42 DECEMBER 2017 • WORLD AQUACULTURE • WWW.WAS.ORG Gracilaria at 2.0 kg/m3. In the second study, only G. birdiae was used and experimental units were stocked with a wet weight of 2.5, 5.0 and 7.5 kg/m3. Light intensity was maintained at about 1,000 lux with a fluorescent lamp at a natural photoperiod. In the first trial, shrimp survival rates were all greater than 50 percent during the 28-day experimental period. Performance parameters of final weight (6.6 g) and weekly growth (0.98 ± 0.07 g/wk) in an IMTBS were significantly greater than the biofloc monoculture. The FCR and yield were not significantly different (Fig. 2). In the second trial, shrimp survival rates were all above 89 percent during the 42-d experimental period. Shrimp FCR (1.201.37), final weight (3.9-4.1 g) and yield (1.7-2.0 kg/m3) in an IMTBS was significantly greater than the biofloc monoculture values (1.7, 3.1 g and 1.4 kg/m3), respectively (Fig. 3). The presence of seaweed improved shrimp growth, suggesting potentially positive economic and environmental aspects with an IMTBS (Fig. 4). Shrimp graze directly on the seaweed and on the biofilm formed on its surface. The use of seaweed in and with shrimp may be a complementary source of food through direct consumption or grazing of the biofilm that forms on the surface of the seaweed, improving zootechnical performance. Additionally, seaweed in IMTBS can combine bioremediation capacity with commercial value as human food. Notes Luis Otavio Brito, Jéssika lima de Abreu, Clarissa Vilela Figueiredo da Silva Campos, Elizabeth Pereira da Silva, Alfredo Olivera Galvez, Departamento de Pesca e Aquicultura, Universidade Federal Rural de Pernambuco Rua Dom Manoel de Medeiros, s/n Dois Irmãos, CEP: 52171-900, Recife, Pernambuco, Brazil, email: engpescalo@hotmail.com; alfredo_oliv@yahoo.com Danielli Matias de Macedo Dantas, Unidade Acadêmica de Serra Talhada, Universidade Federal Rural de Pernambuco, Serra Talhada, Brazil. References Coyle, S.D., L.A. Bright, D.R. Wood, R.S. Neal and J.H. Tidwell. 2011 Performance of Pacific white shrimp, Litopenaeus vannamei, reared in zero-exchange tank systems exposed to different light sources and intensities. Journal of the World Aquaculture Society 42:687-695. Lander, T.R., S.M.C. Robison, B.A. Macdonald and J.D. Martin. 2013 Characterization of the suspended organic particles released from salmon farms and their potential as food supply for the suspension feeder Mytilus edulis in integrated multi-trophic aquaculture (IMTA) systems. Aquaculture 406-407:169-171. Mishra, J.K., T.M. Samocha, S. Patnaik, M. Speed, R.L. Gandy and A.M. Ali. 2008 Performance of an intensive nursery system for the Pacific white shrimp, Litopenaeus vannamei, under limited discharge condition. Aquacultural Engineering 38:2-15. Ren, J.S., J. Stenton-Dozey, D.R. Plew, J. Fang and M. Gall. 2012 An ecosystem model for optimizing production in integrated multitrophic aquaculture systems. Ecological Modelling 246:34-46. Silva, K.R., W. Wasielesky, Jr. and P.C. Abreu. 2013 Nitrogen and phosphorus dynamics in the biofloc production of the Pacific white shrimp Litopenaeus vannamei. Journal of the World Aquaculture Society 44:30-41. Troell, M., A. Joyce, T. Chopin, A. Neori, A. Buschman and J.G. Fang. 2009 Ecological engineering in aquaculture – potential for integrated multi-trophic aquaculture (IMTA) in marine offshore systems. Aquaculture 297:1-9. Vinatea, L., A.O. Galvez, C.L. Browdy, A. Stokes, J. Venero, J. Haveman, B.L. Lewis, A. Lawson, A. Shuler and J.W. Leffler. 2010. Photosynthesis, water respiration and growth performance of Litopenaeus vannamei in a super-intensive raceway culture with zero water exchange: interaction of water quality variables. Aquacultural Engineering 42:17-24. FIGURE 4. Shrimp final weight obtained in an IMTBS (left) and monoculture system (right). FIGURE 2. Final weight of Pacific white shrimp stocked in an integrated multitrophic biofloc system with two species of Gracilaria seaweed. FIGURE 3. Final weight of Pacific white shrimp stocked in an integrated multitrophic biofloc system with three densities of Gracilaria seaweed.
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