Flat heads

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Flat heads
Platycephalus fuscus

Platycephalus fuscus

Systematics
Acanthomorphata
Spinefish (Acanthopterygii)
Perch relatives (Percomorphaceae)
Order : Perch-like (Perciformes)
Subordination : Platycephaloidei
Family : Flat heads
Scientific name
Platycephalidae
Gill , 1872

The flatheads or crocodile fish (Platycephalidae) live near the coast in tropical latitudes of the Indo-Pacific . One species ( Solitas gruveli ) lives in the eastern Atlantic , on the African coast, while three species immigrated into the Mediterranean through the Suez Canal ( Lesseps migration ). The fish prefer continental coasts and are often found in lagoons of coral reefs and in river mouths.

features

The name for the flat heads is their flat, large, often spiked head. Their body is elongated, slightly flattened in front, with a round cross-section and thin, and covered with small comb scales. The lower jaw protrudes. The animals are between 17 centimeters and 1.10 meters long. They have two clearly separated dorsal fins . The spiked rays of the first dorsal fin do not have any poison glands, as they are found e.g. B. own the scorpion fish. The first spiked ray of the first dorsal fin is very short and not connected to the others by the fin membrane. The pelvic fins are behind the pectoral fin base.

Fin formula : dorsal 1 VI – X, dorsal 2 11–15, pectoral 16–22

The large, round eyes of the flat heads lie on the top of the head and are particularly adapted to the sun-drenched shallow water zones thanks to a net-like lid that expands or contracts depending on the light exposure.

Way of life

They are mainly nocturnal bottom dwellers without swim bladders who wait for prey as ambulance hunters. They are well camouflaged on gravel soils because of their spotty, mostly brownish or gray markings, in sandy soils they dig themselves in by shaking their bodies until only their eyes and mouth are visible. If a careless fish approaches, it will be sucked in by opening its big mouth. Fish swimming at a greater distance, up to one meter above the crocodile fish, are caught when the crocodile fish suddenly jump up vertically. In addition to fish, crustaceans , small cephalopods and bristle worms are also eaten. If the flat heads are threatened, they rely on their camouflage and set up their first dorsal fin, which is reinforced with spiked rays, to defend themselves. They only flee at the last moment and only swim a short distance, only to lie down on the ground or dig in afterwards.

Reproduction

The reproduction of the crocodile fish is still largely unknown. Some species make annual spawning migrations. The fish mate at night. The eggs are planktonic and less than a millimeter in diameter.

Genera and species

There are two subfamilies and about 80 species from 19 genera :

Ambiserrula jugosa
Cociella crocodila
Brown-headed flat head ( Cymbacephalus beauforti )
Inegocia japonica
Carpet crocodile fish ( Papilloculiceps longiceps )
Ratabulus diversidens
Thysanophrys cirronasa
Thysanophrys chiltonae

literature

  • Joseph S. Nelson : Fishes of the World . John Wiley & Sons, 2006, ISBN 0-471-25031-7
  • Kurt Fiedler: Textbook of Special Zoology, Volume II, Part 2: Fish . Gustav Fischer Verlag Jena, 1991, ISBN 3-334-00339-6
  • Baensch, Patzner: Mergus Sea Water Atlas Volume 6 Non-Perciformes (non-perch-like) . Mergus-Verlag, Melle, ISBN 3-88244-116-X
  • Dieter Eichler, Robert F. Myers: Coral fish Indo-Pacific . Jahr-Verlag GmbG & Co, ISBN 3-86132-225-0
  • Ewald Lieske, Robert F. Myers: Coral fish of the world . Year Top Special Verlag Hamburg, ISBN 3-86132-112-2

Individual evidence

  1. ↑ Smith, WL, Everman, E. & Richardson, C. (2018): Phylogeny and Taxonomy of Flatheads, Scorpionfishes, Sea Robins, and Stonefishes (Percomorpha: Scorpaeniformes) and the Evolution of the Lachrymal Saber. Copeia 106 (1): 94-119. 2018 doi: 10.1643 / CG-17-669
  2. ↑ Prokofiev, AM (2019): A new genus of Platycephalidae from the western Indian Ocean and a classification of the genus Suggrundus (Teleostei: Scorpaeniformes) . Amurian Zoological Journal, 11 (3): 233-239. DOI: 10.33910 / 2686-9519-2019-11-3-233-239

Web links

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