 1.25–1.45 and caudal peduncle depth 2.31–2.62 in greatest body depth. Head length 3.95–4.35 in SL and 1.05–1.25 in dorso-caudal distance. Eyes relatively small, eye diameter 12.0– 14.1 in SL, 2.95–3.3 in с, 1.25–1.40 in po and 1.0– 1.3 in io.

Pectoral fins long, their length 1.4–1.55 in SL; lP somewhat increasing with growth (from 65.0–67.0% SL in fish 130–142 mm SL to 67.3–70.3% SL in fish 155–179 mm SL). Tip of pectoral fin reaching from end of dorsal-fin base to middle of caudal peduncle (rarely slightly farther). First pectoral-fin ray unbranched, its length 2.4–2.8 in SL and 1.65–1.8 in lP, increasing with growth (35.9–38.6% SL in fish 138–155 mm SL and 39.9–41.6% SL in fish 158–179 mm SL). Pelvic fin base nearer to posterior edge of head than to origin of caudal-fin lower lobe (cV/pV = 0.76–0.88). Pelvic fin length 2.6–3.2 in SL and 1.7–2.2 in lP, notably increasing with growth (35.3–38.6% SL in fish 130–142 mm SL and 30.9–33.0% SL in fish 155–179 mm SL). Tip of pelvic fin reaching from posterior part of anal-fin base to middle of caudal peduncle (rarely slightly farther).

Anal-fin origin well behind dorsal-fin origin (1 st anal-fin ray beneath 6 th –7 th dorsal-fin ray). Dorsal fin with 3–6 rays more than anal fin. Height of dorsal and anal fins 8.6–10.6 and 10.3–15.1 in SL, respectively; height of both fins somewhat decreasing with growth. Longest dorsal- and anal-fin ray—the 2 nd or, more rarely, 3 rd. Tip of last dorsal-fin ray reaching middle of caudal peduncle or beyond, but never reaching origin of caudal fin upper lobe. Middle and posterior dorsal-fin rays not elongated.

Pigmentation. In fish 130–200 mm SL, body with usual flying fish pigmentation—darker dorsally and paler ventrally ( Fig. 2a ). Dark specks on gill covers and under eyes absent or very sparse. Pectoral fins ( Fig. 2b ) black or dark brown to (occasionally to 9 th) 10 th –13 th ray; tip usually pale, posterior pale edging usually absent. Proximal part of pectoral fin often somewhat paler than distal one.

Pelvic fins in fish 130–142 mm SL dark between 2 nd –5 th rays. In fish ≥ 155 mm SL, pelvic fins pale (occasionally faint vestigial pigmentation may persist distally). Dorsal fin gray to pale brown. Anal fin pale (in fish 130–140 mm SL with dark spot posteriorly). Caudal fin pale brown, with darker tip of upper lobe and fork margin.

Coloration in life. According to Imai (1959), the pectoral fins of adults are dark blue or bluish black; in juveniles the pectoral, pelvic and dorsal fins are purplish red. According to Tsukahara (1959), the body of adults is dark bluish dorsally and silvery white ventrally. The pectoral fins are bluish black with transparent lower part. The dorsal, anal and pelvic fins are grayish (pelvic fins dark in juveniles to at least 150 mm FL). Juveniles 23–98 mm FL with dark bluish pectoral and pelvic fins.

Maximum size. The largest specimen of C. starksi studied was 200 mm SL (NSMT P35790). According to Imai (1959) maximum length is 210 mm SL.

Intraspecific variation. No data.

Comparative remarks. Cypselurus starksi is very similar to C. bosha and C. olpar , differing most prominently in number of precaudal (27–29 vs. 24–26) and caudal (14–16 vs. 16–18) vertebrae (although total number is similar), much longer pelvic fins (> 30 vs. <30% SL in fish ≥ 130 mm SL) and in morphology and arrangement of jaw teeth (tricuspid teeth arranged in 2–5 rows in C. starksi vs. conical or with additional cusps teeth in 1–2 rows in C. bosha and C. olpar ).

