Banca de QUALIFICAÇÃO: DÉBORA SAYUMI DOAMI MELO

INTENSIVE LARVICULTURE OF Colossoma macropomum: GENE EXPRESSION AND DEVELOPMENT OF THE GASTROINTESTINAL TRACT

Tambaqui; larvae; digestion; absorption; nutrients; weaning

Brazilian fish farming showed significant growth of 5.325% per year between 2014 and 2023, increasing from 578.8 thousand to 887.03 thousand tons produced, with almost 90% of production concentrated in freshwater species. Tambaqui (Colossoma macropomum) is the most cultivated native species in the country, due to its characteristics of easy feeding and reproductive management, hardiness and productivity, consolidating itself as a fundamental in national fish farming since the 1980s. With the increase in consumption of farmed fish, it becomes essential to advance in larviculture to ensure the supply of fry. To this end, understanding the initial development of the digestive system, digestive physiology and feeding behavior of each species is essential to optimize feeding management and develop diets suitable for ingestion, digestion and absorption by larvae, thus improving the quality and productivity of larviculture. Although C. macropomum plays a major role in national aquaculture production, there is still a lack of technical information on larval culture and the digestive physiology of the species in the larval stage. Therefore, this project aims to describe the morphological development of the digestive system and the expression profile of digestive enzymes, in addition to defining the ideal weaning age of C. macropomum post-larvae grown in intensive farming systems. The objective of the first article is to characterize the initial development of the digestive system and the expression profile of digestive enzyme genes and nutrient transporters. The second article aims to define the ideal weaning age of C. macropomum post-larvae by analyzing zootechnical performance, intestinal histomorphology, and the expression profile of digestive, absorption, and stress genes.