Individual variation in the rate of oxygen consumption by zebrafish embryos

Abstract

A sensitive microsensor‐based method was used to measure oxygen consumption of individual zebrafish Danio rerio embryos at 6 h intervals from 24 to 75 h post‐fertilization. An increase in oxygen consumption rates from 4·54 to 8·29 nmol O2 h−1 was found during this period. At the individual level the differences in oxygen consumption rates caused the total oxygen consumption from 24 to 75 h post‐fertilization to vary between 0·261 and 0·462 μmol O2 per individual with a mean of 0·379 μmol O2 per individual. A separate carbon mass balance study corroborated the mean total oxygen consumption obtained by yielding a respiratory quotient of 0·80 for this period. These results suggest that there is significant intraspecific variation in the metabolic rate of developing zebrafish embryos, which may influence other early life‐history traits such as growth and starvation resistance.