Abstract:
Daphnia magna Straus, 1820, plays a significant role in food supply for fish farming; thus, it is
important to formulate a medium that can increase the D. magna population. This can be achieved by supplying a
direct nutrient for D. magna while supporting the growth of the phytoplankton and zooplankton population.
However, at certain levels, the nutrient source addition adversely affects the culture medium. This study aims to
investigate the effects of different concentrations of poultry excreta included in a culture medium enriched with
chlorella powder on the biomass production of D. magna. An experiment was conducted by adding poultry excreta
at four concentrations (0, 2, 4, and 6 g·L-1
) to the chlorella powder culture medium. The culture was maintained for
15 days, and samples were collected on days 0, 5, 10, and 15 to analyze the D. magna population, water pH, and
concentrations of ammonia, nitrate, and dissolved oxygen (DO). Furthermore, a statistical evaluation was conducted
using one-way analysis of variance in a completely randomized research design. The results showed that an increase
in the poultry excreta concentration reduced the water quality (P < 0.01), as indicated by the water pH and
ammonia, nitrate, and DO concentrations. In addition, a longer duration of the experiment substantially improved
the qualitative parameters evaluated. Similarly, the population of D. magna was significantly affected (P < 0.01) by
both factors. In conclusion, the addition of poultry excreta decreased the water quality of the chlorella powder
medium. The water quality improved on prolonged days; thus, the highest population of D. magna was achieved on
day 15 using 2 g·L-1 of poultry excreta
Description:
Nutrient enrichment could change the water
environment. This study indicated poultry excreta
levels had a significant impact on pH, oxygen
conditions, and other water quality parameters that
determine D. magna growth and reproduction. Higher
levels of poultry excreta caused a decline in the water
quality of mediums enriched with chlorella powder.
This was, however, in the tolerable range for the
growth and reproduction of D. magna. In addition, the
quality parameters were observed to have improved
after prolonged days of culture, which was followed by
an increasing D. magna population, with the highest
amount reported on day 15, using a poultry excreta
concentration of 2 g.L
