Marine Fishes of South-East Asia. Gerry Allen
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waters on sand bottoms; similar to 17 below, but has broad brown margin around white spots; an undescribed species known only from the Timor Sea, off Melville I., N. Territory; to 120 cm. (RHINOBATIDAE)
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17 GIANT SHOVELNOSE RAY
Rhinobatos typus Bennett, 1830
Inhabits coastal waters; similar to 16 above, but lack spots and snout is broader with more rounded tip; found throughout the region; E. Indian Ocean and Indo-Australian Archipelago; to at least 270 cm. (RHINOBATIDAE)
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PLATE 4: SHARKS AND RAYS
1 WESTERN ANGEL SHARK
Squatina sp.
Inhabits deep (150-310 m) trawling grounds; a ray-like shark with distinctive shape, has greatly enlarged pectoral fins that are not entirely fused to the head and body as in rays, also has bilobed tail and 2 small dorsal fins; W. Australia between Shark Bay and Broome; to at least 64 cm. (SQUATINIDAE)
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2 YELLOW SHOVELNOSE-RAY
Aptychotremata sp.
Inhabits sand bottoms; similar to 16 on previous page, but lacks spots and snout is blunter; continental shelf of N.W. Australia; to at least 65 cm. (RHINOBATIDAE)
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3 BROWN STINGAREE
Urolophus westraliensis Last & Gomon, 1987
Inhabits sand bottoms in depths of 150-210 m; distinguished by sharply pointed snout tip, at least one serrated spine on tail, similar to 4 below and 8 (next page) but is plain brown without markings or has 3 indistinct bars on disc; N.W. Australia between Dampier and Buccaneer Archipelago; to at least 36 cm. (UROLOPHIDAE)
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4 BLOTCHED STINGAREE
Urolophus mitosis Last & Gomon, 1987
Inhabits sand bottoms to depths of 200 m; similar to 3 above and 8 (next page) but has pale elongate blotches and lines that surround clusters of dark spots; N.W. Australia, known thus far only from off Port Hedland; to at least 29 cm. (UROLOPHIDAE)
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5a BANDED NUMBFISH
Narcine westraliensis McKay, 1966
Inhabits sand bottoms; distinguished by flattened "tadpole" shape, large round head, and 2 small dorsal fins; colour ranges from plain to spotted; capable of producing mild electrical shock; N.W. Australia only; to 28 cm.
5b ORNATE NUMBFISH
Narcine sp.
This small species has often been confused with Banded Numbfish. It only occurs in the Gulf of Carpentaria; to 17cm. (NARCINIDAE)
6 NUMBFISH
Hypnos monopteiygium (Shaw & Nodder, 1795)
Inhabits sand-weed areas; distinguished by round body with smaller rounded pelvic lobe at rear which bears the tail and 2 small dorsal fins; colour varies from light brown to blackish; can produce a strong electrical shock if handled or accidently trod on; also known as Coffin Ray; St. Vincents Gulf, S. Austraila to Broome, W. Australia and S.Queensland to S. New S. Wales; Australia only; to 69 cm. (HYPNIDAE)
7 EYED SKATE
Raja sp.
Inhabits sand bottoms of continental shelf in 60-200 m depth; distinguished by pointed snout, bilobed pelvic fins, single row of thorns or small spines down middle of tail, and 2 small dorsal fins near end of tail, also has fragmented ocellus-type markings on each side of back; also known as False Argus Skate; continental shelf of N.W. Australia; to at least 20 cm width. (RAJIDAE)
8 WESTERN ROUND SKATE
Irolita sp.
Inhabits sand bottoms of continental shelf in 150-200 m depth; distinguished by round shape, bilobed pelvic fins, short spines or thorns in 1 or more rows on tail, and 2 small dorsal fins near end of tail, also has blue-grey spots or blotches scattered on back; N.W. Australia from Shark Bay to Port Hedland; to 42 cm. (RAJIDAE)
9 BROWN STINGRAY
Dasyatis annotatus Last, 1987
Inhabits sand bottoms in 40-65 m depth; distinguished by kite-shape and 2 long serrated spines on tapering tail; similar to 10 below, but is plain grey-brown without markings and has a more pointed snout; Timor and Arafura seas off N. Australia; to at least 24 cm width and 45 cm length. (DASYATIDAE)
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10 BROWN RETICULATED STINGRAY
Dasyatis leylandi Last, 1987
Inhabits sand bottoms; two distinct colour forms are known, one with numerous irregular pale blotches and another with pepper-like spotting, both have broad dark band or “mask” between eyes; also known as Painted Maskray; N. Australia and S. New Guinea; to at least 25 cm width. (DASYATIDAE)
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11 BLUE-SPOTTED STINGRAY
Dasyatis kuhlii (Muller & Henle, 1841)
Inhabits sand bottoms, frequently in the vicinity of coral reefs; sometimes buries itself with only the eyes protruding above the sand; distinguished by blue spots and frequently has scattered black spots on disc, found throughout the region; Indo-W. Pacific; maximum width about 45 cm. length to 70 cm. (DASYATIDAE)
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SHARK FACTS
Sharks and their cousins, the rays, are very specialised fishes that represent a primitive stage of evolutionary development. The sharks represent an extremely ancient lineage. They were known in Devonian seas, over 350 million years ago. Many of the present genera of sharks, skates, and rays date back more than 100 million years. Approximately 350 species of sharks are currently known. Only a small number of these are considered dangerous. Sharks represent an extremely diverse assemblage, occurring in all seas, and in a variety of depths ranging from shallow intertidal pools to deep oceanic trenches, miles below the surface.
RAYS AND RELATIVES
Rays and their relatives are classified in the Order Rajiformes. Both sharks and rays are characterised by a cartilagenous skeleton. Other typical features of rays include a greatly flattened body that is often disc-shaped, and the presence of five, ventrally located gill openings. Most species bear their young alive except the Rajidae, which deposit egg cases. Many rays have venomous spikes or spines on the tail base that are capable of inflicting painful wounds. The members of the family Torpedinidae possess powerful electric organs situated in the head region. Rays dwell in a variety of habitats, ranging from oceanic depths to shallow reefs, estuaries, and even freshwater streams. They range in size from about 30-40 cm disc-width (some skates) to more than 4 m (manta rays).
PLATE 5: RAYS AND GHOST SHARKS
1 BLACK STINGRAY
Dasyatis thetidis Ogilby, 1899
Inhabits coastal waters off beaches and over sand or mud bottoms to at least 300 m depth; distinguished by blue-grey to blackish colour and short tubercles on top of head and over middle of back; has a pair of spines on tail that can inflict serious wounds; temperate and subtropical Australia northward to Shark Bay in the west and Coff’s Harbour in the east; also New Zealand, and South Africa; to 180 cm disc width, 400 cm total length and 65 kg. (DASYATIDAE)
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2 COWTAIL STINGRAY
Pastinachus sephen (Forsskål, 1775)
Inhabits flat sand or mud bottoms near shore, also common in brackish