5
,
Gk;
a
are
a
the coral used was without the cil scum and had noe count above
background on the survey meter,
The fish in #6 has likewise fed
regularly.
Aquaria #1, 3 and 4 were retained as controls,
Six larger aquaria, 12" x 24" x 16", were set up originally
but were not as satisfactory as the setup for the smaller aquarina
described above. The large aquaria are now being used as supply
tanks for fish and other marine animals as well as for an irradiation
mortality experiment with the marine snail, Thais lamellosa,
Qn April 14th mix more of the smaller aquariawere delivered and
were set up in the same manner as those for the flatfish.
Tide
Pool johmnies, a soulpin, Oligocuttus maculosus, were placed in these
aquaria,
They have not yet been used experinentally but seem well
adapted to their new environment,
The experiment in aquaria #2 and #5 will be continued until it is
believed that the fish is about to die,
At that time tissues will be
praserved for histological studies,
Project VI.
Observations on the amphipods were discontinued because of
high mortalities among the controls.
Marine snails, Thais lamellosa,
A report will be submitted.
that had been surviving well
in 15-gallon aerated aquaria, were individually marked with a number
and X-rayed on April 2.
Exposures given, and numbers of snails
irradiated, weret 10,000 r —- 23 S000 r - 63 2000 r=93
500 r= 93 and 200 r- 9,
1250 r ~ 9;
After 3 weeks the mortalities anong irra-
diated and control snails were approximately equal.
The snails
spawned in the aquaria, attaching their ogg cases to rocks, shells,
and especially to the glass aides of the aquaria.
When only a few
egg oases were deposited, their positions were recorded along with
ve
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