Banderolenkärpfling

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Banderolenkärpfling
Banded parrot, male.

Banded parrot, male.

Systematics
Order : Toothpies (Cyprinodontiformes)
Subordination : Cyprinodontoidei
Family : Highland Parrot (Goodeidae)
Subfamily : Goodeinae
Genre : Xenotoca
Type : Banderolenkärpfling
Scientific name
Xenotoca eiseni
Rutter , 1896

The redtail splitfin ( Xenotoca eiseni ) is a live-bearing freshwater fish from the family of goodeids (Goodeidae). It comes from the highlands of central Mexico in the states of Guanajuato , Jalisco , Michoacán , Nayarit , Querétaro and San Luis Potosí and occurs there in clear waters. The species was named after G. Eisen who caught the type specimens .

features

The fish reach a total length of 6 to 8 cm. Banded parsons have a moderately high-backed body and a relatively long tail stalk. The back and stomach lines are approximately symmetrical to each other. With increasing age the animals become higher back. It is named after a yellow or orange band on the caudal stem, which can extend to the caudal fin and is much more evident in male fish. The color of the fish is otherwise light gray or pale. The back is darker, the fins ocher or yellowish.

Reproduction

After a gestation period of 30 to 65 days, the Banderolenkärpfling gives birth to 50–70 young fish that are over 10 mm long at birth. The birth process of a litter can take two or more days.

Aquaristics

Banded parsnips were first imported to Germany as freshwater ornamental fish at the end of the 1960s. They are suitable for a community aquarium, but if the nutrition is too biased, they can become aggressive towards other fish and begin to pluck their fins.

Optical illusion

Banded parsons, depending on the test group, were trained to tap either the larger or the smaller of two orange circles to leave the test area. As soon as they learned this, scientists confronted them with an Ebbinghaus deception . This is a visual perception illusion in which a central, colored circle is perceived to be of different sizes, depending on the size of a ring made up of additional circles. Although both circles were the same size, the fish that were trained to swim to the larger circle swam to the circle surrounded by smaller circles, and those trained to swim to the smaller circle swam to that Circle surrounded by larger circles. In doing so, they succumbed to the same deception that humans succumb to. The scientists concluded from this that banded parsons form a mental model of their environment. This should also apply to other fish, because the few species tested ( goldfish and bamboo shark ) also succumbed to optical illusions.

literature

  • Dietmar Kunath: Xenotoca eiseni. In: Claus Schaefer, Torsten Schröer (Hrsg.): The large lexicon of aquaristics. Eugen Ulmer, Stuttgart 2004, ISBN 3-8001-7497-9 , p. 983 f.
  • Günther Sterba : The world's freshwater fish. 2nd Edition. Urania, Leipzig / Jena / Berlin 1990, ISBN 3-332-00109-4 .

Individual evidence

  1. ^ ResearchGate. Retrieved October 2, 2018 .
  2. ↑ Balcombe, Jonathan P .: What a fish knows: the inner lives of our underwater cousins . First ed. New York 2016, ISBN 978-0-374-28821-1 (English).

Web links