Acute osmotic tolerance of cultured cells of the oyster pathogen Perkinsus marinus (Apicomplexa:Perkinsida).
Cultured Perkinsus marinus cells were exposed for 24 hr to salinities of 0, 3, 6, 9, 12 and 22 ppt at temperatures of 1, 5, 10, 15 and 28 degrees C in artificial seawater (ASW) and to the same salinities at 28 degrees C in ASW with the osmotic concentration adjusted with sucrose to the equivalent of 22 ppt. At 28 degrees C mortality increased as salinity decreased below 22 ppt. Mortality was greater than 99% at 0 ppt and greater than 90% at 3 ppt. Mortality was 70% at 6 ppt, 43% at 9 ppt and 20% at 12 ppt. Mortality was low (< 5%) and equal to that at 22 ppt in all treatments where osmotic concentration was maintained with sucrose. Mortality occurred rapidly, within 5 min of exposure to experimental conditions. In the region where mortality was most sensitive to salinity changes (6-12 ppt), lower temperature caused an increase in mortality, but the temperature effect was significant only at 9 ppt.
School of Marine Science, Virginia Institute of Marine Science, College of William and Mary, Gloucester Point 23062, USA.
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Ragone Calvo
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D000818:Animals; D016782:Apicomplexa / Q000378:metabolism*; D002478:Cells, Cultured; D009994:Osmolar Concentration; D010125:Ostreidae / Q000469:parasitology*; D012623:Seawater; D013395:Sucrose / Q000494:pharmacology; D013696:Temperature; D013997:Time Factors
D013395:Sucrose