ABSTRACT Quahog Parasite Unknown (QPX) disease has significantly impacted cultured and wild hard clam, Mercenaria mercenaria, populations in the Northeastern United States and is the first formidable disease issue concerning near market sized clams for the industry. Most of what is known about this protistan infection comes from diagnostic reports of mortality events and some preliminary field investigations. Disease dynamics and details of parasite pathobiology are somewhat of an ...
<10 QPX cells on the section), light (11-100), moderate (101-1000) and heavy (><1 mo after challenge. The first replicate (Challenge-1) reached that level after an additional month. An apparent disparity in mortality rates is displayed until the last few weeks of the trial when mortality in the first replicate increased and became comparable to the second batch (>