Effective Anesthetic Dosage and Recovery from Specialized Surgical Methods in Shortnose Gar

Abstract

AbstractA general assumption in the use of biotelemetry is that tags do not affect the animal’s behavior. There is general agreement that internal implantation of transmitters is the preferred method for affixing a tag to a fish relative to external and intragastric transmitters because internal tags have minimal negative impacts on growth and can be used for long‐term research. Internal transmitter attachment methods have only recently been explored for the family Lepisosteidae due to the inability to breach ganoid scales with traditional surgical procedures developed for teleost fishes. In this study, we used a recently developed specialized surgical technique to conduct sham surgeries on Shortnose Gar Lepisosteus platostomus to document short‐ and long‐term recovery and wound healing rates. Shortnose Gar were successfully sedated for surgical purposes with AQUI‐S 20E at a concentration of 250 mg/L, although we discovered that it is necessary to prevent facultative air breathing to ensure sufficient induction. Despite a longer sedation time relative to other species, fish recovered quickly and showed no adverse effects. Surgical wounds closed within approximately 2 weeks, and monofilament sutures were retained long enough to promote healing. On average, fish lost 0.34% body weight per day over the first 7–19 d postsurgery but gained 0.26% body weight per day over the remainder of the 478‐d study. Our study is the first to test the effective dosage of AQUI‐S 20E in Shortnose Gar and to evaluate recovery from surgery using a specialized surgical technique in a controlled setting. Methods used in our study were designed to be directly applied in the field, will allow researchers to safely utilize internal implantation of transmitters in primitive fishes with ganoid scales, and will enable studies that expand our knowledge of the spatial ecology and habitat use in this ancient lineage of fish.