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Invasive Species: Round Goby

Round Goby

(Apollonia melanostomus)
*Established in the Great Lakes*


Report this species:

Use the Midwest Invasive Species Information Network (MISIN) online reporting tool.

- Or - download the MISIN smartphone app and report from your phone -



  • Up to 30.5 cm long; maximum size in the U.S. is 17.8 cm.
  • Young fish are solid slate gray color, older individuals are blotched with black and brown.
  • Black spot on rear of first dorsal fin.
  • Fused pelvic fin.

round goby illustration
Illustration by Joseph R. Tomelleri.

round goby
Photo courtesy of Eric Engbretson. US Fish and Wildlife Service,

round goby
Photo courtesy of David Copplestone, Ontario’s Invading Species Awareness Program.

Habitat: Round gobies are freshwater fish that prefer brackish water conditions. Behavior generally includes perching on rocks and other substrates in shallow areas of water, but round gobies may also flourish in open sandy areas and other varieties of habitat types.

Diet: Zebra mussels, some native snails, aquatic insects, other males’ eggs and smaller individuals.

Native range: Eurasia – Caspian Sea, Black Sea, Sea of Azov and its tributaries.

Local concern: Round gobies have voracious appetites and an aggressive nature which allows them to dominate over native species. Round gobies also have a competitive advantage over native species due to a well-developed sensory system that allows for enhanced water movement detection and the ability to feed in complete darkness.

Means of Introduction: Ballast water.

  • Native look-alikes and how you can tell them apart from round goby:
  • Spoonhead Sculpin: pelvic fins not fused, all fins lightly speckled except for clear pelvic fins.
  • Slimy Sculpin: pelvic fins not fused, no spot on first dorsal fin.
  • Mottled Sculpin: pelvic fins not fused, dark spots all over first dorsal fin.
  • Deepwater Sculpin: pelvic fins not fused, no spots on first dorsal fin.


Status and Strategy for Round Goby Management This document provides in-depth information about round goby in Michigan including identification, distribution, management and control options.

Round Goby Invasive Species Alert (printable PDF)