Date of Award

January 2015

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Biology

First Advisor

Vasyl Tkach

Abstract

Very little is known about the diversity, distribution, and host associations of avian helminths in southern Amazonia. The majority of avian species, families and even orders in the region have not been examined for parasitic worms so far. At the same time, the expected helminth diversity is high, given that Amazonian birds are extremely diverse and their fauna is characterized by a high level of endemism. In this work, we studied helminth fauna of birds from the westernmost region of endemism, Inambari and from the easternmost region, Belém. Two hundred and thirty-four birds belonging to 9 orders were examined for endoparasites in Inambari in November, 2013 and 199 birds belonging to 15 orders were examined in Belém in July, 2013. Birds were examined and parasites were fixed following standard endoparasite collecting protocols. Specimens were processed in the laboratory for morphological and molecular analyses. Morphology was studied on total permanent (cestodes, digeneans) or temporary (nematodes, acanthocephalans) mounts. When necessary, DNA sequences of nuclear ribosomal and mitochondrial genes were obtained to aid in species differentiation and/or phylogenetic analysis. In Inambari, 68 birds (29%) were infected with helminths. Cestodes were the most prevalent group of parasites. They were found in 42 birds (18%), followed by digeneans (23; 10%), nematodes (12; 5%) and acanthocephalans (2; 1%). In Belém, 51 birds (26%) were infected with helminths. Prevalence of infection with nematodes (28 birds; 14%) was nearly equal to that of cestodes (26; 13%), followed by digeneans (7; 4%) and acanthocephalans (6; 3%). The prevalence of infection with digeneans in Inambari was more than twice higher than in Belém which can be explained by the close proximity of Inambari collecting sites to water bodies. Taxonomic diversity and distribution of helminths among systematic and ecological groups of birds are discussed. Our study revealed several new species belonging to the families Brachylaimidae, Diplostomidae, Renschtrematidae and a likely new genus of the Schistosomatidae. Among other notable discoveries, Mesocestoides tethrathiridia have been found for the first time in South American birds. DNA sequences obtained in our study have been incorporated into broader phylogenetic analyses of corresponding groups. The resulting phylogenies are discussed.

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