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A survey of the parasite fauna of freshwater fishes from the Wet Tropics Bioregion in Queensland, Australia, revealed the presence of a new species of Stemmatostoma Cribb, 1986 (Digenea: Cryptogonimidae). Stemmatostoma cribbi n. sp. is described from the intestine and pyloric caeca of 2 species of grunter (Terapontidae), Hephaestus fuliginosus (Macleay) and Hephaestus tulliensis (De Vis), and the Jungle perch (Kuhliidae), Kuhlia rupestris (Lacepède), collected from the Barron and Mulgrave-Russell River drainage divisions in tropical north Queensland, Australia. Stemmatostoma cribbi is primarily distinguished morphologically from the type and only other species in the genus, Stemmatostoma pearsoni Cribb, 1986, in having consistently fewer oral spines (14 in S. cribbi vs. 16 in S. pearsoni). Alignment of novel molecular data for S. cribbi and S. pearsoni revealed that they differ genetically by 26 nucleotides (2.1%) over the 1,258 bp partial large subunit (LSU) region, 1 nucleotide (0.8%) over the 121 bp partial 5.8S region, and 23 nucleotides (7.2%) over the entire 318 bp ITS2 rDNA region. Bayesian inference and maximum likelihood phylogenetic analyses of the partial LSU region for the species of Stemmatostoma sequenced here were used to explore the relationships of these species to other cryptogonimid species reported from freshwater ecosystems., (© American Society of Parasitologists 2020.)

Two new species of myxosporeans are described from the gallbladders of estuarine stonefish, Synanceia horrida, and reef stonefish, Synanceia verrucosa, from localities off Cairns, in tropical north Queensland and in Moreton Bay in southern Queensland, Australia. Sphaeromyxa horrida n. sp. can be distinguished from congeners in the morphologically distinct "balbianii" species group within Sphaeromyxa on the basis of morphometric differences in length and width of mature spores, length and width of polar capsules, and unique small-subunit (SSU) ribosomal (rDNA) sequence composition relative to other taxa. Replicate SSU rDNA sequences generated from Sph. horrida n. sp. collected from Sy. horrida and Sy. verrucosa in tropical north Queensland and from Sy. horrida in Moreton Bay were identical, suggesting that this species is widely distributed along the east coast of Australia. Myxidium lapipiscis n. sp. can be distinguished from the majority of described Myxidium species on the basis of its relatively small mature spore size (6.1-7.9 μm long × 3.1-3.9 μm wide), and its unique SSU rDNA sequence. Specimens putatively identified as M. lapipiscis n. sp. were found in Sy. horrida from both tropical north Queensland and Moreton Bay, suggesting that this taxon is also widely distributed along the east coast of Australia. However, no molecular data were available for the specimens from tropical north Queensland for comparative genetic analyses. Bayesian inference and maximum likelihood analysis of the SSU rDNA sequences for these 2 new species revealed that Sph. horrida n. sp. formed a strongly supported clade with Sphaeromyxa zaharoni Diamant, Whipps, and Kent, 2004, which was described from the scorpaeniform, Pterois miles, from the Red Sea. This is the first report of myxozoans infecting stonefish (Synanceiidae).

The acanthocephalan fauna of Australian freshwater fishes was documented from field surveys, a literature survey and examination of specimens registered in Australian museums. From the 4030 fishes, representing 78 of the 354 Australian freshwater fish species (22%), examined for infection seven species of acanthocephalan were recovered. These species comprised five endemic species, three in endemic genera, two species in cosmopolitan genera, one species not fully identified and 1 putative exotic species recovered from eight species of fish. Of these Edmonsacanthus blairi from Melanotaenia splendida, was the only acanthocephalan found at a relatively high prevalence of 38·6%. These findings are indicative of a highly endemic and possibly depauperate acanthocephalan fauna. Species richness was higher in the tropical regions than the temperate regions of the country. Exotic acanthocephalan species have either not been introduced with their exotic hosts or have been unable to establish their life cycles in Australian conditions. Consequently, acanthocephalans have not yet invaded endemic Australian fish hosts.

Linking morphological studies with molecular phylogeny is important to understanding cryptic speciation and the evolution of host-parasite relationships. Haemosporidian parasites of the Australo-Papuan bird family Artamidae are relatively unstudied. Only one parasite species from the subfamily Cracticinae has been described, and this was based solely on morphological description. This is despite many Cracticinae species being easily observed and abundant over large ranges and in close proximity to human populations. We used morphological and molecular methods to describe a new Haemoproteus species (H. bukaka sp. nov.) from an endemic Butcherbird host (Cracticus louisiadensis) in a relatively unstudied insular area of high avian endemism (Papua New Guinea's Louisiade Archipelago). Phylogenetic reconstructions using parasite cyt-b gene sequences placed the proposed Haemoproteus bukaka sp. nov. close to other host-specialist Haemoproteus species that infect meliphagid honeyeater hosts in the region, e.g. H. ptilotis. Distinct morphological characters of this haemosporidian include macrogametocytes with characteristic large vacuoles opposing a subterminal nucleus on the host cell envelope. Among 27 sampled individuals, prevalence of H. bukaka sp.nov. was high (74 % infection rate) but strongly variable across four islands in the archipelago (ranging from 0 to 100 % prevalence). Parasitaemia levels were low across all infected individuals (0.1-0.6 %). We suspect host density may play a role in maintaining high prevalence given the close proximity and similar physical environments across islands. The findings are discussed in the context of the host genus Cracticus and theory relating to parasite-host evolution and its conservation implications in Papua New Guinea.

