[en] The present study investigated the effect of different wavelengths of light (white, blue, red, and magenta) on the growth and development of the green seaweed Ulva ohnoi. The purpose is to find a light source that allows obtaining the highest productivity, crop quality and biofiltration capacity, while minimizing energy consumption. A controlled experiment was carried out in which Ulva ohnoi samples were exposed to the same light intensity (illumination of 350 ± 20 μmol·m-2·s-1), in 3 different experiments in which 2 different wavelengths were used in each experience. Growth parameters, such as relative wet weight growth rate, and nutrient assimilation rates, were measured at regular intervals for 11 days. The results revealed that the different wavelengths of light had significantly different effects on the growth and biofiltration capacity of Ulva ohnoi, showing higher effectiveness of blue and white LED lights compared to pure red and magenta LED lights. On the other hand, it was observed that red LED light fixtures alone produced considerably lower growth rates than the other types of LEDs. In addition, the energy consumption of each type of light played an important role when comparing their efficiency, ranging from 28.3 W/h for white light to 11.9 W/h for red light. This suggests that the wavelength of light plays an important role in the physiology and growth of Ulva ohnoi, which could have implications for the optimization of culture conditions and the production of this alga in indoor aquaculture systems.

[gl] O presente estudo investigou o efecto de diferentes lonxitudes de onda de luz (branca, azul, vermella e magenta) no crecemento e desenvolvemento do alga Ulva ohnoi. O propósito é atopar unha fonte de iluminación que permita obter a maior produtividade, calidade do cultivo e capacidade de biofiltración, minimizando ao mesmo tempo o consumo enerxético. Levouse a cabo un experimento controlado no cal se expuxeron mostras de Ulva ohnoi á mesma intensidade lumínica (iluminación de 350 ± 20 μmol.m-2s-1), en 3 experiencias diferentes nas que se utilizaron 2 lonxitudes de onda distintas en cada experiencia. Medíronse parámetros de crecemento, tales como a taxa de crecemento relativa en peso húmido e as taxas de asimilación de nutrientes, a intervalos regulares durante 11 días. Os resultados revelaron que as diferentes lonxitudes de onda de luz tiveron efectos con diferenzas significativas no crecemento e capacidade de biofiltración de Ulva ohnoi, mostrando unha maior efectividade de lócelas LED azuis e brancas en comparación coa luz LED vermella ou magenta. Doutra banda observouse que os dispositivos de luz LED vermella por si sós produciron taxas de crecemento considerablemente máis baixas que os outros tipos de LED. Ademais, o consumo enerxético de cada tipo de luz xogou un papel importante ao comparar a súa eficacia, variando desde os 28,3 W/h para a luz branca ata os 11,9 W/h para a luz vermella. Isto suxire que a lonxitude de onda da luz xoga un papel importante na fisioloxía e o crecemento de Ulva ohnoi, o que podería ter implicacións para a optimización de condicións de cultivo e a produción desta alga en sistemas de acuicultura indoor.