Description: Introduced to the Great Lakes region in 1990 in the St. Clair River through ballast tanks of ships.
Identification: Tan-gray with small dark blotches on sides. Body is robust and tapered with a thick caudal peduncle. Large and blunt head with a subterminal mouth and partly dorsal eyes. Small dusky spot at base of the upper pectoral rays. Pelvic fins joined to form a funnel-like sucker, short spiny dorsal fin and long, soft dorsal and anal fins.
Habitat: Native to Europe, specifically the Black and Caspian Seas. Prefer shallow, brackish waters but also occur in fresh water. In fresh water, prefer rocky and vegetated lake shores and areas of large rivers. Can tolerate a wide spectrum of water-quality conditions.
Reproduction: Spawning season is between April and September. Females may repeat spawning during a season. During the mating season the male round goby's body is entirely black. Adhesive eggs are deposited on stones, shells and aquatic plants, and the males guard the eggs until they hatch. Males typically die after spawning season ends.
Impact and Damage: Round gobies' rapids reproduction rates allow this species to establish large populations that outnumber and outcompete native fishes such as sculpins and darters. They also prey on the eggs of native fishes.
Similar species: Native sculpins (Cottus spp.).
Monitoring and rapid response: Preventive measures such as cleaning boats, trailers and equipment before moving to a new body of water can help control round goby populations. Electric barriers and pescicides have also been used to prevent the spread of round gobies into new bodies of water.
Credits: The information contained in this factsheet was provided by the Shedd Aquarium.