Abstract:
Prymnesium parvum is an environmentally harmful algae and well known for its toxic efects to the fsh
culture. However, there is a dearth of studies on the growth behavior of P. parvum and information on
how the availability of nutrients and environmental factors afect their growth rate. To address this
knowledge gap, we used a uniform design approach to quantify the efects of major nutrients (N, P,
Si and Fe) and environmental factors (water temperature, pH and salinity) on the biomass density of
P. parvum. We also generated the growth model for P. parvum as afected by each of these nutrients
and environmental factors to estimate optimum conditions of growth. Results showed that P.
parvum can reach its maximum growth rate of 0.789, when the water temperature, pH and salinity is
18.11 °C, 8.39, and 1.23‰, respectively. Moreover, maximum growth rate (0.895–0.896) of P. parvum
reached when the concentration of nitrogen, phosphorous, silicon and iron reach 3.41, 1.05, 0.69 and
0.53 mg/l, respectively. The order of the efects of the environmental factors impacting the biomass
density of P. parvum was pH> salinity >water temperature, while the order of the efects of nutrients
impacting the biomass density of P. parvum was nitrogen>phosphorous > iron> silicon. These fndings
may assist to implement control measures of the population of P. parvum where this harmful alga
threatens aquaculture industry in the waterbodies such as Ningxia region in China
