An underwater photograph of Sphyraena iburiensis (Perciformes: Sphyraenidae) from the Red Sea: first record outside Japanese waters

Abstract

Sphyraena iburiensis, a small-sized barracuda (family Sphyraenidae) recently described by Doiuchi and Nakabo (2005), belongs to the S. obtusata group sensu Doiuchi and Nakabo (2005), characterized by two gill rakers on the first gill arch. The original description of S. iburiensis was based on the holotype and paratypes collected from Iburi, Kochi Prefecture, with additional paratypes from Kushimoto, Wakayama Pref. and Kawana, Shizuoka Pref., all located on the Pacific coast of southern Japan. Subsequently, a specimen of S. iburiensis was reported from Fukaura, Ehime Pref., Japan by Takagi et al. (2010), although additional records based on underwater photographs include Taketomi Island, Ryukyu Islands, Japan (KPM-NR 12009, taken by J. Nakamoto) and Hachijo Island, Izu Islands, Japan (KPM-NR 91935–91937, taken by S. Kato); the photographs are deposited at the Image Database of Fishes, Kanagawa Prefectural Museum of Natural History (http://research.kahaku.go.jp/zoology/ photoDB/). To date, therefore, S. iburiensis has been considered endemic to Japanese waters, although Sphyraena obtusata and Sphyraena pinguis, also members of the S. obtusata group, are both widely known from the IndoWest Pacific (Doiuchi and Nakabo 2005). In 10 October 2008, an underwater photograph of S. iburiensis (Fig. 1) was taken at Shams Alam reef, Wadi Gimal area, Red Sea coast of Egypt (24 4101800N, 35 0500800E), by the second author (S. B.). This record is the first of S. iburiensis outside Japanese waters; the fishes pictured agree well with the diagnostic characters of the S. obtusata group given by Doiuchi and Nakabo (2005), viz. pored lateral-line scales ca. 81–84; scales below lateral line ca. 10 , orbit diameter ca. 5.5% in standard length, posterior tip of maxilla not reaching anterior margin of eye, anterior tip of lower jaw without a pointed fleshy knob, origin of first dorsal fin well behind that of pelvic fin, and body with two longitudinal stripes on the lateral surface. Among the S. obtusata group, S. iburiensis differs from S. pinguis as follows: two longitudinal stripes, lower stripe running through upper part of pectoral-fin base (a single stripe running above pectoral-fin base in S. pinguis) (Doiuchi and Nakabo 2005). Sphyraena iburiensis differs from S. obtusata in having both longitudinal stripes distinct (somewhat indistinct in S. obtusata), the lower stripe extending to the caudal-fin base just below the lateral line (lower stripe joining lateral line midway between end of second dorsal-fin base and caudal-fin base, extending to middle of caudal-fin base in the latter), in addition to 10 – 11 scales below the lateral line (8 –9 in S. obtusata) (Doiuchi and Nakabo 2005). The individuals in Fig. 1 agree closely with the original description of these characters. Shams Alam reef is a large, semi-enclosed lagoon characterized by sandy areas, seagrass beds, isolated coral reefs and fringing reefs. The pictured individuals were observed at a depth of between 1 and 2 m (over about 3 m). Approximately 20 individuals with total lengths of R. Doiuchi (&) Fisheries Experimental Station, Wakayama Research Center of Agriculture, Forestry, and Fisheries, 1557-20 Kushimoto, Higashimuro-gun, Wakayama 649-3503, Japan e-mail: doiuchi_r0001@pref.wakayama.lg.jp