 The Japanese rice fish ("O. latipes"), also known as the medaka, is a popular model organism used in research in developmental biology.This species has traveled into space, where they have the distinction of being the first vertebrate to mate and produce healthy young in space.Genetic study of the family suggests that it originally evolved on Sulawesi and spread from there to the Asian mainland; the supposed genus "Xenopoecilus" are apparently unrelated, morphologically divergent species of "Oryzias".