Sunfish

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Sunfish
European bass (Enneacanthus chaetodon)

Disc perch ( Enneacanthus chaetodon )

Systematics
Sub-cohort : Neoteleostei
Acanthomorphata
Spinefish (Acanthopterygii)
Perch relatives (Percomorphaceae)
Order : Sunfish-like (Centrarchiformes)
Family : Sunfish
Scientific name
Centrarchidae
Cope , 1865

The sunfish (Centrarchidae; composed of centr-, centro- [from the Greek kentron = sting, spur, center] and archos = anus due to mostly three spiked rays at the front end of the anal fin ) are a family of perch relatives (Percomorphaceae) with over 35 species .

Representatives of the genus Elassoma are sometimes also referred to as sunfish, but belong to the family of dwarf blackfish (Elassomatidae).

distribution

Distribution area in North America

The natural range extends from southern Canada over the USA : North Dakota , Florida and Great Lakes , east to the Atlantic coast and south to Texas .

Introduced by man were sunfish, mainly around the turn of the century, on the west coast of the United States and in many countries of Europe (for example in France , Germany , Great Britain , Italy , Austria , Romania , Switzerland and Hungary ).

In Germany in particular , they have been found in the following bodies of water: Dahme / Spree, Elbe , Recknitz , Fuhse , Lachte , Aschau , Mosel , Erft , Danube , oxbow lakes of the Oder and Rhine , Neckar , Peitz pond , Koberbachtalsperre , several bodies of water in the district Zwickau , the Rosensee in Vogtland, gravel pit Großsteinberg, gravel pit near Dresden- Prohlis , the Garibaldi pond in Berlin- Wilhelmsruh. The green sunfish ( Lepomis cyanellus ) is now widespread in southern Germany (Worms - Karlsruhe area and at the Reifsee in Ingolstadt) . In Austria in several Carinthian lakes , for example in Wörthersee and Ossiacher See , as well as in Burgenland in Neusiedler See or Neufeldersee .

There is a tendency for the species to spread in the non-native areas, but because of their small stature they have so far not achieved any economic importance. Introduced species are for example: Lepomis auritius , Lepomis gibbosus and Enneacanthus obesus .

Way of life

Most sunfish species prefer stagnant and slow-flowing inland waterways , streams and clear ponds with thick vegetation. Some species can also be found in brackish water , for example at estuaries.

Some of the smaller species live in shoals, the larger ones are predatory solitary animals. The animals look for warm and sunny stretches of water in which they are mostly in shallow water.

After severe winters in Europe, older animals in particular come to the surface in large numbers when the ice thaws.

In small bodies of water where no native perch species occur, sunfish can develop into strong brood predators despite their small stature, but do not primarily cause any major damage.

Physique and coloring

Most species are tall and flattened on the sides. Only the genera Aplites , Pomoxis and Micropterus have a more elongated shape. Soft and hard radiating parts of the dorsal fin are usually united, but can also be separated by an incision, as in Micropterus . When fully grown, most species are about 20 to 30 cm long, although extreme sizes of up to one meter (in the largemouth bass ( Micropterus salmoides )) have been reported. The dorsal fin has six to thirteen spines (usually 10–13), the anal fin three to nine spines. The caudal fin is rounded and only slightly incised.

Younger animals are often quite beautifully colored, in almost all species the color decreases with age. The coloring of the fish is adaptable and depends on the well-being. The sexes are usually not easy to distinguish.

Sunfish have a protractile (protruding) premaxillary (intermaxillary bone ). Brush-like teeth stand in several rows in their jaws. The palate ( vomer , palatinum ) is also toothed, as is the tongue. There are strong fangs in the back of the throat . The gill covers are spread apart when threatening. An eye spot increases the threatening effect, as the "eyes" that are further apart simulate a larger fish.

The sideline is complete in most species, and incomplete in some. The lateral line system extends to the lower jaw and is visible as fine pores on the angular and dentals (lower jaw bones). The eye gill is small and hidden. The number of Branchiostegal rays is six or seven. Right and left gill membranes are separated from each other. The number of vertebrae is 28 to 33.

