PTEROBDELLA OCCIDENTALIS N. SP. (HIRUDINIDA: PISCICOLIDAE) FOR P. ABDITOVESICULATA (MOORE, 1952) FROM THE LONGJAW MUDSUCKER, GILLICHTHYS MIRABILIS, AND STAGHORN SCULPIN, LEPTOCOTTUS ARMATUS, AND OTHER FISHES IN THE EASTERN PACIFIC.

Pterobdella occidentalis n. sp. (Hirudinida: Piscicolidae) is described from the longjaw mudsucker, Gillichthys mirabilis Cooper, 1864, and the staghorn sculpin, Leptocottus armatus Girard, 1854, in the eastern Pacific, and the diagnosis of Pterobdella abditovesiculata (Moore, 1952) from the 'o'opu 'akupa, Eleotris sandwicensis Vaillant and Sauvage, 1875, from Hawaii is amended.

A rapid phenotype change in the pathogen Perkinsus marinus was associated with a historically significant marine disease emergence in the eastern oyster.

The protozoan parasite Perkinsus marinus, which causes dermo disease in Crassostrea virginica, is one of the most ecologically important and economically destructive marine pathogens. The rapid and persistent intensification of dermo in the USA in the 1980s has long been enigmatic. Attributed originally to the effects of multi-year drought, climatic factors fail to fully explain the geographic extent of dermo's intensification or the persistence of its intensified activity.

Phylogenetics of Bonamia parasites based on small subunit and internal transcribed spacer region ribosomal DNA sequence data.

The genus Bonamia (Haplosporidia) includes economically significant oyster parasites. Described species were thought to have fairly circumscribed host and geographic ranges: B. ostreae infecting Ostrea edulis in Europe and North America, B.

The haplosporidian Bonamia exitiosa is present in Australia, but the identity of the parasite described as Bonamia (formerly Mikrocytos) roughleyi is uncertain.

Protistan oyster parasites in the genus Bonamia have been observed in recent years infecting new hosts on five continents, with most of these parasites genetically similar to austral species Bonamia exitiosa and Bonamia roughleyi. Identification of the newly observed parasites as one or another of these described species has been complicated by the fact that B. exitiosa and B.

A new species of marine leech (Hirudinida: Piscicolidae) from giant kelpfish, Heterostichus rostratus Girard, in southern California.

Collections of giant kelpfish at inner Cabrillo Beach, San Pedro, California revealed the presence of an undescribed species of Heptacyclus, described here as Heptacyclus cabrilloi n. sp. The leech is small, only up to 14 mm total length including suckers; it has 2 pair of slightly crescentiform eyes on the oral sucker, 1 pair of punctiform ocelli on the second annulus of the trachelosome, 13 pairs of punctiform ocelli dorsally and ventrally on the urosome, and 14 marginal punctiform ocelli on the caudal sucker.

A new species of Mysidobdella (Hirudinida: Piscicolidae) from mysids along the California coast.

Mysidobdella californiensis n. sp. is described from the mysid Holmesimysis sculpta from Bodega Bay on the central California coast and from Holmesimysis costata var.

Observation of a Bonamia sp. infecting the oyster Ostrea stentina in Tunisia, and a consideration of its phylogenetic affinities.

The small non-commercial oyster Ostrea stentina co-occurs with commercially important Ostrea edulis in the Mediterranean Sea, yet its disposition with respect to the destructive pathogens Bonamia ostreae and Marteilia refringens is unknown. We began an evaluation of the Bonamia spp. infection status of O.

Minchinia mercenariae n. sp. (Haplosporidia) in the hard clam Mercenaria mercenaria: implications of a rare parasite in a commercially important host.

During routine histopathology of 180 juvenile hard clams, Mercenaria mercenaria, from a site in Virginia, USA, in 2007, we discovered a single individual heavily infected with a parasite resembling a haplosporidian, some members of which cause lethal bivalve diseases. Scanning electron microscopy of spores and sequencing of small subunit ribosomal DNA confirmed a new species: Minchinia mercenariae n. sp.

Molecular epizootiology of Perkinsus marinus and P. chesapeaki infections among wild oysters and clams in Chesapeake Bay, USA.

Perkinsus marinus and P. chesapeaki host ranges among wild Chesapeake Bay, USA, region bivalves were examined by surveying Crassostrea virginica oysters and members of several sympatric clam species from 11 locations. Perkinsus genus- and species-specific PCR assays were performed on DNA samples from 731 molluscs, and species-specific in situ hybridization assays were performed on a selected subset of histological samples whose PCR results indicated dual or atypical Perkinsus sp.

Misuse of PCR assay for diagnosis of mollusc protistan infections.

Polymerase chain reaction (PCR) assays are useful tools for pathogen surveillance, but they are only proxy indications of pathogen presence in that they detect a DNA sequence. To be useful for detection of actual infections, PCR assays must be thoroughly tested for sensitivity and specificity, and ultimately validated against a technique, typically histology, which allows visualization of the parasite in host tissues. There is growing use of PCR assays for pathogen surveillance, but too often the assumption is made that a positive PCR result verifies an infection in a tested host.

Interacting effects of temperature and salinity on Bonamia sp. parasitism in the Asian oyster Crassostrea ariakensis.

The proposition to introduce the Asian oyster Crassostrea ariakensis to the mid-Atlantic region of the USA is being considered with caution, particularly after the discovery of a novel microcell haplosporidian parasite, Bonamia sp., in North Carolina. Although this parasite was found to be pathogenic in C.

Strong seasonality of Bonamia sp. infection and induced Crassostrea ariakensis mortality in Bogue and Masonboro Sounds, North Carolina, USA.

