Killi is a Dutch word meaning "stream" or brook, but the 300 killifish members of the family Cyprinodontidae in fact inhabit a great variety of waters. These include ephemeral ponds, brackish marshes, lakes, and rivers of the Americas, Africa, Asia, and warmer parts of Europe. Their small cylindrical bodies have upturned mouths for surface feeding. Males are usually more brilliantly colored. In captivity, killifishes accept most types of food. They lay eggs in plants or in the substrate. In both cases, eggs may take weeks or months to hatch and they can survive periods of almost total dehydration. Many subspecies of various coloration have led to confusion with identification.