Metabolic and molecular responses of Oreochromis niloticus juveniles influenced by the interaction between temperature and diet composition

• Grant number: 22/10972-9
• Support Opportunities: Research Grants - Young Investigators Grants
• Start date: December 01, 2023
• End date: November 30, 2028
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Aquaculture
• Principal Investigator: Bruno Cavalheiro Araújo
• 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 researchers: Alexandre Wagner Silva Hilsdorf ; Fabiano Bezerra Menegidio ; Giovani Sampaio Gonçalves ; Marcelo Visentini Kitahara ; Renata Guimarães Moreira Whitton ; Renato Massaaki Honji
• Associated scholarship(s): 25/06367-0 - Advanced technical support for the development of nutritional experiments and laboratory analyses, BP.TT; 24/22234-8 - Influence of different LC-PUFAs levels on the performance and metabolism of tilapia juveniles kept at low temperatures, BP.MS; 24/04663-9 - Metabolic and molecular responses of Oreochromis niloticus juveniles by the interaction between temperature and diet composition, BP.TT; 23/16105-8 - Metabolic and molecular responses of Oreochromis niloticus juveniles influenced by the interaction between temperature and diet composition, BP.JP

Abstract

Oreochromis niloticus (tilapia) is the main fish species produced in Brazil. However, the leading producers in Brazil were established in the south and southeast regions, where the autumn/winter temperatures are out of the optimum range for this species. Previous studies showed better growth and survival of fish at low temperatures were obtained by the incorporation of higher dietary levels of long-chain polyunsaturated fatty acids (LC-PUFA), especially docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and arachidonic acid (ARA). Similarly, current studies observed better production performance of tilapias at suboptimal temperature when fed DHA-rich diets. However, the underlying mechanisms are unknown. In addition, despite the promisor results obtained with other fish species, no studies evaluating the dietary ARA influence on the performance and metabolism of tilapia at low suboptimal temperatures were carried out. Thus, this proposal aims to (1) test different ARA levels on diets of tilapia juveniles at low temperatures, and (2) investigate the effects of different DHA, EPA, and ARA ratios on the performance and metabolism of tilapia juveniles at optimal and suboptimal temperatures. Against this background, we will evaluate the farming performance, morphology, and composition of the main lipolytic and lipogenic tissues, variables related to the immune system, and gene transcription of the hepatic tissue. The outcome of this project will shed light on a body of knowledge regarding the relationship between temperature and diet composition effects on the performance and metabolism of tilapia, providing bases to the industry to develop strategies aiming to mitigate negative impacts resulted by the low temperatures conditions. (AU)