Knife eels
| Knife eels | ||||||||||||
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Gymnotus sp. |
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| Scientific name | ||||||||||||
| Gymnotidae | ||||||||||||
| Rafinesque , 1810 |
The knife eels (Gymnotidae) are a family of the New World knife fish (Gymnotiformes). The fish live in Central America , from southern Mexico to Panama and in northern and central South America . They are missing in northeastern Brazil in the lower reaches of the Rio São Francisco . Gymnotus inaequilabiatus has the southernmost distribution area with the Río Paraguay . Gymnotus carapo is also found in waters in Trinidad .
features
The body of the knife eel is elongated like an eel and has a circular cross-section, at least in the front part. As with all knife fish, the anal fin is elongated and has become the main driving organ. Dorsal , caudal and pelvic fins are missing. Almost all species are brownish in color, some have a pattern of many dark horizontal stripes or spots. Knife eels of the genus Gymnotus are ten to 60 centimeters long; they have small scales and their mouth is upright . The electric eel reaches a maximum length of 2.50 meters; have no scales and the mouth is terminal. All knife eels can use converted muscle cells to generate an electric field , which Gymnotus uses for orientation and communication with other species, and for electric eels to catch prey.
Way of life
The fish are active at twilight and mostly live in low-current areas of large rivers or in swamps. All knife eels are carnivorous on smaller invertebrates and fish.
Systematics
Today there are almost 50 species in two genera of the knife eel family, which are placed in two subfamilies. The electric eel was placed in its own family Electrophoridae until its close relationship with Gymnotus was established.
- Subfamily Electrophorinae Ellis, 1913
- Genus electric eels ( Electrophorus ) Gill, 1864 .
- Subfamily Gymnotinae Ellis, 1913
- Genus Gymnotus Linnaeus, 1758
literature
- Joseph S. Nelson : Fishes of the World. 4th edition. John Wiley & Sons, New York NY 2006, ISBN 0-471-25031-7 .
- Günther Sterba : The world's freshwater fish. 2nd Edition. Urania-Verlag, Leipzig et al. 1990, ISBN 3-332-00109-4 .
Web links
- Knife eels on Fishbase.org (English)
Individual evidence
- ↑ C. David de Santana, William GR Crampton, Casey B. Dillman, Renata G. Frederico, Mark H. Sabaj, Raphaël Covain, Jonathan Ready, Jansen Zuanon, Renildo R. de Oliveira, Raimundo N. Mendes-Júnior, Douglas A. Bastos, Tulio F. Teixeira, Jan Mol, Willian Ohara, Natália Castro e Castro, Luiz A. Peixoto, Cleusa Nagamachi, Leandro Sousa, Luciano FA Montag, Frank Ribeiro, Joseph C. Waddell, Nivaldo M. Piorsky, Richard P. Vari & Wolmar B. Wosiacki: Unexpected species diversity in electric eels with a description of the strongest living bioelectricity generator. Nature Communicationsvolume 10, Article number: 4000 (2019), doi: 10.1038 / s41467-019-11690-z
- ↑ Craig, JM, Kim, LY, Tagliacollo, VA & Albert, JS (2019): Phylogenetic revision of Gymnotidae (Teleostei: Gymnotiformes), with descriptions of six subgenera. PLoS ONE, 14 (11): e0224599. November, 2019, doi: 10.1371 / journal.pone.0224599