Effect of stock density of cultured Amazon Apple Snail Pomacea dolioides (Gastropoda: Ampullariidae) in Brazil

Abstract

This study evaluated the biomass gain, specific growth rate, absolute weight gain, and survival rate of the gastropod Pomacea dolioides cultivated in different stocking densities. To perform the experiment, samples were collected in March and June 2015. A total of 40 adult specimens were collected in the Jauary neighborhood (03°08'19.9"S, 58°27'32.5"W), municipality of Itacoatiara, AM, Brazil. They were kept in the laboratory for breeding to obtain the young P. dolioides, which were distributed into tanks containing 4 L of water and an aeration system, in three densities: 2.5 animals/L, 5 animals/L, and 10 animals/L, and were fed fish ration (34% gross protein). The specimens were measured for shell length and weight every fifteen days. The survival rate did not differ between treatments 2.5 and 5 animals/L (100%) and 10 animals/L (95.83%). The density with the best cultivation results was 2.5 animals/L, being most effective for the parameters of growth, weight gain, specific growth rate, and percentage weight gain, when compared with the other treatments after 225 days of the experiment. For future cultivation of this species, a density of 2.5 animals/L should be used to improve handling performance