Clas
Tridacnid clams,
mostly Tridacna crocea,
vere sampled at Belle
over a longer period
than other invertebrates
except crabs.
Numbers
of specimens used on
each collecting date
ranged from 1 to 5,
averaging 2.1 % 0.2.
Pigure 19 shows the
declines for clam tissues
at Belle.
The early rank-
ing of the tissues from
most to least radioactive,
was visceral mass, kidney,
gill, shell, mantle, and
The more gradual
muscle.
decline rate (¢0.71)
for
kidney than for other
tissues brought kidney to
first place at the end of
the 2-year period, while
other tissues retained
their ranking.
oa ae
aye Or ty 4 O80
Pig. 19
Early absolute levels ranged from 20 to 1000 uc/kg for
muscle and visceral mass, respectively.
Two years later the
rerange was from 0.1 to 4 uc/kg for muscle and kidney,
Le
spectively.