The ultrastructure of Macropodinium moiri and revised diagnosis of the Macropodiniidae (Litostomatea : Trichostomatia)

The ultrastructural features of Macropodinium moiri were investigated. The somatic cortex is composed of two lateral non-ciliated zones covered with trapezoidal plates and separated by a trough-like dorsoventral groove (DVG) which divides the cell into left and right halves. The somatic kineties occupy the margins of the DVG and are composed of monokinetids whose infraciliature shows a typical litostome pattern. The pellicular plates are lamellate, and separated by V-shaped grooves which are lined by thick-walled vacuoles. The DVG cortex is composed of electron-opaque U-shaped ribs which alternate with electron-lucent saccular structures. The DVG surface is composed of small regular pellicular sacs built up to form the ridges of the dorsal DVG. The vestibulum forms a laterally compressed cone with left/right differentiation. The basal section of its non-ciliated right side is internally lined (outer to innermost) by longitudinal fibres, nematodesmata and transverse microtubular ribbons. The left side bears the vestibular kineties and in its basal section is lined (outer to innermost) by small nematodesmata and transverse tubules. Cytoplasmic organelles include endoplasmic reticulum, starch granules and a single contactile vacuole surrounded by patches of nephridioplasm. Hydrogenosomes are absent and coccoid Gram-positive bacteria lie under the ciliated portions of the cell. This set of characteristics differs significantly from those of the all other trichostomes; Macropodiniidae is therefore designated Trichostomatia incertae sedis. A revised familial diagnosis of the Macropodiniidae is proposed.

Isolation of Gemmata-like and Isosphaera-like planctomycete bacteria from soil and freshwater

New cultured strains of the planctomycete division (order Planctomycetales) of the domain Bacteria related to species in the genera Gemmata and Isosphaera were isolated from soil, freshwater, and a laboratory ampicillin solution. Phylogenetic analysis of the 16S rRNA gene from eight representative isolates showed that all the isolates were members of the planctomycete division. Six isolates clustered with Gemmata obscuriglobus and related strains, while two isolates clustered with Isosphaera pallida. A double-membrane-bounded nucleoid was observed in Gemmata-related isolates but not in Isosphaera-related isolates, consistent with the ultrastructures of existing species of each genus. Two isolates from this study represent the first planctomycetes successfully cultivated from soil.

The ultrastructure of Amylovorax dehorityi comb. nov and erection of the Amylovoracidae fam. nov (Ciliophora : Trichostomatia)

The ultrastructural features of the holotrichous ciliates inhabiting macropodid maruspials were investigated to resolve their morphological similarity to other trichostome ciliates with observed differences in their small subunit rRNA gene sequences. The ultrastructure of Amylovorax dehorityi nov. comb. (formerly Dasytricha dehorityi) was determined by transmission electron microscopy. The somatic kineties are composed of monokinetids whose microtubules show a typical litostome pattern. The somatic cortex is composed of ridges which separate kinety rows, granular ectoplasm and a basal layer of hydrogenosomes lining the tela corticalis. The vestibulum is an invagination of the pellicle lined down one side with kineties (invaginated extensions of the somatic kineties); transverse tubules line the surface of the vestibulum and small nematodesmata surround it forming a cone-like network of struts. Cytoplasmic organelles include hydrogenosomes, irregularly shaped contractile vacuoles surrounded by a sparse spongioplasm, food vacuoles containing bacteria and large numbers of starch granules. This set of characteristics differs sufficiently from those of isotrichids and members of the genus Dasytricha to justify the erection of a new genus (Amylovorax) and a new family (Amylovoracidae). Dasytricha dehorityi, D. dogieli and D. mundayi are reassigned to the new genus Amylovorax and a new species A. quokka is erected. While the gross morphological similarities between Amylovorax and Dasytricha may be explained by convergent evolution, ultrastructural features indicate that these two genera have probably diverged independently from haptorian ancestors by successive reduction of the cortical and vestibular support structures.

