The metabolism of Artemia salina (L.)
Some aspects of the metabolism of Artemia have been investigated. Experiments have been made with animals of different stocks, obtained from different localities. The growth of Artemia is influenced not only by the sex of the animal, but also by the stock from which it is derived. Likewise, the effect of the salinity of the medium on growth varies with sex and stock. The growth of Artemia is retarded in brine with a low dissolved oxygen content. Changes in body proportions occur with increase in size of Artemia: in particular, the abdomen becomes relatively longer. Body form is also influenced by the salinity of the external medium. The extent to which this occurs varies with the sex of the animal and the stock from which it is derived. The oxygen consumption of Artemia has been measured in relation to the size and sex of the animal and also to the salinity of the medium and its dissolved oxygen content. Females have the same rate of oxygen uptake in sea water as in more concentrated brine. Malesin sea water have a higher rate of oxygen uptake than in concentratedbrine. This difference has been related to the greater area of the second antennae of males in sea water. The colours of Artemia are due mainly to haem compounds andcarotenoids. Haemoglobin occurs in solution in the blood; the role of this pigment in the life of Artemia has been investigated. The colours of the eggs are due to differences in total haem content of the egg shell. The red colour of the nauplius and of certain adults is due to carotenoids; some of these have been identified.