An experimental trial was conducted to evaluate the effect of the combination of four temperatures (23°, 26°, 29° and 32°C) and four salinities (25, 30, 35 and 40 PSU), on clearance (FR) and filtration (CR) rates, as well as on the assimilation efficiency (AE) of the mangrove oyster Crassostrea corteziensis. The interaction temperature-salinity had a significant effect on the feeding physiology of the oyster; optimum results were observed in the combination of 32°C and 35 PSU with a FR of 38.08 L•h-1•g-1, and a CR of 1.61 mg•h-1•g-1. The AE was higher in the combination of 29°C and 35 PSUs with a value of 65.1%. Results suggest that C. corteziensis maintains its feeding physiology in the gradient of temperature and salinity evaluated, which characterizes the bivalve as an eurythermal and euryhaline organism, with a better performance at moderate temperatures (29-32єC) and salinities (~35 PSU)

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RESUMEN.Los laboratorios acuícolas altamente dependientes de Nannochloropsis sp. desarrollan mecanismos para su producción masiva, con el desafío de poder extraer altas concentraciones celulares. La floculación por agentes alcalinos es una alternativa que promete mayores ventajas, y el hidróxido de sodio puede ser el agente floculante más conveniente. Sin embargo, para lograr una eficiencia máxima de floculación son determinantes la cantidad del agente floculante, tiempo de exposición, concentración celular y tipo de microalga. Por lo anterior, se determinó la cantidad de NaOH 0,5N y el tiempo de exposición necesarios para lograr un pH óptimo de floculación en cosechas de Nannochloropsis sp. con concentraciones celulares mayores a 50x10 6 cél mL -1. Los resultados mostraron que con 17 mL de NaOH 0,5N por litro de cultivo de microalgas se puede lograr una eficiencia de floculación de 94,9% a pH 9,7 en menos de 60 min. Las células del sobrenadante (subproducto del proceso) fueron viables como inóculo de un nuevo cultivo de microalgas. El concentrado microalgal (355,7x10 6 cél mL ) obtenido fue adecuado como alimento para rotíferos. Por lo tanto, se recomienda el empleo de NaOH 0,5N como método simple, práctico y de bajo costo para producir concentrados de Nannochloropsis sp. con fines acuícolas. Palabras clave: Nannochloropsis sp., floculación alcalina, microalgas, acuicultura.Flocculation of Nannochloropsis sp. induced by sodium hydroxide: flocculation efficiency, viability effect on microalgae and their use as food for rotifers ABSTRACT. Aquaculture laboratories highly dependent of Nannochloropsis sp. develop mechanisms for mass production, with the challenge of be able to extract high cell concentrations from the culture medium. Flocculation by alkaline agents is an alternative that promises greater advantages, and sodium hydroxide may be the most convenient. However, to achieve maximum efficiency of flocculation are important the amount of flocculent, exposure time, cell concentration and type of microalgae. Therefore, the amount of 0.5N NaOH and the exposure time required are investigated to Nannochloropsis sp., harvests at high density at 50x10 6 cells mL ) produced was adequate as food for rotifers. Therefore, employment of 0.5N NaOH is recommended as a simple, convenient and inexpensive method for producing Nannochloropsis sp. concentrates for aquaculture purposes.

Abstract.-The purpose of this study was to evaluate the effect of 12 combinations of salinity and temperature on larval growth of Litopenaeus vannamei, starting in nauplius V (NV) and ending at postlarva (PL1), a process which lasted seven days. The results show that the larvae have greater length and weight at temperatures of 30 to 35°C in combination with salinities between 25 and 35. In conclusion, salinity and temperature are important factors to consider for the production of larvae of L. vannamei.

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