Species and Origin: The round goby is an aggressive bottom-dwelling fish that lives in lakes and rivers. They resemble sculpins, which are native, bottom-dwelling fishes. They can spawn several times per year. Adult fish are 3-10 inches long and mostly slate gray in color. There is a single scallop-shaped pelvic fin and a black spot on the dorsal fin. It is native to the freshwater region of the Black and Caspian Seas. They were introduced into the Great Lakes within ballast water discharged from ocean-going ships.
Impacts: Round gobies have been found at densities up to 20 per square meter. They compete with native fish for food and habitat, and eat the eggs and young of native fish.
Status: Present in all the Great Lakes, many of their tributaries, and has spread into the Mississippi River Basin through the Chicago Sanitary and Ship Canal. It has not been found in Minnesota's inland waters. See US map .
Where to look: They live in lakes and rivers. Anglers should examine small fish they catch. They hide along riprap and cobble areas.
Regulatory classification (agency): It is a prohibited invasive species (DNR), which means import, possession, transport, and introduction into the wild is prohibited.
Means of spread: They could be spread through the use and improper disposal of live bait.
How can you help?
- Do not use as live bait
- Remove non-bait minnows, crayfish, and plants from bait containers
- Report new infestations to the DNR Invasive Species Program.