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Cetacea: Odontoceti: Ziphiidae 4025

Mesoplodon pacificus Longman, 1926 BNW En - Longman’s beaked ; Fr - Balaine à bec de Longman; Sp - Zifio de Longman. Known only by 2 weatherworn skulls from Somalia and , respectively. Estimated body length 6 m. In contrast to the other species of the treated here, the teeth are placed on the tip of the lower jaw, not in the middle of the lower jaw. Presumably has a pantropical offshore distribution and may occur in the area.

dorsal view

lateral view

dorsal view of mandible skull

Ziphius cavirostris Cuvier, 1823 BCW En - Cuvier’s ; Fr - Ziphius; Sp - Zifio de Cuvier. A medium-sized whale; body length ranges from 2.7 (new-born) to 7 (females) and 7.5 m (males). Beak not well defined, merely marked by a concavity on the forehead. Two teeth on tip of lower jaw, erupting in males only. Coloration brownish grey, with lighter parts on belly and head; head may be almost white in adult males. Distributed in deeper offshore waters of all oceans except polar waters.

skull 4026 Marine

Cetacea: Odontoceti: Delphinidae DELPHINIDAE Marine or true mall to medium-sized cetaceans with conical teeth and a (the only delphinids without a dorsal Sfin, members of the genus Lissodelphis, occur outside the area). This is the largest family of cetaceans, sometimes divided into a number of subfamilies, 2 of which occur in the Western Central Pacific: the (killer and allies) includes beakless species usually possessing fewer teeth, while the Delphininae (true dolphins senso stricto) typically covers beaked species with many teeth. However, the melonheaded whale (Peponocephala electra) is beakless, but possesses many teeth and its assignment to the Orcininae should be considered preliminary. The humpback dolphins and roughtoothed are sometimes placed in a separate subfamily (Steninae) but are here kept within the Delphininae. The of several species is currently being revised. The tropical form of the (Tursiops truncatus) that occurs in the Western Central Pacific may be considered a separate species (T. aduncus), but for practical reasons it is kept here in T. truncatus. Recently, 2 species of have been recognized, a shortbeaked species (Delphinus delphis) and a longbeaked species (D. capen- sis). A dwarf form of the ( longirostris) has been described from the Gulf of and may be a separate species, but is provisionally kept here in S. longirostris. Hybrids are known, even between genera of different subfamilies (Tursiops X Steno, Tursiops X Grampus, and Tursiops X ).

subfamily Orcininae lateral view of skull

subfamily Delphininae lateral view of skull

beak runs smoothly Key to the species of Delphinidae occurring in the area into forehead 1a. Beak present (Fig. 1a-c) ...... (mainly subfamily Delphininae) ® 2 1b. Beak absent ..(mainly subfamily Orcininae) ® 9

a) beak distinct from forehead beak very short

b)

Fig. 1 c) Cetacea: Odontoceti: Delphinidae 4027

2a. Prominent stripes on flanks ...... ® 3 2b. No stripes ...... ® 6

3a. Small inconspicuous beak; a single broad stripe on flank . . Lagenodelphis hosei (Fraser’s dolphin) 3b. Long well-defined beak; several thin stripes ...... ® 4

4a. V-shaped area on flanks (Fig. 2) . . . . Stenella coeruleoalba () 4b. Distinct hourglass pattern on side, forming a V below dorsal fin ...... ® 5

5a. Body comparatively stocky; beak shorter; (or forehead) Fig. 2 Stenella coeruleoalba rounded; colour pattern highly contrasting, thoracic patch lighter; thinner flipper stripe not approaching gape, narrowing significantly ahead of eye; light patches often on flippers and dorsal fin; anus stripe generally only weakly developed; 42 to 53 teeth on each side of ; maximum length 2.3 m ...... Delphinus delphis (shortbeaked common dolphin) 5b. Body comparatively slender; beak longer; melon (or forehead) flatter; colour pattern more muted, thoracic patch darker; wide flipper stripe approaching or contacting gape, not narrowing significantly ahead of eye; light patches rare on flippers and dorsal fin; anus stripe generally moderately to strongly developed; 47 to 55 teeth on each side of jaws; maximum length 2.6 m ...... Delphinus capensis (longbeaked common dolphin)

6a. Beak without demarcation from the melon (or forehead) (Fig. 1a); teeth rough to touch ...... ® 7 6b. Beak with well-defined crease at the melon (or forehead) (Fig. 1b); teeth smooth to touch .....® 8

