Morphometrical Changes on Korean Rose Bitterling, Rhodeus uyekii, in Early Growth Period

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=5.507e(0.038t) (R(2)=0.916). Further, the body weight growth equation was BW=3.3647e(0.0296t) (R(2)=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, R(2)=0.8333), decreased (y=–0.0569x+42.029, R(2)=0.8395) or maintained (y=0.005x+18.263, R(2)=0.3678) from 21 DPH to 170. These results will provide useful indices for the successful rearing of the R. uyekii.