Cypselurus naresii albitaenia, Shakhovskoy & Parin, 2024

Shakhovskoy, Ilia B. & Parin, Nikolay V., 2024, A review of the flying fish genus Cypselurus (Beloniformes: Exocoetidae). Part 3. Revision of the subgenus Cypselurus sensu stricto with descriptions of one new species and four new subspecies and reinstatement of Cypselurus crockeri Seale and Exocoetus socotranus Steindachner, Zootaxa 5473 (1), pp. 1-125 : 66-69

Cypselurus naresii albitaenia subsp. nov.

Synonymy and bibliography.

Cypselurus naresii . Parin 1961a: 47–49 (description; Indian Ocean; in part: only specimens 168 and 182 mm SL, 6°44’S 60°30’E). Kovalevskaya 1982: 114–116, figs. 5–6 (early life history stages; Indian Ocean; in part). Parin 1984: EXOC Cyp 10 (description, figures, distribution; western Indian Ocean; in part). Winterbottom et al. 1989: 15 (listed; Chagos Archipelago). Fricke 1999: 121 (listed; Mascarene Is.). Shakhovskoy & Collette 2022: 347–349, pl. 59 upper left photograph (short description, distribution; western Indian Ocean; in part).

Cypselurus oligolepis (non Bleeker). Randall 1995: 90, fig. 187 (short description, photo; Gulf of Oman; in part).

Material examined. Sixty nine specimens 50–258 mm SL.

Western and central Indian Ocean. Full morphological study. IORAS 04273 (1, 232 mm SL), 4°00’S 64°30’E, 18.02.1974 . IORAS 04430 (1, 159 mm SL), 5°11’S 52°09’E, 9.05.1967 . IORAS 04432 (1, 226 mm SL), Desroches I., Amirante Is., 10- 11.05.1967 . IORAS 04436 (1, 224 mm SL), 5°38’S 57°47’E, 10.10.1971 . IORAS 04137 (1, 205 mm SL), 11°55’S 84°10’E, 18.10.1962 . IORAS 04151 (1, 254 mm SL), 7°09’S 73°30’E, 16.12.1960 . IORAS 04175 (1, 239 mm SL), 3°56’S 73°10’E, 14.12.1960 . IORAS 04191 (1, 208 mm SL), same data . IORAS 04195 (1, 185.5 mm SL), 0°55’S 62°33’E, 17.11.1960 . IORAS 04197 (1, 244.5 mm SL), 9°37’S 61°19’E, 8- 9.01.1989 . IORAS 04198 (1, 213 mm SL), same data . IORAS 04199 (1, 210 mm SL), 5°21’S 68°28’E, 4.12.1964 . IORAS 04200 (1, 252.5 mm SL), same data . IORAS 04201 (1, 240.5 mm SL), same data . IORAS 04211 (2, 168– 182 mm SL), 6°44’S 59°16’E, 2.06.1956 . IORAS 04215 (2, 119– 144 mm SL), 6°53’S 53°38’E, 5.03.1960 . IORAS 04221 (paratype) (1, 51 mm SL), 3°59’S 75°07’E, 3.02.1974 . IORAS 04224 (5, 50–71.5 mm SL), 4°30’S 75°00’E, 31.01.1974 . IORAS 04243 (1, 151 mm SL), 7°07’N 91°31’E, 14.09.1962 . IORAS 04247 (1, 86 mm SL), 7°10’S 67°39’E, 15.02.1960 . IORAS 04257 (1, 176 mm SL), 5°06’N 91°32’E, September 1962 . IORAS 04272 (1, 52 mm SL), ~ 1°N 55°E, 14.06.1978 . SOSC Field No. LK 64-95 (1, 124 mm SL), 5°08’S 41°37’E, 3.11.1964 . ZMMU P-24609 (holotype, 251 mm SL), 9°19’S 73°12’E, 20.08.1978 . ZMUC uncat. (1, 224 mm SL), 9°02’S 49°20’E, 6- 7.03.1951 . ZMUC uncat. (1, 104 mm SL), 8°52’S 49°25’E, 7.03.1951 . ZMUC uncat. (6, 101– 258 mm SL), 9°31’S 49°29’E, 5.03.1951 .

Partial morphological study. IORAS uncat.* (1, 178 mm SL), 3°N 58°E, 14.04.1980 . IORAS uncat.* (10, 92–225 mm SL), 5°57’S 60°08’E, 8- 9.04.1980 . IORAS uncat.* (1, 253 mm SL), 11°33’S 60°22’E, 8- 9.07.1978 . IORAS uncat.* (1, 211 mm SL), 7°34S 75°40’E, 1.06.1980 . IORAS uncat.* (1, 84.5 mm SL), 7°59’S 76°05’E, 21.01.1960 . ZMUC uncat. (2, 127– 128 mm SL), 8°52’S 49°25’E, 7.03.1951 .

