For selection for disease resistance, environmental conditions, such as temperature and salinity, determine the activity and virulence of both Haplosporidium nelsoni
and Perkinsus marinus within the host (Haskin & Ford 1982, Villalba et al.
KEY WORDS: eastern oyster, Crassostrea virginica, fecundity, Perkinsus marinus, Haplosporidium nelsoni
(MSX) on Delaware Bay seed oyster beds: a host parasite relationship along a salinity gradient.
In addition, artificial selection for 4 generations based on survival, growth, and disease susceptibility has produced a strain with dual resistance to the parasites Haplosporidium nelsoni
The Suminoe oyster is also relatively resistant to the protozoan parasites Haplosporidium nelsoni
and Perkinsus marinus (Calvo et al.
virginica on the east coast of the United States with dual infections of Haplosporidium nelsoni
Differential diagnosis of mixed Haplosporidium costale and Haplosporidium nelsoni
infections in the eastern oyster, Crassostrea virginica, using DNA probes.
Development of a multiplex PCR for the detection of Haplosporidium nelsoni
, Haplosporidium costale and Perkinsus marinus in the eastern oyster Crassostrea virginica, Gmelin, 1971.
Effects of sublethal infection by the parasite Haplosporidium nelsoni
(MSX) on gametogenesis spawning and sex ratios of oysters in Delaware Bay USA.
By 2006, this 54-yr record covered a number of unique periods, including the period of time after the onset of MSX, a disease caused by the protozoan Haplosporidium nelsoni
, circa 1957 (Haskin and Andrews, 1988; Ford, 1997) and the period after the onset of Dermo, a disease caused by the protozoan Perkinsus marinus, circa 1990 (Ford, 1996; Cook et al.
And infection by Haplosporidium nelsoni
(MSX) on the tissue condition of oysters, Crassostrea virginica.
A third "Dark Age" began for the oyster industry in the late 1950's when a new disease, later named MSX aid caused by the Haplosporidium nelsoni
parasite, began to kill huge quantities of oysters in Delaware and Chesapeake Bays.