Cultivation and biomass production of the diatom Thalassiosira weissflogii as a live feed for white-leg shrimp in hatcheries and commercial farms in Vietnam

• Published in: Journal of applied phycology 2021-06, Vol.33 (3), p.1559-1577
• Main Authors: Tam, Luu Thi, Van Cong, Nguyen, Thom, Le Thi, Ha, Nguyen Cam, Hang, Nguyen Thi Minh, Van Minh, Chau, Vien, Do Thi Hoa, Hong, Dang Diem
• Format: Article
• Language: English
• Subjects: Algae; Aquaculture; Biomass; Biomedical and Life Sciences; Body length; Carbohydrates; Cell culture; Cell density; Commercial farms; Control; Density; Developmental stages; Diatoms; Diet; Dry cells; Ecology; Eicosapentaenoic acid; Farms; Fatty acid composition; Fatty acids; Feeds; Fish hatcheries; Flasks; Freshwater & Marine Ecology; Hatcheries; Individual rearing; Larvae; Leg; Length; Life Sciences; Lipids; Litopenaeus vannamei; Live feeds; Metamorphosis; Palmitic acid; Photobioreactors; Plant Physiology; Plant Sciences; Polyunsaturated fatty acids; Ponds; Proteins; Shellfish farming; Shrimp culture; Statistical analysis; Stocking density; Stocks; Survival; Tanks; Thalassiosira weissflogii; Weight
• ISSN: 0921-8971; 1573-5176
• DOI: 10.1007/s10811-021-02371-w

This study investigated the biomass production process from the laboratory to the pilot scale in order to use the nutrient-rich biomass of the diatom Thalassiosira weissflogii as live feed for white-leg shrimp ( Litopenaeus vannamei ) at larval stages (zoeal, mysis, and postlarval) and in commercial production in hatcheries in Vietnam. Our results showed that T . weissflogii was successfully cultured in 1–2 L Erlenmeyer flasks, 0.2–3.5 m 3 composite tanks, and 6.5 m 3 tubular photobioreactors, with the highest cell density of 1.6 × 10 6 cells mL −1 reached after 6 days of culture. Under optimal culture conditions, the protein, lipid, and carbohydrate contents in this algal biomass were 13.2%, 20.0%, and 10.0% of dry cell weight, respectively. The fatty acid composition contains high amount of palmitic acid (C16:0, 43.11% of total fatty acid), and polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA, C20:5ω-3), approximated 16.5% of total fatty acid. In a 50 L larval rearing tank, at the optimal stocking density of 125 nauplii L −1 , the survival percentage (75.55%), the total body length (from 5.376 ± 0.007 to 10.860 ± 0.030 mm), and weight (at from PL 1 to PL 12 stages) (from 0.145 ± 0.002 to 1.158 ± 0.005 g) of the white-leg shrimp larvae reached the highest values but the metamorphosis time (234 h) was shortest compared with the other stocking densities. Further, adding living T . weissflogii biomass to the diet of white-leg shrimp larvae at the nauplii 6 stage led to an increase in the body length, weight, and survival percentage of white-leg shrimp larvae of 21.17%, 35.7%, and 33% higher compared with those of larvae fed the control diet (without the addition of T . weissflogii ), respectively. At the same time, the metamorphosis time of larvae (from Z 1 to PL 1 ) decreased by 4 h compared to the control group. In intensive ponds (area of 6400 m 2 pond −1 ), using seed stocks at the postlarvae 12 stage that had been fed T . weissflogii , the final weight, yield, and survival percentage of the shrimp were increased by 7.3%, 14.2%, and 16.3%, respectively, compared with those of the control group. There were no statistically significant differences in the protein and carbohydrate contents in the shrimp flesh among the experimental and control group ( p > 0.05). The lipid, omega-3, omega-6, and omega-9 fatty acid contents of shrimp flesh in experiment formula (per 100 g shrimp) were 1.21 g, 72.9 mg, 114 mg, and 86.1 mg, 11%, 29%, 21.6%