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Species
Gobius melanostomus Pallas, 1814
IUCN
NCBI
EOL Text
Round gobies are small fish with large, frog-like heads, raised eyes, soft bodies, and spineless dorsal fins. Males are generally larger than females. They have a distinctive black spot on their front dorsal fin. Mature round gobies are covered by black and brown splotches that lighten when threatened. Round gobies are distinguished from Cottidae by their fused pelvic fin, which is also called a suctorial disc and is used to help attach to a surface in flowing water.
Range length: 11 to 30 cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: male larger
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | ©1995-2012, The Regents of the University of Michigan and its licensors |
Source | http://www.biokids.umich.edu/critters/Neogobius_melanostomus/ |
Comments: Diet includes bivalves, large invertebrates, and the eggs and fry of native fishes such as sculpins, darters, and logperches; in the U.S., documented foods include insect large and zebra mussels (Marsden and Jude 1995).
Spawns over a long period in the warmer months; male guards eggs; females mature at 1-2 years, males at 3-4 years (Marsden and Jude 1995).
In its native region of the Black and Caspian Seas, round gobies are prey fish for economically important food fishes, and are also fished for food. In the Great Lakes, they feed on zebra mussels, another exotic species that causes a host of problems. It does not reduce the concentration enough to control these mussels, though.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | ©1995-2013, The Regents of the University of Michigan and its licensors |
Source | http://animaldiversity.ummz.umich.edu/accounts/Neogobius_melanostomus/ |
Dorsal spines (total): 7 - 8; Dorsal soft rays (total): 12 - 17; Analspines: 1; Analsoft rays: 9 - 14; Vertebrae: 31 - 34
License | http://creativecommons.org/licenses/by-nc/3.0/ |
Rights holder/Author | Christine Marie V. Casal, FishBase |
Source | http://www.fishbase.org/summary/SpeciesSummary.php?id=12019 |
Round gobies are voracious feeders. Up to 60% of their diet is made up of Bivalvia in some places. They also eat aquatic insect larvae, the young and eggs of other fish, and aquatic snails. In the Great Lakes they prey on Dreissena polymorpha, another Great Lakes exotic from the same native region. They can eat up to 78 zebra mussels each day. A complete lateral line system allows them to feed in complete darkness. In the Great Lakes they also eat the young and eggs of Cottus bairdii, Percina caprodes, Etheostoma, and Salvelinus namaycush, among other species, making them a threat to those native populations.
Animal Foods: fish; eggs; insects; mollusks; aquatic crustaceans
- Ghedotti, M., J. Smihula, J. Smith. 1995. Zebra mussel predation by round gobies in the laboratory. Journal for Great Lakes Research, 21: 665-669.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | ©1995-2012, The Regents of the University of Michigan and its licensors |
Source | http://www.biokids.umich.edu/critters/Neogobius_melanostomus/ |
Males guard nests and attract females to spawn there. Multiple females may leave their eggs in a single male's nest.
Mating System: polygynous
Female round gobies spawn repeatedly, approximately every 20 days, from April until September while males guard the eggs and young. This repeated spawning gives them an ecological advantage over species which spawn less frequently. Females are mature by 2 to 3 years of age and males at 3 to 4 years. Females deposit 89 to 3841 eggs at a time. Fecundity is directly related to female body size. Eggs are laid on a hard substrate, such as gravel, rocks, or even submerged trash, and are then guarded by the male until hatching.
Breeding interval: Female round gobies can spawn every 20 days during the warm season, from April to September.
Breeding season: Spawning occurs from April to September.
Range number of offspring: 89 to 3841.
Range time to hatching: 18 (high) days.
Range age at sexual or reproductive maturity (female): 2 to 3 years.
Range age at sexual or reproductive maturity (male): 3 to 4 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); oviparous
Males aggressively guard eggs at nest sites until they hatch.
Parental Investment: pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Protecting: Male)
- Marsden, J., D. Jude. 1995. Round gobies invade North America. Great Lakes SeaGrant Factsheet, FS 065.
- Sapota, M. 2006. "NOBANIS – Invasive Alien Species Fact Sheet – Neogobius melanostomus" (On-line). Online Database of the North European and Baltic Network on Invasive Alien Species. Accessed December 11, 2008 at http://www.nobanis.org/files/factsheets/Neogobius_melanostomus.pdf.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | ©1995-2012, The Regents of the University of Michigan and its licensors |
Source | http://www.biokids.umich.edu/critters/Neogobius_melanostomus/ |
Comments: In the Great Lakes area, walleye anglers sometimes are bothered by round gobies attacking baited hooks (Marsden and Jude 1995).
The round goby (Neogobius melanostomus), a native of freshwater and marine waters of Eurasia (particularly the Black and Caspian Seas and the Sea of Azov), was first observed in the Great Lakes Basin in 1990 when recreational anglers caught a specimen in the St. Clair River. It is believed that the species was introduced via international shipping ballast water discharge. Since that time, the fish has spread to all of the Great Lakes (Lake Erie, 1993; Lake St. Clair, 1994; Lake Michigan, 1994; Lake Superior, 1995; Lake Ontario, 1996; Lake Huron, 1998), where it is undergoing a dramatic population explosion (densities of several dozen per square meter of lakebed have been reported). Spread upstream to Lake Superior is believed to have been a result of interlake ballast water transport; downstream spread is most likely attributable to both ballast discharge and natural migration. Round gobies may prey on small fish such as darters, as well as lake trout, sculpin, and darter eggs and fry.
Adult gobies take over prime nearshore spawning sites and aggressively prevent use by native species. Long-term impacts are expected to include declines in native species populations. N. melanostomus has a well-developed lateral line which may give it a competitive advantage over native species feeding in turbid waters. Round gobies are also prolific breeders, spawning every 20 days during the spawning season.
Round gobies are problematic to anglers in that gobies are proficient bait thieves.
Neogobius melanostomus has the beneficial impact of consuming large numbers of zebra mussels; however, given the contamination found in some populations of zebra mussels, this may result in bioaccumulation of toxics in gobies and biomagnification up the food chain to shorebirds and other species which consume the fish.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Tracy Barbaro, Tracy Barbaro |
Source | http://www.nyis.info/index.php?action=invasive_detail&id=23 |
Maximum size: 250 mm TL