Marking small tropical fish with Visual Implant Fluorescent Elastomer (VIFE)

Several fish-marking techniques are used to diagnose the population dynamics of species. However, marks should not interfere with behavior, growth and reproduction of the involved population. For this reason, VIFE (Visible Implant Fluorescent Elastomer) was developed. This study reports the use of VIFE to mark two small tropical species, Bryconamericus iheringii and Rineloricaria malabarbai, in a controlled environment. We captured 30 individuals of B. iheringii and 30 of R. malabarbai by electrofishing. The fish were marked and observed for 90 days, and there was no instant mortality after inserting the elastomer. During the first 70 days there was low mortality and high retention rates, but many elastomers broke into smaller fragments. Based on the low mortality and high retention rates found in this analysis, the use of VIFE is recommended for similar studies.