Avaliação da domesticabilidade do Acarichthys heckelii

Abstract

The word domestication can be defined as a change in the phenotypic characteristics of a group of individuals over a given time, resulting from interactions with humans. This study evaluated the domesticability of the fish *Acarichthys heckelii* through feeding trials with three experimental diets: animal-based (ANI) from an animal protein source; plant-based (VEG) from a plant-based source; and mixed (MIX) containing both animal and plant protein sources, all with ~30% crude protein, over 90 days. A total of 63 *A. heckelii* individuals with an average initial weight (23.85 g) and average total length (11.75 cm) were collected and distributed into tanks (n = 3 tanks per treatment, 7 fish/tank) with a closed recirculation system. For the zootechnical performance experiment, feed was offered twice daily with one replicate in each block, and for palatability, feeding was applied biweekly with timed feeding. After 90 days, the centesimal composition of the fish carcasses and the histomorphometry of the intestine and liver were analyzed to verify the hepatic steatosis index. The ANI and VEG diets proved to be the most palatable foods for A. heckelii, with ANI (72%) obtaining a higher value than the other diets. Zootechnical performance was superior for ANI, which resulted in the best feed conversion rate (0.97 ± 0.06). There were no significant differences in centesimal composition or intestinal morphometry (p > 0.05). However, hepatic steatosis varied significantly between treatments (p = 0.000743), with the highest levels of lipid accumulation observed in the MIX group. Thus, artificial feeding in a fish farming environment proved to be effective for the initial domestication of A. heckelii. The animal-derived diet promoted the best performance, but the variation in hepatic steatosis indicates the need for optimization in the amino acid balance of the diets. The results demonstrate that diets directly influence the feeding and development of fish, with better performance observed in the animal-origin diet (ANI), in addition to highlighting the species' potential for regional fish farming.