Spotted Scat, Scatophagus argus (Linnaeus 1766)
A Spotted Scat, Scatophagus argus. Source: Brian Gratwicke / Flickr: EOL Images. License: CC BY Attribution
The Spotted Scat is deep-bodied silvery fish with the dorsal profile steep before dorsal-fin origin. Adults are silvery or greenish with dark blotches and markings. Small juveniles have alternating dark and whitish to yellowish bars and often reddish-orange patches on the head and along the back.
Spotted Scat, Scatophagus argus (Linnaeus 1766)
More Info
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Distribution |
Widely distributed in northern Australia from Port Hedland, Western Australia, to Sydney, New South Wales. Elsewhere, widespread in the tropical Indo-West Pacific from southern India and Sri Lanka, eastward to Tahiti, and northward to southern Japan. Inhabits sheltered bays, harbours, mangrove creeks and the lower reaches of freshwater streams. |
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Features |
Meristic features: Dorsal fin XI, 16-18; Anal fin IV, 13-15; Pectoral fin 16-17; Pelvic fin I, 5. Body quadrangular, strongly compressed. Head small, dorsal profile steep. Eye moderately large, its diameter somewhat smaller than snout length. Snout rounded. Mouth small, terminal, horizontal, not protractile. Teeth villiform, in several rows on jaws; gill membrane forming a free fold across isthmus; caudal peduncle short. Scales small, ctenoid covering head, body, caudal fin, and soft parts of anal and dorsal fins; lateral line distinct following back profile. First dorsal-fin spine procumbent (lying flat); a deep notch between spinous and soft parts of dorsal fin. Posterior margin of soft portions of dorsal and anal fins more or less vertical. Caudal fin from rounded (in juveniles) to truncate or slightly emarginate. |
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Size |
To around 33 cm SL. |
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Colour |
Brown or greenish with a silvery to golden sheen on sides. Body covered with brown or red-brown spots. In large adults spots may be faint and restricted to dorsal part of flanks. Juveniles with a few large roundish blotches, about size of eye, or with about 5 or 6 broad, dark, vertical bars. |
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Feeding |
Omnivorous scavengers feeding on a variety of food items including algae, mud and benthic invertebrates. |
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Biology |
Little is known of the reproductive biology of this species. Juveniles go through a pelagic “tholichthys” larval stage. |
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Fisheries |
A popular aquarium fish. Also of minor commercial importance in many parts of its range and marketed fresh. |
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Remarks |
Strong fin spines have venom glands at the bases. |
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Species Citation |
Chaetodon argus Linnaeus, 1766, Systema Naturae. 1: 464. Type locality: India. |
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Author |
Martin F. Gomon |
Spotted Scat, Scatophagus argus (Linnaeus 1766)
References
Allen, G.R., Midgley, S.H. & Allen, M. (2002). Field Guide to the Freshwater Fishes of Australia. Perth : Western Australian Museum 394 pp.
Grant, E.M. (1991). Fishes of Australia. Brisbane : E M Grant Pty Ltd 480 pp.
Kuiter, R.H. (1993). Coastal Fishes of South-eastern Australia. Bathurst : Crawford House Press 437 pp.
Kottelat, M. (2001). Scatophagidae. pp. 3623–3626 in Carpenter, K.E. & Niem, V.H. (eds) The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 6 pp. 3381–4218
Lake, J.S. (1978). Australian Freshwater Fishes. Melbourne : Thomas Nelson 160 pp.
Merrick, J.R. & Schmida, G.E. (1984). Australian Freshwater Fishes Biology and Management. Sydney : J.R. Merrick 409 pp.
