Screening and Standardization of Individual Tagging Methods for Crimson Snapper

Individual tagging of crimson snapper lacked a unified process standard: survival and tag-retention rates varied markedly across fish sizes and between chip implantation and external marking, making results hard to compare.

Screen applicable tagging methods through controlled multi-method experiments, establish standardized operating and post-operative care procedures, and produce selection guidance by fish size.

Designed controlled multi-method experiments and ran the full workflow on over one hundred fish across different size classes; established a standardized chip implantation and post-operative care procedure; compared dorsal injection marking and other approaches for survival and retention across size classes, and consolidated the results into selection criteria.

Dorsal injection marking survival for adult fish improved to 80%; a tagging-method selection guide by fish size class was produced, providing a stable marking basis for subsequent individual-recognition dataset construction.