Photo credit: U.S. Geological Survey, Bugwood.org
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Species at a Glance
The European rudd is a medium-sized fish belonging to the minnow family. It is carnivorous when young, feeding on snails, insects, and small crustaceans, but prefers aquatic vegetation as it gets older.
The body of the rudd is somewhat stocky, robust, and elliptical in shape, with large scales and a forked tail. It has a scaled, keel-like belly that runs from the pelvic to the anal fins. Coloration is brownish-green above and brassy yellow to rosy on the sides, fading to silvery underneath. The pectoral, pelvic, and anal fins are a distinctive bright reddish-orange color. The mouth is terminal and lacks barbels, and the lower lip is sharply angled with a protruding lower jaw. The iris of the eye is yellow to orange, often with a red spot that can cover the pupil. Another identifying feature of the rudd is that the beginning of its dorsal fin is set well behind the front of the pelvic fin. Maximum size is up to 48 cm (19 in) in length.
Young rudd can be confused with golden shiners (Notemigonus crysoleucas); however, adult rudd reach much larger sizes. The rudd has 6-9 scales on the belly, whereas the golden shiner has a naked, scale-less belly. In addition, the fins of the golden shiner are clear to pale orange, not bright orange or red, and it lacks the red spot on the iris above the pupil.
The European rudd prefers still and sluggish waters in the weedy shoreline areas of lakes and rivers, but it can adapt to a wide range of environmental conditions, including poor water quality.
Bait bucket release is the primary mechanism by which the rudd has gained access to open waters. Because it is similar to the golden shiner, it can become mixed in with shiner shipments to bait dealers and become introduced into new environments by anglers.
Native to Europe and western Asia, the European rudd was most likely introduced to the United States as a game and food fish. Since its introduction, it has spread throughout much of the country and has been collected in 21 states. In the Mid-Atlantic region, the rudd can be found in New York, Pennsylvania, Virginia, and failed populations have occurred in New Jersey and West Virginia.
Note: Distribution data for this species may have changed since the publication of the Mid-Atlantic Field Guide to Aquatic Invasive Species (2016), the source of information for this description.
Although the rudd’s impacts are mostly unknown, it may compete with native fish for invertebrate food sources and influence the population dynamics of ecosystems.
Information for this species profile comes from the Mid-Atlantic Field Guide to Aquatic Invasive Species (2016).