Stemmatostoma cribbi n. sp. (Digenea: Cryptogonimidae) from Freshwater Fishes in the Wet Tropics Bioregion of Queensland, Australia.

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.

Further characterisation of Leucocytozoon podargii in wild tawny frogmouths (Podargus strigoides) in Western Australia.

The present study assessed the prevalence and morphology of Leucocytozoon podargii from wild tawny frogmouths (Podargus strigoides) in Western Australia (WA) and genetically characterised the cytochrome b gene (cyt b) of L. podargii in wild tawny frogmouths from WA and Queensland (QLD). The prevalence of L. podargii in wild tawny frogmouths from WA was 93.3% (14/15; 95% CI, 68.1-99.8%). The morphological characters of L. podargii from WA were similar to L. podargii from QLD: the gametocytes were round-oval shape, approximately 8-12 µm in diameter; the macrogametocytes were 12.4 µm in diameter; microgametocytes were 10.4 µm in diameter; and the ratio of macrogametocytes and microgametocytes was 3:2. Sequence analysis of partial cyt b gene fragments revealed that L. podargii sequences isolated from wild tawny frogmouths in WA shared the highest similarity (99.8% at nucleotide level and 100% at protein level) with L. podargii isolated from wild tawny frogmouths in QLD. The mitochondrial 18S rRNA gene of L. podargii gametocytes was quantified using droplet digital PCR (ddPCR), and the highest gametocyte load was detected in the lung. This finding corresponds to the results of the histological study. Based on the morphological and molecular studies, it was concluded that the Leucocytozoon parasite identified from wild tawny frogmouths in WA is consistent with L. podargii from wild tawny frogmouths in QLD, and the present study has genetically characterised two different L. podargii genotypes (QLD and WA) for the first time.

Biliary Tract-Infecting Myxosporeans from Estuarine and Reef Stonefish (Scorpaeniformes: Synanceiidae) Off Eastern Australia, with Descriptions of Sphaeromyxa horrida n. sp. and Myxidium lapipiscis n. sp. (Myxosporea: Bivalvulida).

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).

Redescription of Rhabdochona papuanensis (Nematoda: Thelazioidea), a parasite of rainbow fishes (Melanotaenia spp.); the first record of the species of Rhabdochona in Australia.

Numerous specimens of the parasitic nematode Rhabdochona papuanensis Moravec, Riha et Kuchta, 2008 (Spirurida: Rhabdochonidae) were collected from the intestines of the Australian endemic freshwater fish (eastern rainbow fish) Melanotaenia splendida (Peters) (Melanotaeniidae, Atheriniformes) in the Behana Creek, North Queesland during November of 2015. Although many species of Rhabdochona Railliet, 1916 are known to be common parasites of fishes in other continents, the present finding of R. papuanensis represents the first record of the species belonging to this genus from the Australian mainland. Light and scanning electron microscopical examinations of these newly collected specimens made it possible to redescribe in detail this nematode species, originally incompletely described from a congeneric host in Papua New Guinea. Fully developed, filamented eggs of R. papuanensis and the conspecific fourth-stage larva are described for the first time. The present finding of R. papuanensis in M. splendida from Australia represents new host and geographical records.

Molecular and morphological characterization of Haemoproteus (Parahaemoproteus) ptilotis, a parasite infecting Australian honeyeaters (Meliphagidae), with remarks on prevalence and potential cryptic speciation.

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.

Elucidating the life cycle of Marteilia sydneyi, the aetiological agent of QX disease in the Sydney rock oyster (Saccostrea glomerata).

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.

The butterfly effect: parasite diversity, environment, and emerging disease in aquatic wildlife.

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.

Relatedness of novel species of Myxidium Bütschli, 1882, Zschokkella Auerbach, 1910 and Ellipsomyxa Køie, 2003 (Myxosporea: Bivalvulida) from the gall bladders of marine fishes (Teleostei) from Australian waters.

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.

Biogeography of tropical Indo-West Pacific parasites: a cryptic species of Transversotrema and evidence for rarity of Transversotrematidae (Trematoda) in French Polynesia.

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.

Molecular identification of cryptic species of Ceratomyxa Thélohan, 1892 (Myxosporea: Bivalvulida) including the description of eight novel species from apogonid fishes (Perciformes: Apogonidae) from Australian waters.

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.

Intra-specific variation of Kudoa spp. (Myxosporea: Multivalvulida) from apogonid fishes (Perciformes), including the description of two new species, K. cheilodipteri n. sp. and K. cookii n. sp., from Australian waters.

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.

Host specificity and local infection dynamics of Kudoa leptacanthae n. sp. (Multivalvulida: Kudoidae) from the pericardial cavity of two Zoramia spp. (Perciformes: Apogonidae) at Lizard Island lagoon, Queensland, Australia.

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.

Henneguya mauritaniensis n. sp. (Myxozoa) from the arterial bulb of Pagrus caeruleostictus (Valenciennes, 1830) off Mauritania.

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.

Brain infecting kudoids of Australia's coral reefs, including a description of Kudoa lemniscati n. sp. (Myxosporea: Kudoidae) from Lutjanus lemniscatus (Perciformes: Lutjanidae) off Ningaloo Reef, Western Australia.

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.

Morphological and genetic analysis of three new species of Ceratomyxa Thélohan, 1892 (Myxozoa: Myxosporea) from carcharhinid sharks off Australia.

Three new species of Ceratomyxa Thélohan, 1892 are described from the gall-bladders of two species of carcharhinid sharks collected off Heron and Lizard Islands on the Great Barrier Reef, Australia. Ceratomyxa carcharhini n. sp. and C. melanopteri n. sp. are described from Carcharhinus melanopterus (Quoy & Gaimard), and Ceratomyxa negaprioni n. sp. is described from Negaprion acutidens (Rüppell). These species are the first ceratomyxids reported from Australian elasmobranchs, and this is the first paper to formally characterise a novel Ceratomyxa species from an elasmobranch using both morphology and small subunit ribosomal DNA sequence data. Maximum parsimony and Bayesian inference analyses of the SSU rDNA dataset revealed that ceratomyxids from elasmobranchs form a sister clade to that of species infecting marine teleosts and Palliatus indecorus Schulman, Kovaleva & Dubina, 1979. Furthermore, the only sequenced freshwater ceratomyxid, Ceratomyxa shasta Noble, 1950, fell outside the overall marine ceratomyxid clade. These data show that Ceratomyxa, as currently recognised, is polyphyletic and ignites discussion on whether Ceratomyxa should be split. However, further taxon sampling, particularly in freshwater systems, is required to establish relevant biological divisions within the genus.

Geographical and host distribution patterns of Parvicapsula minibicornis (Myxozoa) small subunit ribosomal RNA genetic types.

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.

The life cycle of Cardicola forsteri (Trematoda: Aporocotylidae), a pathogen of ranched southern bluefin tuna, Thunnus maccoyi.

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.

Low host specificity in the Kudoidae (Myxosporea: Multivalvulida) including seventeen new host records for Kudoa thalassomi.

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.

Re-establishment of the family Coccomyxidae and description of five novel species of Auerbachia and Coccomyxa (Myxosporea: Bivalvulida) parasites from Australian fishes.

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.

Cryptic species of Euryakaina n. g. (Digenea: Cryptogonimidae) from sympatric lutjanids in the Indo-West Pacific.

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.