7a. Colour pink to grey, dorsal fin usu- hump ally placed on hump (Fig. 3) . . . Sousa chinensis (Indo-Pacific ) 7b. Colour grey, no hump on back (Fig. 1a) ...... Steno bredanensis (roughtoothed dolphin)

8a. Teeth 22 to 24; beak of medium Fig. 3 Sousa chinensis length ...... Tursiops truncatus (tropical bottlenose dolphin) 8b. Teeth more than 40; long beaks ...... ® 9

9a. Spots present on belly and flanks; tip of snout white (Fig. 4) ...... Stenella attenuata (pantropical ) 9b. No spots; coloration in 3 shades of grey (Fig. 5) ...... Stenella longirostris (spinner dolphin)

Fig. 4 Stenella attenuata Fig. 5 Stenella longirostris

10a. Body black or predominantly black ...... ® 11 10b. Body greyish ...... ® 15 4028 Marine Mammals

11a. Distinctive black-and-white colora- tion: body mostly black, with oval white patch over and behind eye, white lower jaw, white ventrolateral area, and light grey saddle behind dorsal fin (Fig. 6) . . orca () 11b. Lighter parts never bright ...... ® 12

12a. Dorsal fin flat, located in first third of body; head bulbous (Fig. 7) ...... Globicephala macrorhynchus Fig. 6 Orcinus orca (shortfinned ) 12b. Dorsal fin falcate, located in middle of body; head more pointed (Fig. 8) ....® 13 dorsal fin located in dorsal fin near first third of body middle of body

Fig. 7 Globicephala macrorhynchus Fig. 8

13a. Adults more than 3 m in length; flipper with “hump” on leading edge (Fig. 9) ...... Pseudorca crassidens () 13b. Adults less than 3 m in length; flipper without “hump” (Fig. 10) ...... ® 14

no hump on hump on leading edge leading edge Fig. 9 Pseudorca crassidens Fig. 10

14a. Teeth 8 to 13 on each side of upper and lower jaws; flipper tip pointed (Fig. 11) ...... Feresa attenuata () 14b. Teeth 20 to 25 on each side of upper and lower jaws; flipper tip rounded (Fig. 12) ...... Peponocephala electra (melonheaded whale)

flippers rounded at tip 8-13 teeth in flippers pointed 20-25 teeth each half of Fig. 11 Feresa attenuata Fig. 12 Peponocephala electra both jaws in each half of both jaws central crease on forehead 15a. Few teeth (up to 8 in total); a crease centrally on forehead (Fig. 13) . . . . . Grampus griseus (Risso’s dolphin) 15b. Teeth 17 to 20 on each side of upper and lower jaws; no crease . . brevirostris ()

Fig. 13 Grampus griseus Cetacea: Odontoceti: Delphinidae 4029

List of species occurring in the area The symbol 2 is given when species accounts are included. 2 Delphinus capensis Gray, 18281/ 2 Delphinus delphis Linnaeus, 17581/ 2 Feresa attenuata Gray, 1875 2 Globicephala macrorhynchus Gray, 1846 2 Grampus griseus (Cuvier, 1812) 2 Lagenodelphis hosei Fraser, 1956 2 Orcaella brevirostris (Gray, 1866) 2 Orcinus orca (Linnaeus, 1758) 2 Peponocephala electra (Gray, 1846) 2 Pseudorca crassidens (Owen, 1846) 2 Sousa chinensis (Osbeck, 1765) 2 Stenella attenuata (Gray, 1846) 2 Stenella coeruleoalba (Meyen, 1833) 2 Stenella longirostris (Gray, 1829) 2 Steno bredanensis (Lesson, 1828) 2 Tursiops truncatus (Montagu, 1821)

Delphinus capensis Gray, 1828 DLC En - Longbeaked common dolphin; Fr - Dauphin commun à long bec; Sp - Delfín común de rostro longo. A small cetacean; body length ranges from 80 cm (new-born) to 2.3 m; average size believed to be slightly larger than in Delphinus delphis. Coloration generally less clearcut and more diffuse than in shortbeaked dolphin. Thoracic patch darker (ocher) than in D. delphis, not sharply contrasting. Flipper to anus stripe weak to strong. Eye patch not sharply contrasting with thoracic patch. Light patches on dorsal fin and flippers rare in adults. Number of teeth on each side of upper and lower jaws 47 to 55. Individuals with extremely long beaks have been sighted in the . In tropical to warm-temperate waters. In the area, confirmed records are so far known only from . Only recently recognized to be distinct from D. delphis.

