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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)
To investigate the phylogenetic relationships of leeches, branchiobdellidans, and acanthobdellidans, whole nuclear 18S rDNA and over 650 bp of mitochondrial cytochrome c oxidase subunit I were acquired from 101 annelids, including 36 leeches, 18 branchiobdellidans, Acanthobdella peledina, as well as 28 oligochaetes and combined with homologous data for 17(More)
In July 1996, the Virginia Institute of Marine Science initiated a sampling program to examine wild and cultured hard clams Mercenaria mercenaria for QPX, Quahog Parasite Unknown, a protistan parasite associated with severe mortalities of hard clams in localized areas in maritime Canada and Massachusetts, USA. The sampling program set out to seasonally(More)
Perkinsus species presently are classified within the phylum Apicomplexa. This placement, however, is controversial. Based upon morphological observations and phylogenetic analyses of the small subunit ribosomal RNA gene, it has been suggested that Perkinsus may be more closely related to dinoflagellates. To reevaluate the phylogenetic position of(More)
The phylogenetic relationships of leeches were investigated for the first time using molecular data. Twenty-one species were examined representing 7 of the 10 conventionally recognized euhirudinean families. In addition, Acanthobdella peledina, a branchiobdellid, four oligochaetes, and two polychaetes were included. Cladistic analysis of the mitochondrial(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)
Two cases of haplosporidian infection occurred during 1993 in Pacific oysters Crassostrea gigas from the French Atlantic coast. The localization and ultrastructure of the plasmodia are described. In situ hybridization of infected tissue sections was conducted with DNA probes for oyster-infecting haplosporidians. The Haplosporidium nelsoni-specific DNA probe(More)
Pacific Crassostrea gigas and eastern C. virginica oysters were examined between June 2002 and April 2003 from 8 locations along the east, west and south USA coasts for oyster herpes virus (OsHV) infections using the A primer set in a previously developed PCR test. Only surviving Pacific oysters from a mortality event in Tomales Bay, California, USA, where(More)
The transmission of Perkinsus marinus in eastern oysters Crassostrea virginica in relation to water temperature, host oyster mortality, and water-column abundance of anti-P. marinus antibody-labeled cells was systematically examined for 20 mo at a site in the lower York River, Virginia, USA. Uninfected sentinel oysters were naturally exposed to the parasite(More)