Triploid burbot, Lota lota, production: Optimization of thermal and hydrostatic parameters, tetraploid induction, and confirmation of triploid sterility

Abstract

Experiments were conducted to optimize triploid induction parameters, and assess triploid sterility, in burbot. Duration and timing of shocks were based on degree minutes, temperature multiplied by time, denoted as °C min. Hydrostatic shock experiments investigated the duration of shock using 7500 or 8500 psi at 180°C min post‐fertilization. Thermal shocks investigated duration of shock and post‐fertilization shock timing using a shock of 16°C. Sterility experiments investigated egg survival when diploids were crossed with triploids. Hydrostatic shock of 7500 psi for 10 or 20°C min can induce triploidy ≥90% and exhibits survival that is statistically similar, p ≤ 0.05, to controls. Hydrostatic shock of 8500 psi for 5 or 10°C min yielded triploid induction of 93% and 100%, respectively, with survival that is statistically similar to controls, p ≤ 0.05. Thermal induction experiments indicated shocks at 120°C min post‐fertilization, for durations between 350 and 450°C min, have potential to induce triploidy ≥90% while facilitating survival statistically similar to controls, p ≤ 0.05. Induction of tetraploidy was observed. Sterility experiments determined that triploid burbot are functionally sterile. These results may allow production of burbot where sterility is required.