An invasive species in the Great Lakes, the round gobie is a mixed bag. Bottom feeder, competes with some native species, but provides sustenance to larger fish. But it’s consumption of zebra mussels might increase its own Hg contamination, which goes up stream to its predators.
Took this little guy (males darken during spawning season) away from my dog before he ate it. Didn’t know the species, so I took a picture for identification later. My photo shoot took a slight diversion into a quick diorama.