Effect of Low Temperature on the Vertical Distribution of Two Wood-boring Crustaceans

Abstract

WHEREAS normal marine animals may be subjected to a temperature of not less than the freezing point of sea water, animals inhabiting the inter-tidal zone sometimes experience a much lower temperature. This is particularly so in the high-latitude shores of Norway where, during the winter, an inter-tidal zone of 3.5 m. is exposed twice daily to as low a temperature as − 20° C. for 6 hr. or more. While studying the distribution of marine wood-borers in the Norwegian coasts, the possible stress of low temperature on these organisms came under consideration. Kanwisher¹ found some inter-tidal animals able to survive with as much as 75 per cent of their body fluids converted as ice. In Limnoria, Sømme² found that 83 per cent died when frozen in ice for 2.5 hr. With the view of finding out the extent of tolerance and any evidence of an adaptability to sudden drops in temperature which these animals experience when they are exposed to the air by the receding tide, the following experiments were performed.