The family Bramidae in the order Perciformes comprises 7 genera and 22 species worldwide (Nelson, 2006), 6 genera and 10 species in Japan (Hatooka and Kai, 2013), and 4 genera and 6 species in Korea (Kim, 2011; Kim et al., 2012; Lee et al., 2014). The 6 species in Korea are Brama japonica Hilgendorf, 1878, Brama orcini Cuvier, 1831, Pteraclis aesticola (Jordan & Snyder, 1901), Pterycombus petersii (Hilgendorf, 1878), Taractichthys steindachneri (Döderlein, 1883), and Taractes asper Lowe, 1843. Of these, B. orcini was the last to be reported as a new member of the Korean fish fauna (Lee et al., 2014).
We collected 10 specimens that looked like Brama japonica, in the family Bramidae, from waters off Jeju Island, Busan, and Gangneung, Korea, which we identified as Brama dussumieri Cuvier, 1831, based on the taxonomic criteria of Mead (1972), who previously described the morphological characteristics of 6 of 7 genera and 18 of 22 species worldwide. In this study, we also used molecular identification methods, such as DNA barcoding, to clarify the taxonomic status of cosmopolitan species, such as B. dussumieri. This paper presents the first morphological description of B. dussumieri from Korea, and elucidates allometric variations occurring among local populations. We propose the new Korean name “Wae-sae-da-rae” for B. dussumieri in Korea.
Ten specimens of Brama dussumieri were collected from waters off Jeju Island, Busan, by purse sine net, and off Gangnueng, by set net, during 2013-2014 (Fig. 1). Counts and measurements followed Hubbs and Lagler (2004), with measurements performed to the nearest 0.1 mm using Vernier calipers. Vertebrae were counted from radiographs (Softex HA-100, Japan). The specimens are deposited at Pukyong National University (PKU).
Genomic DNA was extracted from muscle tissue using Chelex 100 resin (Bio-Rad, USA), and polymerase chain reaction (PCR) was conducted using universal primer sets VF2 (5′-TCAACCAACCACAAAGACATTGGCAC-3′) and FishR2 (5′-ACTTCAGGGTGACCGAAGAATCAGAA-3′), which amplify mitochondrial DNA (mtDNA) cytochrome c oxidase subunit I (COI) (Ward et al., 2005; Ivanova et al., 2007). The PCR was performed on a total volume of 30 μL of sample, containing 5 μL DNA template, 4 μL dNTP, 5 μL 10X buffer, 0.5 μL Taq polymerase, 1 μL reverse primer, 1 μL forward primer, and distilled water. The PCR was conducted under the following conditions: initial denaturation for 1 min at 95°C, followed by 35 cycles of 1 min at 95°C for denaturation, 1 min at 50°C for annealing, and 1 min at 72°C for extension, with a final extension for 5 min at 72°C. The PCR products were purified using ExoSAP-IT (Biochemical Co., USA) and sequenced using an ABI PRISM Big Dye Terminator v3.1 Ready Reaction Cycle Sequence Kit (Applied Biosystems, USA) on an ABI3730xi DNA Analyzer (Applied Biosystems). The sequence was aligned using ClustalW (Thompson et al., 1994) in BioEdit (ver. 7) (Hall, 1999). A neighbor-joining (NJ) tree (Saitou and Nei, 1987) was constructed using the Kimura two-parameter model (Kimura, 1980) in MEGA 5 (Tamura et al., 2011).
Material examined: PKU 9301 and 9302, 2 specimens, 102.1-153.6 mm standard length (SL), Seogwipo-si, Jeju Island, Korea, 4 July 2013; PKU 9303 and 9304, 2 specimens, 148.7-157.1 mm SL, Seogwipo-si, Jeju Island, Korea, 8 July 2013; PKU 9635, 1 specimen, 162.1 mm SL, Seogwipo-si, Jeju Island, Korea, 13 August 2013; PKU 9884, 1 specimen, 181.1 mm SL, Gangneung-si, Gangwon-do, Korea, 25 September 2013; PKU 10126, 1 specimen, 199.9 mm SL, Geoje-do, Gyeongsangnam-do, Korea, 26 December 2013; PKU 10130, 1 specimen, 200 mm SL, Busan, Korea, 2 January 2014; PKU 10374 and 10375, 2 specimens, 191.3–192.0 mm SL, Seogwipo-si, Jeju Island, Korea, 12 March 2014.
Comparative material examined: Brama dussumieri: FAKU 133306, 100.1 mm SL, Kawajiri-misaki, Yamaguchi, Japan, July 2010; FAKU 134950, 137.5 mm SL, Otomi, Fukui, Japan, July 2012. Brama japonica: PKU562, Wan-do, Korea, September 2008; PKU8590, Jeju Island, Korea, April 2013. Brama orcini: PKU 10115, Jeju Island, Korea, December 2013.
(New Korean name: Wae-sae-da-rae) (Fig. 2)
Brama dussumieri Cuvier, 1831: 294 (type locality: eastern Indian Ocean); Mead, 1972: 55 (Indo-Pacific Ocean, Atlantic Ocean); Masuda et al., 1984: 437 (Ryukyu Island and Ogasawara Island, Japan); Robins and Ray, 1986: 354 (USA); Hatooka and Kai, 2013: 908 (Japan).
