title: Morphometric Characteristics and Fin Dimorphism between Male and Female on the Marine Medaka,Oryzias dancena.
abstract: Sexual dimorphism is the most conspicuous difference between the sexes. This study examines possible sexual dimorphism and the relative growth patterns of morphometric characteristics in the marine medaka,Oryzias dancenafor their potential to help differentiate between males and females of this species. The von Bertalanffy growth parameters estimated by a non-linear regression method were L∞=30.2 mm, K=3.22/year, and τ0=-0.05. All 18 characteristics measured showed a difference between males and females from 70 days after hatching. Each of these characteristics were significantly different between sexes (ANCOVA,P<0.05), and the ratio of standard length between sexes showed that males were larger than females for all five morphometric measurements. Fin length measurements were taken for 21 distances of anal fin and 7 distances of dorsal fin between landmarks. There were all differences for all dorsal fin rays between the males and the females and there is significant difference in 70 days after their hatch when the sexual dimorphism is presented. The significant difference (P<0.05) in fin ray for male and female was more greatly seen as they grow. Male marine medaka showed more rapid growth than females, with longer length, dorsal fins and anal fins. Differences in these characteristics will be useful during experiments when it is necessary to differentiate between sexes of marine medaka.
authors.affiliation: Inland Fisheries Research Institute, National Fisheries Research & Development Institute, Cheongpyeong 12453, Korea.
authors.forename: Jae Hyun
authors.initials: JH
authors.lastname: Im
authors.affiliation: Division of Marine Environment and Bioscience, College of Ocean Science and Technology, Korea Maritime and Ocean University, Busan 49112, Korea.
authors.forename: Hyun Woo
authors.initials: HW
authors.lastname: Gil
authors.affiliation: Division of Marine Environment and Bioscience, College of Ocean Science and Technology, Korea Maritime and Ocean University, Busan 49112, Korea.
authors.forename: Tae Ho
authors.initials: TH
authors.lastname: Lee
authors.affiliation: Biotechnology Research Division, National Fisheries Research & Development Institute, Busan 46083, Korea.
authors.forename: Hee Jeong
authors.initials: HJ
authors.lastname: Kong
authors.affiliation: Biotechnology Research Division, National Fisheries Research & Development Institute, Busan 46083, Korea.
authors.forename: Cheol Min
authors.initials: CM
authors.lastname: Ahn
authors.affiliation: Future Aquaculture Research Center, National Fisheries Research & Development Institute, Jeju 63610, Korea.
authors.forename: Bong Seok
authors.initials: BS
authors.lastname: Kim
authors.affiliation: Institute of Marine Living Modified Organisms (iMLMO), Pukyong National University, Busan 48513, Korea.
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Kim
authors.affiliation: Division of Marine Production System Management, College of Fisheries Sciences, Pukyong National University, Busan 48513, Korea.
authors.forename: Chang Ik
authors.initials: CI
authors.lastname: Zhang
authors.affiliation: Division of Marine Environment and Bioscience, College of Ocean Science and Technology, Korea Maritime and Ocean University, Busan 49112, Korea.
authors.forename: In-Seok
authors.initials: IS
authors.lastname: Park
keywords: Fin dimorphism, Morphometric characteristics; Oryzias dancena; Sexual dimorphism