As oil globules of other species are high in MUFA (Eldridge et al., 1983; Wiegand, 1996), the decrease in MUFA may indicate that lake whitefish embryos utilize the oil, rather than the yolk, as a source of lipid energy during embryonic development. We have observed how the numerous oil globules at fertilization merge into a single oil globule at hatch, but it is unknown if oil volume changes or lipids from the oil are preferentially atabolized (Sreetharan et al., 2015). The use of oil versus yolk for energy cannot be confirmed without separating the yolk and oil globule lipid and examining if the percent contribution of MUFA changes in each component throughoutdevelopment. Thus, the contribution of the oil globule lipid to overall energy use remains unknown.