Fernando Z. Silva1, Tatiane B.M. Baran1, Leila Hayashi1
1Department of Aquaculture, Federal University of Santa Catarina, 88034-001, Florianópolis, Santa Catarina, Brazil
The aim of this work was to establish protocols for the biomass production of Ulva ohnoi using germling clusters. Germling development from zygote germination was evaluated under different densities (10, 20, 30, and 40 x 104 gametes mL-1), nutrients (4, 8, and 16 mL L-1 of von Stosch standard solution), and irradiance (100, 200, and 300 μmol photons m-2 s-1). The influence of density or nutrients on the growth of the seedling clusters was evaluated by adding weekly or daily nutrients to the culture medium. In all these treatments, growth rate and productivity were calculated. The irradiance of 200 μmol photons m-2 s-1 was the main factor that affected germlings’ development. The zygote density was not high enough to form germling clusters; thus, densities above 40 x 104 gametes mL-1 should be investigated. The nutrient concentration did not present significant differences in the germling’s development, so the lowest concentration (4 mL L-1) is recommended. Regarding germling clusters, the lowest density (0.1 g L-1) is indicated, as it provided the highest growth rate (59.52 ± 4.39% day-1). Also, 8 mL L-1 of von Stosch solution is sufficient for germling clusters growth. The maximum cultivation period under the conditions tested was four days. Density is also a limiting factor from the fourth day onwards; harvest and adjustment to the initial density are indicated.