Influence of the temperature and diets with different DHA/ARA ratio in the transcriptome response, lipid metabolism and performance of cobia juveniles (Rachycentron canadum)

• Grant number: 16/12435-0
• Support Opportunities: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): June 01, 2017
• Effective date (End): April 30, 2021
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Aquaculture
• Acordo de Cooperação: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Alexandre Wagner Silva Hilsdorf
• Grantee: Bruno Cavalheiro Araújo
• Host Institution: Pró-Reitoria Acadêmica. Universidade de Mogi das Cruzes (UMC). Campus da Sede Mogi das Cruzes. Mogi das Cruzes , SP, Brazil
• Associated research grant: 17/06765-0 - Reproductive physiology of the Dusky Grouper Epinephelus marginatus (Perciformes: Serranidae) in captivity: hormonal therapies applied to the induction of sexual maturation in pre-spawning phase, AP.JP
• Associated scholarship(s): 18/13000-2 - Replacement of fish by-products by alternative lipid sources supplemented with n3 LC-PUFAs in specific diets for marine fish species, BE.EP.PD

Abstract

Rachycentron canadum (cobia) can be considered the marine fish species with the highest potential of production in Brazil, mainly due to fast growth, good feed conversion rate and excellent fillet quality. However some stages of the production cycle are limiting a large-scale production in Brazil. Nutrition can be considered the most problematic step due to the high costs of the fish oil largely used in most commercial diets. The importance to use fish oil in the feed formulation to marine fishes is due to the elevated levels of n3 long chain fatty acids (n3 LC-PUFA) such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). However few studies evaluated the importance of the n6 series fatty acids, as arachidonic acid (ARA) in marine fish, even knowing that this fatty acid is responsible for important biological functions as the eicosanoids synthesis. Additionally to the fatty acids composition, the temperature can change the lipid metabolism affecting the productive performance in the marine fishes, thus a better understanding about this relationship (temperature/lipid nutrition) is essential to the formulation of aquaculture specific diets. Thus, this proposal aims first, analyze, characterize and provide the gene sequences from the liver, muscle and intestinal transcriptome, besides to investigate the changes in the productive performance and lipid metabolism of cobia juveniles fed with diets containing different concentrations of n3 and n6 LC-PUFAs series (DHA/ARA). Initially three isocaloric, isolipid and isoproteic diets will be formulated (three experimental groups). Diet 1: diet with a high inclusion of the DHA purified oil; Diet 2: the inclusion of a mixed oil in the same proportion of DHA/ARA; Diet 3: inclusion of oil rich in ARA. In the end of the experiment, for all experimental groups, the following variables will be evaluated: the growth performance, apparent digestibility coefficient, fatty acid profile of the liver and muscle tissue, and blood plasma, body fatty acid balance calculation, transcriptome analysis of the liver, muscle and intestinal, and expression of genes related to the fatty acid synthesis and oxidation, and immune system. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ARAUJO, BRUNO CAVALHEIRO; HONJI, RENATO MASSAAKI; ROMBENSO, ARTUR NISHIOKA; DE SOUZA, GABRIELA BRAMBILA; DE MELLO, PAULO HENRIQUE; SILVA HILSDORF, ALEXANDRE WAGNER; MOREIRA, RENATA GUIMARAES. Influences of different arachidonic acid levels and temperature on the growth performance, fatty acid profile, liver morphology and expression of lipid genes in cobia (Rachycentron canadum) juveniles. Aquaculture, v. 511, SEP 15 2019. (16/12435-0, 14/16320-7)