~2?0- that of other fish tissues. Goatfish viscera (Fig. 7), on the other hand, declines similarly to that of sea cucumber gut, the liver of an omnivore, and to some degree, algae. feed largely on brachyuran crabs, which, dead fish, etc., in turn, 30 that the diet of goatfish is, Goatfish feed on algae, to a certain degree, comparable to that of omnivorous fishes. Comparison of Decline with Decay of Radioactivity Figures 7 through 10 show certain marked differences between decline and decay of radioactivity in the same tissues for both goatfish and mullet. In goatfish the differences are evident in the first 100 days after shot, while in mullet the differences are greatest for the first 150 to 200 days. Vari- ations due to sampling and other causes, which have been dis- cussed in a previous section, might explain some of the differences. Also they might be due to the differential affinity of various species for shorter-lived isotopes. In goatfish the radiation varies to around 50 to 170 uc/kg for liver, about 20 to 50 uc/kge for bone and 3 to 7 uc/kg for muscle. Similarities in the decay curves are shown in Figures 7, 8, 9, 10, and 11. For example, liver decay in goatfish (Fig.8) is similar to that of mullet liver after 100 days; muscle decay in goatfish is similar to surgeonfish liver and surgeonfish bone after 200 days; while bone decay of goatfish is similar to bone decay of mullet and surgeonfish after 100 to 250 days. Dissimi- larities in the decay curves appear to be greatest during the first 100 to 200 days after the shot, the curves tending to