feeding clam, feeds on bottom material, which is about 10 times that of plankton. The land-inhabiting hermit crab, Coenobita, and the coconut crab, Birgus, were intermediate in their general level of radioactivity between spider snail and giant clam. As shown in Table 5 and Figures 8 and 6, rates of decline as expressed on logarithmic paper varied from -0.9 for spider snail muscle to -2.8 for hermit crab liver, and averaged -1.75. Negative Slopes of Decline Rate of Invertebrates Logarithmically Graphed in Figures 5-10, Based on First and Last Observations Tissue Coconut Crab - Hermit Crab Muscle Gut and 1.3 2.0 _’ Integument x Liver 1.4 1.9 1.7 2.8 content Kidney Entire Giant Clam 1.7 Spider Snail Sea Cucumber Coral 0.9 2,0 1,7 1.3 1.7 2.1 2.0 wt "in the native diet. These food items included coconut meat and milk and 7 UNIVER UNIV. Ci