The age-specific survivorship curves of female and
male Streptocephalus mackini in relation to different
densities of Chlorella are presented in Fig. 1. Regardless
of sex, test individuals showed better survivorship
at lower food levels. At 0.5 · 106 cells mL)1, both
male and female anostracans had nearly rectangular
survivorship curves. These curves became steeper and
fell sharply when the food supply was increased to
1.5 · 106 cells mL)1. At lower food levels, males lived
longer than females but the trends were reversed at
increased algal levels. The longest average lifespan
observed was 85 ± 2 days for males fed Chlorella at
0.5 · 106 cells mL)1, while the highest food reduced
the lifespan significantly (P < 0.01) to about 20 days
(Fig. 2). The age-specific life expectancy curves
showed trends similar to the survivorship curves
but these trends were nearly the same for male and
female S. mackini (Fig. 3).