THE RAFFLES BULLETIN OF ZOOLOGY 1998 46(2): 324 © National University of Singapore FIRST ACCOUNT OF BRYDE'S WHALES BALAENOPTERA EDEN I (ANDERSON, 1878), AND OF SPINNER DOLPHINS STENELLA LONGIROSTRIS (GRAY, 1828), FROM KOMODO ISLAND, INDONESIA A group of Bryde's whales B.(llaenoptera edeni was observed on 15 and 16 October 1995 in Loh Liang Bay (Lat 8°37'S,Long 119°30'E), Komodo National Park, Indonesia. Concurrently, groups of spinner dolphins Stenel~a longirostris were encountered. Areview ofthe current status of knowledge of cetaceans in Indonesian waters is given by Rudolph et al. 1997 (ZooI.Verh. Leiden 312: 1-42). Loh Liang Bay forms asouth-facing semicircle oftwo kilometers diameter, which slopes towards adepth of60m. Whales were observed ataminimum water depth of20m. Onthefirstday5-7whales (1calf) were observed, and 3whales onthesecond day. Onafew occasions ananimal would approach thedrifting boat when the engine was cut. The lateral ridges on the rostrum from the snout tothe blowhole on either side of the balaenopterid median ridge were clearly visible. The whales were identified as Bryde's whales Balaenoptera edeni. They were between 6-9m long (calfapprox 3m)which wasjudged against theknown length ofthesurvey vessel (10m) whenthewhales swam undertheboat,nomorethan3mfromtheobservers. All animals swam around the bay slowly, changing direction unpredictably from time totime. Acowl calf pair surfaced and dived together. One whale rolled onto its side, and one flipper and the top half ofthe tail fluke were visible. The tail fluke was ventrally lighter, with darker margins. Three breaches were observed in all, two in quick succession. The breaching was almost vertical, with 3/4 of body showing. The b1o)Vswere low and indistinct, but clearly audible in the calm conditions. Most whales surfaced for two orthree breaths, and then performed alonger dive. Their surfacing spot could not easily be predicted after alonger dive, asitcould on the shallow dives. During the surfacing and dive sequence the rostrum and blowhole emerged first at ashallow angle, followed by the back. The dorsal fin emerged as, orjust after the blowhole submerged. Prior to diving the tail stock was arched, sometimes pronounced. The tail flukes never showed. The whales' colouration was dark grey- blue dorsally with some light grey marbled bands laterally and in front of the dorsal fin. The ventral surface was white with grey marbling, which showed up clearly through the water, and during the breaches. The demarcation between dorsal and ventral surface colouration was quite distinct inplaces. No spots or scars on the skin were observed or recorded on the photographs taken. The Bryde's whales observed here were smaller than the 12meters length at sexual maturity given by Cummings 1985 (In: Handbook of Marine Mammals Vol 3, Pp 137-154). The presence of acalf indicated that this was possibly agroup belonging to the small, inshore form of Balaenoptera edeni referred tobyLeatherwood and Reeves 1983(Sierra Club Books, 302Pp). There is,however, increasing evidence that Bryde's whales in Southeast Asia belong to apossible new species of balaenopterids, the pygmy Bryde's whale. This has been discussed by Wada and Numanchi, 1991 (Reports of the International Whaling Commision (Special Issue 13) Pp 125-154) and Dizon et al. 1995 (Eleventh Biennial Conference on the Biology of Marine Mammals, Orlando). Spinner dolphins Stenella longirostris are widespread inIndonesia (Rudolph et aI., 1997, ibid). Three to four groups of 20-30 animals were observed. A few calves were present. Dolphins were noted performing the characteristic multiple spins around their horizontal axis. Caroline C. Hoffmann Napier University, 66 Spylaw Rd, Edinburgh EH10 5BR, Scotland