Umbrella marshmallow

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Umbrella marshmallow
Systematics
Order : Toothpies (Cyprinodontiformes)
Subordination : Cyprinodontoidei
Family : Viviparous toothcarps (Poeciliidae)
Subfamily : Live-bearing toothcarps (Poeciliinae)
Genre : Xenophallus
Type : Umbrella marshmallow
Scientific name of the  genus
Xenophallus
Hubbs , 1924
Scientific name of the  species
Xenophallus umbratilis
( Meek , 1912)

The xenophallus umbratilis ( Xenophallus umbratilis ) is in Nicaragua and Costa Rica occurring freshwater fish of the subfamily of live-bearing tooth carp (Poeciliinae). He is the only representative of the genus Xenophallus, which is monotypical .

features

The Kärpfling reaches a length of up to 6 cm, whereby males remain significantly smaller with a maximum of 4 cm. Both sexes are gray-yellow in color with a white belly side. A transverse banding of 4–8, according to other sources 5–10, thin black lines runs along the sides of the body, which is less pronounced in females than in juvenile fish and males. The fish appear elongated with a pointed head. The fins are usually tinted yellow. The dorsal fin of the males has a dark border and an inner black band. In dominant animals it is also colored yellow to orange. The adult male gonopodium has an upward-pointing hook-shaped process and a membranous swelling below the tip. In addition, the gonopodium is twisted asymmetrically either on the right or on the left.

Occurrence and way of life

Xenophallus umbratilis occurs in both standing and flowing water. The distribution area extends from Lake Nicaragua over the catchment area of ​​the Río Parismina to the Atlantic coast of Costa Rica. It was also found in the river system of the Río Tenorio on the Pacific slope of Costa Rica.

The Kärpflinge prefer to stay in small groups in streams and on the banks of rivers. In Lake Nicaragua, the Kärpfling was caught several kilometers from the coast at depths of 10–12 m. The water temperatures are between 21 and 37 ° C. The fish feed on detritus , algae and aquatic insects .

After a gestation period of 28 days, the females give birth to between 15 and 20 fry, which are already 8 mm long at birth. The fish reach sexual maturity after 3–4 months.

Systematics

Because of similarities in the structure of the skeleton and similarities in the structure of the gonopodium, a relationship with the genus Neoheterandria was assumed for a long time . Recent molecular genetic studies come to the conclusion that the species is closely related to the genus Priapichthys .

Individual evidence

  1. ^ A b c Manfred K. Meyer, Lothar Wischnath, Wolfgang Foerster: Livebearers Zierfische: Species of the world . 1st edition. Mergus, Verlag für Natur- und Heimtierkunde, Melle 1985, ISBN 3-88244-006-6 , p. 358-360 .
  2. ↑ a b c d William Albert Bussing: Peces de las aguas continentales de Costa Rica / Freshwater fishes of Costa Rica . 2nd Edition. Editorial de la Universidad de Costa Rica, San José, Costa Rica 1998, ISBN 978-9977-67-074-4 ( limited preview in Google Book Search).
  3. ↑ Donn Eric Rosen, Reeve M. Bailey: The Poeciliid Fishes (Cyprinodontiformes), Their Structure, Zoogeography and Systematics . In: Bulletin of the American Museum of Natural History . tape 126 . New York 1963, p. 126-128 .
  4. ↑ Tomas Hrbek, Jens Seckinger, Axel Meyer: A phylogenetic and biogeographic perspective on the evolution of poeciliid fishes . In: Molecular Phylogenetics and Evolution . tape 43 , 2007, p. 968-998 , doi : 10.1016 / j.ympev.2006.06.009 .

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