GROWTH EFFICIENCY IN ARTEMIA UNDER LABORATORY CONDITIONS

¹ Zoology Department, University of Southampton, England

1. The efficiency of growth of four laboratory populations of Artemia in different food concentrations was studied over a period from birth to approximately double the time required to reach sexual maturity. Uptake of food and increase in length, and hence weight, were measured daily. Efficiency rose at first, up to the time at which the animals were growing at their maximum rate, when the highest peak cumulative efficiencies (79%) were obtained in the lowest food concentrations. These values then fell as the animals approached their maximum size.

2. In other experiments on young animals in their first few days of growth, it was found that efficiency increased with temperature between 5° and 30° C., that there was an optimum salinity of about 35%0, at which efficiency was greatest, and an optimum food concentration of 25-30 cells/mm.²