Grass perch
Grass perch | ||||||||||||
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![]() Grass perch |
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Systematics | ||||||||||||
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Scientific name | ||||||||||||
Lepomis cyanellus | ||||||||||||
( Rafinesque , 1819) |
The grass perch ( Lepomis cyanellus ), also known as green sunfish , is a fish from the sunfish family (Centrarchidae).
features
The grass perch differs from other Lepomis species mainly by its flatter body structure and its significantly larger mouth. Its body is mostly greenish in color and covered with a few shimmering blue scales. Males are usually more intensely colored than females. The fish usually reach a size of 15 to 20 cm, but in exceptional cases they can grow up to 31 cm.
behavior
Its food consists mainly of small animals such as insects and their larvae , snails and crabs , but small fish are also preyed on. Like its relative, the sun bass , the grass perch also practices intensive brood care. At spawning time , the male looks for shallow water with a sandy or gravel-covered bottom. There it fans out a shallow pit with its tail fin, which it vehemently defends. The female is lured to the nest by conspicuous advertising by the male. There, after a few false pairings, the actual spawning act occurs. The eggs released are clear and colorless, sticky and about one millimeter in diameter. After several matings, the female is driven from the vicinity of the pit. The male alone takes care of and guarding the clutch. It fins the eggs and the hatched larvae with fresh water until they have consumed their yolk sac. The larvae hatch after about two days and are able to take care of themselves after a further seven days.
distribution
Its natural range includes the United States from the Appalachian Mountains in the east to the Rocky Mountains, as well as southern Ontario and northeastern Mexico . However, it has also been introduced in New England , California, and parts of Europe . In Germany it has already been found in the Worms - Karlsruhe area and in Hesse . Its preferred habitat are ponds, lakes and slow flowing rivers with dense vegetation.
ecology
Grass perch should under no circumstances be released in the wild, as they are quite capable of surviving and reproducing in the European climate. As neozoa they can also displace native species such as the ruff and damage the population of small aquatic animals through their voracity.
Aquaristics
This fish enjoys a certain popularity among aquarists and can be kept in a cold water aquarium or garden pond . Depending on its origin, this species can even be overwintered in the garden pond. However, a supply of clear, oxygen-rich water is important for keeping. In addition, the grass perches should be offered various hiding places and enough open swimming space. Therefore, an aquarium for a pair of grass perch should have an edge length of at least 1.2 m.
Web links
- German-language information page on grass perch
- Grass perch on Fishbase.org (English)
- Lepomis cyanellus inthe IUCN Red List of Threatened Species 2013.2. Posted by: NatureServe, 2012. Retrieved February 10, 2014.
literature
- Bent Jörgen Muus: Freshwater fish - biology, catch, economic importance. Munich 1998.
- Günther Sterba : The world's freshwater fish. Augsburg 1990.