OBSERVATIONS ON THE RESPIRATION OF AUSTRALORBIS GLABRATUS AND SOME OTHER AQUATIC SNAILS

Abstract

Pulmonate snails (9 spp.) had always a higher rate of O2 consumption than operculates (8 spp.) if specimens of equal wt. were compared. In both groups, however, the respiratory rate declined with increasing wt. of the specimens if referred to unit wt. It remained approx. steady, if referred to relative surface. A. glabratus belongs to the group of invertebrates capable of maintaining a steady rate of O2 consumption over a wide range of 02 tensions. Its O2 consumption increased in the range 0.3 to 37[degree]C, but 41[degree]C was lethal. The application of Arrenius'' equation gave a straight line in the tolerated temp. range. A good fit to Krogh''s normal curve was obtained and an extension of the latter to a wider temp. range is presented. Four spp. of pulmonates showed a progressively declining rate of O2 consumption during protracted starvation. The RQ of A. glabratus sank during starvation from 0.85 to 0.6 and rose only slowly after resumption of feeding. Some of these findings seem to have a bearing on snail control measures.