鱼类标志放流步骤的优选及其在黄鳍棘鲷中的应用

Optimization of key procedures for fish tagging and releasing with its application to yellowfin seabream (Acanthopagrus latus)

鱼类标志放流过程中,关键细节缺失参考依据易导致标志鱼因标志操作不规范而死亡(或导致标志脱落),从而影响基于标志群体抽样的增殖效果评估、放流群体时空格局等后续研究的准确性。本研究以南海重要增殖放流鱼类黄鳍棘鲷为对象,采用多因素方差分析对比了标志过程中关键操作(标志前麻醉与否、标志部位、植入角度)的生长率、存活率、标志保留率的差异。40 d的实验结果显示,不同标志操作对鱼的生长无显著影响。麻醉与否对实验鱼的存活率影响极显著。标志部位、植入角度对标志保留率影响显著。优选出的最佳标志操作组合为麻醉,将T型标志以45°植入背鳍基前部肌肉(存活率95.56%、标志保留率98.89%)。综合以往资料,本研究提出了黄鳍棘鲷[体长(10.05±0.39)cm]T型标志操作规范建议,为今后科学开展标志放流提供参考依据:①标志前暂养,将待标志鱼放入培育池内暂养3 d或以上,标志前24 h停食;②材料消毒,将T型标志和标志枪针头用75%酒精浸泡消毒5 min;③麻醉,用30 mg/L丁香酚溶液(或MS-222麻醉剂)麻醉至鱼体腹部向上翻转时,迅速进行标志;④标志,用标志枪针头拨去标志部位的1个鳞片,然后针头与鱼体呈45°将T型标志植入背鳍基前部肌肉;⑤鱼体消毒,将标志鱼放入含有5%聚维酮碘(或高锰酸钾)的海水溶液中药浴消毒30 min;⑥标志后暂养,消毒后的标志鱼人工暂养7 d后可放流。

Tagging and releasing techniques are commonly used to obtain information on behavior and assess the effects of stock enhancement in marine fishes,which is based on the sampling of tagged population.However,the lack of the field protocol on fish tagging techniques undoubtedly leads to the tag loss or even the death of a large quantity of tagged fish.In this study,Acanthopagrus latus,one of the main stocking species in northern South China Sea,was employed to conducted the 40 days experiment using T-bar anchor tags.Three factors in the key tagging procedures were considered:(a)anesthetized or not(anesthetized or unanesthetized);(b)tagging locations(anterior dorsal muscle or posterior dorsal muscle)and(c)implanted angles(45°or 90°).According to a 2×2×2 factorial design,the experiment was divided into 8 tagged groups and 1 control group,with 3 replicates per group and 30 juvenile A.latus[initial average body length(10.05±0.39)cm]per replicate.Rates of growth,survival and tag retention were evaluated quantitatively by multifactor analysis of variance.The results showed that there was no significant difference in the specific growth rate among groups.Anesthetized or not was the factor that produced very significant difference in survival rate.Tagging locations and implanted angles produced significant difference in tag retention rate.Tagging by T with 45°into the anterior dorsal muscle of A.latus was the optimal procedures,which had the highest survival rate of 95.56%with tag retention rate of 98.89%.Finally,the field protocol suggestion was proposed:①the fish should be reared no less than 3 days before being tagged;②the tagging equipment should be sterilized using 75%alcohol for 5 minutes;③the fish should be anesthetized using 30 mg/L eugenol solution or MS-222 until they could not maintain equilibrium;④the fish should be tagged with angles of 45°into the anterior dorsal muscle;⑤the fish should be sterilized using 5%povidone iodine or KMnO4 for 30 minutes;⑥the tagged fish should be then reared for 7 days before being released.This study will provide basic data for fish tagging studies in the future.