Arabian Sea. Full morphological study. IORAS 04395 (1, 153 mm SL), 4°57’N 78°17’E, 20- 21.07.1978 . IORAS 04142 (1, 217 mm SL), Cochin, India . IORAS 04161 (1, 198.5 mm SL), 13°39’N 62°14’E, 10.11.1960 . IORAS 04165 (1, 198 mm SL), 19°15’N 65°56’E, 26- 27.11.1960 . IORAS 04168 (1, 217 mm SL), 16°49’N 62°02’E, 9.11.1960 . IORAS 04171 (1, 236.5 mm SL), 9°17’N 71°00’E, 9.12.1960 . IORAS 04186 (1, 202 mm SL), 13°39’N 62°14’E, 10.11.1960 . IORAS 04188 (1, 195.5 mm SL), 16°49’N 62°02’E, 9.11.1960 . IORAS 04190 (1, 227.5 mm SL), same data . IORAS 04192 (1, 206 mm SL), 9°17’N 71°00’E, 9.12.1960 . IORAS uncat* (1, 114 mm SL), 16°38’N 70°13’E, 3.04.1960 .

Partial morphological study. INBYUM uncat* (1, 227 mm SL), 8°20’N 54°30’E, 10.06.1980. INBYUM uncat* (3, 232– 256 mm SL), 9°N 58°20’E, 18.04.1980.

Holotype ( Figs. 27f , 28h ). ZMMU P-24609, R / V Pantikapei, 9°19’S 73°12’E, 20 August 1978. Length 251 mm SL (immature female). D 11, A 8, P I 13, Spred 35, Str 8½, Sp.br 26 (7 + 19), Vert 43 (28 + 15). Measurements (in % SL): aA 80.5, aD 72.7, aV 62.1, cV 38.3, pV 34.7, c 23.8, po 10.8, o 6.9, ao 5.2, io 8.7, Hc 16.5, H 19.0, h 6.9, Dc 24.7, lP 68.9, lP1 43.4, lV 28.3, lD 16.4, lA 9.5, HD 9.4 , HA 5.9, p 12.8. Body dark dorsally, paler ventrally. Head with few dark specks on gill cover. Pectoral fins dark brown to 9th ray with a pale tip and narrow pale posterior edging. Tip of pectoral fin nearly reaching middle of caudal peduncle. Pelvic fins pale with a large dark spot between 3rd–5th rays distally ( Fig. 28h ), pelvic-fin tip protruding slightly beyond end of anal-fin base. Dorsal fin pale-brownish, tip of its last ray slightly protruding beyond middle of caudal peduncle. Anal fin pale with 2–3 dots barely discernible on 7th ray; first anal-fin ray beneath 5th–6th dorsal-fin ray. The 2nd dorsal- and anal-fin ray longest. Caudal fin brown with slightly darker upper lobe. Lower jaw shorter than upper jaw. Jaw teeth very small (not visible with the naked eye), mainly conical, some teeth with additional cusps; arranged in 2 rows. Palatine teeth present.

Paratypes. IORAS 04175 , 239 mm SL, 3°56’S 73°10’E, 14 December 1960 . IORAS 04221 , 51 mm SL, 3°59’S 75°07’E, 3 February 1974 .

Differential diagnosis. Cypselurus n. albitaenia differs from other subspecies in chin barbel morphology and pigmentation ( Figs. 18–19 , 20d , 22 , 27 ): barbel long with two lateral triangular flaps basally, its end widened; pigmentation dark with a paler median keel and a pale longitudinal streak distally; as well as in more predorsal scales and vertebrae ( Tables 3, 6) and longer pelvic fins ( Fig. 20c ). Also, juveniles of C. n. albitaenia have paler lower surface of body and head ( Fig. 21 ) and have some peculiarity in pigmentation of pectoral, anal and caudal fins (see above).

Cypselurus n. albitaenia is the largest subspecies of C. naresii , its maximal size is 258 mm SL vs. 240 mm SL in C. n. ordinarius, 212 mm SL in C. n. naresii and 182 mm SL in C. n. socotranus .

Intrasubspecies variation. Fish from the Arabian Sea somewhat differ from others in deeper body and smaller eye ( Fig. 29 ) and fewer predorsal scales (usually ≤ 31 vs. usually ≥ 32) and precaudal vertebrae (usually ≤ 28 vs. usually ≥ 29). Therefore the population from the Arabian Sea merits further taxonomic study.

Etymology. The subspecies’ name C. n. albitaenia reflects one of its diagnostic characters—the presence of a pale longitudinal streak on the chin barbel of juveniles (from Latin “ albidus ”—whitish and “ taenia ”—tape, a narrow stripe).

Common name. The name “Indian Ocean pharao flying fish” (Russian: “индоокеанский стрижехвост-фараон”) is proposed here.

