Effect of visible implant elastomers (VIE) and coded wire tags (CWT) on the growth, survival, and tag retention of juvenile European whitefish (Coregonus lavaretus)

This study examined the effect of visual implant elastomers (VIE) and coded wire tags (CWT) on the growth, survival, and tag retention of juvenile European whitefish, Coregonus lavaretus (L.), (mean body weight 18.7 ± 0.4 g, mean body length 9.7 ± 0.4 cm). The VIE tags were implanted subcutaneously in the anterior head, and the CWTs were implanted intramuscularly under the left gill operculum. The experiment consisted of two stages. The first stage (70 days) examined the effects of tagging on growth and survival, while the second stage (days 71-140) focused on assessing tag retention. Daily and specific growth rates, feed conversion factor, condition factor, coefficient of body weight variation, and survival did not differ significantly between the control fish and those tagged with the VIE tags and CWTs. Tag retention was high in the fish tagged with both VIE tags (100%) and CWTs (93%).