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Embryo and larva development in common dentex (Dentex dentex), a pelagophil teleost: The quantitative composition of egg-free amino acids and their interrelations

Samaee, S-M., Mente, E., Estévez, A., Giménez, G., Lahnsteiner, F.
Theriogenology 2010 v.73 no.7 pp. 909-919
fish farms, farmed fish, Dentex dentex, developmental stages, fish eggs, embryo (animal), fish larvae, egg hatchability, viability, physicochemical properties, weight, water content, free fatty acids, physiological regulation, biochemical mechanisms, animal breeding
Free amino acids (FAAs) play a key role in the physiology of marine teleosts (eggs, embryos, and larvae). However, the relationship between the egg FAAs content and the production of viable embryos and larvae (at different developmental stages) in batch spawner pelagophils has not yet comprehensively been investigated. Viable eggs of common dentex, Dentex dentex, were obtained from captive broodstocks. Egg wet weight (WW), dry weight (DW), and water content (%W) and viability parameters, or VPs (egg floating rate [FR], hatching rate [HR], and larval survival rate [SR] at days 0 to 5 posthatch) were determined for 45 egg batches. The egg batches were classified according to their HR magnitude. Twelve egg batches with the same WW, DW, and %W were taken from the same broodstock and at the same developmental stage to determine the qualitative and quantitative composition of FAAs. The total FAA (TFAA) content, glutamic acid (Glu), asparagine (Asn), glutamine (Gln), and arginine (Arg) were correlated with VPs. The Glu was significantly correlated with HR and SR at 0 day posthatch (dph), the Asn with SR at 1 dph, and the Gln and Arg with FR and HR. Of the 361 ratios made based on the absolute concentrations of FAAs, 24 ratios were correlated with VPs (P < 0.005) through 42 simple regression models (R² =0.641 to 0.846). Of the 42 significant relationships found ∼10%, ∼28%, ∼12%, ∼30%, ∼8%, ∼4%, ∼2%, ∼2%, and ∼2% of the models show the relations of the egg FAAs ratios with FR, HR, SR at days 1 to 5 posthatch, and %W, respectively. A path coefficient in combination with a Pearson's correlation coefficient provided a series of statistical evidences to show the effects of the egg FAAs interrelations on the relationships found between quantitative composition of a FAA and a VP.