Distribution. Cypselurus n. albitaenia, unlike other subspecies of C. naresii , found mainly in oceanic waters, especially off oceanic islands ( Fig. 24 ). According to our data, C. n. albitaenia is distributed from East Africa (SOSC Field No. LK 64-95, 5°08’S 41°37’E) to Nicobar Islands (IORAS 04243,7°07’N 91°31’E; IORAS 04257, 5°06’N 91°32’E) and from Gulf of Oman (USNM FIN 28137, 213 mm SL, Muttrah market, 12 May 1990) to 12°S (IORAS 04137, 11°55’S 84°10’E; IORAS uncat., 11°33’S 60°22’E). However, the subspecies probably occurs southwards at least to about 20°S, because Fricke et al. (2009) and Kovalevskaya (1982) reported C. naresii from the waters of Reunion, Mauritius, Rodrigues and Madagascar.

Figures

FIGURE 18. Cypselurus naresii ordinarius. (A)—42 mm SL, IORAS 04227, 5°00’N 90°52’E (drawing by G.N. Pokhilskaya); (B)—68 mm SL, IORAS 04232, 1°57’N 135°14’E (after Parin 1961a); (C)—196 mm SL, IORAS uncat., 3°06’N 128°09’E (after Parin 1961a).

FIGURE 19. Cypselurus naresii ordinarius. (A)—47.5 mm SL, IORAS 04209, 0°59’N 134°31’E; (B)—68 mm SL, IORAS 04255, 9°29’N 89°54’E; (C)—103.5 mm SL, IORAS 04241, 10°03’S 108°00’E; (D)—144 mm SL, IORAS 04245, 9°00’S 105°24’E; (E)—176 mm SL (flipped horizontally), ZMMU P-24607 (holotype), 9°20’S 111°53’E; (F)—207 mm SL, IORAS 04277, 6°33’N 82°18’E.

FIGURE 21. Ventral side of head in juveniles of Cypselurus naresii. (A)—C. n. ordinarius, 55 mm SL, IORAS 04228, 8°18’N 120°25’E; (B)—C. n. albitaenia, 56 mm SL, IORAS 04224, 4°30’S 75°00’E.

FIGURE 22. Chin barbel of Cypselurus naresii ordinarius (A–C) and C. n. albitaenia (D–F) (ventral view of head). (A)—51.5 mm SL, IORAS 04222, 10°48’S 104°38’E; (B)—78 mm SL, IORAS 04223, 6°20’N 122°36’E; (C)—121 mm SL, IORAS 04244, 5°38’S 147°04’E; (D)—53 mm SL, IORAS 04224, 4°30’S 75°00’E; (E)—86 mm SL, IORAS 04247, 7°10’S 67°39’E; (F)—168 mm SL, IORAS 04211, 6°44’S 59°16’E.

FIGURE 24.Distribution of Cypselurus naresii (∆—C.n.naresii, —C.n. septentrionalis (our data), —C. n. septentrionalis (data of Imai 1959, Tsukahara 1959 and Chen 1987), ○—C. n. ordinarius, ◊—C. n. albitaenia, □—C. n. socotranus). Filled symbols indicate capture location for fishes ≤ 100 mm SL, open symbols indicate capture location for fishes> 100 mm SL; holotype position marked with asterisk.

FIGURE 27. Cypselurus naresii albitaenia. (A)—52 mm SL, IORAS 04272, ~ 1°N 55°E; (B)—86 mm SL, IORAS 04247, 7°10’S 67°39’E; (C)—119 mm SL, IORAS 04215, 6°53’S 53°38’E; (D)—151 mm SL, IORAS 04243, 7°07’N 91°31’E; (E)— 198 mm SL, IORAS 04165, 19°15’N 65°56’E; (F)—251 mm SL, ZMMU P-24609 (holotype), 9°19’S 73°12’E.

FIGURE 28. Pectoral (A–C) and pelvic (D–H) fins of Cypselurus naresii albitaenia.(A)—51 mm SL, IORAS 04221 (paratype), 3°59’S 75°07’E; (B)—168 mm SL, IORAS 04211, 6°44’S 59°16’E; (C)—232 mm SL, IORAS 04273, 4°00’S 64°30’E; (D)— 56 mm SL, IORAS 04224, 4°30’S 75°00’E; (E)—119 mm SL, IORAS 04215, 6°53’S 53°38’E; (F)—151 mm SL, IORAS 04243, 7°07’N 91°31’E; (G)—198 mm SL, IORAS 04165, 19°15’N 65°56’E; (H)—251 mm SL, ZMMU P-24609 (holotype), 9°19’S 73°12’E.

FIGURE 29. Size variation of body depth divided by eye diameter (index H/o) in Cypselurus naresii albitaenia from the Arabian Sea (♦) and the Indian Ocean (○).

FIGURE20.Sizevariationofmorphometriccharacters(in%SL)inCypselurusnaresii:x—C.n.naresii;◊—C.n.septentrionalis; □—C. n. socotranus; Δ—C. n. ordinarius (lilac—western Pacific Ocean, red—eastern Indian Ocean, orange—Bay of Bengal and Andaman Sea); ○—C. n. albitaenia (dark blue—Indian Ocean, light blue—Arabian Sea). (A)—preventral distance (aV); (B)—greatest body depth (H); (C)—pelvic-fin length (lV); (D)—length of chin barbel (Lcir).