A highly aggressive species of fish has been found in Lake Tahoe, and environmental scientists are afraid the nonnative invader will gobble up native fish and ruin decades of work to improve water clarity, researchers said Tuesday. ... "It really shocked us. You can think of it this way: There is a new bully in the neighborhood," said Sudeep Chandra, a university limnologist who was working with the California Department of Fish and Game on a study of invasive species when the discovery was made six weeks ago. .. The Department of Fish and Game has been working with Chandra...