Dinámica poblacional del rotífero Brachionus ibericus aislado de estanques para camarón, alimentado con diferentes dietas

Abstract

The production of live microalgae to cultivate rotifers is one of the largest operating costs in fish hatcheries. Commercial substitutes of microalgae are being developed to feed and produce rotifers. The effect of commercial formulations on the population dynamics of native rotifers of northwestern Mexico is unknown, so in this study the effect of four commercial diets (Spirulina, RotiMac®, Nanno 3600®, RotiGrow-Plus®) was evaluated as well as the live macroalgae Nannochloropsis sp., on the population growth and fecundity of the rotifer Brachionus ibericus (GenBank KJ949043), isolated from a white shrimp farm (Litopenaeus vannamei). Five replicates per dietary treatment were performed using 12 L containers with temperature of 29 ± 1°C and salinity of 35 ± 1 respectively. The results showed that during the experimental period, the diets tested were suitable to feed B. ibericus, with mean growth rates, duplication times, maximum densities and fecundities that ranged from 0.20 to 0.27 rotifers day-1, 2.60 to 3.42 days, 0.16 to 0.39 eggs per female and 215.4 to 357.0 rotifers mL-1, respectively. Differences between treatments were significant (P < 0.05); lower doubling times and higher growth rates, fecundities and population densities were obtained with RotiGrow-Plus®; however, duplication times and growth rates observed in rotifers fed RotiGrow-Plus® were not significantly different (P > 0.05) to values observed with Nanno 3600®.