Aquaculture of boga (Megaleporinus obtusidens) in intensive recirculating systems

Abstract

The boga (Megaleporinus obtusidens) is a fish native to South American basins, caught for the domestic and foreign markets. Current fisheries development has led to the overexploitation of native species, including bogue, making aquaculture an alternative for producing fish without removing them from their natural habitats. The objective of this study was to evaluate the adaptability of boga to intensive recirculating systems. The trial was conducted in a greenhouse at the COE-INTA-Ángel Gallardo, Santa Fe, Argentina, in 5 m3 circular tanks with a recirculating system for 6 months (beginning in May). The density was 20 ind./m3 of 5.2 g and the standard length was 6.01 cm. Physicochemical and biological parameters were regularly measured. At temperatures below 20°C, extruded feed was supplied at a 2.5% biomass concentration, and higher temperatures, at a 5% biomass concentration. Temperatures ranged from 12.2°C to 31.5°C, with 105 days of temperatures below 20°C. Growth during this period was minimal and increases in size and biomass at higher temperatures were logarithmic with time (Size = 15.47 * ln (time) - 61.69; r2 0.9894 and Biomass = 551.62 * ln (time) - 2617.12; r2 0.9974). At the end, the maximum values reached were 31.8 cm and 568.2 g, with an exponential relationship between these (Biomass = 0.0276 * size 2.8974; r2 0.9928). The Feed Conversion Factor (FCR) at temperatures above 20°C was 1.43, while for the entire trial it was 1.82. Growth projections at temperatures above 20°C would allow reaching plate size (30-35 cm) in 10-12 months with weights of 900-1000 g. Optimal FCRs in aquaculture range from 1.2 to 2.2, falling within this range in this experiment. Due to its meat quality and market acceptance, boga is a good option for farming in recirculating systems in temperate climates.