In order to investigate the retention and elimination of furacillin metabolites (semicarbazide,SEM) in the muscle of T.flavidus following the use of furacilin during the breeding process,the aquaculture pond was treated with 0.50 g/m³ of furacillin.Muscle samples of T.flavidus were then collected at regular intervals.The concentrations of SEM were determined using high-performance liquid chromatography-tandem mass spectrometry,and the data was analyzed by using Excel 2013.The results showed that furacillin was rapidly metabolized to SEM in T.flavidus after dosing.The levels of SEM in the muscles increased rapidly,reaching their highest value after approximately 4 days.The elimination rate of SEM was initially fast,but slowed down over time.Even after 77 days following dosing,the residual amount of SEM in the muscles was still around 2.50 μg/kg,which was above the limit of detection.This suggests that SEM has a prolonged residual time in T.flavidus after the administration of furacilin.Based on these findings,it is strongly recommended to strictly prohibit the use of nitrofurans,such as furacilin,during the breeding process of T.flavidus,in order to ensure the quality and safety of puffer fish.

A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for the quantitative determination of mebendazole in aquaculture water.The limit of quantification was 0.5 μg/L.The average recoveries of the three spiked levels ranged from 79.0% to 93.9%.The intra-day and inter-day relative standard deviations (RSDs) were 7.57%-8.27% and 7.43%-8.11%,respectively.The actual application concentrations of 15 μg/L and 50 μg/L were used as the tested concentrations for the elimination experiments of mebendazole in aquaculture water,respectively.The results showed that mebendazole was a photosensitive drug whose photodegradation followed the first-order kinetics.The photolytic degradation rate of mebendazole in outdoor aquaculture water under natural light was more than 80% after 648 h.The elimination half-life of mebendazole was 231.05 h at 15-18℃.At the end of the experiment (648 h),6.4 μg/L of mebendazole was still detected in the high concentration group(50 μg/L).Therefore,the results of this study could provide basic data for the pharmacokinetic study of mebendazole in aquaculture animals.

Methods of cleaning the fouling organisms in the process of aquaculture is related to production benefit, because of the aquaculture facilities, mariculture objects or aquaculture process can be affected by fouling organisms.The present paper investigated the treatment methods for fouling organisms of marine aquaculture facilities in the main aquaculture areas of Fujian Province.According to the survey, there was a lack of effective preventive measures while manual removal was the main way.Actually, the fish farmers usually ignored it, even if needed to clean, dry or manual removal were the preferred methods.Only a few were treated with a screen washer or sprayed with formalin.The survey showed that the main treatment methods for fouling organisms in Fujian province were traditional, time-consuming, inefficient, and labor intensive, even more, advanced technique and equipment were difficult to adapt to actual production.