 They can withstand cold and can be shipped easily.Nearly all aspects of the life cycle of medaka have been analyzed by researchers including sexual behavior, genetic inheritance of coloration, spawning habits, feeding, pathology, embryological development, ecology, etc.It has relatively small genome (~800 mega base pairs, half the size of the genome of another popular model fish, the zebrafish) as well as a generation time of 7 weeks (rather than 9 weeks for zebrafish) and hardier growth in a broad temperature range ().