New arsenite-oxidizing bacteria isolated from Australian gold mining environments - Phylogenetic relationships

Nine novel arsenite-oxidizing bacteria have been isolated from two different gold mine environments in Australia. Four of these organisms grow chemolithoautotrophically with oxygen as the terminal electron acceptor, arsenite as the electron donor, and carbon dioxide-bicarbonate as the sole carbon source. Five heterotrophic arsenite-oxidizing bacteria were also isolated, one of which was found to be both phylogenetically and physiologically identical to the previously described heterotrophic arsenite oxidizer misidentified as Alcaligenes faecalis. The results showed that this strain belongs to the genus Achromobacter. Phylogenetically, the arsenite-oxidizing bacteria fall within two separate subdivisions of the Proteobacteria. Interestingly, the chemolithoautotrophic arsenite oxidizers belong to the alpha-Proteobacteria, whereas the heterotrophic arsenite oxidizers belong to the beta-Proteobacteria.

Candidatus "Scalindua brodae", spec. nov., Candidatus "Scalindua wagneri", spec. nov., two new species of anaerobic ammonium oxidizing bacteria

Anaerobic ammonium oxidation (anammox) is both a promising process in wastewater treatment and a long overlooked microbial physiology that can contribute significantly to biological nitrogen cycling in the world's oceans. Anammox is mediated by a monophyletic group of bacteria that branches deeply in the Planctomycetales. Here we describe a new genus and species of anaerobic ammonium oxidizing planctomycetes, discovered in a wastewater treatment plant (wwtp) treating landfill leachate in Pitsea, UK. The biomass from this wwtp showed high anammox activity (5.0 +/- 0.5 nmol/mg protein/min) and produced hydrazine from hydroxylamine, one of the unique features of anammox bacteria. Eight new planctomycete 16S rRNA gene sequences were present in the 16S rRNA gene clone library generated from the biomass. Four of these were affiliated to known anammox 16S rRNA gene sequences, but branched much closer to the root of the planctomycete line of descent. Fluorescence in situ hybridization (FISH) with oligonucleotide probes specific for these new sequences showed that two species (belonging to the same genus) together made up > 99% of the planctomycete population which constituted 20% of the total microbial community. The identification of these organisms as typical anammox bacteria was confirmed with electron microscopy and lipid analysis. The new species, provisionally named Candidatus Scalindua brodae and Scalindua wagneri considerably extend the biodiversity of the anammox lineage on the 16S rRNA gene level, but otherwise resemble known anammox bacteria. Simultaneously, another new species of the same genus, Candidatus Scalindua sorokinii, was detected in the water column of the Black Sea, making this genus the most widespread of all anammox bacteria described so far.

Are Ichthyosporea animals or fungi? Bayesian phylogenetic analysis of elongation factor 1α of Ichthyophonus irregularis

Ichthyosporea is a recently recognized group of morphologically simple eukaryotes, many of which cause disease in aquatic organisms. Ribosomal RNA sequence analyses place Ichthyosporea near the divergence of the animal and fungal lineages, but do not allow resolution of its exact phylogenetic position. Some of the best evidence for a specific grouping of animals and fungi (Opisthokonta) has come from elongation factor 1alpha, not only phylogenetic analysis of sequences but also the presence or absence of short insertions and deletions. We sequenced the EF-1alpha gene from the ichthyosporean parasite Ichthyophonus irregularis and determined its phylogenetic position using neighbor-joining, parsimony and Bayesian methods. We also sequenced EF-1alpha genes from four chytrids to provide broader representation within fungi. Sequence analyses and the presence of a characteristic 12 amino acid insertion strongly indicate that I. irregularis is a member of Opisthokonta, but do not resolve whether I. irregularis is a specific relative of animals or of fungi. However, the EF-1alpha of I. irregularis exhibits a two amino acid deletion heretofore reported only among fungi. (C) 2003 Elsevier Science (USA). All rights reserved.

Ptychogyliauchen, a new genus of Gyliauchenidae (Platyhelminthes: Digenea) from siganid fishes of the Indo-West Pacific

