Phytoplanktonic composition of three cultivation systems used in Litopenaeus vannamei (BOONE, 1931) marine shrimp farms - doi: 10.4025/actascibiolsci.v32i3.4816

Resumo

The aim of this work is to assess the different compositions of phytoplankton in three cultivation systems of marine shrimps Litopenaeus vannamei (BOONE, 1931), denominated as organic, intensive and semi intensive. The samples were done fortnightly, when phytoplankton was collected by a net for phytoplankton, 65 µm mesh, being then filtrated in a total volume of water of 100 L, and preserved in formaldehyde solution at 4% and identified according to the methodology of Cordeiro et al. (1997). The results show that the densities of Diatoms were of 16.65, 10.47 and 7.57 cel. 10³ mL^-1 for the organic, intensive and semi intensive cultivations, respectively. As for cyanobacteria, the average figures were 42.06 cel. 10³ mL^-1 for semi intensive 17.27 cel. 10³ mL^-1, in the intensive cultivation and 6.11 cel. 10³ mL^-1 for the organic cultivation system. The dinoflagellates had the highest cellular density in the phytoplankton community analyzed with 61.9 cel. 10³ mL^-1 in the intensive cultivation, 0.33 and 0.03 cel. 10³ mL^-1 for both semi intensive and organic cultivation systems respectively. Euglenas presented the results of 4.98 and 14.86 cel. 10³ mL^-1 only for semi intensive and intensive cultivations. It was then concluded that all cultivations presented average rates below recommended for such studied systems.