Triploidy affects standard and postprandial metabolism in brook charr, Salvelinus fontinalis

Abstract

The use of sterile triploids in aquaculture is currently limited because of reduced performance in situations of aerobic stress such as high temperature, hypoxia, and exhaustive exercise. Many studies have therefore attempted to find underlying metabolic differences between triploids and their diploid counterparts to improve triploid rearing protocols. This study investigated the effects of triploidy on postprandial metabolism (and therefore also pre-feeding standard metabolic rate; SMR) by measuring oxygen uptake and total ammonia nitrogen (TAN) excretion at 14-15°C of previously fasted (for eight days) diploid and triploid brook charr, Salvelinus fontinalis, from 48h before to 48h after being fed a single ration of 0.4% body mass. Triploids had significantly lower SMRs and higher postprandial metabolic rates (i.e., specific dynamic action) and net TAN excretion than diploids. While this greater cost of processing a meal may not represent a major diversion of metabolic reserves for triploids, it could affect their growth and survival when simultaneously faced with oxygen-limiting conditions.