The effect of triploidy on postprandial metabolism and ammonia excretion in brook charr, Salvelinus fontinalis

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University of New Brunswick


Many studies have attempted to find physiological differences between sterile (triploid) and normal (diploid) salmonids with the goal of increasing triploid performance for aquaculture. The objective of this thesis was to study the effects of triploidy on specific dynamic action (SDA) and net total ammonia nitrogen (TAN) excretion by measuring aerobic metabolic rate (MR) and TAN excretion of brook charr, Salvelinus fontinalis, from 48h before to 48h after being fed a single ration (measured as % body mass; BM). A first experiment determined an appropriate ration size (0.4% BM) and validated the tube-feeding procedure. The process of tube-feeding itself only affected the MR factorial scope, which was significantly higher (by 5%) in the sham-fed group. The second experiment compared the same parameters between ploidies and demonstrated that triploids had significantly lower standard metabolic rates and a higher net TAN excretion than diploids when fed 0.4% BM.