Affiliation: | a Department of Civil Engineering, National University of Singapore, Kent Ridge, Singapore b Department of Microbiology, National University of Singapore, Kent Ridge, Singapore c Primary Industries Enterprise, 100 Beach Road, # 31-00 Shaw Towers, Singapore d Primary Production Department, Aquaculture Branch, National Development Building, Maxwell Road, Singapore |
Abstract: | The rational design of closed aquaculture systems requires data on metabolite production rates. The metabolite of primary concern is often ammonia. Ammonia formation rates for a number of tropical ornamental fish types and sizes were determined. Cyprinus carpio, Barbus conchonius, Pseudotropheus auratus and Carassius auratus auratus were used as representative egg-layers while Xiphophorus variatus and Xiphophorus helleri represented the live-bearers. Specific metabolite production rates, R′, were determined not only in terms of mass of fish but also the amount of feed. For instance, R′ (Amm-N) for 1.33 g unit size Barbus conchonius was determined to be 155.9 mg Amm-N kg-fish−1% feed−1 day−1. In an attempt to produce a general model for all the ornamental fish investigated, all values of R′ obtained were correlated with fish sizes to produce an equation R′ (Amm-N) = 1.57-[30×log(itUW)] where UW = unit fish size. |