Avian Haemoproteus (Haemosporida) parasites occur in birds on all continents apart from Antarctica. Molecular screening techniques have uncovered previously unforeseen levels of Haemoproteus lineage diversity; however, fewer than 20% of genetic parasite lineages have been linked to morphological descriptions. The process of linking morphological descriptions to DNA barcodes for Haemoproteus spp. is important for the study of host-parasite interactions and the potential for cryptic speciation. Here, we describe cytochrome-b barcodes and morphological diagnostics for the identification of Haemoproteus (Parahaemoproteus) ptilotis, a systematically confusing parasite found in Australian honeyeaters (family Meliphagidae). We characterised infections from the original type host (Lichenostomus chrysops; Family Meliphagidae) as well as from four co-occurring meliphagid species in southeast Queensland, Australia, to investigate intraspecific variation in morphology and lineage identity. We recorded eight lineages that grouped into a well-supported monophyletic group, supporting the linkage of the described lineages to H. ptilotis. However, comparisons of diagnostics between the type host and co-occurring meliphagid hosts revealed high genetic diversity and variable morphology that could be indicative of cryptic speciation. This study highlights that morphological descriptions alongside molecular characterisation remain crucial if we are to gain an understanding of the true diversity and host specificity of protozoan parasites in Australia and elsewhere.

Marteilia sydneyi (Phylum Paramyxea, Class Marteiliidea, Order Marteiliida) (the causative agent of QX disease) is recognised as the most severe parasite to infect Saccostrea glomerata, the Sydney rock oyster, on the east coast of Australia. Despite its potential impact on industry (>95% mortality), research towards lessening these effects has been hindered by the lack of an experimental laboratory model of infection as a consequence of our incomplete understanding of the life cycle of this parasite. Here, we explored the presence of this parasite in hosts other than a bivalve mollusc from two study sites on the Hawkesbury River, New South Wales, Australia. We employed PCR-based in situ hybridisation and sequence analysis of a portion of the first internal transcribed spacer of rDNA in an attempt to detect M. sydneyi DNA in 21 species of polychaete worm. Marteilia DNA was detected in 6% of 1247 samples examined by PCR; the analysis of all amplicons defined one distinct sequence type for first internal transcribed spacer, representing M. sydneyi. Of the polychaete operational taxonomic units test-positive in PCR, we examined 116 samples via in situ hybridisation DNA probe staining and identified M. sydneyi DNA in the epithelium of the intestine of two specimens of Nephtys australiensis. Two differing morphological forms were identified: a 'primordial' cell that contained a well-defined nucleus but had little differentiation in the cytoplasm, and a 'plasmodial' cell that showed an apparent syncytial structure. This finding represents the first known record of the identification of M. sydneyi being parasitic in an organism other than an oyster, and only the third record of any species of Marteilia identified from non-molluscan hosts. Future work aims at determining if N. australiensis and S. glomerata are the only hosts in the life cycle of this paramyxean, and the development of experimental models to aid the production of QX disease-resistant oysters., (Copyright © 2015 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.)

Aquatic wildlife is increasingly subjected to emerging diseases often due to perturbations of the existing dynamic balance between hosts and their parasites. Accelerating changes in environmental factors, together with anthropogenic translocation of hosts and parasites, act synergistically to produce hard-to-predict disease outcomes in freshwater and marine systems. These outcomes are further complicated by the intimate links between diseases in wildlife and diseases in humans and domestic animals. Here, we explore the interactions of parasites in aquatic wildlife in terms of their biodiversity, their response to environmental change, their emerging diseases, and the contribution of humans and domestic animals to parasitic disease outcomes. This work highlights the clear need for interdisciplinary approaches to ameliorate disease impacts in aquatic wildlife systems., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

We sought transversotrematid trematodes from French Polynesian fishes by examining 304 individual scaled fishes of 53 species from seven families known to harbour the family elsewhere. A single species was found at two locations in the Tuamotus Archipelago on two species of Chaetodontidae (Chaetodon auriga and Chaetodon ephippium) and one species of Lutjanidae (Lutjanus gibbus). The species closely resembles Transversotrema borboleta Hunter & Cribb, 2012 from chaetodontids and lutjanids of the northern Great Barrier Reef (GBR) but differs from it consistently in 8 base positions of ITS2 rDNA. This level of variation exceeds that between some clearly morphologically distinct pairs of species of Transversotrema and the form from French Polynesia is thus interpreted as a distinct, though cryptic, species and named Transversotrema polynesiae n. sp. The new species forms part of a complex of species, here characterised as the T. borboleta complex, associated with chaetodontids and lutjanids in the tropical Indo-West Pacific. Most of the putative species within this complex are yet to be described. Comparison of identical numbers of matched samples of fishes from French Polynesia, Heron Island (southern GBR) and Lizard Island (northern GBR) revealed 1, 4 and 10 species of Transversotrema respectively suggesting that the French Polynesian fauna is depauperate for this family. In addition to those species apparently missing from suitable hosts in French Polynesia, several species from further west infect fishes (especially Nemipteridae) that are themselves absent from French Polynesia. This dramatic east-west decline in richness contrasts strongly with what is known for monogeneans, which appear to maintain their richness over the same scale, and is more precipitate than is known for other groups of trematodes. The decline might be explained in part by the absence of the as yet unknown first intermediate hosts in French Polynesia. However, we predict that it is explained by other life cycle traits. We hypothesise that the characters of large short-lived cercariae, short-lived miracidia, the absence in the life-cycle of second intermediate hosts that are capable of transporting the species, and definitive and first intermediate hosts that have limited vagility combine to give marine Transversotrematidae limited dispersal capacity and a propensity for localised speciation., (Copyright © 2013. Published by Elsevier Ireland Ltd.)

During a parasitological survey, Myxidium-like spores were identified in the gall bladders of marine fishes from Australian waters. This paper describes four novel species of Ellipsomyxa Køie, 2003, three novel species of Myxidium Bütschli, 1882 and six novel species of Zschokkella Auerbach, 1910 from teleosts from Australian waters using a combination of morphological, biological and molecular characters. Phylogenetic analyses showed a monophyletic relationship of all Ellipsomyxa spp. sequences with Sigmomyxa sphaerica (Thélohan, 1895) and Myxidium queenslandicus Gunter & Adlard, 2008 as sister species to the clade. The validity of genus Sigmomyxa Karlsbakk & Køie, 2012 is discussed. In phylogenetic analyses, the novel species of Myxidium fell within the 'marine' clade of Fiala (2006). However, the novel species of Zschokkella fell within the 'freshwater' clade of Fiala (2006) and formed a distinct clade with all other sequences of Zschokkella spp. from the gall bladder of marine fish and a sequence of a species of Myxobolus Bütschli 1882, also from the gall bladder of a marine fish. This is the second distinct marine lineage to emerge within the freshwater clade.

