Round goby

Introduction

The Round goby (Neogobius melanostomus) is a small, bottom-dwelling invasive fish, native to the Black and Caspian seas in Eastern Europe. It was first discovered in North America in the St. Clair River in 1990.

Description

The Round goby is a small fish, typically measuring between 6 and 16 cm in length. It has a distinctive large, rounded body with a fused pelvic fin. The coloration varies from a pale grey to a dark splotchy black, often with a distinctive black spot on the first dorsal fin.

Habitat and Distribution

Round gobies are highly adaptable and can be found in a variety of habitats, including rocky and sandy bottoms, and in both brackish and fresh water. They are tolerant of poor water quality and low oxygen levels. Since their introduction to North America, they have spread rapidly throughout the Great Lakes region and have been found in several river systems, including the Mississippi River and the Hudson River.

Diet and Predation

Round gobies are opportunistic feeders, consuming a variety of invertebrates, small fish, and fish eggs. They are known to eat the eggs of native fish species, which has led to a decline in some populations. Round gobies are also prey for larger fish, such as smallmouth bass, walleye, and lake trout.

Impact on Ecosystem

The introduction of the Round goby into non-native ecosystems has had significant impacts. They compete with native species for food and habitat, and their predation on native fish eggs has led to declines in some fish populations. However, they also provide a new food source for larger fish and have been linked to increases in the populations of some predatory fish.

Control Measures

Efforts to control the spread of Round gobies include public education, regulations on bait use, and research into potential biological controls. In some areas, efforts are also being made to restore native fish populations that have been impacted by Round goby predation.

Conclusion

The Round goby is a prime example of the potential impacts of invasive species on non-native ecosystems. While they have become a part of the ecosystem in areas where they have been introduced, efforts continue to control their spread and mitigate their impacts.

See Also

• Invasive species
• Great Lakes
• Neogobius melanostomus
• Black Sea
• Caspian Sea