Photographer: Peter van der Sluijs Source: commons.wikimedia.org Copyright: (CC BY-SA 3.0)
The round goby (Neogobius melanostomus) is a small and soft bodied fish that is native to central Eurasia. Round gobies are 4 to 10 inches long, have a gray body, and a distinctive black spot on the anterior most dorsal fin. Juvenile round gobies are cloudy gray and become darker with maturation. Round gobies have large eyes and well developed sense that enable them to detect changes in water movement. This trait provides the round goby with an advantage of hunting in the dark when most other fish species rely on eyesight.
Round gobies are aggressive fish that defend their spawning territory ruthlessly, preventing native fish species from having access to the best spawning areas. The round goby is able to hunt in the dark providing an advantage for feeding above native fish species that can only hunt during daylight hours and in the photic zone of lakes. With reduced food availability and less than preferred spawning sites, native fish species become quickly threatened when round goby populations become established.
The round goby is also a known host for several parasites, some of which are transmittable to humans. The most prevalent parasite carried by the round goby are nematodes from the family Heterophyidae. Some of the known trematodes found in the round goby are Cryptocotyle concavum, C. lingua, and Pygidiopsis genata. Cryptocotyle lingua and Pygidiopsis genata are capable of transferring to human hosts. The round goby is also a host for epizootic nematodes Tetrameres fissispina and Streptocara crassicauda, which utilize ducklings as hosts rather than humans. Of further concern, the round goby is a common carrier of the invasive nematode parasite Anguillicoloides crassus, which has also been discovered in the invasive European eel. This invasive nematode threatens to further reduce dwindling populations of native American eels.
Within the Great Lakes, the parasite load of the round goby has remained relatively low in comparison to their native habitat. However, infection by the cestode Proteocephalus sp. and the trematode Neochasmus umbellus remains common in the U.S. habitat.
Spawning occurs during the summer months. Round gobies are able to reproduce and become established quickly in a new area because of their high fecundity and defense of spawning territory. Female round gobies will spawn repeatedly over the summer months and produce egg clutches of up to 5,000. Following spawning, the male round goby dies.
The round goby was first introduced to the United States in 1990 in the Saint Clair River. The first recorded discovery in the Great Lakes was in 1995 at the Duluth Harbor area in Lake Superior. It was likely released accidentally via ship ballast water from the ocean that was discharged.
Black Sea and Caspian Sea
U.S. Present: The Great Lakes
U.S. Habitat: The round goby is a bottom dwelling euryhaline (salt tolerant) fish that can live in freshwater or saltwater. In the United States the round goby is found in the Great Lakes and known to feed on insect larvae, clams, mussels, fish eggs, large invertebrates, and the zebra mussel (another invasive species).
The Department of Natural Resources and other wildlife officials are working to contain the spread and establishment of the round goby in the United States with the use of electrical barriers and piscicides. Further spread of the round goby can be prevented by taking precautions when fishing. Dispose of left over bait in trash cans and not in lakes. Do not empty a bucket of water or bait into a different body of water. If you believe you have seen a round goby in a new body of water, notify the Department of Natural Resources immediately.
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Jude D. J., R. H. Reider, G. R. Smith. 1992. Establishment of Gobiidae in the Great Lakes basin. Canadian Journal of Fisheries and Aquatic Science 49: 416—421.
Kvach Y., V. Zamorov. 2001. Feeding preferences of the round goby Neogobius melanostomus and mushroom goby Neogobius cephalarges in the Odessa Bay. Oceanological Studies 30(3-4): 91-101.
Kvach Y. 2004. The Far-Eastern nematode Anguillicola crassus – new parasite of the invasive round goby Neogobius melanostomus in the Baltic Sea. Vestnik Zoologii 38(2): 38.
Kvach Y., K. E. Skóra. 2007. Metazoa parasites of the invasive round goby Apollonia melanostoma (Neogobius melanostomus) (Pallas) (Gobiidae: Osteichthyes) in the Gulf of Gdańsk, Baltic Sea, Poland: a comparison with the Black Sea. Parasitology Research 100(4): 767–774.
Kvach Y., C. A. Stepien. 2008. The invasive round goby Apollonia melanostoma (Actinopterygii: Gobiidae) – a new intermediate host of the trematode Neochasmus umbellus (Trematoda: Cryptogonimidae) in Lake Erie, Ohio, USA. Journal of Applied Ichthyology 24: 103-105
Lydersen, Karl. 2011. "The Round Goby, an Uninvited Resident of the Great Lakes, Is Doing Some Good". The New York Times. http://www.nytimes.com/2011/05/27/us/27cncgoby.html.
Muzzall P. M., C. R. Peebles, M. V. Thomas. 1995. Parasites of the round goby, Neogobius melanostomus, and tubenose goby, Proterorhinus marmoratus (Perciformes: Gobiidae), from the St. Clair River and Lake St. Clair, Michigan. Journal of the Helminthological Society of Washington 62(2): 226–228.
Round Goby Fact Sheet 065. J.E. Marsden, Illinois Natural Historic Survey and David J. Jude, University of Michigan. 1995. Information provided by the Ohio Sea Grant College Program. (http://www.sg.ohio-state.edu/publications/nuisances/gobies/fs-065.html).