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Scardinius erythrophthalmus

Common rudd
Scardinius erythropthalmus 2009 G1.jpg
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cypriniformes
Family: Cyprinidae
Genus: Scardinius
Species: S. erythrophthalmus
Binomial name
Scardinius erythrophthalmus
(Linnaeus, 1758)

The common rudd Scardinius erythrophthalmus is a bentho-pelagic freshwater fish, widely spread in Europe and middle Asia, around the basins of the North, Baltic, Black, Caspian and Aral seas.

It has been artificially introduced to Ireland, United States, Morocco, Madagascar, Norway, Tunisia, New Zealand, Canada and Spain.

Rudd have been found in the US states of Alabama, Arkansas, Colorado, Connecticut, Illinois, Indiana, Kansas, Massachusetts, Maine, Missouri, Nebraska, New Jersey, New York, Oklahoma, Pennsylvania, South Dakota, Texas, Vermont, Virginia, West Virginia, Wisconsin. This list may not include all states containing an introduced population of rudd.

Rudd were illegally introduced into New Zealand in the 1960s and have been actively spread around the country. They have the potential to irreversibly damage indigenous ecosystems.

Rudd have been reported in the United States at least as early as 1925.

It is unlawful to possess or transport live specimens in the US state of Tennessee.

No person, firm, corporation, partnership, or association shall possess, sell, offer for sale, import, bring, release or cause to be brought or imported into the State of Alabama... Any species of fish “rudd” (Scardinius erythrophthalmus) or “roach” (Rutilus rutilus) or any hybrids of either species. This species was reported in Alabama from First Creek in Lauderdale County, Alabama, ca. 1987.

Morphologically, this species is very similar to the roach (Rutilus rutilus), with which it can be easily confused. It can be identified by the yellow eye colour. The eye of the roach has a big red spot above the pupil, that can be more or less conspicuous. The rudd has an upturned mouth allowing it to feed easily at the top of the water. The placement of the dorsal fin is more to the rear which is even visible in very young fish. There are normally only one or two scales between the tip of the pelvic fins and the anal fins, while on the roach there are five. Also the skin of the rudd is yellowish green, while the roach is bluish on the flanks. Also the upturned mouth is visible even in young fish. Furthermore, the rudd's number of soft rays in the dorsal fin (8–9 compared to 10–12). There can be confusion with the ide also, which has smaller scales however.


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Wikipedia

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