Results
A total of 200 jars with live Daphnia and 100 jars with ephippia
were used, at the same time in the same incubators. Of the 100 ephippia
jars all but three (one each at 10, 12.5 and 20 oC)
had at least one D. magna from the 10 ephippia hatch, with an
average number of hatchlings of 6.4 ± 0.33 (32 %). All jars experienced
mortality (unexplained and parasite-mediated) over the course of the
experiment (74.3 ± 1.9 % for ephippia and 69.4 ± 1.4 % for live
treatments).
D. magna Development
Time to hatch (slope estimate = -0.76 ± 0.06, p<0.0001)
(Figure 1) and time to maturation (slope estimate= -0.76 ± 0.06,
p<0.001) (Figure 2b) decreased with increased temperature for
ephippia treatments. Time to maturation also decreased with increased
temperature for the live D. magna experiment (slope estimate=
-0.86 ± 0.82, p<0.001), with no effect of resistotype detected
(Figure 2a).