ENRIQUECIMENTO DE Artemia COM ÁCIDOS GRAXOS ALTAMENTE INSATURADOS NA LARVICULTURA DE Farfantepenaeus paulensis E DESEMPENHO NAS FASES POSTERIORES DE CULTIVO.
From mysis I to eight day-old postlarvae (PL8), groups of shrimp (Farfantepenaeus paulensis) larvae were fed two different dietary treatments: enriched (TE), in which larvae received Artemia metanauplii enriched with a emulsion containing high levels of highly unsaturated fatty acids (n-3 HUFA), and control (TC), where larvae were fed newly hatched Artemia nauplii. Larvae were reared at the density of 67/L in two 180L tanks. PL8 were submitted to stress tolerance tests to salinity and total ammonia (N-AT). At the end of the larviculture period, eighteen day-old postlarvae (PL18) were transferred to cages (1m2 bottom area and 1.5mm mesh opening) placed in the Patos Lagoon estuary, southern Brazil, were they were nursery-reared for 30 days. PL fed the enriched Artemia presented significantly higher tolerance to both salinity and total ammonia. Lethal salinity for 50% of the population during 24 hours (SL50 24h) were 18.93 and 20.53 for TE and TC, respectively, whereas the lethal total ammonia concentration for 50% of the population during 24 hours (LC50 24 h) for TE and TC were 32.6 and 30.0 mg/L N-AT, respectively. Weight of PL18 from TE was significantly higher than in the control group. Fatty acid analysis indicated significantly higher levels of n-3 HUFA, especially eicosapentaenoic (EPA) and docosahexaenoic acids (DHA), in the enriched Artemia (TE). In the postlarvae, higher levels of highly unsaturated fatty acids of the n-6 and n-3 series were observed in the PL from TE, while PL from TC presented higher levels of linolenic (18:3n-3) and estearidonic (18:4n-3) acids. Although at the end of the nursery rearing no significant differences in survival were observed, final weight was significantly higher in TE (TC = 0.896g and TE = 1.082g). Results demonstrate that the supplementation of n-3 HUFA during larval rearing increases the tolerance of F. paulensis postlarvae to salinity and total ammonia and positively affects growth. Moreover, the weight difference in PL from the different treatments observed at the end of the larval rearing remained after 30 days of nursery rearing. Therefore, the supplementation of n-3 HUFA during the larviculture of F. paulensis, through Artemia enrichment, is recommended as a way to produce postlarvae with higher stress tolerance and larger size.
Advisor:Ronaldo Olivera Cavalli; Wilson Francisco Britto Wasielesky Junior; Luis Alejandro Vinatea Arana
School:Fundação Universidade Federal do Rio Grande
Source Type:Master's Thesis
Date of Publication:02/15/2007