AVALIAÇAO BACTERIOLÓGICA APLICADA À PRODUÇÃO DE PÓS-LARVAS DE Penaeus vannamei

Abstract

This study aimed to track the sources of water contamination in the Laboratorio de Camaroes Marinhos (LCM) pertaining to the Universidade Federal de Santa Catarina (UFSC); to quantify the bacterial load during the stages of shrimp production; to evaluate chlorination efficiency as desinfectant, as well as to evaluate the effect of oxitetracicline on larval quality by application of a multiple criteria method. Bacterial load was quantified by direct counting in plates with Marine Agar and TCBS Agar. A bacterial load of 1 x 103 CFU/mL (colony-forming units) was observed in the water used for larvae production. Differences in bacterial load were not detected between water with and without chlorine addition in the cisterns, indicating the low efficiency of conventional water disinfection. Similarly, the presence of filters not only did not reduce bacterial load in the water network, but was responsible for its increase. Water from hatchery presented a high counting of Vibrio genus, between 1 x 102 and 1 x 103 CFU/mL. When this load reached 1 x 104 CFU/mL, decrease in larval quality was detected, demonstrating that the application of multiple criteria may prevent enfermities. After antibiotic application (oxitetracicline) at 1ppm, the Vibrio load in hatchery water decreased as the larval quality improved. The bacteriological assessing has optimized production management and disinfection of water system in an effective and rational way, reducing the excessive use of chemicals and antimicrobians in marine shrimp hatchery.