Most Unwanted: Ruffe
Gymnocephalus cernuus
Habitat: Freshwater
Threat: Competes with native fish species
Status: Potential
Ruffe is a species of freshwater fish that has become invasive in parts of Europe and North America. Ruffe has a high reproduction ablity with a minimum population doubling time less than 15 months. It has wide environmental tolerance and is considered as an aggressive predatory species of zooplankton and other food sources of native species of fish.
What is it?
This is a small species of fish generally reaching only up to 20 cm in length. It is brownish in colour with dark spots over its body. Ruffe have large spiny dorsal fin which is fused.
Impact
The rapid growth and reproduction rate of this species impacts on fish communities as food and resources for native and desirable fish species become reduced. Fish eggs are also a target food source for this species.
Where is it from?
Native to Europe and Asia.
Where is it now?
This species has become invasive in parts of continental Europe, Britain and also the Great Lakes in North America.
How can it get here?
Introductions of this species are generally accidental or unintentional. This species can be introduced as live bait or in ballast water.
What you can do to prevent its arrival
Do not dispose of live bait material in a waterbody.
Report all sightings.