Reproduction

Sunfish spawn in Central Europe from May to July in waters with a sandy bottom. The male occupies a few meters of flat banks as a territory for reproduction and digs a spawning hole with its tail fin , which it guards and defends from other species. During this time of year, the sexually mature females roam around in small groups and females ready to spawn select a territory or its owner. When spawning, the female is usually more beautifully colored. Then the male guards the sticky, sand-colored spawn that adheres to the bottom until the end of the development period, which takes one to ten days depending on the temperature - it remains with the hatched young until they are big enough to go their own way. swim ”. The fry then stay close to the shore in dense populations of aquatic plants , into which they can take refuge if necessary. The fry grow relatively slowly in the wild because the temperatures are often too low.

Internal system

The sunfish are a very old group, the oldest known representative of which, Centrarchites, lived as early as the Eocene . Genetic studies by Roe, Harris and Mayden have shown that it is a monophyletic taxon . Sunfish are traditionally classified within the real perch - but so far it has not been possible to determine the sister group or the exact place of the sunfish in the system of perch-like fish.

The internal system is also unclear. As early as 1877 the sunfish were divided into three subfamilies. The American ichthyologist Joseph S. Nelson states in his standard work on the fish system, Fishes of the World , taking over the phylogenetic study of Roe, Harris and Mayden, two subfamilies, Centrarchidae for Ambloplites , Archoplites , Centrarchus , Enneacanthus and Pomoxis and Lepominae for Lepomis . Acantharchus and Micropterus remain unassigned.

However, none of several systems has prevailed to this day. The fish database Fishbase does not subdivide into subfamilies. Therefore the genera and species are named here in alphabetical order.

External system

Sunfish are traditionally assigned to the perch-like (Perciformes). The dwarf black perch ( Elassoma ), which belonged to the sun perch family in the 1980s and before , were increasingly viewed as an independent family from 1962 onwards, and sun perch and dwarf black perch were later even classified in different subordinates within the perch-like family. However, new molecular biological investigations show that sun and dwarf blackfish are closely related and sister groups , while they are only distantly related to real perch (Percidae). The team of ichthyologist Thomas J. Near and that of fish systematic specialist Ricardo Betancur-R. therefore assigned sunfish and black bass to the Centrarchiformes order established by the German-Dutch zoologist Max Carl Wilhelm Weber and the Dutch biologist Lieven Ferdinand de Beaufort and named after the sunfish in the 19th century .

The following simplified cladogram shows the position of the sunfish within the order Centrarchiformes according to Near et al. (2013):

  Centrarchiformes  





 Flag tails (Kuhliidae)


   

 Grunzers (Terapontidae)



   

 Steerable fish (Kyphosidae)



   

 Beakfish (Oplegnathidae)



   

 Rodent perch (Girellidae)



   


 Percalates


   

 Double dorsal fin (Enoplosidae)


   

 Temperate perch (Percichthyidae) incl. Südbarsche ( Percilia )




   

 Tufted perch (Cirrhitoidea (Cirrhitioidei bei Betancur-R. Et al.))


   

 Sinipercidae


   

 Dwarf blackfish (Elassomatidae)


   

 Sunfish (Centrarchidae)







Human and sunfish

Aquarium keeping

For maintenance, sunfish need well-planted aquariums with shelters and clean, oxygen-rich, stale water. Ventilation is recommended. Old animals prove to be sensitive to sudden changes in the environment (susceptible to skin diseases ), so the water should be changed more often. Natural sunlight should be able to enter the pools.

Sunfish behave calmly, and some species appear intelligent, for example by learning to recognize their keeper. Sunfish are predatory fish, but are compatible with fish of the same size. Large surface fish are particularly suitable for socialization.

The fish should be overwintered in a cool place, around 10 to 15 ° C. During this time they eat less or not at all and severely limit their activity. All species are sensitive to sudden changes in water quality and temperature and are susceptible to medication.