We propose a new genus of the Gyliauchenidae Fukui, 1929 ( Digenea), Ptychogyliauchen, gen. nov., for four new species that infect Indo-West Pacific siganid fishes. Ptychogyliauchen, gen. nov. is a morphologically distinctive genus, diagnosed principally by the presence of a highly convoluted oesophagus, which generally exceeds the total body length of the worm, and by the unusual folded structure of the ejaculatory duct. Ptychogyliauchen thetidis, sp. nov. is designated as the type species, and is described from the intestine of Siganus punctatus (Siganidae) from Heron Island, Great Barrier Reef, Queensland, Australia. Ptychogyliauchen himinglaeva, sp. nov. is described from the intestine of Siganus corallinus ( Siganidae) from Lizard Island, Great Barrier Reef, Queensland, Australia. Ptychogyliauchen leucothea, sp. nov. is described from the intestine of S. argenteus, and further recorded from S. fuscescens, off Ningaloo, Western Australia, Australia. Ptychogyliauchen thistilbardi, sp. nov. is described from the intestine of S. doliatus from Noumea, New Caledonia, and is also found in S. argenteus, S. canaliculatus, S. corallinus and S. spinus from Noumea, New Caledonia, and Moorea, Tahiti, French Pacific. Ptychogyliauchen thistilbardi, sp. nov. also occurs in the intestine of Chaetodon citrinellus (Chaetodontidae) from Moorea. A key to species is provided. All species have been described following morphological examination using light microscopy, and specimens of P. thetidis, sp. nov., P. leucothea, sp. nov. and P. thistilbardi, sp. nov. have been characterised using molecular methods. Sequences were obtained for a combination of nuclear ribosomal (28S (D1-D3) and ITS2) and mitochondrial (ND1) genes. A phylogenetic analysis of sequenced specimens of Ptychogyliauchen, gen. nov. was conducted using species of Petalocotyle Ozaki, 1934 for outgroup comparison. This analysis, based on alignments of the ITS2 and 28S (D1-D3) rDNA genes, supports monophyly of the geographically widespread P. thistilbardi, sp. nov., which is known from both siganid and chaetodontid hosts. We discuss the taxonomy of the genus and the host associations of each species and the group.

The life cycle of Paracardicoloides yamagutii Martin, 1974 (Digenea: Sanguinicolidae)

The sanguinicolids Paracardicoloides yamagutii Martin, 1974 and Plethorchis acanthus Martin, 1975 were obtained from their definitive hosts, Anguilla reinhardtii Steindachner and Mugil cephalus Linnaeus (respectively) in the tributaries of the Brisbane River, Queensland, Australia. Two putative sanguinicolid cercariae were collected from a hydrobiid gastropod, Posticobia brazieri Smith, in the same waters. The two cercariae differ markedly in size and the form of their sporocysts. Both putative cercariae develop in the digestive gland of Po. brazieri. The ITS2 rDNA region from these sanguinicolids and a Clinostomum species (utilised as an outgroup due to the close morphological similarities between the cercarial stages of the Clinostomidae and the Sanguinicolidae) were sequenced and aligned. Comparison of the ITS2 sequences showed one cercaria to be that of P. yamagutii. This is the first sanguinicolid life history determined by a molecular method. P. yamagutii is the fourth sanguinicolid known to utilise a freshwater hydrobiid gastropod as its intermediate host. ITS2 rDNA is effective in distinguishing sanguinicolids at the species level.

Living on the edge: parasite taxonomy in Australia

The way in which the huge Australian parasite fauna is described (discovery and naming) is the subject of this address. The approach to the task has never been well-organised so that a few groups of parasites are now relatively well-known because of the efforts of small groups of workers who have made sustained efforts in these groups, but equally some host-parasite systems have been almost completely ignored in that no worker has ever given them sustained attention. A high proportion of Australian parasites have been described by international workers; The sustaining of interest in a group of parasites over a long period is the key to real progress being made. The nature of the organisation of Australian science presently means that few positions are available for parasite taxonomists and funding for taxonomic research is scarce. Thus, parasite taxonomy (like the taxonomy of many groups of Australian plants and animals) can only be considered to be in crisis. (C) 2003 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Species of Lecithocladium Luhe, 1901 (Digenea, Hemiuridae) from Australian marine fishes, with a description of a new species from various hosts off eastern Australia

Lecithocladium moretonense sp. nov. is described from Monodactylus argenteus (type-host), Abudefduf sordidus, A. whitleyi, Herklotsichthys castelnaui, Lutjanus russelli, Platycephalus indicus, Rhabdosargus sarba, Siganus nebulosus and Scorpis lineolata from Moreton Bay, southern Queensland, and Acanthopagrus australis from off northern New South Wales. It differs from most Lecithocladium species in having a subglobular oral sucker and pharynx. Other distinguishing features are the thin-walled recurved seminal vesicle and the pars prostatica coiling over the seminal vesicle to the level of the anterior testis. Lecithocladium megalaspis Yamaguti, 1953 from Alepes apercna, Moreton Bay and L. angustiovum Yamaguti, 1953 from Scomber australasicus, Fremantle, Western Australia, are also reported, illustrated and measured.