This species differs from C. poecilopterus , C. simus and C. callopterus in pectoral-fin pigmentation. The dark morph of C. poecilopterus lacks the distinct spottiness on the pectoral fins (see below) and it is hard to distinguish from C. starksi . Additional characters to separate these species include number of total (42–44, usually 43–44 in C. starksi vs. 39–43, usually 40–42 in C. poecilopterus ) and precaudal (27–29, usually 28 vs. 25–28, usually 26–27) vertebrae and predorsal scales (26–33, usually 28 or more vs. 23–32, usually 24–28).

Biology. A small collection of C. starksi at our disposal allows us to note only that fish from waters of China (IORAS 03963–03965) were mature or close to maturity, indicating that in this area spawning takes place at least in June–July. According to Imai (1959), spawning takes place off Amakusa Is. and Siganoshima in the first 10–20 days of July in water with temperatures 25–26°C; juveniles appear in coastal waters of Kyushu from 10 th day of July to first 10 days of September.

Distribution. The distribution of C. starksi based on specimens studied by us is shown in Figure 3 . According to our data and the available literature, this species is distributed in neritic waters of the Japan, Yellow, East China and South China seas and off the Pacific coast of Japan. Its northernmost occurrence is Yentai, China (IORAS 03963) and Tokyo Bay (CAS 107329); the southernmost is Hong Kong (CAS 17790) and, probably, Danang, Vietnam (IORAS 03962). Honma (1963) also listed C. starksi from Sado I., Japan.

Kyushin et al. (1977) reported C. starksi from the Andaman Sea, but we regard this occurrence as a misidentification of C. oligolepis .

Figures

FIGURE 2. Cypselurus starksi: (A)—IORAS 03963 (Yentai, China), 179 mm SL; (B)—the same specimen, pectoral fin.

FIGURE 3. Distribution of Cypselurus starksi (□), C. oligolepis oligolepis (○), C. o. persicus (◊), C. o. georgii ( ) and C . izumii (Δ). Filled symbols indicate capture location for fishes ≤ 100 mm SL, open symbols indicate capture location for fishes> 100 mm SL. Positions of holotypes marked with asterisk.

FIGURE 4. Flying fish drawings from Bleeker 1866-1872: (A)—Exocoetus oligolepis; (B)—E. brachysoma; (C)—E. neglectus.

FIGURE 5. Cypselurus oligolepis oligolepis: (A)—37 mm SL, IORAS 03985, 15°47’N 123°28’E; (B)—43 mm SL, ZMUC uncat., 4°30’N 103°28’E; (C)—76 mm SL, IORAS 03975, 12°28’S 128°05’E; (D)—94 mm SL, IORAS 03978, 5°37’N 94°46’E; (E)—124 mm SL, IORAS 03972, Singapore; (F)—166 mm SL, IORAS 03967, Nha Trang.

FIGURE 6. Size variation of morphometric characters (in % SL) in Cypselurus oligolepis (□— C. o. oligolepis, ○— C. o. apus, ∆— C. o. persicus, +—C. o. georgii), C. clariangulatus (◊) and C. izumii (x): (A)—diameter of eye (o); (B)—width of interorbital space (io); (C)—length of pectoral fin (lP); (D)—length of pelvic fin (lV); (E)—postorbital distance divided by diameter of eye (index po/o); (F)—pectoral fin length divided by pelvic fin length (index lP/lV).

FIGURE 7. Pectoral fins in Cypselurus oligolepis oligolepis: (A)—31.5 mm SL, IORAS 03985, 15°47’N 123°28’E; (B)—76 mm SL, IORAS 03975, 12°28’S 128°05’E; (C)—94 mm SL, IORAS 03978, 5°37’N 94°46’E; (D)—140 mm SL, IORAS 03972, Singapore.

FIGURE 8. Pelvic fins in Cypselurus oligolepis oligolepis: (A)—31.5 mm SL, IORAS 03985, 15°47’N 123°28’E; (B)—70.5 mm SL, CAS 81864, Linapacan I.; (C)—99 mm SL, CAS 81829, 6°56’N 121°45’E; (D)—124 mm SL, IORAS 03972, Singapore.

FIGURE 9. Cypselurus oligolepis persicus: (A)—181 mm SL, USNM 147840 (holotype), Ras Tanura, West Pier; (B)—same specimen, pectoral fin; (C)—182 mm SL, USNM FIN 28135, Saudi Arabia, Jubail (photo by J.E. Randall, from the USNM website); (D)—171 mm SL, MTUF uncat, Kuwait fishmarket (drawing by T.N. Steyker).

