Effect of Shrimp Feed Supplemented with Astaxanthin on Golden Apple Snail Pomacea diffusa

Popularmente conhecidas como ampularias, esses moluscos gastropodes sao usualmente cultivados como organismos ornamentais pelo mundo. A coloracao desses animais ornamentais e um dos pontos que atrai os seus admiradores e estimula sua aquisicao no mercado. O pigmento mais difundido como suplemento para intensificacao de cor em organismos aquaticos e a astaxantina. Ainda nao existem racoes especificas para a ampularia reforcando a necessidade de testar alternativas de alimentos e suplementos que melhorem o desempenho produtivo e a atratividade do animal. Os objetivos desse estudo foram mensurar a capacidade de acumulacao de astaxantina sintetica em diferentes niveis de inclusao na dieta de Pomacea diffusa, sua influencia na concentracao do pigmento e nos indices zootecnicos ao final do cultivo. E em paralelo verificar a influencia da mudanca da dieta de racao de peixes para racao de camarao na condicao corporal dos moluscos em comparacao com o inicio do trabalho. As ampularias alimentadas com racao comercial extrusada para camarao marinho tiveram baixos indices de conversao alimentar (126,7 ± 18,3), altos indices de eficiencia alimentar (126,7 ± 18,3%) e fator de condicao (1,0 ± 0,14) acima da media inicial (0,90 ± 0,17), o que demonstra que esse alimento pode ser utilizado para seu cultivo. A suplementacao dietetica de astaxantina sintetica nao resulta em aumento significativo da concentracao desse pigmento na musculatura desse molusco (P˃0,05). Palavras-chave: Ampularia. Moluscos. Gastropodes. Pigmentos. Carotenoides. Abstract Known as apple snail, these gastropods are popular as aquarium pets around the world. The bright color of these animals is one of the key points that attract their attention in the ornamental aquaculture, where deep-colored animals are well appreciated. Astaxanthin is the most widespread color enhancing pigment used as a food supplement for aquatic organisms. There is no specific commercial food for apple snails, emphasizing the need to search for food alternatives and supplements that improve their performance and attractiveness. The objectives of this study are to measure the synthetic astaxanthin accumulation capacity of Pomacea diffusa at different levels of diet supplementation, and the effect on pigment concentration and zootechnical indexes at the end of the culture. It was also aimed to verify the effect of the diet change from fish food to extruded shrimp food on the mollusks’ body condition. Apple snails fed with commercial shrimp ration had low feed conversion rates (0.81 ± 0.13), high food efficiency (126.7 ± 18.3%), and condition factor (1.0 ± 0.14) above the initial average (0.90 ± 0.17), demonstrating that this might be an advantageous alternative food. Dietary supplementation with synthetic astaxanthin did not result in a significant concentration increase of this pigment in muscle tissue of these mollusks (P˃0.05). Keywords: Aquaculture. Mollusks. Gastropods. Pigments. Carotenoids