Retention of PIT and T-Bar Anchor Tags in Blue Catfish

We quantified retention of PIT and T-bar anchor tags in Blue Catfish Ictalurus furcatus. Eighty-one fish (364-1,005mm TL) were injected with a PIT tag in the dorsal musculature immediately posterior to the dorsal fin and a T-bar anchor tag below the dorsal fin between the pterygiophores. Fish were held in a 0.24-ha earthen pond and retention was evaluated at 2, 4, and 6 months. Retention of PIT tags was 100% over the duration of the study. T-bar anchor tag retention was about 94% at 2 months and 76% at 6 months and was linearly related to time. We estimated that by 25 months, all T-bar tags would be lost. Our results suggest PIT tags can effectively be used in long-term studies (>6 months), whereas T-bar anchor tags are suited for short-term experiments. Received July 29, 2013; accepted October 15, 2013