Effects of bacilli, molasses, and reducing feeding rate on biofloc formation, growth, and gene expression in Litopenaeus vannamei cultured with zero water exchange

The effects of reducing feeding rate and molasses on water quality, growth, and gene expression of Litopenaeus vannamei was evaluated in a superintensive system with zero water exchange. A bioassay of 35 d (0,75 ± 0,22 g, 36 shrimp tank -1 , 450 shrimp m -3 ) with treatments in triplicate was performed: I) 100% commercial feed (control group) with water exchange; II) 100% commercial feed without water exchange; III) 100% commercial feed + B. licheniformis BCR 4-3 + molasses without water exchange; IV) 90% commercial feed + B. licheniformis BCR 4-3 + molasses without water exchange; V) 80% commercial feed + B. licheniformis BCR 4-3 + molasses without water exchange . Shrimp survival, weight, nitrogenous wastes, settleable solids (SS), and t he relative expression (RT-qPCR) of stress and digestive genes were determined. Shrimp survival was 100% in all treatments. The reduced diet, bioflocs, and bacilli did not affect shrimp growth. The culture conditions reduced nitrogenous wastes and modulated mRNA expression of trypsin, chymotrypsin, and heat shock protein 70. Culture conditions reduce stress, increase water quality, and did not affect growth and shrimp digestive capacity. Normal 0 21 false false false ES-MX JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif"; mso-ansi-language:ES; mso-fareast-language:ES;}