Effects of Passive Integrated Transponder Tags on the Physiology and Swimming Performance of a Small‐Bodied Stream Fish

Abstract

AbstractWithin the past few decades, telemetry has proven to be a valuable tool for tracking and monitoring fish. Although the advent of smaller transmitters has made these methods increasingly applicable to small‐bodied fishes, limited information currently exists regarding the efficacy of these transmitters or their putative effects on small‐bodied fishes. I evaluated the physiological and performance consequences of PIT tag implantation in a small‐bodied, sexually dimorphic stream fish, the Blackspotted Topminnow Fundulus olivaceus. First, I used a common‐garden experiment in an outdoor mesocosm setting to assess the long‐term effects (184 d) of PIT tag implantation on a suite of physiological and phenotypic metrics. I randomly assigned 216 individuals (50–73 mm SL; equal sex ratio) to one of three tagging treatments: control (no PIT tag), small (8 mm) PIT tag, or large (12 mm) PIT tag. Survivorship did not vary among treatment groups, and the presence of the tags had no apparent effects on the condition or development of the intraperitoneal organs relative to that observed in control fish. Fish that received large PIT tags showed reduced growth rates relative to fish that received small PIT tags; however, this appeared to result in a trade‐off that prioritized reproductive output. Second, I evaluated fish swimming performance (kinematics and endurance) to assess potential hydrodynamic consequences of PIT tag implantation. Kinematics (tail‐beat frequency, amplitude, and total displacement) and endurance swimming were similar across all treatments and between sexes, with only slight idiosyncratic effects observed. These results indicate that 8‐mm and 12‐mm PIT tags are appropriate for use in adult Blackspotted Topminnow as no detrimental long‐term effects were observed.Received February 26, 2016; accepted July 12, 2016 Published online September 26, 2016