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

Author(s)

Araujo, Bruno Cavalheiro ^[1] ; Honji, Renato Massaaki ^[2] ; Rombenso, Artur Nishioka ^[3] ; de Souza, Gabriela Brambila ^[4] ; de Mello, Paulo Henrique ^[4] ; Silva Hilsdorf, Alexandre Wagner ^[1] ; Moreira, Renata Guimaraes ^[5]

Affiliation

^[1] Univ Mogi das Cruzes, Nucl Integrado Biotecnol, Av Dr Candido Xavier de Almeida Souza 200, BR-08780911 Mogi Das Cruzes, SP - Brazil

^[2] Univ Sao Paulo CEBIMar USP, Ctr Biol Marinha, Rodovia Manoel Hipolito Rego Km 131, 5, BR-11600000 Sao Sebastiao, SP - Brazil

^[3] CSIRO, Agr & Food, Aquaculture Program, Bribie Isl Res Ctr, Woorim, Qld 4507 - Australia

^[4] Univ Estadual Paulista Julio de Mesquita Filho CA, Ctr Aquicultura, Via Acesso Prof Paulo Donato Castellane S-N, BR-14884900 Jaboticabal, SP - Brazil

^[5] Univ Sao Paulo, Inst Biociencias, Dept Fisiol, Rua Matao, Trav 14, 321, BR-05508090 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Aquaculture; v. 511, SEP 15 2019.
• Web of Science Citations: 0

Abstract

An 8-week nutritional experiment was conducted with the aim of evaluating the influences of different arachidonic acid (ARA) levels and two different temperatures (29.5 degrees C and 26.5 degrees C) on the growth performance, tissue and whole-body fatty acid (FA) compositions, plasma prostaglandin concentration, liver morphology and expression of genes related to lipid metabolism in cobia juveniles. A basal fat-reduced diet was manufactured and subsequently coated with different FA sources, distinct levels of ARA (ARA1, 0.5%; ARA2, 1.2%; and ARA3, 1.9%) and fish oil (FO: 8.8%, as a control diet). All diets were formulated to be isoproteic and isolipidic. Cobia juveniles (5.86 +/- 0.40 g) were randomly divided into 24 tanks with 18 animals each. Twelve tanks were kept at 29.5 degrees C, and 12 tanks were kept at 26.5 degrees C. The animals were fed twice per day with each experimental diet until apparent satiation in triplicate tanks at both temperatures. The results revealed that the animals maintained at 26.5 degrees C and fed with the ARA diets exhibited better growth than those fed with the FO diet and kept at 29.5 degrees C. In contrast to observations in other teleost species, ARA excess did not reduce growth or survival. The FA compositions of the livers, fillets and whole bodies generally reflected the diet compositions, i.e., gradual increases in ARA were observed according to the diet level. Additionally, greater depositions of docosahexaenoic acid (DHA) in the fillets of the animals from the ARA2 group that was kept at 26.5 degrees C were observed. The plasma prostaglandin levels were greater in the animals that were kept at 29.5 degrees C for all experimental diets and in the ARA2 animals compared with the FO groups at both temperatures. The FAS and SREBP-1 expressions in the livers were down-regulated in the ARA1 and ARA2 animals that were maintained at 26.5 degrees C compared with the animals that were fed the same diets but kept at 29.5 degrees C. Additionally, SREBP-1 expression was up-regulated in the ARA2 animals compared with the FO animals at both temperatures. The results of this study indicated that ARA inclusion between 0.5 and 1.9% combined with a temperature of 26.5 degrees C can improve juvenile cobia growth performance and directly influence the modulation of prostaglandin synthesis and the relative expressions of lipid genes. (AU)

• FAPESP's process: 16/12435-0 - Influence of the temperature and diets with different DHA/ARA ratio in the transcriptome response, lipid metabolism and performance of cobia juveniles (Rachycentron canadum)
• Grantee: Bruno Cavalheiro Araújo
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 14/16320-7 - Impacts of climate/environmental change on the fauna: an integrative approach
• Grantee: Carlos Arturo Navas Iannini
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants