Research Of The Marking Techniques On Acanthopagrus Schlegelii

Two fluorescence marking techniques on Acanthopagrus schlegelii were studied in this research,aiming to provide theoretical basis for artificial enhancement of this fish species.This dissertation was divided into three chapters and the main results were shown as follows:The first chapter had two parts.Firstly,different tagging methods of aquatic organisms around the world were reviewed,including external and internal marking,biological tagging,electronic and molecular marking techniques.The effects of different tagging techniques and their utilization in the fields of population dynamics,behavioral and physiological research of aquatic animals were introduced.Then,the development of marking techniques,especially the current application status and prospect of fluorescence tagging techniques on aquatic organisms in our country were reviewed and discussed in the second part.The marking effects of alizarin red S(ARS)method on juveniles of A.schlegelii were researched in the second chapter.The tagging concentration of ARS was set between 100 and400 mg/L,the results showed good(tagging quality ? 2)and all the marking groups on the fin spines got significant effects.The concentration serial of ARS were 100mg/L,200mg/L,300mg/L and 400mg/L and each group was marked for 18 h and 24 h,finally the marking-mortality was calculated.The tagging A.schlegelii were cultured for 50 days,after that,the variation of weight and length of the fishes was analyzed between the treated groups and control groups.After dissecting the tagging fishes,the purple marking fluorescence still could be found on the scales(those located between the eyes and dorsal and pectoral fins),otoliths,fins(dorsal fin,pectoral fin,ventral fin,anal fin and caudal fin)and fin spines(dorsal fin spines,pectoral fin spines,ventral fin spines,anal fin spines and caudal fin spines).The most effective groups were present in the 400mg/L and 24 h ones,which the fluorescence could be distinguished by eyes on the scales,fins and fin spines(tagging quality? 4),and the second tagging quality was found on the otoliths and scales(? 3).In the ARS fluorescence sinking experiment,the 400 mg/L and 24 h group had the most marking effect.The 50 days culturing experiment showed that there was no significant difference between the treated groups and the control groups on the survival rate,length and the weight.Finally,when the marking cost and the survival rate were considered together,the most optimal tagging time,concentration and body part on the juvenile A.schlegelii(length between 40 and 50 mm)was 24 h,400mg/L and caudal fin,respectively.The marking method and effect of Calcein(CAL)were studied in this chapter.The tagging concentration of ARS was set between 50 mg/L and 350 mg/L,the experiment showed good results(tagging quality ? 2)and all the marking groups on the fin spines got significant effects.The concentration serial of ARS were 50mg/L,150mg/L,250mg/L and350mg/L and each group was marked for 18 h and 24 h,finally the marking-mortality was calculated after 48 h.The tagging A.schlegelii were cultured for 50 days,after that,the variation of weight and length of the fishes was analyzed between the treated groups and control groups.After dissecting the tagging fishes,the yellow green tagging fluorescence still could be found on the scales(those located between the eyes and dorsal and pectoral fins),otoliths,fins(dorsal fin,pectoral fin,ventral fin,anal fin and caudal fin)and fin spines(dorsal fin spines,pectoral fin spines,ventral fin spines,anal fin spines and caudal fin spines).The tagging effect showed good(? 2.4)when observed under fluorescence microscope.Comparably,the 24 h and 350 mg/L group had the best marking effect in the CAL sinking experiment.There was no significant difference between the treated groups and the control groups on the survival rate,length and the weight.Finally,when combined the marking cost and the survival rate together,for the juvenile A.schlegelii whose body length between 40 and 50 mm,the most optimal tagging time,concentration and body part was 18 h,350mg/L and caudal fin,respectively.