The land hermit crab. Coenobita, has been reported upom by
Held (1957), primarily from the standpoint of its sensitivity
as an indicator of radiostrontium.
Individual sample values
were given in appendix form showing d/m/g based on the usual
decay correction factors 85ers for carepece, which was based
upon the decay rate of Sr¥9 and Sr70-Y90,
Declines vere show
semi-log in order to relate them to half life, and to scceataate fluctuations in the later trends of the curves.
For purposes of comparison with other organisas, this
section presents, in the form used throughout the paper, tae
same crab data tabulated by Held, (1957: 26).
observations on April 26, 1956,
In eddition, the
just tefore the next series of
tests, are shown as the last points on the guscle end carepace
graphs.
However, instead of decay factors based only upon
strontium, the usual decay factors employed in the present
paper were used for carapace.
Numbers of specimens on each
collecting date ranged from 1 to 5, averaging 2.9 © 0.2.
Pigure 25 shows the declines for five creb tissues.
x
|
-
\
}
pone
~.
°
-
3
a
NO
-
“~
°
\
Align-
\
\
an Me ANS Y
|
ome wae ney +80
-
onde mow — F&F
Fig. 25
ment of points was good in the cases of liver and gill. Rates
of decline ranged from -.95 to -1.46. A dip shortly efter 100
days in all of the curves appears to be followed by a leveling
tendency.
The decline curve for carapace differs from that shown by
Held, who used decay correction factors based solely on
strontium, in that it extends through @ vertica] renge of ebeut
2.3 orders of magnitude, while his extends through only ebeut
a.) orders Of magnituds, possibly teceuss is. tus seceent pager
short-lived products
in the sard-deritved decay factors vere ta-
cluded, while in Held's ccnsideration these possible short-lived
products were excluded.