Asian oyster Crassostrea ariakensis is being considered for introduction to Atlantic coastal waters of the USA. Successful aquaculture of this species will depend partly on mitigating impacts by Bonamia sp., a parasite that has caused high C.

Hemoflagellates of Oregon marine fishes with the description of new species of Trypanosoma and Trypanoplasma.

Of 2,122 marine fishes representing 36 species collected in the northeastern Pacific Ocean in the vicinity of Newport, Oregon from 1971 to 1973, 541 individuals (25.5%) representing 8 species (22.2%) were infected with hemoflagellates.

Multiplication of Trypanosoma pacifica (Euglenozoa: Kinetoplastea) in English sole, Parophrys vetulus, from Oregon coastal waters.

Multiplication of Trypanosoma pacifica was common in the fish host from observations of live flagellates and Giemsa-stained blood smears. Multiplication began with the elongation of the kinetoplast, thickening of the posterior portion of the body, and appearance of a new flagellum near the kinetoplast. The new flagellum was very rigid when less than 3 microm in length, but it became flexible as it elongated.

A collection of fish leeches (Hirudinida: Piscicolidae) from Japan and surrounding waters, including redescriptions of three species.

Leeches were observed incidentally on fishes in collections made from 1975 to 2006 in Japan and surrounding waters, or from mariculture facilities or public aquaria in Japan. Seven species of leeches in 7 genera were collected--Crangonobdella maculosa, Johanssonia arctica, Limnotrachelobdella okae, Platybdella olriki, Stibarobdella bimaculata, Taimenobdella amurensis, and Trachelobdella livanovi. The transfer of Calliobdella livanovi to Trachelobdella is supported, and Trachelobdella livanovi and Taimenobdella amurensis are redescribed based on new specimens.

Experimental cross-infections by Perkinsus marinus and P. chesapeaki in three sympatric species of Chesapeake Bay oysters and clams.

In controlled laboratory transmission experiments, uniform doses of axenic in vitro isolate cultures of Perkinsus marinus from a Crassostrea virginica oyster, and of independent P. chesapeaki isolates from Chesapeake Bay Mya arenaria and Macoma balthica clams, were used to reciprocally challenge Perkinsus sp.-free C.

Two new species of Austrobdella (Hirudinida: Piscicolidae) from Chile.

Austrobdella coliumicus n. sp. is described from Coliumo Bay, Chile.

Spore ornamentation of Haplosporidium nelsoni and Haplosporidium costale (Haplosporidia), and incongruence of molecular phylogeny and spore ornamentation in the Haplosporidia.

Spore ornamentation of Haplosporidium nelsoni and Haplosporidium costale was determined by scanning electron microscopy. For H. nelsoni, the spore surface was covered with individual ribbons that were tightly bound together and occurred as a single sheet.

A redescription of the fish leech Pterobdella amara (= Rhopalobdella japonica) (Hirudinida: Piscicolidae) based on specimens from the type locality in India and from Australia.

Pterobdella amara is redescribed from specimens from the type locality in India, and from the type host in Queensland, Australia. A neotype is designated from the type locality. The presence of conspicuous finlike bodies along the lateral margins of P.

Bonamia perspora n. sp. (Haplosporidia), a parasite of the oyster Ostreola equestris, is the first Bonamia species known to produce spores.

Examination of the oyster Ostreola equestris as a potential reservoir host for a species of Bonamia discovered in Crassostrea ariakensis in North Carolina (NC), USA, revealed a second novel Bonamia sp. Histopathology, electron microscopy, and molecular phylogenetic analysis support the designation of a new parasite species, Bonamia perspora n. sp.

A new species of Malmiana (Oligochaeta: Hirudinida: Piscicolidae) from tidepool fishes in northern California.

Malmiana buthi n. sp. is described from the body and fins of the fluffy sculpin, Oligocottus snyderi, the tidepool sculpin, Oligocottus maculosus, and the woolly sculpin, Clinocottus analis, collected from tidepools at Horseshoe Cove on the Bodega Marine Reserve in Sonoma County, California.

Ultrastructural and molecular characterization of Haplosporidium montforti n. sp., parasite of the European abalone Haliotis tuberculata.

A new member of the parasitic phylum Haplosporidia, which was found infecting the connective tissue, gill, digestive gland, and foot muscle of Haliotis tuberculata imported from Ireland and experimentally grown in Galicia (NW Spain), is described. Scanning electron microscopy, transmission electron microscopy, and molecular characterization of the small subunit ribosomal RNA (SSU rRNA) gene were carried out to confirm the description of this species. The ultrastructural morphology of the spores and their surrounding ornaments attached to the spore wall was described from light, scanning, and transmission electron microscopy observations.

Molecular, morphological, and experimental evidence support the synonymy of Perkinsus chesapeaki and Perkinsus andrewsi.

Diverse analytical and experimental results confirm that two protistan parasites, Perkinsus chesapeaki and Perkinsus andrewsi, described separately as parasites of Mya arenaria and Macoma balthica clams sympatric in Chesapeake Bay, USA, represent a single species. Ribosomal RNA (rRNA) internal transcribed spacer (ITS) regions, rRNA large subunit (LSU) gene, and actin gene sequences were obtained from clonal Perkinsus spp. cultured in vitro.

Herpes virus in juvenile Pacific oysters Crassostrea gigas from Tomales Bay, California, coincides with summer mortality episodes.

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 annual losses of oysters have occurred each summer since 1993, were infected with a herpes-like virus in 2002.

Molecular phylogeny of the Haplosporidia based on two independent gene sequences.

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 taxa within the group, as well as placement of this group among Eukaryota. Analyses were conducted using DNA sequence data from more than 100 eukaryotic taxa with various combinations of data sets including nucleotide sequence data for each gene separately and combined, as well as SSU ribosomal DNA data combined with translated actin amino acids.