The biomass of rotifers is used as live food in aquaculture; their quality is determined by the content of the main polyunsaturated fatty acids and the weight it acquires over time. The objective of this work was to evaluate the variables involved in this process to achieve higher quality. Within the rotifer culture, the following evaluations were carried out nine times (0, 12, 24, 48, 72, 96, 120, 144, 168 hr); with two types of food TRA = 0 (Nannochloropsis oceanica) and TRA = 1 (N.oceanica + Isochrysis galbana); assessing three types of fatty acids (μg/g) eicosapentaenoic (EPA; 20:5nÀ3), docosahexaenoic (DHA; 22:6nÀ3), and arachidonic (ARA; 20:4ωÀ6); and biomass weight in grams from 7,000 individuals per sample. The results showed that the maximum biomass weight was 77.5 g at 96 hr with the mixed treatment.In both treatments, the EPA and DHA fatty acid content exhibited the exact same temporal pattern, while ARA fatty acid was recorded during the entirety of the mixed treatment.The relationship of biomass weight over time versus the fatty acids exhibited significant differences in the mixed treatment, where an increasing trend over time is observed.

Chlorophyte microalgae Dunaliella are halophilic flagellated cells; they can resist high salinities, producing β-carotene to balance osmotic stress. This pigment has important antioxidant properties for biotechnology, the prevention of tissue aging, the efficiency of the immune system, and sun protection against UV-B rays. The objective of this study was to characterize native strains of the genus Dunaliella from the Marine Institute of Peru, under the influence of stress factors for the production and concentration of β-carotene. Different tools were used to characterize these strains through molecular analysis, optimization of parameters for carotene accumulation, growth curves, life cycle, and carotene analysis. The accumulation of this pigment was mainly due to adaptation to salt stress. The differences between Dunaliella strains according to their population growth demonstrated that they did not have the same capacity to respond to the same cultivation conditions, although most of them are from the same species. The IMP-BG-001 strain, from Piura, can accumulate high concentrations of β-carotene

Se determinó la composición de ácidos grasos de 54 cepas microalgales colectadas del Perú y mantenidas en el Banco de Germoplasma de Organismos Acuáticos (IMARPE) con la finalidad de determinar su uso nutricional en la acuicultura. Para ello se realizaron cultivos en un volumen de 50 mL y se determinaron los porcentajes relativos de ácidos grasos mediante transesterificación directa y cromatografía de gases. En el grupo Chlorophyta las microalgas que presentaron los mayores valores de porcentaje relativo de ácidos grasos fueron Chlamydomonas reinhardtii (16:0; 41.2%), Scenedesmus obtusus (18:1n-7; 33.6%), Acutodesmus dimorphus (18:1n-9; 37.1%), Desmodesmus armatus (18:3n-3; 32.2%) y Tetraselmis contracta (16:4n-3; 16.5%). En cambio en el grupo Bacillariophyta, los ácidos grasos más abundantes fueron 16:1n-7 en Chaetoceros didymus (20.2%), 18:4n-3 en Navicula sp. (28.3%) y EPA en Asterionellopsis sp. (31.5%). Por otro lado, en el grupo Dinophyta, todas las cepas superaron el 20% de DHA, en particular, la cepa de Akashiwo sanguinea presentó el mayor porcentaje relativo de este ácido graso (29.9%) y de los ácidos grasos 16:0 (24.8%) y EPA (16%). Se discute el uso de estas cepas según su contenido de ácidos grasos.