Eel-like
Eel-like | ||||||||||||
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European eel ( Anguilla anguilla ) |
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Systematics | ||||||||||||
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Scientific name | ||||||||||||
Anguilliformes | ||||||||||||
Goodrich , 1909 |
The eel-like (Anguilliformes, German and eels ) are about 940 kinds comprehensive order serpentine, almost exclusively in the Sea of living bony fish . They are mostly nocturnal predatory fish.
distribution
Most eel species live in tropical and subtropical seas around the world , both in shallow coastal waters, coral reefs and in the deep sea . Only the river eels (Anguillidae) live in fresh waters and only move into the sea to reproduce. Two of their species, the European eel ( Anguilla anguilla ) and the American eel ( Anguilla rostrata ) are also the only ones whose range extends far into the temperate climate zone.
anatomy
All eel-like have a serpentine, elongated body. Their body length ranges from a few centimeters to many Einkieferaalen up to a length of four meters in the giant Deltamuräne ( Strophidon sathete ). It can be round in cross section or flattened on the side. The dorsal fin and anal fin form a continuous fin edge. Ventral fins are no longer present in today's species , but can still be seen in some fossil forms. The spine can have up to 770 vertebrae and ends straight ( protocerk ). Eel-like are mostly scaly, in some species there are small round scales under the skin, and the side line is often missing. Some skull bones are missing, e.g. B. the post-temporal, which connects the skull with the shoulder girdle in many fish. During metamorphosis, some bones (premaxillary, ethmo, vomer) fuse on the jaw , which are still separated during the larval phase . The gill opening is narrow, the gill cover is missing, the gill chamber is supported by the radii branchiostegi , a skull bone.
Systematics
The order of the eel-like is divided into 20 families, which can be summarized in eight sub-orders.
- Suborder Protanguilloidei
- Subordination synaphobranchoid
- Pit eels (Synaphobranchidae)
- Suborder Muraenoidei
- Heterenchelyidae
- Myrocongridae
- Moray eels (Muraenidae)
- Subordination Chlopsoidei
- Subordination Congroidei
- Long-necked eels (Derichthyidae)
- Snake eels (Ophichthidae)
- Pike conger (Muraenesocidae)
- Duck bill eels (Nettastomatidae)
- Conger eels (Congridae)
- Subordination Moringuoidei
- Worm Eels (Moringuidae)
- Subordination pelican eel-like (Saccopharyngoidei)
- Cyematidae
- Pelican eels (Eurypharyngidae)
- Single- jaw eels (Monognathidae)
- Neocyematidae
- Sacmouths (Saccopharyngidae)
- Suborder Anguilloidei
- Snipe eels (Nemichthyidae)
- Sawtooth snipe eels (Serrivomeridae)
- River eels (Anguillidae)
Fossil record
The first are eel-like fossil from the upper layers of chalk of Lebanon with the genera Urencelys and Enchelion known. Enchelion can already be assigned to a current family, the conger eels (Congridae). There are also fossils from the lower Oligocene . The conger eel Pavelichthys from the northern Caucasus and the sawtooth snipe eel (Serrivomeridae) Proserrivomer from Iran .
An important site is the Monte Bolca formation in northern Italy , which arose from Tethys deposits in the Eocene . From it the no current family associated species were Anguilloides , Bolcanguilla , Dalphiaziella , Eomyrophis , Milanangullia , Parangullia , Patavichthys , Proteomycus , Veronagullia and Whitapodus that Meeraale Bolycus and Voltaconger , and Schlangenaal Goslinophis described.
The recent conger eels of the genus Conger have been found in fossils from Europe, North America and New Zealand since the Eocene . Today's river eels ( Anguilla ) can be identified since the Miocene . Fossils were found near Öhningen on the Upper Rhine (Baden-Württemberg) , among other places .
literature
- Joseph S. Nelson , Terry C. Grande, Mark VH Wilson: Fishes of the World . John Wiley & Sons, 2016, ISBN 978-1-118-34233-6 .
swell
- ↑ Erwin Hentschel, Günther Wagner: Dictionary of Zoology. 7th edition. Elsevier, Munich / Heidelberg 2004, ISBN 3-8274-1479-2 , page 39, article "Aalfische"
- ↑ Strophidon sathete on Fishbase.org (English)
- ^ Karl A. Frickhinger: Fossil Atlas of Fishes . Mergus-Verlag, Melle, 1999, ISBN 3-88244-018-X .
Web links
- Eel-like on Fishbase.org (English)