Carl Henry Eigenmann (March 9, 1863 – April 24, 1927) was a German-American ichthyologist of the late nineteenth and early twentieth centuries, who, along with his wife Rosa Smith Eigenmann, and his zoology students is credited with identifying and describing for the first time 195 genera containing nearly 600 species of fishes of North America and South America. Especially notable among his published papers are his studies of the freshwater fishes of South America, the evolution and systematics of South American fishes, and for his analysis of degenerative evolution based on his studies of blind cave fishes found in parts of North America and in Cuba. His most notable works are The American Characidae (1917–1929) and A revision of the South American Nematognathi or cat-fishes (1890), in a