Effects of different culture medium and harvest rations on the development of the diatom Thalassiosira sp.

Abstract

Thalassiosira sp. belongs to the phylum Bacillariophyta (diatoms) and has high nutritional content; therefore, it plays an important role in aquaculture, particularly as a feed for marine shrimp larvae. This study aimed to determine the optimal nutrient medium and harvest ratio for the cultivation of Thalassiosira sp. under laboratory conditions (25–26°C, salinity 25‰, light intensity 3,000 lux from white LED, continuous aeration). Thalassiosira sp. was cultured in 5-L jars, and two experiments were conducted. In the first experiment, Thalassiosira sp. was grown in Walne, F/2, and AGP (20%) media, each with three replicates. AGP (20%) treatment achieved a maximum cell density of 1.28 × 10⁶ cells mL-1 and a carotenoid concentration of 347.2 µg L -1 . In the second experiment, Thalassiosira sp. was cultured with AGP (20%) at harvest ratios of 0%, 20%, and 30%, with the 30% harvest treatment yielding the highest biomass production (93.56 g batch-1 ). These results indicated that AGP (20%) was an effective medium for biomass production of Thalassiosira sp., and a 30% harvest ratio maximizes yield.