Ceratomyxa parasites from the gall bladders of 23 species of cardinalfishes (family Apogonidae) from Australian waters were examined for their taxonomic identity and phylogenetic relatedness. We identified 15 of the 23 apogonid fish species infected with species of Ceratomyxa. Although the majority of apogonid species harboured only a single Ceratomyxa species, four were found with multiple species of Ceratomyxa. This study describes eight novel species using a combination of morphological, small subunit ribosomal DNA (SSU rDNA) and biological characters. Six Ceratomyxa species are reported from single apogonid species, while two are reported from multiple host species. Molecular data were critical in identifying several morphologically cryptic species. However, our results suggest that SSU rDNA was not capable of distinguishing all the species present in the current study system and alternative genetic markers should be investigated in the future.

We explored the distribution of Cardicola chaetodontis in chaetodontid fishes from the Great Barrier Reef. We found just four infections of adult worms in 238 individuals of 26 chaetodontid species. By contrast, eggs were present in hearts of 75 fishes (31·5%) and 19 of 26 chaetodontid species (all Chaetodon species). In 10 cases eggs contained moving miracidia; all the others were dead and degenerating. Eggs were sought in the gills of 51 individual fish. There were 17 cases of eggs being present in gills while present in the heart, but also 13 cases where eggs were absent from gills but present in the heart, suggesting that eggs remain longer in heart tissue than in gills. ITS2 rDNA sequences from two adult worms and eggs extracted from gills of five fishes (all different species) were identical to previously reported sequences of C. chaetodontis except for a single base-pair difference in two samples. We conclude that aporocotylid eggs trapped in fish heart tissues may inform understanding of the distributions and host ranges of aporocotylids, especially where adult prevalence is low. The low host-specificity of C. chaetodontis contrasts with higher specificity of trematodes of chaetodontids that have trophic transmission.

A survey of the myxosporean fauna of Australian marine fishes revealed the presence of three previously unreported species of Unicapsula (Multivalvulida: Trilosporidae) from sites off Southeast Queensland, off Lizard Island on the Great Barrier Reef, Queensland, and from Jurien Bay in Western Australia. Morphometric data (spore, polar capsule and caudal appendage dimensions) combined with Bayesian inference and maximum likelihood analyses of small subunit (SSU) and large subunit (LSU) ribosomal DNA (rDNA) were used for species identification and to explore relationships among these taxa. The four species of Unicapsula for which DNA data are now available for comparative purposes (Unicapsula andersenae n. sp., Unicapsula pflugfelderi, Unicapsula seriolae and Unicapsula pyramidata) formed a well-supported monophyletic sister clade to the other major multivalvulidan group, the Kudoidae. The combined morphometric and genetic diagnostic approach identified an undescribed taxon, U. andersenae n. sp., from the muscle of Argyrosomus japonicus, Acanthopagrus australis and Eleutheronema tetradactylum off the Southeast Queensland coast and in Lutjanus russellii and Sillago ciliata off Lizard Island. Intra-specific variation within U. andersenae n. sp. varied from 2-4 (0.2-0.4%) nucleotides over the SSU region to 2-20 (0.3-3.2%) over the LSU region. Inter-specific variation between U. andersenae n. sp. and the other three species for which genetic sequence data are now available ranged from 15-66 (3-6.5%) nucleotides over the SSU region to 103-120 (17.6-21.2%) nucleotides over the LSU region. The host distribution observed here for U. andersenae n. sp. (five fish species from five different fish families) represents the broadest specificity known for a single species of Unicapsula. U. pyramidata Naidjenova & Zaika 1970, whose spore morphology and presence of caudal appendages immediately distinguish it from other species, was recovered from the nemipterid, Scolopsis monogramma, off Lizard Island. U. seriolae Lester 1982 is reported here from Yellowtail Kingfish, Seriola lalandi, from sites off Queensland and from Jurien Bay, Western Australia. Comparative genetic analyses also revealed that an unidentified species of Unicapsula from Epinephelus septemfasciatus off Japan whose rDNA sequence data are available on GenBank is consistent with U. seriolae. This suggests that U. seriolae may also exhibit low host specificity and may be distributed widely throughout the Indo-West Pacific region. In comparison to other myxozoan genera, it is clear that the species richness of Unicapsula spp. falls well below that displayed by either Ceratomyxa spp. or Kudoa spp. The discovery of a further new species of Unicapsula in Australia now brings the total worldwide number of formally described Unicapsula species to a modest 11. Nonetheless, this taxon remains of significant interest to commercial and recreational fisheries through the potential production of macroscopic pseudocysts in fish muscle and post-mortem muscle liquefaction, both of which can render fish fillets unpalatable and unmarketable.

Kudoa spp. from the musculature and intestinal mucosa of species of the teleost family Apogonidae were examined for their taxonomic identity. Two novel species are characterised: Kudoa cheilodipteri n. sp. from the musculature of Cheilodipterus quinquelineatus Cuvier, Ostorhinchus cyanosoma (Bleeker) and O. aureus (Lacépède); and Kudoa cookii n. sp. from the submucosa of the intestines of O. cookii (Macleay) only. Both species are characterised using morphology, small subunit ribosomal DNA (SSU rDNA), large subunit ribosomal DNA (LSU rDNA), and biological characters. Three new host records, O. cyanosoma, O. aureus and Apogon doederleini, and associated geographical, morphological and genetic data are also provided for Kudoa whippsi Burger & Adlard, 2010. Morphological and molecular intra-specific variation of all isolates assigned to K. whippsi is also examined. Phylogenetic analyses further support the idea that tissue tropism is a distinguishing character between morphologically similar species; species reported here display close relatedness to morphologically similar species infecting the same tissue within their hosts.