They prefer live food (such as flies, grasshoppers, worms and water snails), but also eat dry or frozen food.

breed

All species practice very intensive brood care , which makes rearing very easy. Some species can only be grown in the indoor aquarium, others only in the field. Many species are hardy, but the water should be prevented from freezing over. The best results for the reproduction of the animals that are hardy are achieved if you put a small group in an open-air pond in autumn and let nature take its course the following spring. Reproduction can also be stimulated through cool wintering . When keeping an aquarium, it is best to remove the female after the act of spawning. With good feeding, the pairs spawn again after six to eight weeks. Up to a thousand offspring can arise per clutch.

Some species are inter-reproductive, with many crosses not sterile and often larger than the parent species.

literature

  • Thomas J. Near, Jeff Koppelman: Species Diversity, Phylogeny and Phylogeography of Centrarchidae. DOI: 10.1002 / 9781444316032.ch1 in Steven Cooke, David P. Philipp: Centrarchid Fishes: Diversity, Biology, and Conservation , pp. 1 - 38, December 2009, ISBN 978-1405133425
  • Günther Sterba : The world's freshwater fish. Urania Verlag, Leipzig 1990, ISBN 3-332-00109-4 , p. 640. (Reprint: Weltbild Verlag, 1996, ISBN 3-89350-991-7 )
  • Norbert Simon, Rodolf Reinboth: Adenohypophysis and Hypothalamus: Histophysiological examinations in Lepomis (Centrarchidae). Springer-Verlag, Berlin 1974, ISBN 0-387-06749-3 .

Individual evidence

  1. Centrarchidae In: Lexikon der Biologie , Spektrum Akademischer Verlag , Heidelberg 1999, accessed on July 11, 2017
  2. Sonnenbarsche In: Lexikon der Biologie, Spektrum Akademischer Verlag, Heidelberg 1999, accessed on July 12, 2017
  3. Tropical species in the Erft? ( Memento from August 21, 2007 in the Internet Archive ) at erftverband.de
  4. http://www.fotocommunity.it/pc/pc/display/18190159
  5. a b c d Joseph S. Nelson : Fishes of the World , John Wiley & Sons, 2006, ISBN 0-471-25031-7
  6. Kurt Fiedler: Textbook of Special Zoology, Volume II, Part 2: Fish . P. 350, Gustav Fischer Verlag, Jena 1991, ISBN 3-334-00339-6 .
  7. Kevin J. Roe, Phillip M. Harris, Richard L. Mayden: Phylogenetic Relationships of the Genera of North American Sunfishes and Basses (Percoidei: Centrarchidae) as Evidenced by the Mitochondrial Cytochrome b Gene . In: Copeia , 2002, No. 4, pp. 897-905, doi : 10.1643 / 0045-8511 (2002) 002 [0897: PROTGO] 2.0.CO; 2
  8. Thomas J. Near, Michael Sandel, Kristen L. Kuhn, Peter J. Unmack, Peter C. Wainwright, Wm. Leo Smith: Nuclear gene-inferred phylogenies resolve the relationships of the enigmatic Pygmy Sunfishes, Elassoma (Teleostei: Percomorpha). Molecular Phylogenetics and Evolution 63 (2012) 388-395, doi: 10.1016 / j.ympev.2012.01.011
  9. ^ A b Thomas J. Near, A. Dornburg, RI Eytan, BP Keck, WL Smith, KL Kuhn, JA Moore, SA Price, FT Burbrink, M. Friedman & PC Wainwright. 2013. Phylogeny and tempo of diversification in the superradiation of spiny-rayed fishes. Proceedings of the National Academy of Sciences of the United States of America. 101: 12738-21743. doi: 10.1073 / pnas.1304661110 , PDF
  10. Ricardo Betancur-R, Edward O. Wiley, Gloria Arratia, Arturo Acero, Nicolas Bailly, Masaki Miya, Guillaume Lecointre and Guillermo Ortí: Phylogenetic classification of bony fishes . BMC Evolutionary Biology, BMC series - July 2017, DOI: 10.1186 / s12862-017-0958-3

Web links

Commons : Sunfish (Centrarchidae)  - Collection of images, videos and audio files
This version was added to the list of articles worth reading on December 15, 2005 .