1/ The genus Delphinus traditionally has been considered to be monotypic and has only recently been split into 2 species. The 2 species look very similar in general appearance. 4030 Marine Mammals

Delphinus delphis Linnaeus, 1758 DCO En - Shortbeaked common dolphin; Fr - Dauphin commun à petit bec; Sp - Delfin común de rostro corto. A small cetacean; body length ranges from 80 cm (new-born) to 2 m. Coloration generally more contrasting than in Delphinus capensis. Thoracic patch lighter (yellow) than in D. capensis,very sharply contrasting with spinal field. Flipper to anus stripe weak or absent. Eye patch very sharply contrasting with thoracic patch. Light patches on dorsal fin and flippers frequently present. Almost always in deep waters, but also found in shore waters. Beak shorter, with 42 to 53 teeth on each side of upper and lower jaws. Warm to tropical waters of the Atlantic and Pacific oceans; there are no confirmed records of the species from the or western Central Pacific but it is believed to occur there.

Feresa attenuata Gray, 1875 KPW En - Pygmy killer whale; Fr - Orque pygmée; Sp - Orca pigmea. A small cetacean; body length ranges from 80 cm (new-born) to 2.6 m. Coloration very similar to melonheaded whale, but with narrower “cape”. Head rounded in shape (in contrast to the more triangular head in the melonheaded whale). Teeth 8 to 13 on each side of upper and lower jaws. Tip of flippers rounded. Occurs throughout the world in tropical pelagic waters.

Globicephala macrorhynchus Gray, 1846 SHW En - Shortfinned pilot whale; Fr - Globicéphale tropical; Sp - Calderón de aletas cortas. A medium-sized cetacean; body length ranges from 1.4 (new-born) to 5.5 m (females) and 6.1 m (males). Overall coloration black, with a grey saddle behind dorsal fin. Dorsal fin flat, placed in first third of back (in contrast to false killer whale). Head bulbous (compared to the more pointed head of false killer whale). Flippers long and slender. Teeth small, 7 to 9 in anteriormost part of each side of upper and lower jaws. Occurs in temperate to tropical pelagic waters. Cetacea: Odontoceti: Delphinidae 4031

Grampus griseus (Cuvier, 1812) DRR En - Risso’s dolphin; Fr - Grampus; Sp - Delfín de Risso. A small dolphin; body length ranges from 1.2 (new-born) to nearly 4 m. Shape of head round, with a diagnostic crease located centrally on forehead. Dorsal fin high and falcate, placed on centre of back. Coloration dark grey on back and white on belly; adult individuals have prominent scars on flanks of body; some adults with head and parts of flanks entirely white. No teeth in upper jaw, 2 to 7 pairs in lower jaw. Occurs in temperate to tropical in pelagic waters.

Lagenodelphis hosei Fraser, 1956 FRD En - Fraser’s dolphin; Fr - Dauphin de Fraser; Sp - Delfín de Fraser. A small cetacean; body length ranges from 1 (new-born) to 2.7 m. Beak very short. A broad black stripe marking border between flanks and belly; back dark grey around dorsal fin. A grey field beneath “cape”, becoming lighter towards belly, distinctly contrasting with the broad black stripe. Teeth 38 to 44 in each tooth row. In the , one of the most important species taken incidentally in offshore gill-net fisheries. Occurs in warm to tropical in pelagic waters.

Orcaella brevirostris (Gray, 1866) IRD En - Irrawaddy dolphin; Fr - Orcelle; Sp - Delfín del Irrawaddy. A small dolphin, body length ranges from 1 (new-born) to 3 m. Overall dark grey, with a slightly lighter colour on belly. Dorsal fin small, placed slightly behind centre point of back. Neck prominent. Teeth 17 to 20 on each side of upper and lower jaws. Distributed in coastal, brackish, and riverine waters of Thailand, , Indo-, , , and northern Australia. 4032 Marine Mammals

Orcinus orca (Linnaeus, 1758 KIW En - Killer whale; Fr - Orque; Sp - Orca. A medium-sized cetacean; body length ranges from 2 (young) to 8.5 m in females and almost 10 m in males. Prominent coloration of black and white; an oval area just above eye and a large “white finger” pointing backwards on flanks behind dorsal fin; a comma-shaped grey saddle-shaped patch behind dorsal fin. Flippers large and paddle-shaped. Teeth 10 to 12 on each side of upper and lower jaws. Killer whales are sexually dimorphic: in adult males, the dorsal fin has a high sword-like appearance, reaching a height up to 2 m; females and younger males have the usual falcate dorsal fin. A cosmopolitan species distributed in coastal and pelagic waters.