Kudoa leptacanthae n. sp. was identified within the pericardial cavities of two apogonid species, Zoramia leptacantha and Zoramia viridiventer, from waters off Lizard Island on the Great Barrier Reef. The species shows a close taxonomic affinity, both morphologically and genetically, to Kudoa shiomitsui Egusa & Shiomitsu 1983 reported from a tetraodontid and scombrid, both from Japan. The infection was at high prevalences (average = 75.8% ± 0.63, n = 343) within schools of the two host species. Different sporogonic stages ('developing' and 'fully-developed') were observed in pseudocysts within the pericardium of the hosts. Kudoa leptacanthae n. sp. appears to be a persistent infection within the Zoramia species hosts. No seasonal variation was detected for this host/parasite system and the parasite did not affect host condition, when assessed using host length/weight ratio as a coarse indicator. We hypothesise that a source of infection in close proximity to the home patch reef of apogonid schools may lead to the high prevalence and intensity of infection reported in this study., (Copyright © 2012 Elsevier B.V. All rights reserved.)

We describe a new species of myxozoan, Henneguya mauritaniensis n. sp., extracted from the arterial bulb of the bluespotted seabream, Pagrus caeruleostictus (Valenciennes, 1830), collected in Mauritanian waters. Out of the 209 individuals examined, 30.1 % were infected with this new taxon. Spore total length ranged from 15.0 to 20.5 μm with a mean of 17.9 μm. The two polar capsules were equal in size, and pyriform and caudal appendages joined until mid-length. Morphometric analysis revealed significant differences between H. mauritaniensis n. sp. and morphologically similar species from this region as well as congeners known from other sparid hosts. Phylogenetic analysis of 18 S rDNA indicated that this new species is closely related to Henneguya pagri, reported recently from Pagrus major off Japan. Bayesian inference and maximum likelihood analyses of the 18 S rDNA dataset also revealed that species of marine Henneguya reported forming pseudocysts in the hearts of their fish hosts were closely related. Histological analysis of the H. mauritaniensis n. sp. pseudocysts embedded in the arterial bulb of P. caeruleostictus suggests that these parasites may cause considerable pathology, which may impact negatively on the health of the fish host. Finally, we discussed the importance of a combination of morphological and molecular analysis for species description because of high variability in size within the same taxa.

Six novel species of Chloromyxum Mingazzini, 1890 are described using a whole evidence approach combining morphometric and molecular data, together with features of their biology. Elasmobranchs were collected in Australian waters, from the Great Barrier Reef, Queensland, off Lizard and Heron Islands; from Moreton Bay, southeast Queensland; off Hobart, Tasmania; and from the Tamar River, Launceston, Tasmania. The novel species proposed here are: Chloromyxum hemiscyllii n.sp. from Hemiscyllium ocellatum; Chloromyxum kuhlii n.sp. from Neotrygon kuhlii; Chloromyxum lesteri n.sp. from Cephaloscyllium laticeps; Chloromyxum mingazzinii n.sp. from Pristiophorus nudipinnis; Chloromyxum myliobati n.sp. from Myliobatis australis; and Chloromyxum squali n.sp. from Squalus acanthias. A seventh species from Squalus acanthias is also reported but due to limited material is not formally described. Molecular phylogenetic analyses revealed that the genus Chloromyxum is polyphyletic, and species from elasmobranchs form a well-supported sister clade, with the type species Chloromyxum leydigi, to all other congeneric species clustering within the freshwater myxosporean clade. Morphological analysis showed that elasmobranch-infecting species are predominantly pyriform shaped, have clearly thickened spore apex and possess caudal filaments, compared to other Chloromyxum species which are generally spherical or subspherical, and lack caudal filaments. These morphological and phylogenetic data provide further support for the erection of new genera, but we conservatively consider the species described in this study and other elasmobranch-infecting Chloromyxum species as Chloromyxum sensu strictu, whilst the freshwater teleost infecting and amphibian infecting species we will assign as Chloromyxum sensu lato, until more comprehensive data are available., (Crown Copyright © 2011. Published by Elsevier Ireland Ltd. All rights reserved.)

Species richness and biogeography of the monorchiid genus Hurleytrematoides was studied by the examination of 2834 individuals of 45 species of Chaetodontidae at six major sites in the tropical Indo-West Pacific: Heron Island, Lizard Island, Ningaloo (Western Australia), Palau, New Caledonia and Moorea (French Polynesia). In total, 18 species were distributed among six sites; descriptions are provided for eight new species: H. boucheti n. sp., H. combesi n. sp., H. deblocki n. sp., H. dollfusi n. sp., H. euzeti n. sp., H. kulbickii n. sp., H. pasteuri n. sp., and H. planesi n. sp. Overall richness ranged from zero to five Hurleytrematoides species per chaetodontid species. Seven Hurleytrematoides species were found at only one locality and eleven were found at multiple localities. Only one species, H. morandi, was found at all localities. Individual localities had between six (Moorea) and 10 (Heron Island) species; we attribute Moorea's depauperate parasite fauna to its isolation and distance from the Indo-Philippine centre of biological diversity. Using cluster analysis of 18 species of Hurleytrematoides and 45 species of chaetodontids sampled in the Indo-West Pacific, we show that the localities on the Great Barrier Reef (Heron Island and Lizard Island) and New Caledonia have the most similar chaetodontid and parasite fauna of any locality pairs. Cluster analysis results also show that the similarity of the chaetodontid assemblages at five of the six localities is relatively high and that Ningaloo has the most distinct fauna. Similarity values based on sharing of species of Hurleytrematoides are generally lower than those for their hosts; Moorea, Ningaloo and Palau all have low similarity to New Caledonia and Great Barrier Reef sites. We attribute these distinctions to the differential dispersal capability of the fish and their parasites. Chaetodontids have long-lived mobile pelagic larvae, the dispersal of which would be most affected by prominent biogeographical barriers, such as that between the Indian and Pacific Oceans. In contrast, monorchiids have no obvious dispersal stage, and vast distances have the capacity to act as effective barriers to dispersal. We conclude that the present distributions of species of Hurleytrematoides in the Indo-Pacific are driven by historical opportunity and capacity to disperse, and that some disjunct distributions are sculpted by stochasticity., (Copyright © 2011. Published by Elsevier Ireland Ltd.)

