Long-term individual marking of small freshwater fish: the utility of Visual Implant Elastomer tags

• Published in: Behavioral ecology and sociobiology 2019-04, Vol.73 (4), p.1-11, Article 49
• Main Authors: Jungwirth, Arne, Balzarini, Valentina, Zöttl, Markus, Salzmann, Andrea, Taborsky, Michael, Frommen, Joachim G.
• Format: Article
• Language: English
• Subjects: Amphibians; Animal Ecology; Animal reproduction; Behavioral Sciences; Bias; Biomedical and Life Sciences; Breeding; Breeding success; Cichlid fish; Collection; Communal breeding; Dispersal; Ecology; Ekologi; Elastomer tagging; Elastomers; Fish; Fresh water; Freshwater fish; Health risks; Individual identification; Life Sciences; Life span; Marking; METHODS PAPERS; Mortality risk; Reproduction; Social behavior; Social behaviour; Survival; Tagging; Tags; Transplants & implants; Tropical fish; VIE tags; Wild animals; Zoology
• ISSN: 0340-5443; 1432-0762; 1432-0762
• DOI: 10.1007/s00265-019-2659-y

Tracking wild animals over long periods of time is a non-trivial challenge. This has caused a bias in the availability of individualbased long-term datasets with the majority including birds and mammals. Visual Implant Elastomer (VIE) tags are now a widely used technique that may facilitate the collection of such data for fish and amphibians. However, VIE tags might have important drawbacks. Overall, four potential issues with VIE tags have been proposed: tag loss or misidentification, limited number of individual identifiers, enhanced mortality risk, and effects on intra-specific interactions. Here, we present three experiments in which we investigated these potential problems with VIE tagging in small freshwater fish both in the laboratory and in the wild, using the cooperatively breeding Lake Tanganyika cichlid Neolamprologus pulcher. We find VIE tags to be generally suitable for work with these fish as they did not impair survival, were recognisable up to 2 years after injection, and did not generally disturb group formation. Nevertheless, we identify specific issues of VIE tagging, including colour-and position-dependent variation in tag identification rates, and indications that specific colours may influence social behaviour. Our results demonstrate the suitability of VIE tags for long-term studies on small freshwater fish, while also highlighting the need of validating this method carefully for any species and study.