DAO 71:59-74 (2006)  -  doi:10.3354/dao071059

Salinity effects on viability, metabolic activity and proliferation of three Perkinsus species

Megan La Peyre1, Sandra Casas2,3, Jerome La Peyre2,*

1US Geological Survey, Louisiana Fish and Wildlife Cooperative Research Unit, School of Renewable Natural Resources, and
2Department of Veterinary Science, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803, USA
3Present address: Centro de Investigaciónes Mariñas, Consellería de Pesca e Asuntos Maritimos, Xunta de Galicia, Apartado 13, 36620 Vilanova de Arousa, Spain
*Corresponding author · Email:

ABSTRACT: Little is known regarding the range of conditions in which many Perkinsus species may proliferate, making it difficult to predict conditions favorable for their expansion, to identify conditions inducing mortality, or to identify instances of potential cross-infectivity among sympatric host species. In this study, the effects of salinity on viability, metabolic activity and proliferation of P. marinus, P. olseni and P. chesapeaki were determined. Specifically, this research examined the effects of 5 salinities (7, 11, 15, 25, 35‰), (1) without acclimation, on the viability and metabolic activity of 2 isolates of each Perkinsus species, and (2) with acclimation, on the viability, metabolic activity, size and number of 1 isolate of each species. P. chesapeaki showed the widest range of salinity tolerance of the 3 species, with high viability and cell proliferation at all salinities tested. Although P. chesapeaki originated from low salinity areas (i.e. <15‰), several measures (i.e. cell number and metabolic activity) indicated that higher salinities (15, 25‰) were more favorable for its growth. P. olseni, originating from high salinity areas, had better viability and proliferation at the higher salinities (15, 25, 35‰). Distinct differences in acute salinity response of the 2 P. olseni isolates at lower salinities (7, 11‰), however, suggest the need for a more expansive comparison of isolates to better define the lower salinity tolerance. Lastly, P. marinus was more tolerant of the lower salinities (7 and 11‰) than P. olseni, but exhibited reduced viability at 7‰, even after acclimation.

KEY WORDS: Salinity · Perkinsus marinus · P. olseni · P. chesapeaki · Viability · Metabolic activity · Proliferation

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