LE3 .A278 2012

2012

Smith, Todd

Acadia University

Master of Science

Masters

Biology

Biology

Hepatozoon species are heteroxenous parasites that commonly infect blood of vertebrates and various organs of arthropods. Despite their ubiquity, virtually nothing is known about how these parasites affect host phenotype, including whether or not these parasites induce changes in hosts to increase transmission success. The objectives of this research were to investigate influences of frog blood parasites Hepatozoon clamatae and snake blood parasites Hepatozoon sipedon on host-seeking and host-choice behaviour of the mosquitoes Culex territans and Culex pipiens, respectively, and to determine changes in fecundity in gonotrophic cycles of C. pipiens infected with H. sipedon. During development of H. sipedon, the number of infected C. pipiens that fed on snakes was significantly lower than uninfected mosquitoes. When H. sipedon was mature, the number of infected and uninfected C. pipiens that fed on snakes was not significantly different. Higher numbers of mosquitoes fed on naturally infected snakes and frogs compared to laboratory–reared, uninfected control animals. However, paired-choice experiments using laboratory-raised frogs revealed that infection did not significantly affect mosquito choice. Fecundity of mosquitoes infected with H. sipedon compared (mean = 26) to uninfected mosquitoes (mean = 88) was significantly reduced in only the second gonotrophic cycle, by as much as 100% in high infections. Oocyst burden was negatively correlated with egg number, suggesting that growing parasites compete for nutrients with mosquitoes or impede production of egg proteins by the fat body.

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https://scholar.acadiau.ca/islandora/object/theses:235