The finding is important because if non-native and invasive prey survive getting eaten by gobies, then they could be spread as far as the fish swim. The round goby was accidentally introduced by ballast water in the early- to mid-1990s, as were zebra and quagga mussels, said Seth Herbst, a fisheries biologist for the Department of Natural Resources. One not-so-bad thing about the goby is that it eats these invasive mussels because they are part of their natural diet and “constantly in their face,” Herbst said. “None passed through alive,” said biology professor Gregory Andraso of Gannon University in Pennsylvania and one of the study’s authors. The mussels make up about 92 percent of the round goby’s diet.