Anticipating the free amino acid concentrations in newly hatched pelagic fish larvae based on recently fertilized eggs and temperature

A survey on the loss of free amino acids (FAA) in aquaculture reared fish embryos and larvae was conducted. Twelve fish species from 14 studies were selected and a relationship between the rates of decay for total FAAs and temperature was observed. A Q10 coefficient of 2.98 ± 0.33 SD was estimated and applied as a correction factor in order to achieve a rate of decay of total FAAs common for all species. Based on the Q10 adjusted rate of decay and the overall FAA pool in newly spawned eggs, predictions on the estimated time of FAA depletion and daily loss of FAAs after hatching were achieved. Variation between the species for different FAAs was low, and the most outstanding essential FAAs were leucine, lysine, valine and isoleucine while alanine and serine dominated non-essential FAAs. Overall, leucine could be regarded as the most important among all species due to its common occurrence in newly spawned eggs and fast rate of decay. Based on the functions considered in the present study, it is possible to anticipate the availability of FAA diet needed in the form of live feed for pelagic first feeding marine fish larvae in aquaculture at different temperatures.