Humans have successfully bred over 40 species of river ducks in captivity, but chromosomal analysis and comparisons of morphology show that of the many breeds of domestic duck reared today, most are descended from mallards and the spotbilled duck.
人類世界曾經將四十種河鴨成功養殖，今天眾多家鴨品系，經過染色體檢驗、外型比對，大部份來自綠頭鴨、斑嘴鴨。