These tropical freshwater fishes come in so many colors, shapes, and sizes, it's nearly impossible to sum up the family of Cichlidae. But with all their many differences in appearance and behavior, the more than 1,500 species share a few characteristics: they're (almost always) colorful, intelligent, social, and they know how to care for their offspring!

Family: Cichlidae
Size: varies from one inch to three feet long
Habitat: freshwater habitats in South and Central America, India, Madagascar, and Africa
Diet: varies by species, but may include algae, plants, insects, or fish
Characteristics: single nostril on either side of the head, long straight line of scales divided into two rows along the sides of the body

Image credits: main image, courtesy of Larry Johnson.