A survey of the myxosporean fauna of Australian marine fishes revealed the presence of a number of putative species of Kudoidae (Multivalvulida) forming pseudocysts between the outer meningeal layer and the outer surface of the brains of the lutjanids Caesio cuning, Lutjanus carponotatus, Lutjanus ehrenbergii and Lutjanus fulviflamma and the mugilid Liza vaigiensis from Lizard Island on the Great Barrier Reef, Australia and Lutjanus lemniscatus off Ningaloo Reef, Western Australia. Morphometric data combined with Bayesian inference and maximum likelihood analyses of small subunit (SSU) and large subunit (LSU) ribosomal DNA (rDNA) was used for species identification and to explore relationships among these taxa. The brain-infecting taxa examined here formed a well-supported clade to the exclusion of non-brain infecting species in the phylogenetic analyses. The combined diagnostic approach identified an undescribed taxon, Kudoa lemniscati n. sp., from the brain of L. lemniscatus (Perciformes: Lutjanidae) off Ningaloo Reef, Western Australia, which we describe and characterise here. K. lemniscati n. sp. can be distinguished from all other species of Kudoa based on the combination of the distinct tropism for forming pseudocysts in the brain tissue, spores with 7 or 8 equal shell valves and 7 or 8 polar capsules, spore size and the differences in the SSU and LSU rDNA sequence data relative to other kudoids. Kudoa chaetodoni was found in the lutjanids C. cuning and L. carponotatus, expanding the known host range for this species to include chaetodontids and lutjanids. L. ehrenbergii and L. fulviflamma were infected with Kudoa lethrini off Lizard Island, a parasite previously known only from lethrinids. Specimens putatively identified as Kudoa yasunagai from Liza vaigiensis and Lutjanus ehrenbergii were morphologically similar and genetically identical over the SSU rDNA dataset to previously reported specimens, but differed by 4 to 11 nucleotides over the LSU dataset from the remaining isolates examined here. While these data are not definitive, they suggest the presence of a K. yasunagai complex., (Crown Copyright © 2012. Published by Elsevier Ireland Ltd. All rights reserved.)

Aporocotylids (fish blood flukes) are emerging as pathogens of fishes in both marine and freshwater aquaculture. Efforts to control these parasites are hampered by a lack of life cycle information. Here we report on the life cycle of Cardicola forsteri, which is considered a significant pathogen in southern bluefin tuna, Thunnus maccoyi, ranched in South Australia. We surveyed polychaetes, bivalves and gastropods from sites close to tuna pontoons. Infections consistent with the Aporocotylidae were found in terebellid polychaetes, a single Longicarpus modestus and five individuals of Reterebella aloba. All infections were comprised of hundreds of sporocysts in the body cavity of the host, each filled with developing and mature cercariae. Sequences of ITS-2 and lsrDNA from the infection from L. modestus were a perfect match with those of adult C. forsteri from T. maccoyi. This life cycle link is considered confirmed but it is possible that additional terebellid species are infected in South Australia; equally, other species of intermediate host are likely to be involved in other parts of the range of this cosmopolitan trematode. Sequences of the species from R. aloba did not match a known adult but phylogenetic analysis of lsrDNA suggests that it is also a species of Cardicola Short, 1953. These findings show that terebellid polychaetes are a major host group for marine aporocotylids, especially given that Cardicola is the largest marine aporocotylid genus. The two cercarial types are among the smallest known for the family and are unusual, but not unique, in having short, simple tails. We speculate that the form of the tail means that these cercariae are not active swimmers and are thus heavily dependent on currents for dispersal. Control of this parasite might be effected by moving the tuna pontoons appropriate distances to avoid encounter with current-dispersed cercariae, or by increasing the separation of the nets from the sea floor, either by raising the nets or moving to deeper water., (Copyright © 2011 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.)

Parvicapsula minibicornis is a myxozoan parasite implicated in mortalities of both juvenile and pre-spawning adult salmon in the Pacific Northwest of North America. Disease severity and presentation varies between salmon species and geographical localities. To better characterize population structure of the parasite, we sought genetic markers in the P. minibicornis ribosomal RNA gene. We compared samples from California with the type specimen from British Columbia, identified sequence variations, and then sequenced 197 samples from fish, river water and the parasite's polychaete worm host. Although DNA sequences of the parasite were >98·9% similar, there was enough variation to define 15 genotypes. All genotypes were detected in fish samples, although not in all species. A single genotype only was found in sockeye and pink salmon in the Fraser River Basin, but was not detected in sockeye from the adjacent Columbia River Basin. All coho salmon, irrespective of river basin, were infected with a unique mix of 2 genotypes. These data indicated that the P. minibicornis population exhibited strong signals of structuring by both geography and salmonid host species. Particular genotypes may correlate with disease differences seen in salmon populations in the Pacific Northwest.

Five novel species, Auerbachia scomberoidi n. sp., Auerbachia chaetodoni n. sp., Auerbachia caranxi n. sp., Coccomyxa colurodontidis n. sp. and Coccomyxa gobiodoni n. sp. are described from the gall bladders of marine teleosts. These species descriptions provide the first record of Auerbachia from Australian waters. Each species is characterized morphologically, including additional measurements for Auerbachia spp. and small subunit ribosomal DNA (SSU rDNA) sequences were determined for molecular phylogenetic analyses. All 5 species were each recovered from a single (and different) species of host. Phylogenetic analyses revealed a close genetic relatedness between members of Auerbachia and Coccomyxa. Based on these phylogenetic data, on obvious paraphyly displayed by the Myxidiidae and on priority, we propose the re-establishment of the family Coccomyxidae to house all species of the genera, Coccomyxa, Auerbachia and Globospora.

Kudoid parasites are known to infect a large variety of fish. A significant proportion of Kudoa species have relatively low host specificity, with a single species able to infect multiple host species representing various host families even from different host orders. Since DNA sequences have been associated with myxosporean species characterisations, it has become far easier to determine host range of new species and validate host records from earlier descriptions. This study investigated the host specificity of a kudoid parasite, Kudoa thalassomi Adlard, Bryant, Whipps et Kent, 2005, from the Great Barrier Reef in Australia using DNA sequence analysis and morphology. The results revealed the host specificity to be broad, with K. thalassomi identified in 18 different fish species representing six different fish families. This study also compares current genetic information from different host isolates of Kudoa Meglitsch, 1947 to their host ranges recorded in existing literature. From this analysis, only half of the Kudoa species with multiple host records (27 Kudoa species) have half or more isolates that are genetically characterised, and thus specifically identified with a high confidence, from their known hosts. Only five kudoid species have genetically characterised isolates from all of their recorded hosts.

