The Sonora tlger salamander Ambystoma tignnuni stebb~nsi Lowe is a genetically d~stinct race restricted to about 30 small ponds in the San Rafael Valley 111 southern Arizona, USA, which was added recently to the USA Federal List of Endangered Species Populations of these salamanders periodically expenence decimating epizootics. Virus was ~solated from diseased salamanders using fish cell cultures, injected into healthy laboratory-reared salamanders, and then reisolated in cell culture. Electron microscopy of thin sections from dying salamanders revealed abundant enveloped and nonenveloped icosahedral virus particles approximately 160 to 180 nm in diameter in the cytoplasm of skin and liver cells and free in the intercellular spaces. This virus, believed to be an iridovirus based on viral morphology and host pathology, was demonstrated to be the primary pathogen in these epizootics, and is the first lethal epizootic virus reported from salamanders. We have named the virus Ambystoma tigrinum Virus (ATV). Hemolytic bacteria were isolated from sick individuals, but we were unable to induce the disease by exposing salamanders to isolated bacteria at concentrations up to 10' ml-' KEY WORDS: Salamander. Ambystoma tigrinum stebbinsi. Virus. Indovirus. Amphibian decline

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Hematodinium is a genus of parasitic dinoflagellates that infects crustaceans worldwide including Tanner crabs Chionoecetes bairdi and snow crabs C. opilio in the Northeast Pacific Ocean. The present study describes the optimization of a PCR-based assay for the detection and monitoring of Hematodinium sp. in snow and Tanner crabs. Two fragments, 1682 and 187 bp, were amplified from the 18S ribosomal DNA region of the parasite. The assay performed well in 6 additional decapod species (1 lobster and 5 crabs) infected with Hematodinium spp., suggesting that it could be used to detect Hematodinium spp. in other decapods. We also report Hematodinium spp. infections in the majid crab, Hyas coarctatus, and the lithodid crab, Lithodes couesi. Sequencing of 18S rDNA and the adjacent internal transcribed spacer 1 (ITS1) region of Hematodinium spp. isolated from 7 host species in the present study revealed the presence of 2 Hematodinium clades, one in the blue crab Callinectes sapidus and a second in all other host species. The ITS1 sequences of the 2 clades could not be aligned, but showed a conserved secondary structure that may be related to a functional diversification during a host switch. Comparison of our data with 18S and ITS1 sequence data available in GenBank placed the north Pacific Hematodinium sp. in a clade separate from the Hematodinium sp. infecting the portunoids, C. sapidus, Liocarcinus depurator and Scylla serrata, and within a second clade that infected all other decapod hosts located in the North Pacific and North Atlantic Oceans.KEY WORDS: ITS1 · Secondary structure · 18S rDNA · Parasite · PCR · Crustacean · Parasitic · Dinoflagellate · Disease Resale or republication not permitted without written consent of the publisher OPEN PEN ACCESS CCESSDis Aquat Org 89: [155][156][157][158][159][160][161][162][163][164][165][166] 2010 including Portunus pelagicus, Norway lobsters Nephrops norvegicus and blue crabs Callinectes sapidus (reviewed in Stentiford & Shields 2005, Small et al. 2006, 2007b. Despite the potential economic and ecological impact of Hematodinium-related mortality on affected populations, little is known about the method of infection, the life history of the parasite outside the host and the underlying causes for the recent worldwide increase in frequency of Hematodiniumassociated disease.Traditional techniques of disease detection involve macroscopic examination of pleopods that generally result in detection of only relatively advanced infections (Stentiford et al. 2001) or microscopic examination of hemolymph smears. More sensitive, immunological methods for Hematodinium detection (Field & Appleton 1996, Stentiford et al. 2001, Small et al. 2002 are of insufficient specificity or may not recognize life stages of Hematodinium absent in the original inoculum or in alternate hosts (Bushek et al. 2002, Small et al. 2006. Use of the PCR has become increasingly widespread in pathogen identification and disease detection and monitoring and is particularly useful in the diagnosis of c...

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Muscle samples from 178 Merluccitis productus were examined for two myxosporean parasites, Kudoa thyrsitis and K. patiiformis. Kudoa paniformis was found in 51% of the samples, while K. thyrsitis and mixed infections were observed in 7% and \7% of the samples respectively. An inflammatory response that resulted in an encapsulation around a completely replaced muscle fibre was observed in infections with either parasite. Presporogenic and sporogenic stages were common while stages that may represent early forms of the parasites were only rarely observed.

An apostome ciliate, Collinia oregonensis n. sp., is reported inhabiting the cephalothorax and abdomen of 3 euphausiid species from the Oregon-Washington coast: Euphausia pacifica Hansen, 1911, Thysanoessa spinifera Holmes, 1900, and Thysanoessa gregaria G.O. Sars, 1883. This ciliate is the 7th species described for the genus Collinia and the 2nd species known to infect euphausiids. Disease progression and ciliate morphology are described using (1) modified protargol stain, (2) hematoxylin counterstained with Fast Green, and (3) Scanning Electron Microscopy (SEM). All endoparasitic developmental stages (trophont, tomont, tomitogenesis, protomite, and tomite) of C. oregonensis are astomatous and possess between 14 and 22 kineties. C. oregonensis is smaller than C. beringensis Capriulo & Small, 1986, which infects the euphausiid Thysanoessa inermis Krøyer, 1846 in the Bering Sea and which possesses between 24 and 80 kineties. The ciliate is a parasitoid because it must kill the host to complete its life cycle. Infections and mortalities in multiple host species likely reflect the virulent nature of the ciliate. Adult euphausiids infected with this parasitoid possess a swollen and bright orange cephalothorax. C. oregonensis feeds and proliferates inside euphausiids, producing fulminating infections that rupture the cephalothorax and release large numbers of tomites into the surrounding water. After several hours in the free swimming stage under shipboard conditions in the present study, the tomites adhered to each other, forming filaments. Infection rates ranged between 3 and 20% within individual euphausiid aggregations, but infected aggregations were randomly and sparingly distributed. Infected euphausiids were found at 6.7% of 316 stations sampled during 3 summer cruises. No infected euphausiids were collected in winter. Because E. pacifica and T. spinifera account for about 90% of the euphausiid standing stock in the northern California Current System, this parasitoid ciliate may have a significant impact on euphausiid population abundance, distribution and secondary productivity.KEY WORDS: Euphausiids · Apostomatidae · Ciliates · Endoparasitoid · Colliniidae · Collinia · Oregon coast Resale or republication not permitted without written consent of the publisherDis Aquat Org 71: [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49] 2006 Gómez- and Gómez-Gutiérrez (2003, 2004 reported on an undescribed parasitoid ciliate of the genus Collinia responsible for a mass mortality of the euphausiid Euphausia pacifica Hansen, 1911 in Astoria Canyon, Oregon, USA. A parasitoid is an organism that must kill the host to complete its life history, sensu Lafferty & Kuris (2002) and although the term is most frequently applied to an arthropod that infects another arthropod, a parasitoid may be any eukaryote meeting the above criterion. The present ciliate also infects 2 other euphausiid species along the Oregon-Washington coast: Thysanoessa spinifera Holmes, 1900 and Thysanoessa gregaria G.O. Sar...

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