The Complete Analysis of the Distribution Kinetics of the Oxytetracycline Antibiotic in the Exoskeleton of Farmed Pacific White Shrimp, Litopenaeus vannamei

Abstract

Oxytetracycline (OTC) in shrimp shells may be dispersed to the environment as shrimp shred old cuticle in growout ponds. The study aims to assess the kinetics of OTC accumulated in shrimp shell. Sub-adult male Litopenaeus vannamei in the C-D 0 molting stage, were force fed with medicated feeds at various accurate dose levels that included 50, 500 and 1000 mg/kg-body weight (BW). In addition to hemolymph, hepatopancreas and muscle were serially collected for 50 mg/kg-BW-dose group while cuticle was sampled for higher dose levels. All were assayed for OTC by a validated high-performance liquid chromatography (HPLC) method. Mineral contents in shell samples of 500 mg/kg-BW-dose were also determined. The bioavailability markedly decreased with increasing dose due to incomplete dissolution and/or mild dysfunction in absorption. Administered doses, 2.69 and 2.25%, ended up in the shell after dosing with 500 and 1000 mg/kg-BW, respectively. OTC data after a dose of 50 mg/kg-BW was fitted into a three-compartment model with an added shell compartment with r 2 of 0.9920. The model was successfully extrapolated to predict OTC distribution in shell at higher doses. In addition, there was evidence that OTC may disturb the biomineralization process via complex formation with calcium and magnesium lowering the exoskeleton mineral contents.

Moulting in the grow‐out of farmed shrimp: a review

“…Factors that halt moulting include oxytetracycline that is reported to disturb the mineralization process via complex formation with calcium and magnesium, and decrease exoskeleton mineral content in juvenile L. vannamei (Faroongsarng et al, 2013). Further examples of anti-moulting compounds (anti-ecdysteroid activity) include 4-nonylphenol, propiconazole and bisphenol A. Chitin synthesis disruption was reported with oestrogenic compounds such as Arochlor 1242, PcB29, DES, endosulphan and diethyl phthalate (Hosamani et al, 2017).…”