The Effect of Nanosilica on the Growth of Skeletonema costatum

The marine diatom Skeletonema costatum is very important as natural feed for shrimp larva in the hatchery and brackish water pond. This diatom needs fertlizer like silica as limiting factor. The purpose of this research is to determine the most effective nanosilica to increase the growth of S. costatum cells. This research was conducted from March to April 2018 in the Laboratory of Invertebrates, Faculty of Fisheries and Marine Sciences, Universitas Padjadjaran.In this study, different source of silica was used, namely the silica natrium fertilizer (control), nanosilica chemical reaction (amorf), and nanosilica of quartz sand as much as 10 mg / l with 3 replications each. The lag phase, exponential phase, stationary phase and death phase of S. Costatum was observed at 16, 34, 38 and 72 hours after inoculum spreading, respectively. The highest cell density was observed on the second day of experiment, at 02.00 am for all treatments. The highest density of the cells was achieved on the treatment of silica natrium fertilizer, with cell density of 2.72 x 106 cells / ml, followed by nanosilica chemical reaction and nanosilica fertilizer from quartz sand with density of 2.16 x 106and 1.84 x 106 cells / ml.