Evaluation of Three Northern Quahog (=Hard Clam)Mercenaria mercenaria(Linnaeus) Strains Grown in Massachusetts and New Jersey for QPX-Resistance

Differential Gene Expression in Five Isolates of the Clam Pathogen, Quahog Parasite Unknown (QPX)

“…It is important to note that QPX disease is endemic in MA and has been regularly causing severe mortality events in clams since the 1990s (Kraeuter et al. ; Smolowitz et al. ).…”

The ecology, evolution, impacts and management of host–parasite interactions of marine molluscs

“…The parasite, a fungus-like protest of the Phylum Labyrinthulomycota, causes an inflammatory response by the animal's hemocytes. It has been observed in both cultivated and wild clam populations in Canada (Prince Edward Island) since the 1950s and from the eastern U.S. coast in Massachusetts to North Carolina (e.g., Smolowitz et al, 1998;Ragone Calvo et al, 1998;Kraeuter et al, 2011). In a reciprocal transplant experiment, Ragone Calvo et al (2007) found that cultivated populations of hard clams, Mercenaria mercenaria originating from non-local (more southern, Florida, U.S.A.) sources appeared to be more susceptible to Quahog Parasite Unknown (QPX), than clams from local sources.…”

“…At local and regional scales, 'farmers' often move molluscs between hatcheries and grow-out facilities, and within and among water bodies at different stages of their reproductive and developmental cycle in order to take advantage of optimal environmental conditions for growth and survival (e.g., Smolowitz et al, 1998;Ragone Calvo et al, 1998;Nell, 2001;Cranfield et al, 2005;Kraeuter et al, 2011;Herbert et al, 2012).…”

“…In response to this perceived disease issue, increased biosecurity measures have been put in place to reduce the translocation of disease, and aquaculture production has increasingly shifted to cultivation of animals selectively bred for disease resistance or non-native species that are less susceptible to native parasites (e.g., Littlewood et al, 1992;Culloty et al, 2004;Encomio et al, 2005;Harding, 2007;Elston and Ford, 2011;Kraeuter et al, 2011;. As selectively bred and non-native molluscs have been increasingly adopted by aquaculture industries, there has also been interest in applying them to restoration projects (e.g., Allen et al, 2003;Arnold et al, 2005;Crane et al, 2013).…”

“…Selective breeding programs have been widely applied to oyster aquaculture industries to produce lines that are resistant to diseases caused by protozoan parasites (e.g., Littlewood et al, 1992;Culloty et al, 2004;Elston and Ford, 2011;Kraeuter et al, 2011). These programs typically use a mass selection approach, where multiple generations of animals are exposed to epizootics and the survivors are successively mated with one another.…”