Mark Edward Siddall

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In the last few years two factors have helped to significantly advance our understanding of the Myxozoa. First, the phenomenal increase in fin fish aquaculture in the 1990s has lead to the increased importance of these parasites; in turn this has lead to intensified research efforts, which have increased knowledge of the development, diagnosis. and(More)
The notion that members of the phylum Myxozoa Grassé, 1970 do not properly belong in classifications of protists has frequently been suggested because the infective spores of these parasites are not unicellular. Systematists have failed to be decisive about myxozoan phylogenetic affinities, either finding the suggestion of a cnidarian connection to be(More)
The European medicinal leech is one of vanishingly few animal species with direct application in modern medicine. In addition to the therapeutic potential held by many protease inhibitors purified from leech saliva, and notwithstanding the historical association with quackery, Hirudo medicinalis has been approved by the United States Food and Drug(More)
The phylogenetic affinities of the oyster pathogen Perkinsus marinus were investigated with morphology, 18S-like rDNA data and actin sequence data. Morphological investigations revealed that Perkinsus species do not have a conoid and that other criteria which have been used to place them in the Apicomplexa are general to alveolates. When considered(More)
The phylogenetic position of the Haplosporidia has confounded taxonomists for more than a century because of the unique morphology of these parasites. We collected DNA sequence data for small subunit (SSU) ribosomal RNA and actin genes from haplosporidians and other protists for conducting molecular phylogenetic analyses to help elucidate relationships of(More)
A remarkable diversity of life history strategies, geographic distributions, and morphological characters provide a rich substrate for investigating the evolutionary relationships of arhynchobdellid leeches. The phylogenetic relationships, using parsimony analysis, of the order Arhynchobdellida were investigated using nuclear 18S and 28S rDNA, mitochondrial(More)
The evolutionary patterns of divergence of seven euhirudinean families were investigated by cladistic analysis of 33 euhirudinean species. Oligochaetes, Acanthobdella peledina, and branchiobdellidans were included as outgroup taxa. Cladistic analysis employed 1.8 kb of nuclear 18S ribosomal DNA and 651 bp of mitochondrial cytochrome c oxidase subunit I in(More)
The phylogenetic relationships of taxa representative of blood parasitic adeleids were investigated in a cladistic analysis. Two phylogenetic analyses were performed. Monophyly of species of Haemogregarina (sensu lato) of some marine fishes with species of Haemogregarina (sensu stricto) was not supported in either analysis. A new genus, Desseria n.g., was(More)
We assess the phylogenetic position of Siboglinidae (previously known as the phyla Pogonophora and Vestimentifera, but now referred to Annelida) in parsimony analyses of 1100 bp from 18S rRNA, 320 bp from the D1 region of 28S rRNA, and 107 morphological characters, totaling 667 parsimony informative characters. The 34 terminal taxa, apart from six(More)
Medicinal leeches became infamous for their utility in bloodletting popularized in the 19th century, and have seen a recent resurgence in post-operative treatments for flap and replantation surgeries, and in terms of characterization of salivary anticoagulants. Notorious throughout the world, the quintessential leech family Hirudinidae has been taken for(More)