BETA-HYDROXYBUTYRATE IN DEVELOPING NAUPLII OF BRINE SHRIMP (ARTEMIA FRANCISCANA K.) UNDER FEEDING AND NON-FEEDING CONDITIONS


F.A. Weltzien, G.I. Hemre, J.O. Evjemo, Y. Olsen, H.J. Fyhn-2000

Comparative Biochemistry and Physiology B. Biochemistry and Molecular Biology, 125 (1): 63-69 (from Current Contents)

Abstract :

Body content of beta-hydroxybutyrate, and individual dry mass, carbon content, and survival rate, were studied in developing nauplii of the brine shrimp Artemia franciscana K. from hatching to 96-97 h post hatching at 27 +/- 1 degrees C. The effect of two diets was studied in the experiment: Super Selco(R) (SS) with a high lipid content; and Protein Selco(R) (PS) with a high protein content. A starving group (S) was used as reference. The level of beta-hydroxybutyrate at hatching was 0.6 nmol.ind(-1); it increased to 1.0-1.5 nmol.ind(-1) in the SS- and S-groups. While in the PS-group it remained stable between 0.6-0.8 nmol.ind(-1). At 60-80 h post hatch in the SS- and S-groups, the levels of beta-hydroxybutyrate were similar to the initial levels. The survival rate remained higher than 95% until 24 h post hatching in all groups. At the end of the experiment, the survival rate was 63% in the PS-group, 13% in the S-group and 3%, in the SS-group. The Artemia nauplii individual dry mass and carbon content remained relatively stable in the SS-group; both parameters showed a significant increase in the PS-group and a significant decrease in the S-group. The results suggest that Artemia nauplii utilise ketone bodies as a fuel during development and growth, but that ketone catabolism may be overloaded by excessive lipid feeding resulting in increased mortality and possibly a ketotic acidosis.

(Inst Marine Res, Austevoll Aquaculture Res Stn, N-5392 Storebo, Norway, e-mail: finn-arne.weltzien@imr.no)

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