JULIE E. WALLIN, JOHN M. RANSIER, SONDRA FOX, AND ROBERT H. MCMICHAEL, JR., Florida Marine Research Institute, Florida Department of Environmental Protection, 100 Eighth Ave. SE, St. Petersburg, Florida 33701, USA

We evaluated the retention of coded wire tags and two types of internal anchor tags and tagging-related mortality in hatchery-reared juvenile snook Centropomus undecimalis. Retention of coded wire tags was evaluated in snook 60 - 115 mm SL for 60 d posttagging, and retention of internal anchor tags with disk- and T-style anchors was evaluated in snook 110 - 180 mm SL for 30 d posttagging. An average of 93.8% of the coded wire tags were retained for 60 d. Initial fish size significantly affected coded wire tag retention rates; retention rates were 95-100% in fish >70 mm SL and 87-92% in fish <70 mm SL. Coded wire tag retention rates decreased during the first 30 d of the experiment but not thereafter. The retention rate of both types of internal anchor tags was >99% after 30 d. Initial fish size did not affect retention of internal anchor tags. Disk-style anchors were more likely to be encapsulated in the peritoneum and attached to the inside of the body, which may enhance retention of this tag type. For all types of tags and fish sizes tested, tagging did not significantly affect snook survival.