Taxonomy and Systematics of Fish Blood Flukes (Digenea: Schistosomatoidea) using Morphology, Phylogenetics, and Life History

Abstract

The monophyletic fish blood flukes (Platyhelminthes: Digenea: Schistosomatoidea Stiles, 1898) comprise ~186 species of 46 genera infecting freshwater, marine, and estuarine fishes. They are occasional pathogens of cultured fishes and are ancestral to the turtle blood flukes and the human-pathogenic blood flukes (Schistosomatidae Stiles and Hassal, 1898). The life cycles of aporocotylids include a mollusk or polychaete intermediate host (wherein the parasite undergoes clonal asexual reproduction) and a fish definitive host (wherein the parasite matures). Blood flukes described in this dissertation were collected from 410 fish assigned to nine genera in nine families. I use alpha taxonomy, scanning electron microscopy (SEM), genetic sequence techniques (PCR; large subunit ribosomal DNA [28S], and internal transcribed spacer 2 [ITS2]), and molecular phylogenetic analysis (Bayesian inference) to characterize two new families, four new genera, and five new species as well as revise two genera. I describe Cardicola uterohamus n. sp. from the heart of the yellowedge grouper, Hyporthodus flavolimbatus, Aetohemecus kirstenjensenae n. gen., n. sp. and Homestios janinecairae n. gen., n. sp. from the heart of the banded eagle ray, Aetomylaeus nichofii, Sanguinicola plehnae n. sp. from the heart of the Northern pike, Esox lucius, Pseudosanguinicola occidentalis n. gen., n. comb. from the heart of the walleye, Sander vitreus, and a new genus and new species from the heart of the white mullet, Mugil curema as well as provide supplemental descriptions for Cardicola cardiocola Manter, 1954, Nomasanguinicola dentata Paperna, 1964, and Sanguinicola volgensis (Rašín, 1929) Mcintosh, 1934. I revise and diagnose the fish blood fluke families: Chimaerohemecidae Yamaguti, 1971, Acipensericolidae n. fam., Elopicolidae n. fam., Sanguinicolidae Poche, 1926, and Aporocotylidae Odhner, 1912. This work culminates in the revision of all families of fish blood flukes as well as several genera, the first report of a chimaerohemecid host infected with more than one species of blood fluke, and the first blood fluke infecting mullet from North America. Further, I provide the first genetic sequences from species of Sanguinicolidae and the first genetic sequence from an adult sanguinicolid from Africa. Further, I include 12 nucleotide sequences belonging to nominal and innominate chimaerohemecids and aporocotylids. This work has resulted in publications in Journal of Parasitology and International Journal for Parasitology: Parasites and Wildlife.