Taxonomy of myxobolid parasites of fishes

点击翻译按钮获取中文摘要

The proposed reseach examines the taxonomy and life history of species of Myxobolus (Myxozoa) parasitic in tissues of freshwater and some marine fishes of North America. This group of parasites (currently having 118 nominal species) is one of the most speciose lineages parasitic in fishes yet one of the poorest understood. It is argued that our understanding of the nature of the rich communities formed by these parasites cannot be achieved until a sound system of taxonomy is available, and one useable by non-specialists. The research will undertake taxonomic revisions of numerous species described earlier in the last century, through reexamination of material collected from type hosts and other fishes. It will also conduct extensive searches in other fishes for species of parasites needing formal description and documentation. An important aspect of the program is the exposure of undergraduate and graduate students to zoological nomenclature and morphologically and molecularly (18S rDNA) based taxonomy. One graduate student will examine the hypothesis that we have underestimated myxobolid diversity - this will be tested through a revision of Thelohanellus notatus from different cyprinid host species (Is there a single species or separate cryptic species cycling independently through the various host species?). A second graduate student will examine the taxonomy and life history of assemblages of species of Myxobolus parasitizing populations Fundulus diaphanus and Fundulus heteroclitus in their respective freshwater and marine habitats, as well as with hybrids of the two species in replicate coastal sites in Nova Scotia. This work will involve a blend of designed field studies, experimental transmissions, and rigorous morphological and molecular assessments of species status in the three host groups. A long term goal is to produce an ecologically-based atlas of myxobolid parasites of fishes of North America