When Japan's Osaka Tennoji Zoo took in a hippo named Gen-chan seven years ago, they were told the young animal was a male. Recently, they took a DNA test and found out the mammal is actually a female.

HOUSTON, Texas (KTRK) -- There's a new pygmy hippo in town! The Houston Zoo announced Tuesday that it has welcomed a 450-pound male pygmy hippopotamus named Silas. The 2-and-a-half-year-old hippo ...