Myxosporean parasites are significant parasites of fishes not only for their apparent high diversity but also for their potential impact on fish health and/or marketability. Regardless, our knowledge of most myxosporeans, especially those found in elasmobranch hosts, is superficial. A study of multivalvulidan diversity in a range of elasmobranchs from Queensland, Western Australia and the Northern Territory (Australia) was conducted to address this knowledge gap. Specimens were collected from a total of 3 orders, 9 families and 31 species of elasmobranchs. Myxosporean infections referable to the genus Kudoa were discovered in host muscle and characterized morphologically and genetically. Both small subunit (SSU) and large subunit (LSU) rDNA sequences were used in molecular phylogenetic analyses. Kudoa spp. infected 27 of the 31 species of elasmobranchs examined, representing new records of this parasite genus in 26, of the 27, host species. Kudoids were observed in all 3 orders, and 7 out of the 9 families of elasmobranchs investigated. This paper reports the first 2 multivalvulidan species to be formally described from elasmobranchs, Kudoa hemiscylli n.sp. characterized from Hemiscyllium ocellatum (and 8 other host species) and Kudoa carcharhini n. sp. characterized from Carcharhinus cautus (and 2 other host species). Phylogenetic analyses revealed that kudoids from elasmobranchs form a separate lineage to those of teleosts, but are anchored within the overall kudoid clade.

A survey of the endohelminth fauna of Indo-West Pacific Lutjanidae (Perciformes) revealed the presence of the species Siphoderina manilensis (Velasquez, 1961) Miller & Cribb, 2008 and S. marina (Hafeezullah & Siddiqi, 1970) Miller & Cribb, 2008 in seven Lutjanus spp. from sites off the Great Barrier Reef, the Maldives, New Caledonia and Ningaloo Reef, Western Australia. A combination of morphological and ribosomal DNA analyses of these cryptogonimids prompted the transfer of these taxa to a new genus, Euryakaina n. g., as E. manilensis n. comb. and E. marina n. comb., based on comparative analysis with other cryptogonimid taxa. Euryakaina n. g. is distinguished from all other cryptogonimid genera by the combination of a fusiform body, the few relatively small, widely spaced oral spines (sometimes absent), a highly lobed ovary, opposite to slightly oblique testes, vitelline follicles that extend from the anterior margin of the testes to slightly posterior to the intestinal bifurcation, and an excretory vesicle that bifurcates dorsal to the ovary and reunites briefly slightly posterior to the intestinal bifurcation. Morphometric analysis of these taxa alone suggests they should be reduced to synonymy, but DNA sequence analyses and ecological niche partitioning provide evidence that they form a cryptic species complex in sympatric lutjanids in the Indo-West Pacific. The secondary structure of the ITS2 rDNA for species of Euryakaina was also modelled and analysed for the presences of compensatory base changes (CBCs) or hemi-CBCs in order to explore the usefulness of these changes as a tool to help elucidate the taxonomy of this complex system. We also report what we interpret here as intraspecific variation in the ITS2 rDNA between individuals of E. manilensis from Lutjanus vitta recovered off the Great Barrier Reef and New Caledonia.

Some Kudoa species display variations in the number of polar capsules in spores within an individual pseudocyst. Nonetheless, there is usually a dominant morphotype which forms a significant element of diagnosis. In 2007, a Kudoa isolate from whiting (spores with 5 (dominant) or 6 (minor) polar capsules) was characterized by Burger et al. (2007) as being 100% identical in SSU rDNA to Kudoa yasunagai (spores with 7 polar capsules) from a halibut, despite its obvious morphological differences. The authors hypothesized that either SSU rDNA had reached its level of resolution or that the genetic identity revealed conspecificity. To further investigate these hypotheses, SSU and LSU rDNA sequence data were coupled with principal components, correlation, and regression analyses of morphometric data from different kudoid isolates that infect brain tissue to determine the relationships between spore morphotypes and different kudoid isolates. The trends in morphometrics between the spores of particular isolates were so similar that it was concluded that the molecular results did indicate conspecificity rather than SSU reaching its level of resolution. This phenotypic influence on a significant diagnostic character within the Kudoidae has a major impact on the diagnosis of this, and potentially other, pathogenic species.

Kudoid parasites are significant pathogens of marine fish. In the past, specific identification has been difficult due to a paucity of detailed morphological and biological information provided in the original description of some species. However, the introduction of DNA analysis has dramatically improved diagnosis. For morphological characterization, this paper proposes a new set of schematics including additional measurements to give a more thorough description of spore morphology, and provides evidence for uniqueness of 4 new species: Kudoa gunterae n. sp. (from 10 pomacentrid species and 1 apogonid species), K. kenti n. sp. (from 4 pomacentrid species), K. paraquadricornis n. sp. (from 4 carangid species), and K. whippsi n. sp. (from 8 pomacentrid species and 1 apogonid species). Subtle morphological differences found between closely related species were reflected in their genetics, with increased resolution provided by the large subunit, compared with that of the small subunit, of the ribosomal DNA gene region. This article proposes comprehensive requirements for species descriptions within the Kudoidae that incorporate biology, morphology, and genetic sequence.

Four new species of Ceratomyxa Thélohan, 1892 are described from the gall bladders of fishes collected off Lizard Island, Australia. These species are characterised using a combination of morphometric and molecular data. Ceratomyxa bartholomewae sp. n. is described from Hyporhamphus dussumieri (Valenciennes) (family Hemirhamphidae); C. koieae sp. n. is described from Sphyraena forsteri Cuvier (family Sphyraenidae); C. pantherini sp. n. is described from Bothus pantherinus (Rüppell) (family Bothidae) and C. reidi sp. n. is described from Chaetodon vagabundus Linnaeus (family Chaetodontidae). A fifth species from Zebrasoma veliferum (Bloch) (family Acanthuridae) is also reported but due to limited material is not formally described here.

