Evaluation of polymer-based fluorescent dyes for fish tagging

The aim of our study was to evaluate small-sized fish tagging by three types of polymers which are the basis for the fluorescent pigment. We examined the efficiency of small-sized fish tagging with acrylic and silicone-based fluorescent dyes. The acrylic tag was blue fluorescent water-dispersion dye. For silicone tag preparation, we mixed compounds with fluorescent pigment and curing agent. The mixture was cured during 72 hours (Pentelast-712) and during 30 minutes (Pentelast-750 FF). Under laboratory conditions we marked Siberian gudgeons Gobio cynocephalus (average body length about 10 cm) with three types of hypodermic tags. The tags were implanted in the pectoral fin by an insulin syringe. We evaluated mortality, growth rate, tag retention and visibility. We showed that injected polymer tags had no influence on the growth rate and surviving comparing with the control group. The visibility of acrylic tags under UV-light was 100% after 134 days, but some tags changed their size and shape. Silicone tag loss was more than 85% on the 44th day of the experiment but the remaining tags were readable during six months. Tissue inflammation in the tag location area disappeared completely in all variations on the 44th day of the experiment. The experimental results allow us to recommend acrylic tags for using in short-term tagging of small-sized fish; silicone - medium-sized and large-sized fish for long-term studies. The process of implanting acrylic tags is technically simpler than silicone. Silicone tags should be implanted in a less mobile body location with the following control of their integrity before fish releasing. The cost of the material used in the work is significantly cheaper than the current commercial product - fluorescent tags (VIE tags) of Northwest Marine Technology company (NMT, USA).

Keywords

Authors

References