Folate in eggs and developing larvae of Atlantic halibut, Hippoglossus hippoglossus L.

Abstract Folate mobilization from the yolk compartment during larval development was studied by analysing the folate concentration in whole body, embryo and yolk in a single batch of Atlantic halibut, Hippoglossus hippoglossus L., eggs and larvae that showed successful fertilization and development. There was a net loss of approx. 50% of folate from yolk during endogenous feeding. Further, only 23% of the decrease in yolk folate was retained in the larval body. The data suggest a need for folate for metabolic and growth purposes during embryogenesis of approximately 2 μ g g^-1 weight gain. Relative to these data and published folate requirement for cold-water species, batches of egg from 16 Atlantic halibut brood fish contained variable and, for some batches, critically low levels of folate. This may constitute a potential problem for larval development until start feeding. [ABSTRACT FROM AUTHOR]