The systematics of the pseudoscorpion genus Indohya (Pseudoscorpiones: Hyidae) in Australia.

The pseudoscorpion genus Indohya Beier, 1974 is known to occur in three Gondwanan fragments around the Indian Oceansouthern India, Madagascar and north-western Australiasuggesting that the genus had evolved prior to the breakup of Gondwana and was present on each landmass as they rifted apart during the Mesozoic. The Australian fauna is the most diverse, with nine species previously described from Cape Range and the Kimberley region of north-western Australia. The present study documents the genus Indohya in Australia using a combination of morphology and DNA sequence data. We found a total of 36 species, including 27 new species. The majority of the Pilbara fauna consist of blind troglobites collected from subterranean ecosystems, with an additional three eyed species from epigean habitats. The new species consist of one from Cape Range (I. anastomosa Harvey & Burger, n. sp.), 21 from the Pilbara (I. adlardi Harvey & Burger, n. sp., I. alexanderi Harvey & Burger, n. sp., I. aphana Harvey & Burger, n. sp., I. aquila Harvey & Burger, n. sp., I. arcana Harvey & Burger, n. sp., I. arnoldstrongi Harvey & Burger, n. sp., I. boltoni Harvey & Burger, n. sp., I. cardo Harvey & Burger, n. sp., I. catherineae Harvey & Burger, n. sp., I. cockingi Harvey & Burger, n. sp., I. cribbi Harvey & Burger, n. sp., I. draconis Harvey & Burger, n. sp., I. furtiva Harvey & Burger, n. sp., I. incomperta Harvey & Burger, n. sp., I. jessicae Harvey & Burger, n. sp., I. lynbeazlyeae Harvey & Burger, n. sp., I. morganstrongi Harvey & Burger, n. sp., I. rixi Harvey & Burger, n. sp., I. sagmata Harvey & Burger, n. sp., I. scanloni Harvey & Burger, n. sp. and I. silenda Harvey & Burger, n. sp.) and five from the Kimberley (I. currani Harvey & Burger, n. sp., I. finitima Harvey & Burger, n. sp., I. julianneae Harvey & Burger, n. sp., I. karenae Harvey & Burger, n. sp. and I. sachsei Harvey & Burger, n. sp.). The study is augmented with sequence data from 29 species of Indohya, including all of the 24 species recorded from the Pilbara and Cape Range, and five of the 12 known Kimberley species. Seven clades recovered during the molecular analysis are only represented by nymphs, but we used COI sequence data to diagnose these species in the absence of adult morphological data.

New pathological condition in cultured mulloway Argyrosomus japonicus: histopathological, ultrastructural and molecular studies.

Mulloway Argyrosomus japonicus is a native fish species in Western Australia, for which aquaculture production has recently been developed. A single cohort was stocked in a cage offshore at Geraldton, Western Australia, at a water depth of 6 m. Fish appeared healthy before stocking. Routine histological analysis was carried out from 10 mo post stocking and until completion of harvest (about 2.5 yr post stocking). No gross pathology was evident. Microscopically, however, granulomatous lesions were present in the kidneys of almost 100% of the fish examined. Enclosed in the granuloma was an aggregate of organisms, 4.2 to 5.4 µm in diameter. Kidney granulomas appeared as multi-focal aggregates. Granulomas at different stages of formation and finally fibrosing granulomas were observed. Granulomas also appeared infrequently in other organs: a few granulomas were found in the liver and spleen and a single granuloma in the heart of one fish. Transmission electron microscopy (TEM) revealed that the organism was composed of 2 cells, an outer cell enclosing an inner cell. The inner cell was surrounded by a double membrane and the outer cell by a single membrane. Cellular material, presumably of parasitic nature, surrounded the outer cell. The organism contained primitive mitochondria and abundant free ribosomes. Small subunit ribosomal DNA (SSU rDNA) sequence obtained by PCR revealed an 84% sequence identity with the myxosporean Latyspora scomberomori. Based on TEM and preliminary molecular results, we suggest that the organism is the extrasporogonic developmental stage of a myxozoan parasite, which failed to form spores in the mulloway host.

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.

Phenotypic variation in a significant spore character in Kudoa (Myxosporea: Multivalvulida) species infecting brain tissue.

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.

Morphometric and molecular characterisation of four new Ceratomyxa species (Myxosporea: Bivalvulida: Ceratomyxidae) from fishes off Lizard Island, Australia.

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.