Effect of implanting a passive integrated transponder tag in juvenile chub, Squalius cephalus (L.), on their condition, growth and survival

The effect of implanting a Passive Integrated Transponder (PIT) tag on the survival, growth and condition of a small cyprinid, juvenile chub Squalius cephalus (L.) with a mean weight of 2.4 g was studied in the laboratory. During this experiment, which lasted for 31 days, 80 specimens were tagged. The changes in Fulton’s condition factor (K), specific growth rate of mass (GM) and specific increase in length (LS) were evaluated. The results showed that implanting PIT tags did not affect the survival or growth of the fish; however, it had a negative effect on their condition. The initial size of the fish had a significant effect on the specific growth rate in terms of mass, but not in terms of length. Survival was 98.8% and tag retention 97.5%, when the tag made up 4.3% of the mass of the fish. These results demonstrate that PIT tagging is an appropriate method for chub heavier than 2 g. For this size category, we recommend that PIT tagging is suitable when the tag makes up 4.3% of the body mass of the individuals.