Morphometric Characteristics of Diploid and Triploid Marine Medaka, Oryzias dancena

The morphometric truss characteristics and classical dimensions of the marine medaka, Oryzias dancena, that might distinguish diploid and triploid fish were examined. Significant differences in all the classical and truss dimensions of the diploid and triploid fish were observed in both sexes (p<0.01). All the dimensions of the triploid fish were greater than those of the diploid fish. The triploid marine medaka shows sexual dimorphism in these characters, and the sexual dimorphism of the triploid marine medaka is similar to that of the diploid marine medaka. Thus, when their classical dimension and truss dimension was measured, the growth of triploid marine medaka is faster than that of the diploid fish, and it displays clear sexual dimorphism, with male fish having longer dorsal and anal fins than female fish.