Fig. 3. Time course changes of active mitochondria-rich cells (MRCs) (A) and total MRCs (B) in yolk-sac membrane of tilapia larvae transferred from control water to low-Cl^– or high-Cl^– water for 48 h. Values are means ± S.D. (N=5). Different letters indicate significance at the P<0.05 level (one-way ANOVA followed by Tukey's pair-wise comparison).