Common argus fish
| Common argus fish | ||||||||||||
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Common argus fish ( Scatophagus argus ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Scatophagus argus | ||||||||||||
| ( Linnaeus , 1766) |
The common argus fish ( Scatophagus argus ) is a brackish water fish that occurs on the coast of South Asia and Oceania from Kuwait to Fiji , north to southern Japan and south to New Caledonia , possibly also in Samoa , Tonga and the Society Islands . It is very common in its area of distribution.
features
It reaches a maximum length of 38 cm, but usually remains at a length of 20 cm. The body, without a head, is almost rectangular and strongly flattened on the sides. Due to the wide distribution area, the coloration is quite different. The basic color is green-gray, greenish or bluish-silvery or coffee-brown with a golden shimmering back. A color form with reddish tint on the back and forehead has been described as a separate species (Red Argus or Red- fronted Argus, Scatophagus rubrifons ), but is only a color morph . Young fish, the size of a euro cent, are initially dark. Later they have some large round spots, about the size of their eyes, or 5 to 6 vertical dark stripes in "Scatophagus tetracanthus". The number of spots increases with age, but may be reduced again in large adults and confined to the back and the upper part of the sides. The fish go through a metamorphosis in which their larva (tholichthys stage) is characterized by a large head with thick bone plates. Over time, the tholichthys stage passes over into the adult fish through the regression of the head armor. The eye diameter is smaller than the length of the mouth. The mouth is small, horizontal and not protractile (cannot be extended). The teeth are brush-shaped and arranged in several rows.
- Fin formula : dorsal XI / 16–18, anal IV / 14–15, pectoral 17, ventral I / 5.
- Dandruff formula : mLR over 100.
ecology
The common argus fish mainly lives in brackish mangroves and estuaries, harbors and the lower reaches of rivers. It feeds on worms, crustaceans, insects and plants.
swell
- Günther Sterba : The world's freshwater fish. 2nd Edition. Urania, Leipzig / Jena / Berlin 1990, ISBN 3-332-00109-4 .
Web links
- Common Argus fish on Fishbase.org (English)
- Scatophagus argus inthe IUCN 2013 Red List of Threatened Species . Submitted by: Collen, B., Richman, N., Beresford, A., Chenery, A. & Ram, M. (Sampled Red List Index Coordinating Team), 2009. Retrieved February 5, 2014.