Oysters were collected from coastal locations in China from 1999-2006 for parasite analyses by molecular, culture, and histological techniques. Polymerase chain reaction-based assays targeting the internal transcribed spacer (ITS) region of the ribosomal RNA gene complex were performed to detect the presence of Perkinsus species. Sequencing and phylogenetic analysis of amplified Perkinsus sp. DNAs indicated that a novel Perkinsus sp. infects Crassostrea hongkongensis, Crassostrea ariakensis, and other bivalve hosts from Fujian to Guangxi provinces in southern China. Prevalence of this Perkinsus sp. reaches as high as 60% in affected oyster populations. Analyses of nucleotide sequences of the rRNA ITS region and of large subunit rRNA and actin genes, consistently confirmed the genus affiliation of this Perkinsus sp., but distinguished it from currently accepted Perkinsus species. Parasite cell types, such as signet ring trophozoites of 2-8 microm diameter, were observed by histology, and application of both genus Perkinsus and Perkinsus species-specific in situ hybridization probes consistently labelled the same Perkinsus sp. cells in histological sections from infected oyster tissues. Combined phylogenetic and histological results support the identity of a new parasite species, Perkinsus beihaiensis n. sp.

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The emergence of epizootic shell disease in the American lobster (Homarus americanus) has been devastating to the industry in the coastal waters of southern New England. A comprehensive assessment of the disease syndrome, known as the ''100 Lobsters'' Project, was initiated to examine health and physiological parameters among laboratories involved in the research on lobster shell disease. A histological study of the 100 lobsters was undertaken as part of that assessment. Tissues from 90 lobsters from Rhode Island and 19 lobsters from Maine were examined as a general health assessment of the 100 lobsters. Approximately half the lobsters from Rhode Island were selected because they had frank epizootic shell disease, whereas none of the lobsters from Maine exhibited the syndrome. In addition to epizootic shell disease, the histological findings revealed 3 other idiopathic syndromes-necrotizing hepatopancreatitis, idiopathic blindness, and nonspecific granulomas-in higher prevalences in lobsters from Rhode Island compared with those from Maine. Necrotizing hepatopancreatitis, a newly described disease syndrome in lobsters, was observed in 15% of the lobsters from Rhode Island. Idiopathic blindness was present in 54% of the lobsters from Rhode Island, and 16% of the animals from Maine. This is the first report of the syndrome in lobsters from Maine. None of the idiopathic syndromes was associated with epizootic shell disease. The detection of multiple disease syndromes such as epizootic shell disease, necrotizing hepatopancreatitis, and idiopathic blindness may be indicative of exposure to environmental stressors in Narragansett Bay, RI.

Epicaridean isopods are parasitic on other crustaceans. They represent a diverse group of highly derived taxa in two superfamilies and 10 families. Little work has been done on the phylogeny of these parasites because of the difficulty in defining homologous characters for adults above the genus level. The females exhibit morphological reduction of characters and the males have few distinguishing characters. Moreover, epicarideans have only rarely been included in past studies of isopod phylogeny. Our objective was to derive a phylogeny of epicaridean taxa based on 18S rDNA, then use that phylogeny to examine the relationships of the bopyrid subfamilies, bopyroid families and epicarideans to cymothoid isopods. We tested the monophyly of the Epicaridea, evaluated hypotheses on relationships among epicaridean families and subfamilies, examined the evolution of the abdominal mode of infestation on caridean, gebiidean, axiidean and anomuran hosts and examined coevolution between epicarideans and their crustacean hosts. The molecular phylogeny indicated that Epicaridea were monophyletic with respect to Cymothooidea. Bopyroidea formed a monophyletic group without Dajidae and Entophilinae (now as Entophilidae). Both latter taxa grouped with Cryptoniscoidea, and this group was the sister taxon to the redefined Bopyroidea in all trees. The bopyrid subfamily Ioninae is the sister taxon to the other bopyrid subfamilies (except Entophilidae). Ioninae was elevated to family status but found not to be monophyletic; a new subfamily, Keponinae, was erected for all genera formerly placed in Ioninae except the type genus. The abdominal mode of parasitism appears to have evolved independently among the subfamilies. Coevolution between host and parasite phylogenies showed extensive incongruence, indicating frequent host-switching as a general pattern in Epicaridea.http://www.zoobank.org/urn:lsid:zoobank.

Parasitic dinoflagellates in the genus Hematodinium infect a number of decapod crustaceans in waters off the UK, including the Norway lobster Nephrops norvegicus and the edible crab Cancer pagurus. This study investigated sequence variability in the first internal transcribed spacer (ITS1) region of the ribosomal RNA complex of Hematodinium spp. infecting N. norvegicus, C. pagurus, and Pagurus bernhardus from 4 locations in the UK and from the Hematodinium sp. infecting Chionoecetes opilio from the province of Newfoundland and Labrador, Canada. Phylogenetic analysis of the Hematodinium ITS1 sequences from N. norvegicus, C. pagurus, P. bernhardus and C. opilio suggest that these crustaceans are infected with the same species of Hematodinium. Length variability of the ITS1 region was observed (324 to 345 bp) and attributed to 4 variable microsatellite regions (CATG) n , (GCC) n TCCGC(TG) n , (TA) n , and (GAA) n (GGA) n within the sequenced ITS1 fragment. The observed variation may be due to co-infection of the host crustacean with several different strains of Hematodinium or differences among copies of ITS1 region within the genome of a single parasite cell. The Hematodinium ITS1 sequence from N. norvegicus, C. pagurus, P. bernhardus and C. opilio isolates was sufficiently conserved in primer binding regions targeted by previous molecular diagnostic assays; therefore, we suggest that this assay could be used to screen for Hematodinium infections in these crustacean hosts. KEY WORDS: Hematodinium · Conservation of ITS1 · Crustacean hosts · Parasite Resale or republication not permitted without written consent of the publisherDis Aquat Org 75: [251][252][253][254][255][256][257][258] 2007 In waters surrounding the UK Hematodinium-like infections have been reported in Nephrops norvegicus from the Clyde and Irish seas (Field et al. 1992, Briggs & McAliskey 2002 and in Cancer pagurus from the English Channel (Stentiford et al. 2002) and from the Atlantic Ocean (Anonymous 2004). Both N. norvegicus and C. pagurus support large and valuable fisheries in UK waters; however, it is unknown whether different species of Hematodinium parasites infect each of these different hosts or whether one species infects multiple hosts.PCR-based diagnostics to detect Hematodinium spp. have been developed for detecting infections in several host species (Hudson & Adlard 1994, Gruebl et al. 2002, Small et al. 2006, 2007. In the first 2 studies the primer binding regions were in the 18S and 5.8S ribosomal RNA genes and are almost certainly genus specific, not species specific, due to the conserved nature of these genes. Small et al. (2006) developed a potentially species-specific set of PCR primers to target the Hematodinium sp. infecting Nephrops norvegicus using the conserved 18S rRNA gene and variable first internal transcribed spacer region (ITS) of the rRNA gene complex. This PCR assay also detected infections in Cancer pagurus from the English Channel tentatively suggesting that this is either the same species or a closel...