P. parvum grows in a
salinity range of 0.5 - 30 psu (Practical Salinity Unit) with an optimum at 15 psu although strains collected in different places appear to have different salinity tolerances. A strain called LB 2797 (isolated from Colorado River in Texas) shows a biphasic growth pattern namely, maximum cell densities increased as salinity increased from 5 to 15 psu but decreased at higher levels in laboratory culture. The alga produces
dimethylsulfoniopropionate (DMSP) and other unknown
polyols, likely as an adaptation to
osmoregulation. The environment must be between and for
P. parvum to live. Growth at a
pH of as low as 5.8 has been observed, but cells typically prefer higher pH ranges. The organism prefers highly light environments, but growth can be inhibited by excessive light (
photoinhibition). The organism is capable of
heterotrophic growth in the dark in the presence of
glycerol and grazes on bacteria, especially when
phosphate is limited. It has therefore been hypothesized that
P. parvum satisfies its phosphate needs by consuming bacteria.
P. parvum can use a wide range of
nitrogen sources, including
ammonium,
nitrate,
amino acids (which ones apparently depends on pH),
creatine, but is unable to use
urea. New evidence has shown that the toxins produced by this alga are induced by physiological stresses, such as nitrogen and phosphorus depletion due to competition with the environment. == Notable
Prymnesium harmful algal blooms ==