102
(3) Total tissue zine concentrations, used as an estimate
of gine binding capacity, were highest in liver,
G.
I.
tract,
eye,
bone,
followed by
muscle and gill filament.
(4) The specific activity of zinc-65, used as an estimate
of zinc exchange capacity for goatfish tissues, was highest in
bone,
followed in order by gill filament, eye,
liver,
G.I. tract
and muscle.
(5)
The relative zinc turnover rate for various goatfish
tissues was estimated by multiplying the relative zinc exchange
capacity by a factor based on laboratory observations of zine
uptake in catfish tissues,
From these estimates,
order of zinc turnover was: G.
muscle and bone.
I.
tract,
the relative
gill filament,
liver,
Eye turnover was not estimated as data were
not available for rate of uptake for this tissue.
(6) For studying the distribution
of radiozine ina
marine environment by analyses of fish samples,
the eye has
the following advantages as an index tissue:
(a)
It is simple to remove from either fresh or frozen
samples,
{(b) There is a high concentration of zinc in the retina.
(c)
The metabolic activity of the retina is steady and
not subject to radical changes.