FIGURE 10. Holotype of Cypselurus oligolepis georgii (145 mm SL, ZMMU P-24451, road of Suez): (A)—side view; (B)— close up of head; (C)—pectoral fin.

FIGURE 11. Cypselurus oligolepis georgii: (A)—39 mm SL, IORAS 03990, 14°05’N 42°20’E; (B)—56 mm SL, IORAS 03990, 14°05’N 42°20’E; (C)—71.5 mm SL, IORAS 03991, Gulf of Aden; (D)—76 mm SL, IORAS 03990, 14°05’N 42°20’E; (E)—113 mm SL, IORAS 03989, 14°05’N 42°20’E.

FIGURE 12. Pectoral fins in Cypselurus oligolepis georgii: (A)—39 mm SL, IORAS 03990, 14°05’N 42°20’E; (B)—56 mm SL, IORAS 03990, same place; (C)—71.5 mm SL, IORAS 03991, Gulf of Aden; (D)—76.5 mm SL, IORAS 03989, 14°05’N 42°20’E; (E)—111 mm SL, IORAS 03988, 13°14’N 42°59’E; (F)—123.5 mm SL, IORAS 03988, same place.

FIGURE 13. Pelvic fins in Cypselurus oligolepis georgii: (A)—71.5 mm SL, IORAS 03991, Gulf of Aden; (B)—76 mm SL, IORAS 03990, 14°05’N 42°20’E; (C)—103.5 mm SL, IORAS 03989, 14°05’N 42°20’E; (D)—117 mm SL, IORAS 03986, 13°03’N 42°58’E.

FIGURE 14. Cypselurus oligolepis subsp. (131 mm SL, IORAS 03993, Red Sea?).

FIGURE 15. Type of Exocoetus apus (122 mm SL, MNHN B834, Macao): (A)—side view; (B)—view from above. Photos provided by Jonathan Pfliger and Zouhaira Gabsi (MNHN).

FIGURE 16. Cypselurus oligolepis apus: (A)—32 mm SL, AMS uncat., Sek Harbour; (B)—41 mm SL, SOSC uncat., 00°51’S 135°35’E; (C)—94.5 mm SL, SOSC uncat., 01°53’N 127°39’E; (D)—116.5 mm SL, SOSC uncat., 01°20’N 128°01’E; (E)— 134 mm SL, IORAS 04006, Rabaul.

FIGURE 17. Pectoral (A–C) and pelvic (D–F) fins in Cypselurus oligolepis apus: (A)—41 mm SL, SOSC uncat., 00°51’S 135°35’E; (B)—92.5 mm SL, SOSC uncat., 1°00’N 127°56’E; (C)—144 mm SL, IORAS 04006, Rabaul; (D)—32 mm SL, AMS uncat., Sek Harbour; (E)—43 mm SL, CAS 128237 (SU 28237), Madang; (F)—110 mm SL, IORAS 04006, Rabaul.

FIGURE 18. Distribution of Cypselurus oligolepis apus (○) and C. clariangulatus (◊). Filled symbols indicate capture loca- tion for fish ≤ 100 mm SL, open symbols indicate capture location for fish> 100 mm SL. Positions of holotypes marked with asterisk.

FIGURE 19. Cypselurus izumii: (A)—187 mm SL (holotype), IORAS 03995, 20°01’S 115°00’E; (B)—pectoral fin of specimen 174 mm SL (paratype), IORAS 03997, 26°27’S 112°44’E.

FIGURE 20. Holotype of Cypselurus clariangulatus (50 mm SL, ZMMU P-24452, 8°18’N 120°25’E): (A)—side view; (B)— pectoral fin; (C)—pelvic fin.

FIGURE 21. Cypselurus clariangulatus: (A)—32 mm SL, CAS 81823, 8°43’N 122°40’E; (B)—61 mm SL, ZMUC uncat., 2°54’N 120°04’E; (C)—92 mm SL, CAS 81829, 6°56’N 121°45’E; (D)—128.5 mm SL, IORAS 03999, Philippines (Camotes Sea?); (E)—147 mm SL, CAS 81829, 6°56’N 121°45’E.