Effects of microbubble aeration on water quality and growth performance of Litopenaeus vannamei in biofloc system

Abstract

This study investigated the water quality and growth performance of white shrimps, Litopenaeus vannamei, for 70 days using microbubble (MB) aeration with biofloc culture. Similar investigations were conducted based on larger air bubbles produced by a conventional aquarium air stone. The water quality parameters, such as, dissolved oxygen (DO), temperature, pH, salinity, alkalinity, total ammonia nitrogen (TAN), nitrite-N, nitrate-N, suspended solids (SS) and total suspended solids (TSS) were recorded throughout the culture period. The growth of L. vannamei was compared between cultures using microbubble and macro-bubble aerations in terms of weight and length weekly throughout the 70-days. Although the microbubble aeration increased the water temperature by 2 ℃, the increased rate of pH reduction and conversion of TAN to nitrate indicated that microbubble aeration enhanced the water quality. Based on the results, with a lower average food conversion ratio (FCR) value of 0.80, the shrimps cultured using the MB aeration yielded a higher mean weight (5.93 g ± 1.90) and length (9.80 cm ± 1.03) at the end of the culture period. However, large bubbles (LB) aeration yielded an FCR value of 1.41 to produce shrimps with a lower mean weight (2.77 g ± 0.66) and length (7.78 cm ± 0.57). In conclusion, this study revealed that the MB aeration could boost the growth of both biofloc and L. vannamei by reducing the FCR value.