We investigated the process of yolk absorption in Korean rose bitterling, Rhodeus uyekii, and determined the changes in its morphometric characteristics. The R. uyekii from 1 days post hatching (DPH) to 21 DPH, the eye diameter (ED) was 5.4 at 5 DPH. Thereafter, the ED/total length (TL) ratio increased to 10.7 at 21 DPH (p<0.05). The yolk length (YL) decreased from 95.4 to 1.1 by 21 DPH, and this rate of decrease was greater than that for any other dimension (p<0.05). 12 morphometric dimensions/TL for the R. uyekii were measured at each sampling day from 21 DPH to 170 DPH. At just hatching, the average TL and BW were 6.1±0.09 mm and 4.9±0.07 mg, respectively. At 53 DPH, the average TL was 12.9±0.28 mm and the average BW was 14.7±0.72 mg; the total length growth equation was TL=5.507e0.038t (R²=0.916). Further, the body weight growth equation was BW=3.3647e0.0296t (R²=0.9354). The dimensions with regard to body depth showed the greatest growth rates in the external characteristics of the fish (p<0.05). The patterns of the morphometric characteristics measured in this study can be classified in three ways. The patterns were shown to be increased (y=0.0992x+ 12.07, R²=0.8333), decreased (y=–0.0569x+42.029, R²=0.8395) or maintained (y=0.005x+18.263, R²=0.3678) from 21 DPH to 170. These results will provide useful indices for the successful rearing of the R. uyekii.

• In Bon Goo(Inland Aquaculture Research Center, National Fisheries Research & Development Institute (NFRDI)) Corresponding author
• Sang Gu Lim(Inland Aquaculture Research Center, National Fisheries Research & Development Institute (NFRDI))
• Hyung Kyun Han(Inland Aquaculture Research Center, National Fisheries Research & Development Institute (NFRDI))
• In-Seok Park(Division of Marine Environment and Bioscience, Korea Maritime and Ocean University)