Peponocephala electra (Gray, 1846) MEW En - Melonheaded whale; Fr - Peponocéphale; Sp - Calderón pequeño. A small cetacean; body length ranges from 1 (new-born) to 2.75 m. General coloration black, with white portions around lip and on belly (dark coloration of back, the “cap”, is more extensively distributed, “dipping deeper” at dorsal fin than in Feresa attenuata). Head triangular in shape (in contrast to the more rounded head of the pygmy killer). Teeth 20 to 25 in both upper and lower jaws. Tip of flippers pointed. Worldwide distributed in pelagic tropical and subtropical waters.

Pseudorca crassidens (Owen, 1846) FAW En - False killer whale; Fr - Faux-orque; Sp - Orca falsa. A medium-sized cetacean; body length ranges from 1.5 (new-born) to 5 m (females) and 6 m (males). Coloration black overall, with a lighter dark grey area between eyes and in front of dorsal fin. Dorsal fin placed on centre of back (in contrast to shortfinned pilot whale where it is found in first third of back). Head more pointed than in the shortfinned pilot whale. Teeth robust, 7 to 12 on each side of upper and lower jaws. Inner leading edge of flipper exhibits a hump that is diagnostic for the species. Worldwide distributed in warm and tropical pelagic waters. Cetacea: Odontoceti: Delphinidae 4033

Sousa chinensis (Osbeck, 1765) DHI En - Indo-Pacific humpbacked dolphin; Fr - Dauphin à bosse de l’Indo-Pacifique; Sp - Delfín jorobado del Pacífico. A small cetacean; body length ranges from 1 (new-born) to about 3 m. Coloration highly variable: body ashy grey, pinkish, or white; some individuals with various degrees of pinkish white all over the back; belly pinkish. New-born dolphins ashy grey, the white patches developing with age. Shape of dorsal fin likewise shows large variation: some individuals have a very conspicuous hump, while others lack it completely. Both coloration and shape of dorsal fin may also vary geographically. Individuals from Indonesia lack the hump. Between 29 and 38 teeth on each side of upper and lower jaws. Distributed in warm to tropical coastal waters of the Indo-Pacific.

Stenella attenuata (Gray, 1846) DPN En - Pantropical spotted dolphin; Fr - Dauphin tacheté pantropical; Sp - Estenela moteada. A small cetacean; body length ranges from 85 cm (new-born) to 2.4 (females) and 2.6 m (males). Dark dorsal “cape” covered with numerous white spots, but spotting shows both age-related and geographical variation: calves are born without spots, the spotting developing with age; spotting can be faint or even absent in some areas, but heavy in other areas. A dark grey band on the flanks encircles eye. Tip of beak tends to be brilliant white. Teeth 34 to 48 on each side of upper and lower jaws. Distributed in warm to tropical, pelagic, offshore and inshore waters. Our knowledge on populations in the area is very poor.

Stenella coeruleoalba (Meyen, 1833) DST En - Striped dolphin; Fr - Dauphin bleu et blanc; Sp - Estenela listada. A small cetacean; body length ranges 1 (new-born) to 2.6 m. Of more robust appearance compared to spotted dolphins or spinner dolphins. A white chevron-shaped area on each flank, the tip of chevron pointing forward. Coloration black on back, the flanks grey, and belly white, sometimes pinkish. A narrow stripe running from eye to anus; sometimes accessory, much shorter stripes are found. Teeth 40 to 55 on each side of upper and lower jaws. Distribution temperate to tropical in pelagic and offshore waters. 4034 Marine Mammals

Stenella longirostris (Gray, 1829) DSI En - Spinner dolphin; Fr - Dauphin longirostre; Sp - Estenela giradora. A small cetacean. The spinner dolphin includes morphologically different forms, the status of which is still uncertain. In the area, a dwarf form from Thailand ranges in size from 60 cm (new-born) to 1.5 m (adult), while individuals found in other areas reach almost 2.5 m. The beak is generally very long (comparatively shorter in dwarf form). Colour of back is dark grey to black; a lighter grey band on flanks; belly white, in some forms pinkish. Usually a marked eye-to-flipper stripe present. Shape of dorsal fin shows variation: typically falcate, but occasionally erect and triangular. Some individuals with bulb on belly around genital slit. Teeth 45 to 62 on each side of upper and lower jaws (only 41 to 49 teeth in dwarf form). Distributed subtropical to tropical in pelagic waters; the dwarf form mentioned above was described from the Gulf of Thailand but may range over a larger area.

