Format and mode of artificial substrate fixation affect the performance of Litopenaeus vannamei in high‐density rearing systems |
| |
| Authors: | Rodrigo Schveitzer Thais Sabino Zanetti Leite Natacha Estér Orteney Fabrini Copetti Temistocles Menezes Igor Dias Medeiros |
| |
| Institution: | Department of Marine Sciences, Federal University of S?o Paulo (UNIFESP), Santos, Brazil |
| |
| Abstract: | We investigated whether the positive impacts of artificial substrates on shrimp performance are altered in any way by their format or mode of fixation in the tanks. To examine this question, substrates were fixed vertically in the water column in three different configurations: SCF treatment (Substrate Completely Fixed), SPF treatment (Substrate Partially Fixed) and SFF (Substrate in Frond Format). Another treatment received no substrate and served as control (WS = Without Substrate). The shrimp were cultured for 38 days in intensive biofloc culture tanks at a stocking density of 1,125 shrimp m?3. In general, water quality variables were similar among treatments and remained within the appropriate range for shrimp culture. The final biomass was higher (8.5 kg m?3) and the feed conversion ratio (FCR) lower (1.6) in all tanks with substrates when compared with the WS treatment tanks (final biomass = 6.3 kg m?3 and FCR = 3.1). However, only shrimp from the SCF and SPF treatments had a higher survival rate (>95.0%) compared to those in WS tanks (75.9%), which was statistically similar to the SFF treatment (88.0%). These results show that substrate format and its mode of fixation in tanks can alter shrimp performance. In well‐aerated intensive tanks, substrates in frond format are constantly pushed to the tank surface, making it difficult for shrimp to adhere to the screens. In such situation, the extra surface provided by the substrates is not always available to the shrimp, a fact that minimizes the positive effects of substrate. |
| |
| Keywords: | artificial substrate biofloc system biofloc technology intensive shrimp |
|
|
