Growth performance of Amur catfish (Silurus asotus) in various aeration rates in an indoor BFT system
Mariel Benigno1, Jeonghwan Park2
1Cavite State University (NAIC), Fisheries and Aquatic Sciences, Philippines
The development of Biofloc technology (BFT) as a sustainable and environmentally friendly aquaculture technology includes discovering new species suitable for it. Amur catfish (Silurus asotus) is an important freshwater fish in East Asian countries that has the potential to be reared in BFT system. This study evaluates the growth performance of Amur catfish in an indoor BFT system with aeration rates as variable. Twenty catfish with an average weight of 4.17± 0.20 g and length of 8.11±0.32 cm were stocked in eighteen aquaria. Six treatments i.e., 2lpm, 3lpm, 4lpm, 5lpm, 6lpm, and 7 lpm aeration rates with equivalent surface area loading rates 43, 64, 85, 107, 128, and 149 m3/m2/d were designed in triplicates. Fish were fed 5% of body weight and dextrose was added at a 15:1 C:N ratio. Dissolved oxygen, temperature, and pH were monitored twice daily. Total ammonia nitrogen and nitrite along with total suspended solids and floc volume were monitored once a week. Growth was monitored after week 4 and week 8. DO and the temperature was maintained at >8ppm and -24°C respectively. The pH was statistically higher in the 128, 149, and 107 m3/m2/d as compared to 43, 64 m3/m2/d SALR. Inorganic nitrogen species were not significantly different while solids were higher at higher aeration rates. Survival of catfish was low and among the treatments with fish in 2lpm aquaria having high mortalities as early as 5th week of the experiment and not exceeding 58% for all treatments. Individual weight and length gain, specific growth rate, condition factor, total weight gain, and FCR, were not significantly different among the treatments except for 43 m3/m2/d tanks (which exhibited a low survival rate). Aeration plays an important role in the management and control of biofloc in BFT systems, however, other factors may have influenced the growth performance of catfish in this study such as cannibalism and floc properties.
Keywords: Biofloc, catfish, growth
Contact Address: Mariel Benigno, Cavite State University (NAIC), Fisheries and Aquatic Sciences, Namillangan, 3608 Alfonso lista, Philippines, e-mail: mbenigno1895gmail.com