Marking on Scales by Immersion in Chemicals for Estimate of the Early Survival Rate of Released Fish on Marine Ranching Area

Abstract

We evaluated the efficiency of chemical marking of black rockfish scales by immersion in oxytetracycline hydrochloride (OTC), alizarin red S (AS) and calcein (CAL) diluted rearing water. Immersion treatment of chemicals had no effects on both mortality and growth of black rockfish. Marking success was 100% in all treatment durations (24, 48, 72 hours.). Marking retention rates at 24 weeks after treatment were 100% in OTC and CAL treated group, but marking quality was higher in CAL treated group (brilliant 92%, bright 8%, dim 0%). Than in OTC treated group (brilliant 4%, bright 70% and dim 26%). AR treated group had lower marking retention rates and marking quality than OTC and CAL treated group. As a result, immersion treatment with OTC and CAL was effective in marking scales of fish and practical in releasing programn both mortality and growth of black rockfish. Marking success was 100% in all treatment durations (24, 48, 72 hours.). Marking retention rates at 24 weeks after treatment were 100% in OTC and CAL treated group, but marking quality was higher in CAL treated group (brilliant 92%, bright 8%, dim 0%). Than in OTC treated group (brilliant 4%, bright 70% and dim 26%). AR treated group had lower marking retention rates and marking quality than OTC and CAL treated group. As a result, immersion treatment with OTC and CAL was effective in marking scales of fish and practical in releasing program