Water quality and growth of Pacific white shrimp Litopenaeus vannamei (Boone) in co-culture with green seaweed Ulva lactuca (Linaeus) in intensive system

An indoor trial was conducted for 28 days to evaluate the effects and interactions of biofloc and seaweed Ulva lactuca in water quality and growth of Pacific white shrimp Litopenaeus vannamei in intensive system. L. vannamei (4.54 +/- A 0.09 g) were stocked in experimental tanks at a density 132 shrimp m(-2) (566 shrimp m(-3)) and the U. lactuca was stocked at a density 0.46 kg m(-2) (2.0 kg m(-3)). Biofloc with seaweed (BF-S) significantly reduced (P < 0.05) total ammonia nitrogen (TAN) by 25.9 %, nitrite-nitrogen (NO2-N) by 72.8 %, phosphate (PO (4) (3) -P) by 24.6 %, and total suspended solids by 12.9 % in the water and significantly increased (P < 0.05) settleable solids by 34.2 % and final weight of shrimp by 6.9 % as compared to biofloc without seaweed. The BF-S can contribute by reducing nitrogen compounds (TAN and NO2-N), phosphate (PO (4) (3) -P), and total suspended solids in water and increased final weight of shrimp.