Reynaldo Patino
Emily T. Richardson
2021
<p><i>Prymnesium parvum</i><span> is a euryhaline, toxin-producing microalga. Although its abundance in inland waters and growth potential in the laboratory is reduced at high salinity (>20), the ability of inland strains to adjust their growth after long-term residence in high salinity is uncertain. An inland strain of </span><i>P. parvum</i><span> maintained at salinity of 5 in modified artificial seawater medium (ASM-5) was subjected to the following treatments over five sequential batch culture rounds: ASM-5 (control); modified ASM at salinity of 30, raised with NaCl; modified ASM at salinity incrementally increased to 30 with NaCl; and Instant Ocean</span><sup>®</sup><span> at salinity of 30 (IO-30). Exponential growth rate (</span><i>r</i><span>) was reduced when salinity was increased from 5 to 30 in ASM but returned to control values during the second round. When salinity was incrementally increased, a reduction in </span><i>r</i><span> still occurred when salinity reached 25-30. Maximum density was reduced at salinity of 30 in ASM upon abrupt transfer or incremental increase, and compensation did not occur. Growth performance in IO-30 was comparable to control values. In conclusion, (i) long-term compensation for acute inhibitory effects of high salinity occurred for </span><i>r</i><span> but not maximum density, (ii) incremental increases in salinity did not prevent growth inhibition, suggesting the existence of a salinity threshold of 25–30 for onset of salinity stress, and (iii) the presence of a seawater-like salt mixture prevented growth inhibition by high salinity. These findings provide new insights on </span><i>P. parvum</i><span>'s long-term ability to adjust its growth in environments of different salinity and ionic composition.</span></p>
application/pdf
10.1111/jpy.13172
en
Phycological Society of America
Long-term salinity change and growth of the harmful alga, Prymnesium parvum
article