Fatty acid profile of cultured green abalone (Haliotis fulgens) exposed to lipid restriction and long-term starvation

Abstract

The fatty acid composition of juvenile green abalone (Haliotis fulgens) exposed to lipid restriction and long-term starvation was studied. Juvenile organisms were acclimated during 26 days and then randomly separated into three treatment groups. One group was fed a restricted diet containing low lipid content (0.14%), another was fed a rich diet containing the optimal lipid content (5.1%), and the third was kept under starvation conditions. After 90 days, the abalone fed the restricted diet showed a significant increase in 18:1n-9 content and a decrease in n-3 and n-6 polyunsaturated fatty acids (PUFA), but the total lipid level remained similar to that observed before the treatment, suggesting lipogenesis. On the other hand, no changes in total lipid content and fatty acid profile were found during the 90-day treatment using the rich lipid diet compared with the initial samples. Starved abalone showed that lipids did not constitute the main energy source and that the concentrations of long-chain PUFA did not change throughout the 90-day starvation period.

Abalone growth and associated aspects: now from a metabolic perspective

“…). Generally, the neutral lipids of abalone are only metabolised as an energy source, when protein and carbohydrates are depleted, during extended periods of fasting (Durazo & Viana ).…”

“…Interestingly, the primary function of n-3 and n-6 polyunsaturated fatty acids in abalone is to serve as substrates for structural components (Durazo-Beltr an et al 2003). Generally, the neutral lipids of abalone are only metabolised as an energy source, when protein and carbohydrates are depleted, during extended periods of fasting (Durazo & Viana 2013).…”

“…Studies investigating the effect of starvation, dietary composition, water temperature variation, and pre-and post-spawning cycles on abalone lipid and/or fatty acid content are present in the literature. Very few mechanistic studies investigating the breakdown of these lipids, however, have been performed, with most of the research to date focused more towards describing the varying compositions of the fatty acids during such conditions (Durazo-Beltr an et al 2004;Grubert et al 2004;Durazo & Viana 2013;Hern andez et al 2013;Wang et al 2014).…”

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“…Sin embargo, se reporta que es posible obtener altas tasas de crecimiento con el uso de alimento formulado con 1.5% de lípidos de fuente marina (Fleming et al, 1996). En la nutrición del abulón, los lípidos de la dieta deben de cubrir principalmente los requerimientos de ácidos grasos n-3 y n-6 del organismo, el aporte energético no presenta preponderancia (Durazo y Viana, 2013). Con base en estudios en H. discus hannai, se estima que los requerimientos de AGPCL como 20:5n-3 y 22:6n-3 se cubren con un aporte en los lípidos de la dieta de 20% de n-3 y 2% de n-6.…”

“…Al término del ensayo se tomaron 20 abulones por tanque para la extracción de lípidos totales (Folch et al, 1956) en tejido muscular por tratamiento y la posterior determinación del contenido de ácidos grasos. La determinación analítica de ácidos grasos se efectuó mediante cromatografía de gases capilar con detector de ionización de flama, los cuales se identificaron mediante estándares de ésteres metílicos de ácidos grasos bien caracterizados (Durazo y Viana, 2013). El análisis químico proximal de los alimentos se realizó por triplicado de acuerdo con métodos estándar (AOAC, 1995).…”