Razor-tailed carp
| Razor-tailed carp | ||||||||||||
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Razor-tailed Parrot ( Alfaro cultratus ) |
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| Scientific name | ||||||||||||
| Alfaro cultratus | ||||||||||||
| ( Regan , 1908) |
The Messerschwanzkärpfling ( Alfaro cultratus ), also Messerkärpfling or Amazon molly called, is a freshwater fish of the subfamily of live-bearing tooth carp . Its distribution area includes southern Central America and extends from Nicaragua and Costa Rica to Panama . It lives in clear flowing waters, in more or less fast flowing streams and on the banks of larger rivers.
features
Females reach a total length of 6–8 cm, males a length of 4–6 cm. Razor-tailed parsons have a moderately slender, laterally strongly flattened body. It is named after the long tail stem, which forms a sharp edge on its underside. This keel edge consists of two narrow rows of scales on both sides of the body. The male reproductive organ, the gonopodium , has a simple structure, which is why Alfaro cultratus is assigned to a very original type of viviparous toothcarps. The color of the fish is greenish gray or clay with a bluish tinge on the sides of the body. The body is covered with very fine black spots. The fins are colorless or slightly yellowish.
- Fin formula : dorsal 7–9, anal 9–10, ventral 6.
- Scale formula : 32-35 (mLR).
Way of life
The razor-tailed carp forms small groups that are mainly located in a depth range of 20 cm. Young fish feed on aquatic insects, adult fish specialize in approach food (insects that fall on the surface of the water). During courtship, the male swims over the female and strokes the head of the female with his long ventral fins. If the female then jerks forward, mating occurs. Razor-tailed fishes give birth to 10–30 fry after an average gestation period of 24 days, which are 8–10 mm in length at birth.
ecology
The Austrian aquarist Alfred Radda found Alfaro cultratus in 1980 in a small, fast-flowing rainforest stream in the Sarapiqui system, six kilometers northeast of La Virgen in Costa Rica. The stream was one to three meters wide and an average of 30 centimeters deep. Water temperature in February, 11.30 a.m.: 24.5 ° C, electrical conductivity 55 µS / cm, pH 6.6, below 1 ° dGH.
Systematics
The razor-tailed carp was first described as Petalosoma cultratum by the British ichthyologist Charles Tate Regan in 1908 . The type locality is the Rio Iroquois in Costa Rica. The description is based on a single preparation, which is deposited under the catalog number BMNH 1909.3.13.58 in the Natural History Museum London . Regan himself described the species again in 1911 as Petalosoma amazonum (the holotype, which is also deposited in London, is said to have been caught in the Brazilian Amazon, in the state of Pará, near the city of Obidos; this erroneous assignment is decisive for the popular designation Amazon penguin) and found it in 1913 in the genus Alfaro . Further synonyms are Alfaro acutiventralis Meek , 1912 and Petalurichthys cultratus Regan, 1912.
literature
- Dieter Gentzsch: Alfaro cultratus. In: In: Claus Schaefer, Torsten Schröer (Hrsg.): The large lexicon of aquaristics. Eugen Ulmer, Stuttgart 2004, ISBN 3-8001-7497-9 , p. 32.
- Günther Sterba : The world's freshwater fish. 2nd Edition. Urania, Leipzig / Jena / Berlin 1990, ISBN 3-332-00109-4 .
- MK Meyer, L. Wischnath, W. Foerster: Livebearers ornamental fish . Mergus, Melle 1985, ISBN 3-88244-006-6 .
- CT Regan: A collection of fresh water fishes made by Mr. CF Underwood in Costa Rica. In: Ann. Mag. Nat. Hist. 8 (2). 1908, pp. 455-464.
- AC Radda: Poeciloid Studies in the Caribbean. In: Aquaria. 27. 1980, pp. 77-88.
Web links
- Razor-tailed carrion on Fishbase.org (English)