Koi fish have got a lot going for them. "[They are] not only a pet, but also art," says Taro Kodama, president of Kodama Koi Farm. "They are called living jewels — beautiful as one koi, even more ...

According to a researcher with the Great Lakes Institute for Environmental Research (GLIER), it's Cyprinus carpio — the common carp. "They've been around here for several decades now," said ...