The Fraser’s dolphin, Lagenodelphis hosei is poorly known cetacean species, which was relatively recently described by Fraser (1956) based on a skeleton collected from a beach in Sarawak, Borneo in 1895. It was rediscovered by Perrin et al. (1973) based on external coloration and form of the species.

This species has a pantropical distribution, largely between 30°N and 30°S (Jefferson et al., 1993). Several stranding records were reported in temperate areas such as France and United Kingdom (Duguy, 1984; Bones et al., 1998). However, these were considered unusual and were probably influenced by temporary oceanographic events (Louella and Dolar, 2009).

In the north-west Pacific region, there are only 4 documented stranding or catch records of the species in Japan (Amano, 2009). Some were sighted and taken in fisheries in Taiwan (Kaiya et al., 1995). However, the species was not recognized from Korea.

An adult female L. hosei carcass (registration No: CRI 00009) was found on the beach at Pyoseon-ri, Seogwipo-si, Jeju-do, Korea (33°19′N, 126°50′E), 15 Jun 2006. External characters of CRI 00009 were measured following Norris (1961). Specimen measurement was taken using a steel tape to the precision of 0.1 cm. Cranial characters were measured as described by Perrin (1975) with vernier calipers to 1 mm. Dental and vertebral formula were counted as meristic characters. The examined specimen was deposited in the Cetacean Research Institute (CRI), National Fisheries Research and Development Institute, Korea. We present the first record of L. hosei in Korean waters and provide the information on external and osteological characters.

Infraorder Cetacea Brisson, 1762

Superfamily Odontoceti Flower, 1867

Family Delphinidae Gray, 1821

1*Genus Lagenodelphis Fraser, 1957

^2*Lagenodelphis hosei Fraser, 1956 (Table 1, Figs. 1,2)

Lagenodelphis hosei Fraser, 1956: 496; Perrin et al., 1973:

345; Tobayama et al., 1973: 251; Bones et al., 1998: 460; Mignucci-Giannoni et al., 1999: 15.

Description. External morphology: Body streamlined and robust. Gently rounded head. Distinct short beak. Number of teeth 40 in each upper row, 44 in left under row and 41 in right under row. Relatively short appendages. Triangular but slightly falcate dorsal fin located mid-back. Small flippers with pointed tips. Flukes concave edges and distinct notch in the middle. Body color is dark gray on the back yellowish and white on the belly.

External measurements (cm): Total body length 221.0,

snout to gape 26.7, snout to blowhole 32.5, snout to eye 32.5, snout to external auditory meatus 38.0, snout to anterior insertion of flipper 40.5, snout to posterior dorsal fin 93.2, snout to umbilicus 101.3, snout to genital aperture 143.1, snout to anus 156.4, maximum width of dorsal fin 29.3, height of dorsal fin 14.5, anterior length of flipper 24.5, posterior length of flipper 17.0, maximum width of flipper 7.5, width of flukes 47.5, nearest point on anterior border of flukes to notch 13.5, girth on anus 63.0, girth on umbilicus 97.0.

Osteological characters: Cranial characters of CRI 00009 are shown in Table 1. Dorsal view of the skull is slightly asymmetry especially around external nares part (Fig. 2). The vertebral formula was cervical 7, thoracic 15, lumber 21 and caudal 29. Some caudal vertebrae which were missed during preparation were not included. The first two cervical vertebrae were fused. The junction of spinous process between fifth and sixth cervical vertebrae was also observed.

Remarks. Lagenodelphis hosei can be confused with striped dolphin (Stenella coeruleoalba) in external appearance at a distance. However, they have the most robust body shape among the pantropical dolphin species. The flippers, dorsal fin and flukes of the species are small, compared with those of other dolphins. The flipper length of L. hosei is about 10- 13% of the total length. The height of dorsal fin represent ？9% of the total body length. Flipper length and width of fluke represent about 10-13% and 20-24% of the total body length, respectively (Jefferson and Leatherwood, 1994). Normal tooth counts L. hosei are 36-44 in each upper row and 34-44 in each lower row (Perrin et al., 1994). The present specimen shows the same external appearance ratio (6.5% in dorsal fin height, 11.1% in flipper length and 21.5% in fluke width) and range in the number of teeth with L. hosei formerly described in the papers.

Cranial measurements of the present specimen also well corresponded to condylobasal length proportions given in the previous descriptions of the holotype provided by Fraser (1956) (Table 1).

Korean name: 1*？？？？？？？？？ (？？？), 2*？？？？？？？ (？？？)