Two new blood flukes (Digenea: Sanguinicolidae) from epinephelinae (Perciformes: Serranidae) of the Pacific Ocean

Pearsonellum pygmaeus n. sp. is described from Cromileptes altivelis (Serranidae), the Barramundi Cod, from Heron Island (southern Great Barrier Reef) and Lizard Island (northern Great Bat-Her Reef). This new species differs from Pearsonellum eorventum (type and only species) in the combination of smaller overall body size, the relative distance of the brain from the anterior end, the relative lengths of both the oesophagus and the testis, the degree to which the testis extends outside the intercaecal field, the shape of the testis, the shape and size of the ovary and the extent to which the uterzus loops around the ovary. There are in addition, 20 base pair differences between the ITS2 rDNA sequence of P. pygmaeus n. sp. and that of P corventum. Three new host records for P. corventum are reported. Adelomyllos teenae n. g., n. sp. is described from Epinephelus coioides (Serranidae), the Estuary Cod, from Moreton Bay, southeast Queensland. The new genus differs from the 22 other sanguinicolid genera in the combined possession of two testes, a cirrus-sac, separate genital pores, a post-ovarian uterus and an H-shaped intestine. A. teenae n. sp. is the third sanguinicolid described from the Epinephelinae. Sanguinicolids have now been reported from 11 species of Serranidae. (C) 2004 Elsevier Ireland Ltd. All rights reserved.

Stephanostomum tantabiddii n. sp. (Digenea: Acanthocolpidae) from Carangoides fulvoguttatus (Forsskal, 1775) (Perciformes: Carangidae) from Ningaloo Reef, Western Australia

A new species, Stephanostomum tantabiddii n. sp., is described from the yellowspotted trevally Carangoides fulvoguttatus from Ningaloo Reef, Western Australia. It has 38 - 45 circum-oral spines and the vitellarium reaches to no less than 17% of the hindbody length from the ventral sucker. It differs from other species of Stephanostomum with these characteristics by various combinations of the ventral hiatus of the circum-oral spine rows, the relatively long pars prostatica and short ejaculatory duct, the elongate body and the wide gaps between the gonads.

Revision of Affecauda Hall & Chambers, 1999 (Digenea: Gyliauchenidae Fukui, 1929), including the description of two new species from fishes of the Indo-West Pacific

We describe 2 new species of Affecauda from the intestine of acanthuroid fishes of the Indo-West Pacific. Affecauda rugosa n. sp. is described from 1 mature specimen in excellent condition and 1 immature fractured specimen from the intestine of the sailfin tang, Zebrasoma veliferum (Acanthuridae), from Noumea, New Caledonia. Affecauda salacia n. sp. is described from the intestine of the ocellated spinefoot, Siganus corallinus (Siganidae), from Lizard Island, Great Barrier Reef, Queensland, Australia. Each of these species is made distinct from the type-species, Affecauda annulata Hall & Chambers, 1999, by combinations of the extent of tegumental annulations, conformation of the oesophagus and position of the ovary. The description of 2 new species of Affecauda necessitates a revision of the generic diagnosis, which is here amended to incorporate the additional species. A key to species is provided. The description of further species of Affecauda from waters external to the Great Barrier Reef and from siganid fishes expands the biogeographical range for species of Affecauda, from species of Naso on the Great Barrier Reef, to acanthuroid fishes of the western Pacific.

Ankistromeces mariae n. g., n. sp (Digenea : Sanguinicolidae) from Meuschenia freycineti (Monacanthidae) off Tasmania

Ankistromeces mariae n. g., n. sp. is described from Meuschenia freycineti (Monacanthidae), the six-spined leatherjacket, from off northern Tasmania. The new genus differs from the 21 other sanguinicolid genera in the combination of the anteriorly intercaecal and posteriorly post-caecal single testis, the presence of a cirrus-sac, the absence of an auxiliary external seminal vesicle, separate genital pores, the typically post-ovarian uterus and the H-shaped intestine. A. mariae is the first sanguinicolid to be reported from a monacanthid fish.