New York State (Cayuga Lake) and the first round goby was discovered by the state of New York in the Hudson River in 2021. Round gobies are euryhaline (salt-tolerant) and live in both freshwater and marine ecosystems, up to a mineralization of 18–24%. They are commonly found on continental shelves with sandy and rocky bottoms with low silting at depths from to . Feeding Round gobies actively feed both nocturnally and diurnally and are believed to detect prey only while stationary. The primary diet of round gobies includes mollusks, crustaceans, worms, fish eggs, zebra mussels, small fish, insect larvae, and other small invertebrates (insects and amphipods) living on the bottom of lakes and streams. In spring, the main elements of their diet in the Sasyk Lagoon are Hydrobia, Cerastoderma, and Abra. In the same season, near the Romanian coasts of the Black Sea, the round goby feeds on polychaetes, crustaceans (Idotea balthica, Pachygrapsus marmoratus, Xantho poressa, etc.), and juvenile gobies. Near Sevastopol, the round goby feeds on molluscs (Mytilaster lineatus and Abra sp.). In the Gulf of Odessa, twenty-three items are identified in the diet of the round goby; Mytilus galloprovincialis, Setia pulcherrima, Mytilaster lineatus, Lentidium mediterraneum, Idotea balthica, and Alitta (Nereis) succinea dominate in the spring, while in the summer, the diet consists mainly of Sphaeroma pulchellum and L. mediterraneum. The mussels M. galloprovincialis and M. lineatus are important in all seasons. Reproduction Female round gobies reach sexual maturity in one to two years while males do so in three to four years. Gobies in the Laurentian Great Lakes typically mature up to one year earlier than in their native habitat in Europe. Females can spawn up to six times during the spawning season, which spans April to September in most areas. Males will migrate from deeper water, where overwintering occurs, into shallower breeding grounds during the beginning of the mating season. They then release a steroid sex pheromone that attracts females to their territory. Males also use visual displays, including posturing and changing color from beige to black during mating season, and can produce sounds during courtship. The females deposit their eggs in male-guarded crevices between rocks. Eggs are in size, while egg clutches can contain up to five thousand eggs. Males are territorial and will defend eggs from predators as well as continuously fan them to provide the developing embryos with oxygenated water. This results in successful