Steno bredanensis (Lesson, 1828) RTD En - Roughtoothed dolphin; Fr - Sténo; Sp - Esteno. A small cetacean; body length ranges from presumably 1 (new-born) to 2.8 m. Back dark grey, with lighter grey on flanks; belly white. Clearcut delineation of the “cape”. No demarcation between melon (or forehead) and snout. Beak gradually emerging from head. Teeth rough to touch, 20 to 27 on each side of upper and lower jaws. Worldwide distributed in warm to tropical, pelagic waters.

Tursiops truncatus (Montagu, 1821) DBO En - Bottlenose dolphin; Fr - Grand dauphin; Sp - Tursión. A small cetacean; body length ranges from 1 (new-born) to about 2.5 m. Tropical (or aduncus) form of significantly smaller size than its conspecific temperate (or truncatus) form. Coloration dark bluish grey on back, whitish on belly; more or less prominent spotting on flanks and belly. A well-defined beak with 23 to 26 teeth on each side of upper and lower jaw. Distributed in temperate and tropical coastal and inshore waters. Cetacea: Odontoceti: Phoenidae 4035

Cetacea: Odontoceti: Phoenidae PHOCOENIDAE

his family includes 6 species world- Twide; a single species is known from the Western Central Pacific. Por- poises are small cetaceans of less than 2 m. Among other osteological features, the presence of spatulate teeth is the most important diagnostic character to separate this family from the Delphini- genital dae. The single species occurring in the slit area lacks a dorsal fin. In phocoenids the distance between the anus and male anus genital slit is very long and significantly tubercle longer than in all delphinids. field

male phocoenid male delphinid

ventral view dorsal view

A single species occurring in the area.

Neophocaena phocaenoides (Cuvier, 1829) PFI En - Finless ; Fr - Marsouin aptère; Sp - Marsopa lisa o sin aleta. A small cetacean; body length ranges from 60 cm (new-born) to 1.5 m. General body coloration dark ashy grey, lighter on belly. No beak. Dorsal fin absent. An area with tubercles present on back (see above figure). Teeth 16 to 18 on each side of upper and lower jaws. Found in temperate and tropical coastal waters of the Indo-Pacific; known to enter fresh waters (Yangze kiang River, China). 4036 Marine Mammals

Order Sirenia - Dugongidae Order SIRENIA Sirenians or seacows irenians are fully adapted to their aquatic habitat. They are found in the coastal brackish waters of the SIndo-Pacific and the Atlantic oceans. The body shape is generally less fusiform and more plump than in cetaceans. Sirenians possess a thick skin with very sparse hair, which in contrast to cetaceans can be found all over the body. There are no external ears and hind limbs. There is a muzzle with 2 nostrils located anteriorly on top of the head, not set back on the head as in most cetaceans. Forelimbs are transformed into flippers. In females, the mammae are clearly visible and located anteriorly near the axillae, not hidden in mammary slits and placed posteriorly near the genital slit, as in cetaceans. Sirenians are herbivorous, in contrast to cetaceans. Two families are recognized, a single family occurs in the Western Central Pacific.

nipples

nares

umbilicus

genital muzzle aperture

-

ventral view

DUGONGIDAE Dugong A single species in this family.

Dugong dugon (Müller, 1776) DUG En - Dugong; Fr - Dugong; Sp - Dugón. Body length ranges from 1 (new-born) to 3.3 m. Colour medium grey, with lighter coloration on belly. Presence of bristles on snout and few small hairs all over body (unlike cetaceans). In contrast to cetaceans, different types of teeth are present: incisives, canines (tusks), premolars, and molars, altogether up to 18 teeth. Males possess tusks in upper jaw, while in females they only erupt in very old individuals. A tail with flukes, similar to cetaceans. Widely distributed in coastal and estuarine waters of the tropical Indo-Pacific; in the area ranging from the Philippines and Taiwan Province of China to the north coast of Australia and New Caledonia.

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