Large Subunit Ribosomal DNA Sequences Research Articles

Morphology and phylogeny of Pentapharsodinium jinhaense sp. nov. (Dinophyceae) producing a calcareous resting cyst

:A new species, Pentapharsodinium jinhaense sp. nov., was established by incubating resting cysts, which were collected from trap samples from Jinhae-Masan Bay, Korea. The resting cysts of P. jinhaense were spherical or ovoidal, with a large reddish pigment body and a thick wall covered by numerous needle-shaped calcareous crystals. The size, shape and plate tabulation of motile cells that germinated from the resting cysts were similar to those of Pentapharsodinium tyrrhenicum and Ensiculifera carinata; however, the motile cells had a spine located in the anterior sulcal plate and many pores and spines on the thecal surface. Molecular phylogenetic analysis using internal transcribed spacer and 5.8s rDNA showed that P. jinhaense was closely related to P. tyrrhenicum. Large subunit ribosomal DNA sequences also revealed that P. jinhaense was nested within Pentapharsodinium and formed a strongly supported clade with Pentapharsodinium dalei and P. tyrrhenicum.

Cyst-motile stage relationship, morphology, ultrastructure, and molecular phylogeny of the gymnodinioid dinoflagellateBarrufeta resplendenscomb. nov., formerly known asGyrodinium resplendens, isolated from the Gulf of Mexico

In the present study, we redescribed Gyrodinium resplendens through incubation of process bearing cysts extracted from sediment collected in the northern Gulf of Mexico. The morphology and ultrastructure of the motile stage and cyst stage were examined using light microscopy, scanning electron microscopy, and transmission electron microscopy and this revealed that the species should be transferred to the genus Barrufeta. This genus differs from other gymnodinioid genera in possessing a Smurf-cap apical structure complex (ASC) and currently encompasses only one species, Barrufeta bravensis. B.resplendens shows a Smurf-cap ASC that consists of three rows of elongated vesicles with small knobs in the middle one. B.resplendens is very similar to B.bravensis in cell morphology, but can be separated using the ultrastructure such as the shape and location of nucleus and pyrenoids, which highlights the importance of ultrastructure at inter-specific level in the genus Barrufeta. The unique cysts of B.resplendens are brown and process bearing, and have a tremic archeopyle with a zigzag margin on the dorsal side of the epicyst, and not polar as in cysts of Polykrikos. The cysts do not survive the palynological treatment used here and probably have a wide distribution. Maximum-likelihood and Bayesian inference were carried out based on partial large subunit ribosomal DNA (LSU rDNA) sequences. Molecular phylogeny supports that the genus Barrufeta is monophyletic, and that the genus Gymnodinium is polyphyletic. Our results suggest that details of the ASC together with ultrastructure are potential features to subdivide the genus Gymnodinium.

The molecular characterization of the enigmatic dinoflagellate Kolkwitziella acuta reveals an affinity to the Excentrica section of the genus Protoperidinium

Kolkwitziella acuta is a cyst-forming dinoflagellate with a unique tabulation, occurring in freshwater to brackish environments of Eurasia and the USA. Based on the unique thecal plate arrangement, this species was previously interpreted as a missing link in the evolution between the genus Protoperidinium and the Diplopsalioideae. We isolated living K. acuta cysts from the south-western Caspian Sea and the central Baltic (Finland), and re-established the cyst-theca relationship. The cysts had a distinctive polar and dorsoventral compression and a characteristic wrinkly texture. The plate formula of the thecate stage was Po, X, 4′, 2a, 7′′, 3c+t, ?s, 5′′′, 1′′′′. Large subunit (LSU) and small subunit (SSU) ribosomal DNA sequences obtained through single-cell PCR of these cysts reveal that this species is close to Protoperidinum excentricum which belongs to the Excentrica section of the genus Protoperidinium. We suggest that it evolved from the genus Diplopsalis through a split of the apical and anterior intercalary plates. Furthermore, that the split of the antapical plates occurred several times independently in the evolution of Protoperidinium and Diplopsalioideae and is therefore a polyphyletic trait. The cyst of Kolkwitziella is considered an indicator of low salinities, specifically between 0 and 22 psu. Geochemical analysis of the cyst walls suggests a heterotrophic mode of nutrition.

Skin lesions on yellowfin tuna Thunnus albacares from Gulf of Mexico outer continental shelf: Morphological, molecular, and histological diagnosis of infection by a capsalid monogenoid

