The potencial of red seaweed meal as fed additive for prawn Artemesia longinaris

MARCOVAL M.A; VELURTAS S.; ARZOZ N.; ESPINO L.; DIAZ A.C.; FENUCCI JORGE L

Ciudad Autónoma de Buenos Aires

Jornada; XX Jornadas anuales de la Sociedad Argentina de Biología ( SAB); 2018

Artemesia longinaris is a species of commercial interest distributed in the Southwestern region of the Atlantic Ocean from Southern Brazil to Patagonia (23-50 °S). Under culture conditions juveniles are kept in ponds at less than 2 m deep, so they are exposed to extreme environmental conditions like ultraviolet radiation. It has been shown that many species of red seaweed synthesize high concentrations of photoprotective compounds (PPCs) like UV absorbing compounds and carotenoids and these may constitute an interesting alternative in aquaculture feeds. The aim of this study was to determine the effects of a diet added with red seaweed meal of the family Halymeneaceae on physiological state of Artemesia longinaris. An experiment of 45 days was carried out on juveniles of A. longinaris (1.84±0.46g) obtained from the coastal waters of Mar del Plata Argentina (38°S 57º 33?W). Individuals were placed in 150L glass aquaria and fed every day with three isoproteic and isolipidic diets (45% protein, 8% lipid, 7% water, and 7% ash) with 0 (D), 1 (D1) and 2% (D2) of red seaweed meal. Each diet was tested in five replicated groups of six prawns each one. At the end of the experiment, survival, percentage of increase in weight, metabolites in serum haemolymph and PPCs concentration in tegument were determined. The survival varied between 50 and 76.6%, recorded the highest value in D2 treatment, although there were no significant differences between other treatments. The percentage increase in weight was 35% for individuals fed with diets D and D2 and 26% for those fed with diet D1. For metabolic variables, there was a significant decrease (p< 0.05) in cholesterol and triglycerides, in animals fed with added diets D1 and D2 respect to the animals fed with diet D. UV absorbing compounds only were detected in animals of treatment D1 and D2 with concentration of 0.16 (±0.03) OD g-1 and 0.23 (±0.08) OD g-1 respectively, but no significant differences were found. Carotenoids concentration show significant differences between treatments and recorded the highest values in treatment D2 (17.9 ±6.9 µg g-1 dry weight (p< 0.05). These results show that the use of red seaweed meal is feasible as additive in diets for A. longinaris. The recommended concentration should be 2% that which contributes to a better physiological state.