Survival, Growth, and Mark Persistence in Juvenile Black Crappies Marked with Fin Clips, Freeze Brands, or Oxytetracycline

Abstract

Abstract We tested the relative performance of fin clips, freeze brands, and oxytetracycline (OTC) marks on juvenile black crappies Pomoxis nigromaculatus. Fish held for 5 d after treatment in laboratory aquaria at 18, 21, 24, and 27°C showed no significant difference in survival (100% in most replicates). Continuing effects of the marks on growth and survival were tested by stocking juveniles with each mark and nonmarked fish into research ponds. No significant differences in survival, length, weight, or condition factor (K) were observed after 31 weeks. Freeze brands, fin clips, and OTC marks all proved to be effective for marking juvenile black crappies; however the fin clips and freeze brands persisted significantly better (P = 0.0007) than the OTC marks through 31 weeks. Abstract We tested the relative performance of fin clips, freeze brands, and oxytetracycline (OTC) marks on juvenile black crappies Pomoxis nigromaculatus. Fish held for 5 d after treatment in laboratory aquaria at 18, 21, 24, and 27°C showed no significant difference in survival (100% in most replicates). Continuing effects of the marks on growth and survival were tested by stocking juveniles with each mark and nonmarked fish into research ponds. No significant differences in survival, length, weight, or condition factor (K) were observed after 31 weeks. Freeze brands, fin clips, and OTC marks all proved to be effective for marking juvenile black crappies; however the fin clips and freeze brands persisted significantly better (P = 0.0007) than the OTC marks through 31 weeks.