Date of Award
Master of Science (MS) in Biology
"The purpose of this study is to determine biological parameters of salmon lice (Lepeophtheirus salmonis) as they parasitize different species of Pacific Ocean salmonids off the north Pacific coast of Washington State. Parasite load counts of L. salmonis were made and individuals were collected from salmonids in their natural environment. Louse morphology and fecundity were examined using microscopy. Parasite loads were equal between different species of salmonids (p = 0.231). Lice that infected chinook salmon (n= 48) were smaller in total body length (p < 0.001), cephalothorax length (p < 0.001), and cephalothorax width (p < 0.001) when compared to lice that infected coho salmon (n = 44) or pink salmon (n=45). Lice that infected coho and pink salmon were not statistically different in body length (p = 0.213), cephalothorax length (p = 0.996), or cephalothorax width (p = 0.149). Also, L. salmonis produced fewer eggs when infecting chinook salmon (n = 24) than when infecting coho salmon (p < 0.001) or pink salmon (p < 0.001). Whereas, lice that infected coho salmon (n = 41) or pink salmon (n = 22) produced similar number of eggs (p = 0.60). These results indicate that there are factors associated with infecting chinook salmon hosts that reduce the size and fecundity of salmon lice"--Document.
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Flanagan, Stephen, "Lepeophtheirus salmonis, parasitizing three species of pacific salmon (Oncorhynchus spp.): host variations in load, morphology, fecundity, and genetics of the salmon louse" (2012). EWU Masters Thesis Collection. Paper 76.