-20-
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.
Goatfish
feed largely on brachyuran crabs, which, in turn, feed on algae,
dead fish, etc., so that the dlet of goatfish is, to a certain
|
degree, comparable to that of omnivorous fishes.
Comparison of Decline with Decay of Radioactivity
Figures 7 through 19 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 discussed in a previous section, might explain some of the differ-
ences.
Also they might be due to the differential affinity of
various species for shorter-lived Lsotopes.
In goatfish the
radiation varies to around 50 to 170 uc/kg for liver, about 20
to 50 uc/kg for bone and 3 to 7 uc/kg for muscle.
Similarities in the decay curves are shown in Figures 7,
8, 9, 10, and ll.
For example, liver decay in goatfish (Fig.8)
is similar to that of millet 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 millet 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