Evaluation of Visible Implant Elastomer (VIE) for Marking Fingerling Blue Catfish

Visible implant elastomer (VIE) was evaluated as a means of marking advanced fingerling (∼152‐mm) blue catfish Ictalurus furcatus. A laboratory study was conducted using hatchery‐reared blue catfish to examine tag retention for 270 d, tag visibility, and mortality (instantaneous and delayed). Twenty blue catfish were tagged in each of three locations: the upper lip, the base of the pelvic fin, and the cheek. Another group of 20 served as the control and were not marked with VIE. The tag retention rates were 89.5, 100, and 100%, respectively, for fish tagged in the upper lip, at the base of the pelvic fin, and in the cheek, though the VIE sometimes had a tendency to fragment or migrate. Marks in the cheek had the best visibility overall. No instantaneous mortality was observed, and delayed mortality was low (5%) for all groups except those tagged at the base of the pelvic fin (30%). Overall, the cheek proved to be the best location for tagging fingerling blue catfish with VIE.