Translation Series No.997

7.
in high glass jars holding 200 ml. The density of rotifers
was 10 specimens/mi. After 48 hours the concentration of
rotifers was counted in the experimental jars, after which
the entire increase of rotifers was collected by filtering
a part of the culture proportional to the increase through 4
layers of gauze No, 74. The algae concentration was
counted and brought up to the original altount every 24 hours,
whereby the volume of the culture was kept constant, The
experiment lasted for one month (from the 6th of September to
the 6th of October 1961). Figure 4 shows the histograms for
all three variations of the experiments. Knowing the initial
amount of rotifers in the experiment (E 0 )
and their number
after 2 days (E t ), we computed the diurnal increase.
calculated increase is given in table 2.
The calculation is
based on the assumption at the increase followed the exponential
law . Observation of the spread of algae in the control jars
showed uratically no growth among the algae 1 When computing
the daily ration, a correction was applied only for consumption
The
due to the increase in rotifers.
The daily ration computed in
the experiment agreed with the rations obtained in special
experiments on the change in feeding rate which will be described
elsewhere.
At food concentration of 0.5, 1.0, and 3.0 million cd1s/m1
the diurnal increase was respectively, 53, 101, and 175% (table 2).
1 The algae used in this experiment were raisedin a suecial
environment for cultivating algae in stable conditions
of current, temperature and light. The algae used in all
the remaining experiments were raised in non-standard
conditions.