Investigations into the Growth of Haddock, Melanogrammus Aeglefinus (L) and Whiting, Merlangius Merlangus (L) in Aquaria

Abstract

Haddock and whiting were maintained in aquaria and were individually fed different amounts of squid at a temperature of 13–14°C. Daily gains in weight increased more or less linearly with increasing ration. Rates of increase in length however, at least among the larger fish of 26–32 cm in length, increased towards a maximum level of 4·0 mm/10 days in the haddock and 6·5 mm/10 days in whiting. An investigation was made of the effect of tank size in the case of haddock, and stock density in the case of whiting on the results. It was found that for the range of tank sizes and stock densities used in these experiments, neither of these factors had a significant effect on the results. Measurements were also made of condition factors and girths at each length. These were both found to increase as the rates of feeding were increased.