Brama agassizi Poey, 1860: 204 (type locality: Cuba).
Brama leucotaenia Fowler, 1938: 44 (type locality: Basilan Island, Sulu Archipelago).
Dorsal fin rays, 32-34; pectoral fin rays, 19-20; anal fin rays, 26-29; lateral line scales, 58-64; gill rakers, 13-15; vertebrae, 39-42 (Table 1).
Proportion of measurements as a percentage of SL: head length 24.4-27.1; predorsal length 36.7-40.5; length of dorsal fin base 55.7-60.1; snout to pectoral fin 25.8-27.8; snout to pelvic fin 32.8-38.6; snout to anal fin 50.5-55.4; fork length 108.0-112.9; body depth 45.7-50.7; body width 11.1-13.0; upper caudal fin length 33.6-46.2; lower caudal fin length, 25.3-33.9
Body ovate, strongly compressed; head large (24.4-27.1% SL), forehead feebly arched; snout short (5.5-7.3% SL), slightly blunt, mouth strongly oblique; interorbital region convex, anterior nostril round and located at anterior tip of snout, posterior nostril is a slit midway between anterior nostril and orbit; eye elliptical in shape, with horizontal axis shorter than vertical axis; branchiostegal ray number, 7; membrane completely covered by opercular flap; posterior margin of upper jaw extending slightly beyond line vertical to the middle of the pupil; upper jaw protruding more than lower jaw; one row of small conical teeth in upper jaw, one row or two rows of teeth in lower jaw, some mid-section teeth markedly large and recurved; dorsal fin originating slightly posterior to base of pectoral fin, reaching anterior caudal peduncle; pectoral fin starts under edge of opercle and reaches to mid body; pelvic fin short, originating on a vertical line slightly posterior to the origin of the pectoral fin; caudal fin strongly forked, length of upper lobe (32.3-46.2% SL) longer than that of lower lobe (25.3-33.9% SL); body and head mostly covered with oblong ctenoid scales; dorsal and anal fins covered with large oblong ctenoid scales.
Color when fresh. Head and body silvery, but slightly darker dorsally; pectoral and pelvic fins translucent; dorsal and anal fin dark.
Color after fixation. Head and body mainly grayish brown, but margin of upper jaw, inner pectoral fin base, and orbital rim black; fin color same as when fresh.
Tropical regions of all oceans (Mead, 1972), Ryukyu Is. and Ogasawara Is., Japan (Hatooka and Kai, 2013), and waters off Jeju Island, Busan, and Gangneung, Korea (present study).
The specimens in the present study were identified as belonging to the genus Brama, based on the following morphological characteristics: dorsal fin originating behind the head, over base of pectoral fin, with most elements of the dorsal and anal fins branched, both fins moderately stiff, and with fins erect and covered with ctenoid scales (Mead, 1972). Our specimens were very comparable to those described in other references (Mead, 1972; Hatooka and Kai, 2013), in terms of most counts and measurements. The specimens were identified as belonging to B. dussumieri, based on numbers of gill rakers (13-15) (Fig. 3, Table 1, 2), vertebrae (39-42) (Table 3), lateral line scales (58-64) (Table 4), and the distance between the origin of the pectoral fin base and the insertion of the pelvic fin base (<12% SL). However, the specimens were different from those in other references based on prepectoral length, preanal length, and upper jaw length (Table 1); these differences may represent local variations, as mtDNA COI sequences were well matched among local populations. We compared a 567-base pair mtDNA COI sequence in Korean B. dussumieri with that of B. dussumieri from distant areas (USA, India, and Japan). The sequences in 10 specimens from this study corresponded well with the sequences in specimens from the USA, India, and Japan (genetic distance, d = 0.000-0.018), but differed dramatically from sequences in Korean B. japonica (d = 0.154-0.168) (Fig. 4). Korean and Japanese B. dussumieri differed from congeneric species in the western and eastern Atlantic and East Pacific Oceans in length of the pelvic fin and head width. The specimens from Korea and Japan exhibit a shorter pelvic fin and narrower head width than those from the Atlantic Ocean and East Pacific Ocean (Fig. 5; Mead, 1972); also representing local variation. Brama dussumieri is most similar to B. japonica and B. orcini; however, the three species are easily distinguished by the number of gill rakers (13-15 in B. dussumieri vs. 17-20 in B. japonica vs. 12-16 in B. orcini), number of lateral line scales (57-65 in B. dussumieri vs. 65-75 in B. japonica vs.52-54 in B. orcini), and distance between the origin of the pectoral fin base and the insertion of the pelvic fin base (< 12% SL in B. dussumieri and B. japonica vs. > 12% SL in B. orcini) (Mead, 1972; Hatooka and Kai, 2013). We propose the new Korean name “Wae-sae-da-rae” for B. dussumieri, because of its relatively small size (maximum length: 22.5 cm SL; Pavlov, 1991) as compared to that of congeneric species.