The 2000 species of gobies are usually small and usually marine. Two species, the round goby and the tubenose goby, were accidently introduced into the Great Lakes in ballast water from tankers in the 1980s. They are native to the Black and Caspian Sea drainage, along with zebra and quagga mussels, which have a similar history of introduction to the Great Lakes. Round gobies compete with native fishes. They can eat zebra mussels in large numbers--over 100 per day, but because the gobies are strictly benthic, they do not reach those zebra mussels on boats and pilings. Both species vigorously defend nests with eggs and young. Female round gobies may lay more than 5000 eggs.
|