The genus Ceratomyxa (Myxozoa: Myxosporea: Bivalvulida) contains parasites that typically infect the gall bladders of marine teleosts. Species of this genus have also been recorded from elasmobranchs, while the best known species (Ceratomyxa shasta) is a systemic pathogen of fresh water salmonid fishes. Here we characterise 10 new species of Ceratomyxa from marine teleosts using morphometric and rDNA sequence data. A phylogeny of all Ceratomyxa species for which ssrDNA sequence is available was estimated by parsimony, maximum likelihood and Bayesian analyses. Mapping host fish taxonomy, geographic locality and morphology onto the phylogenetic tree provided some concordance of these characters to groups of Ceratomyxa species, but in no case was it consistent throughout the inferred phylogeny. The position of C. shasta as a sister species to the Ceratomyxa clade contradicts previous estimates of marine myxozoan phylogeny which suggested C. shasta was an unrelated lineage. Comparative DNA sequence data is available for more than 17% of some 200 described Ceratomyxa species and the genus now represents one of the most cohesive lineages within the Myxozoa. The independent branching of all atypical Ceratomyxa species and Palliatusindecorus, indicates a review of the diagnostic characters and possible division into more genera is warranted when further data are available.

Ceratomyxa spp. from the gall-bladder of five members of the family Serranidae were examined for their taxonomic identity. This paper describes seven new ceratomyxid species, i.e. C. brayi n. sp. and C. whippsi n. sp from Cephalopholis boenak (Bloch); C. cutmorei n. sp. from Epinephelus fasciatus (Forsskål); C. gleesoni n. sp. from Plectropomus leopardus (Lacépède); C. hooperi n. sp. and C. nolani n. sp. from E. quoyanus (Valenciennes); and C. yokoyamai n. sp. from E. maculatus (Bloch). Each species is characterised morphologically and small subunit (SSU) rDNA sequences. All seven new species have so far been found in only a single host species.

Sydney rock oysters (Saccostrea glomerata) selectively bred for disease resistance (R) and wild-caught control oysters (W) were exposed to a field infection of disseminating neoplasia. Cumulative mortality of W oysters (31.7%) was significantly greater than R oysters (0.0%) over the 118 days of the experiment. In an attempt to understand the biochemical and molecular pathways involved in disease resistance, differentially expressed sequence tags (ESTs) between R and W S. glomerata hemocytes were identified using the PCR technique, suppression subtractive hybridisation (SSH). Sequencing of 300 clones from two SSH libraries revealed 183 distinct sequences of which 113 shared high similarity to sequences in the public databases. Putative function could be assigned to 64 of the sequences. Expression of nine ESTs homologous to genes previously shown to be involved in bivalve immunity was further studied using quantitative reverse-transcriptase PCR (qRT-PCR). The base-line expression of an extracellular superoxide dismutase (ecSOD) and a small heat shock protein (sHsP) were significantly increased, whilst peroxiredoxin 6 (Prx6) and interferon inhibiting cytokine factor (IK) were significantly decreased in R oysters. From these results it was hypothesised that R oysters would be able to generate the anti-parasitic compound, hydrogen peroxide (H(2)O(2)) faster and to higher concentrations during respiratory burst due to the differential expression of genes for the two anti-oxidant enzymes of ecSOD and Prx6. To investigate this hypothesis, protein extracts from hemolymph were analysed for oxidative burst enzyme activity. Analysis of the cell free hemolymph proteins separated by native-polyacrylamide gel electrophoresis (PAGE) failed to detect true superoxide dismutase (SOD) activity by assaying dismutation of superoxide anion in zymograms. However, the ecSOD enzyme appears to generate hydrogen peroxide, presumably via another process, which is yet to be elucidated. This corroborates our hypothesis, whilst phylogenetic analysis of the complete coding sequence (CDS) of the S. glomerata ecSOD gene is supportive of the atypical nature of the ecSOD enzyme. Results obtained from this work further the current understanding of the molecular mechanisms involved in resistance to disease in this economically important bivalve, and shed further light on the anomalous oxidative processes involved.

Parasites of the genus Kudoa (Phylum Myxozoa) have long been known to cause considerable losses to finfish aquaculture. One such parasite species, Kudoa amamiensis, causes unsightly white cysts in the skeletal muscle of yellowtail kingfish, Seriola quinqueradiata, in Japan rendering the fillets unmarketable. The authors who characterized K. amamiensis, Egusa & Nakajima, 1980, hypothesized that yellowtail kingfish, as non-natives to the area, were accidental hosts of the parasite and that it normally infects native reef fish (damselfish, Family Pomacentridae). Since then, we have found parasites that are consistent with the description of K. amamiensis in two species of damselfish and one species of carangid fish in Australia, and it has been recorded previously in another species of reef-associated fish. Our morphometric, histological and DNA results suggest that these specimens are K. amamiensis, and are new host records for that species. Furthermore, our observations show that reef fish may act as a reservoir of myxozoan infection for commercial species, and as such should be considered an infection pathway for species in aquaculture.

Bivalvulidan parasites from the gall bladder of 31 species of damselfishes (family Pomacentridae) were examined for their taxonomic identity and their relatedness to other species of myxozoans. This paper describes 11 novel ceratomyxid species and a novel Myxidium sp. Each species is characterized morphologically and small subunit (SSU) rDNA sequences were used in molecular phylogenetic analyses. Five pomacentrid species were found to harbour multiple infections of bivalvulidan species. One species of Ceratomyxa and Myxidium were found to infect more than a single species of damselfish. Phylogenetic analyses revealed there has been no radiation of ceratomyxids that can be associated with the fish host taxon and that Myxidium queenslandicus n.sp. was more closely related to Zschokkella mugilis and Ellipsomyxa gobii than other members of the genus Myxidium.

Ceratomyxid parasites from the gall bladder of fishes from the family Labridae were examined for their taxonomic identity and their relatedness to other species of myxozoans. This paper describes four novel species Ceratomyxa choerodonae n. sp. from Choerodon cyanodus; Ceratomyxa cheilinae n. sp. from Cheilinus chlorourus; Ceratomyxa oxycheilinae n. sp. from Oxycheilinus digramma; and Ceratomyxa thalassomae n. sp. from Thalassoma lunare. Each species is characterised morphologically and small subunit (18 S) rDNA sequences were used in molecular phylogenetic analyses. Comparison of the small subunit rDNA sequences revealed four distinct species even though morphological differences indicated the presence of only two morphologically distinctive spore types. Phylogenetic analyses revealed that the ceratomyxids from labrid fishes did not form a clade to the exclusion of all other myxosporeans and provides evidence that host relatedness is not a good character to discriminate between species within the genus Ceratomyxa.

