Regional asymmetry of metabolic and antioxidant profile in the sciaenid fish shi drum (Umbrina cirrosa) white muscle. Response to starvation and refeeding.

The objective of the present study is to characterize the metabolic and antioxidant profile of white muscle of shi drum in two sites of the body, anterior dorsal (AM) and posterior dorsal (PM) portions. In addition, it will be analyzed the possible effect of starvation and a subsequent refeeding, with two different protocols, pair feeding and ad libitum. Activities of key enzymes of intermediary metabolism and of antioxidant enzymes, as well as lipid peroxidation, as an index of oxidative stress, were evaluated. The results indicate the existence of a regional asymmetry of the metabolic capacities of the white muscle of shi drum, which is likely related to the different contribution to swimming of the body regions examined. Starvation induces a metabolic depression that is more marked in those activities that support burst swimming in PM, while those activities supporting maintenance requirements are conserved. The greatest energy demands during starvation appear to lie in AM, which showed the highest oxidative metabolism rate. The increased use of fatty acids as energy source for AM leads to oxidative stress. A period of more than four weeks of refeeding for full restoration of metabolic capacities in AM is needed, probably related to the higher muscle mass located in this region. On the contrary, all enzyme activities in PM returned to control levels in both refeeding protocols, but pair feeding seems to be advantageous since compensatory growth has been taking place without signs of oxidative stress. This work was addressed to gain knowledge on the physiology of a promising fish species in aquaculture like shi drum. The results displayed here show how the starving and further re-feeding events could generate oxidative stress situations characterized by high lipid peroxidation levels which may influence negatively on the quality of the edible part of the fish. This study opens an interesting field on this fish species which deserves being investigated in the future.Versión del edito

EFECTO DE LOS FOSFOLÍPIDOS MARINOS SOBRE BIOMARCADORES NUTRICIONALES Y DE ESTRÉS FISIOLÓGICO DE LAS PARALARVAS DEL PULPO COMÚN (OCTOPUS VULGARIS) BAJO CONDICIONES DE CULTIVO ESTANDARIZADAS EN TRES CENTROS

El efecto del enriquecimiento de la Artemia con fosfolípidos marinos (LC60), sobre el crecimiento, la supervivencia y los biomarcadores de condición nutricional (ARN/ADN) y de estrés fisiológico (proteínas de estrés (HSP70), enzimas antioxidantes y peroxidación lipídica) en paralarvas cultivadas de pulpo común (Octopus vulgaris) se evaluó bajo un protocolo estandarizado en tres centros. Las paralarvas recién eclosionadas mostraron diferencias significativas entre centros en peso seco y en la mayor parte de los biomarcadores analizados. Por el contario, en paralarvas cultivadas de 15 días, se encontraron diferencias significativas debidas a la dieta, presentando un incremento en la tasa de crecimiento específica (TCE) en el grupo alimentado con Artemia enriquecida con LC60 y mayores niveles de actividad GPX T y GR. Sin embargo, la dieta no tuvo efecto en la supervivencia de las paralarvas. Los biomarcadores de condición nutricional y de estrés fisiológicos presentaron diferencias entre los centros. Los resultados indican que el uso de fosfolípidos marinos como enriquecimiento de Artemia mejora el crecimiento de las paralarvas, si bien no se observa un efecto positivo de dicho tratamiento sobre la supervivencia de las mismas