月鳢仔鱼耳石的荧光标记及其日轮确证

利用茜素络合物对体长(9.99±0.56)mm的月鳢(Channa asiatica)仔鱼耳石进行浸泡标记试验。结果表明,经荧光显微镜检测,80 mg/L、100 mg/L和120 mg/L的溶液浸泡24 h后均可以在月鳢仔鱼的耳石上形成橘红色标记环,星耳石、微耳石和矢耳石的标记率均为100%;其中,以星耳石标记环荧光强度最大,且在普通光学显微镜下也可观察到紫红色标记环。经100 mg/L和120 mg/L溶液浸泡后,月鳢仔鱼在其后饲养阶段出现较高的死亡率,显示高浓度茜素络合物溶液对月鳢仔鱼有一定毒性。标记后星耳石上的新增轮纹数(N)和饲养天数(D)密切相关,其线性方程为:N=0.9291D-0.2974(R2=0.9793,n=64,P<0.01),斜率0.9291与1无显著差异(P>0.05),表明星耳石上的生长轮即为日轮。研究表明,在追踪月鳢仔鱼迁移行为时,可采用80 mg/L的茜素络合物溶液对其星耳石进行染色标记。

Otolith Tagging and Daily Increments Validation with Fluorescent Substance in Larval Channa asiatica

The efficiency of otolith tagging for larval snake head fish standard length,(9.99±0.56)mm],Channa asiatica,with fluorescent substance alizarin complexone(ALC) was analyzed.A distinct scarlet-pink fluorescent marker on the larval otolith was detected with UV light excitation under the fluorescence microscope,and the ratio of tagging on astanscus,lapillus and sagitta were all 100% after the larvae were immersed in 80 mg/L,100 mg/L and 120 mg/L ALC solution for 24 hours,respectively.However,the efficiency of tagging on astanscus was better than that of on the others,because an amaranth marker on astanscus could be detected under the optical microscope while the other could not.The larvae exposed to 100 mg/L and 120 mg/L ALC suffered a high mortality during the following culture in the clean water.It was proposed that the high concentration ALC had a toxic effect on the larval C.asiatica.The number of new daily increments on the larval astanscus(N) was strongly related to the rearing days(D).The correlation equation was as follows:N=0.9291D-0.2974(R2=0.9793,n=64,P<0.01).The slope of this equation was 0.9291,and it was not significantly different from 1(P>0.05).It suggested that the new increments on the astanscus of larval C.asiatica were formed daily.The results of our study suggest that tagging on the larval astanscus by exposing the larva to 80 mg/L ALC solution could be one of the recommended techniques for the study on the larval C.asiatica migration behavior.