Two morphologically novel Kudoa species are characterized from brain tissue of fish, Kudoa chaetodoni n. sp. from Chaetodon unimaculatus (Chaetodontidae) and Kudoa lethrini n. sp. from Gymnocranius audleyi and Lethrinus harak (Lethrinidae). Additionally we characterized a 5-spore valve (SV) Kudoa species from the brain of Sillago ciliata (Sillaginidae). Intriguingly, its 18S rDNA sequence was identical to that of the 7 SV Kudoa yasunagai extracted from the brain of a paralichthyid halibut in Japan. These 2 species may either prove to be con-specific, even though morphology and distribution differ, or demonstrate the limit of specific resolution in the small subunit rDNA gene region. Small subunit rDNA sequences from these new species were used in molecular phylogenetic analyses of kudoids to examine congruence of phylogeny with tissue tropism, geographical distribution, and host specificity. There was significant correlation between tissue tropism in the form of well-supported brain and heart-infecting clades. Host specificity and geographical distribution showed some correlations with genotype.

Kudoa monodactyli n. sp. is described from the somatic musculature of Monodactylus argenteus from several localities in southern Queensland, Australia. This is the first record of a myxozoan parasite from the family Monodactylidae. The spores typically have five polar capsules, making this species similar to the four other five-valved Kudoa species (K. neurophila, K. muscularis, K. shulmani, K. cutanea) that have been described to date. However, morphometric measurements particularly of spore length and width make the species from M. argenteus distinct from the other species. Comparison of the small subunit ribosomal DNA sequence of this species with its congeners for which sequence data are available, provides further evidence of novelty. Kudoa monodactyli n. sp. displays 38 (of 1,554) nucleotide differences compared with rDNA sequence of Kudoa neurophila, which on phylogenetic analysis places these species in clades exclusive of each other. Phylogenetic analyses also provide evidence that the number of valves per spore in this genus is an imperfect indicator of relatedness.

Little is known of the blood parasites of coral reef fishes and nothing of how they are transmitted. We examined 497 fishes from 22 families, 47 genera, and 78 species captured at Lizard Island, Australia, between May 1997 and April 2003 for hematozoa and ectoparasites. We also investigated whether gnathiid isopods might serve as potential vectors of fish hemogregarines. Fifty-eight of 124 fishes caught in March 2002 had larval gnathiid isopods, up to 80 per host fish, and these were identified experimentally to be of 2 types, Gnathia sp. A and Gnathia sp. B. Caligid copepods were also recorded but no leeches. Hematozoa, found in 68 teleosts, were broadly hemogregarines of 4 types and an infection resembling Haemohormidium. Mixed infections (hemogregarine with Haemohormidium) were also observed, but no trypanosomes were detected in blood films. The hemogregarines were identified as Haemogregarina balistapi n. sp., Haemogregarina tetraodontis, possibly Haemogregarina bigemina, and an intraleukocytic hemogregarine of uncertain status. Laboratory-reared Gnathia sp. A larvae, fed experimentally on brushtail tangs, the latter heavily infected with the H. bigemina-like hemogregarine, contained hemogregarine gamonts and possibly young oocysts up to 3 days postfeeding, but no firm evidence that gnathiids transmit hemogregarines at Lizard Island was obtained.

Three new species of Kudoa, each having 6 polar capsules, are described from the somatic muscle of fishes collected on the Great Barrier Reef, Queensland, Australia. Kudoa grammatorcyni n. sp. was observed in the shark mackerel Grammatorcynus bicarinatus. Spores are stellate in apical view, width (all measurements in microm) 8.62 (8.03-8.95); thickness 8.14 (7.63-8.68); suture width 7.7 (7.24-8.16); length 6.54 (6.32-6.71); polar capsule length 3.68 (3.55-3.82); polar capsule width 1.72 (1.65-1.84). Kudoa scomberomori n. sp. is described from the Spanish mackerel Scomberomorus commerson. Spores are stellate in apical view, width 7.56 (6.84-8.16); thickness 6.79 (6.18-7.63); suture width 5.92 (5.26-6.32); length 5.43 (5.00-6.18); polar capsule length 3.24 (3.03-3.55); polar capsule width 1.37 (1.25-1.51). Kudoa thalassomi n. sp. is described from the moon wrasse Thalassoma lunare. Spores are stellate in apical view, width 10.66 (9.47-11.84); thickness 9.37 (8.55-10.79); suture width 7.98 (6.84-8.82); length 6.65 (6.18-7.11); polar capsule length 4.92 (4.74-5.00); polar capsule width 2.12 (2.04-2.24). All 3 species differ in spore morphology from the 1 previously described myxozoan with 6 polar capsules, Hexacapsula neothunni from yellowfin tuna Neothunnus macropterus, which has since been reassigned to Kudoa.

A new species of the apicomplexan genus Leucocytozoon Berestneff, 1904, L. artamidis n. sp., is described from the Australian avian family Artamidae. Gametocytes and endogenous stages of the life-cycle are described together with early erythrocytic and leucocytic developing forms rarely described for species of this genus.

A study was undertaken on the pathology and associated schizont morphology of apicomplexan species of avian haematozoa. Some 32 birds from the families Artamidae, Meliphagidae, Oriolidae, Podargidae, Columbidae, Alcedinidae and Psittacidae were identified as having schizonts in various tissues. Based on blood stages observed, the probable relationship to tissue stages was considered. The majority of schizonts were referable to the genera Leucocytozoon and Haemoproteus. The comparative morphology of tissue stages previously described in the literature is discussed and the involvement of protozoa other than haematozoa considered. The naturally occurring infections in wild birds described in this study represent previously unreported data on the life-cycle stages involved. Some schizonts measured up to 640 microm. While pathological changes in some hosts were noticeable, in others no significant findings were observed. The role of endogenous stages in avian morbidity is discussed briefly., (Copyright 2004 Houghton Trust Ltd)