A new and emerging myxozoan parasite of fathead minnows: species description, life-cycle, and effects to the host

This thesis aims to characterize a new species of myxozoan, nominated Myxobolus rasmusseni n. sp., parasitizing Fathead Minnows in southern Alberta and to understand its effects on individual hosts. The results of my thesis are the first to document and image the host-parasite interface of M. rasmusseni n. sp.- infected minnows and to confirm the identity of both hosts: Fathead Minnow and Tubifex tubifex in its complete life cycle. Based upon the observations of distinctive lesions that are associated with the head of infected minnows, I used a combination of approaches to demonstrate that lesion-bearing minnows have reduced physiological performance and poorer survival than non-lesion bearing minnows. My experiments also demonstrate that M. rasmusseni n. sp. influences some host behaviours which raise questions regarding parasite-mediated transmission. Ultimately, my results suggest that the lesions caused by the development of Myxobolus rasmusseni n. sp. in Fathead Minnow are pathological and an emerging infectious disease that may negatively influence Albertan minnow populations.