RESIDUES OF OXYTETRACYCLINE IN CULTURED JUVENILE BLUE SHRIMP, PENAEUS-STYLIROSTRIS (CRUSTACEA, DECAPOD), FED MEDICATED FEED FOR 14 DAYS

Juvenile shrimp fed for 14 days on oxytetracycline (OTC) medicated fee d with a potency of 1500 mg OTC kg(-1) of feed reached a level of 3.3 mu g OTC g(-1) of shrimp tail muscle within 4 days, as measured by the microbial agar plate diffusion assay method for oxytetracycline in ti ssues, approved by the Association of Official Analytical Chemists. Th e concentration of OTC remained between 3.3-5.2 mu g OTC g(-1) of shri mp tail muscle from Day 4 through Day 14 of the feeding period. These concentrations were greater than the Minimum Inhibitory Concentration for sensitive organisms. By the fifth day following cessation of feedi ng medicated feed the drug content in shrimp tail muscle was less than the detectable limit for the method, or 0.4 mu g of OTC g(-1) shrimp tissue. (C) 1997 Elsevier Science B.V.