We characterize lesion-associated capsaline infections on yellowfin tuna, Thunnus albacares, in the Gulf of Mexico by comparing our specimens with published descriptions and museum specimens ascribed to Capsala biparasiticum and its synonyms: vouchers of C. biparasiticum from parasitic copepods; the holotype of Capsala neothunni; and vouchers of Capsala abidjani. Those from parasitic copepods differed by having a small, rounded body, large anterior attachment organs, closely spaced dorsomarginal body sclerites, small testes, and a short and wide testicular field. No morphometric feature in the holotype of C. neothunni ranged outside of that reported for the newly-collected specimens, indicating conspecificity of our specimens. The specimens of C. abidjani differed by having a large anterior attachment organ, few and dendritic testes, and a short, wide testicular field. Large subunit ribosomal DNA (28S) sequences grouped our specimens and Capsala sp. as sister taxa and indicated a phylogenetic affinity of Nasicola klawei. The haptoral attachment site comprised a crater-like depression surrounded by a blackish-colored halo of extensively rugose skin, with abundant pockmarked-like, irregularly-shaped oblong or semi-circular epidermal pits surrounding these attachment sites. Histology confirmed extensive folding of epidermis and underlying stratum laxum, likely epidermal hyperplasia, foci of weak cell-to-cell adhesions among apical malpighian cells as well as that between stratum germinativum and stratum laxum, myriad goblet cells in epidermis, rodlet cells in apical layer of epidermis, and lymphocytic infiltrates and melanin in dermis. The present study comprises (i) the first published report of this parasite from yellowfin tuna captured in the Gulf of Mexico–NW Atlantic Ocean Basin, (ii) confirmation of its infection on the skin (rather than on a parasitic copepod), (iii) the first molecular data for this capsaline, and (iv) the first observations of histopathological changes associated with a capsalid infection on a wild-caught epipelagic fish.

Morphological examination and phylogenetic position of the newly recorded heterotrophic brackish dinoflagellate Diplopsalis caspica (Dinophyceae) in freshwater habitat from China

AbstractA heterotrophic dinoflagellate was identified as Diplopsalis caspica Ostenfeld by morphological characteristics, with the plate formula: Po, x, 3′, 1a, 6″, 4c, 4s, 5″′, 1″″. The newly recorded dinoflagellate was encountered during autumn in the phytoplankton community of Jihongtan Reservoir and some small ponds near the reservoir in Shandong Province, China. The species had been reported only in brackish ecosystems; however, our material fit with D. caspica occurred in freshwater habitat. The phylogenetic relationship of D. caspica was elucidated through small and large subunit ribosomal DNA sequences. In small and large subunit ribosomal DNA phylogenies, all Protoperidiniaceae species, including diplopsalids and Protoperidinium Bergh, could cluster into a monophyletic group. The molecular phylogenies indicated that the genus Diplopsalis would provide a link to the common ancestor of the Peridinium Ehrenberg and the Protoperidinium.

Cyst‐theca relationships and phylogenetic positions of Peridiniales (Dinophyceae) with two anterior intercalary plates, with description of Archaeperidinium bailongense sp. nov. and Protoperidinium fuzhouense sp. nov

SummaryProtoperidinium species with two anterior intercalary plates were originally classified by Jörgensen in the subgenus Archaeperidinium and assigned to the sections Excentrica, Avellana and Archaeperidinium by Taylor, on the basis of the relative size of anterior intercalary plates and the extent of cingulum displacement. Phylogenetic relationships among these three sections have not been fully explored. Recently, Archaeperidinium was reinstated as a genus, but several species fitting the emended description have not been transferred formally as molecular data were not available. In the present study we examined the cyst‐theca relationship of seven species with two anterior intercalary plates: four species assigned to Protoperidinium and three to Archaeperidinium, from the China Sea. Partial large subunit ribosomal DNA sequences were obtained from these seven species by single‐cell polymerase chain reaction, and for the cyst of Protoperidinium stellatum from France. Two new species, Archaeperidinium bailongense and Protoperidinium fuzhouense, were described based on both theca and cyst morphology, and the cyst‐theca relationships of A. constrictum and P. abei var. rotunda were established for the first time. Maximum‐likelihood and Bayesian inference analyses revealed that P. fuzhouense was nested within the Protoperidinium sensu stricto clade despite having only six postcingular plates, and sections Excentrica, Avellana and the genus Archaeperidinium were all monophyletic. Our results suggest that the presence/absence of a sulcal fin and antapical horns and the displacement of the cingulum are the most stable characteristics of the motile stages within the respective clades.

Fukuyoa paulensis gen. et sp. nov., a new genus for the globular species of the dinoflagellate Gambierdiscus (Dinophyceae).

The marine epiphytic dinoflagellate Gambierdiscus is a toxicologically important genus responsible for ciguatera fish poisoning, the principal cause of non-bacterial illness associated with fish consumption. The genus currently contains species exhibiting either globular or anterior-posteriorly compressed morphologies with marked differences in cell shape and plate arrangement. Here we report a third globular, epiphytic and tychoplanktonic species from the coasts of Ubatuba, Brazil. The new species can be distinguished from G. yasumotoi and G. ruetzleri by its broader first apical plate that occupies a larger portion of the epitheca. Accordingly, phylogenetic trees from small subunit (SSU) and large subunit (LSU) ribosomal DNA sequences also showed strongly supported separation of the new species from the G. yasumotoi / G. ruetzleri group albeit with short distance. The molecular phylogenies, which included new sequences of the planktonic species Goniodoma polyedricum, further indicated that the globular species of Gambierdiscus formed a tight clade, clearly separated (with strong bootstrap support) from the clade of lenticular species including the type for Gambierdiscus. The morphological and molecular data in concert support the split of Gambierdiscus sensu lato into two genera. Gambierdiscus sensu stricto should be reserved for the species with lenticular shapes, highly compressed anterioposteriorly, with short-shank fishhook apical pore plate, large 2' plate, low and ascending cingular displacement, and pouch-like sulcal morphology. The new genus name Fukuyoa gen. nov. should be applied to the globular species, slightly laterally compressed, with long-shank fishhook apical pore plate, large 1' plate, greater and descending cingular displacement, and not pouch-like vertically-oriented sulcal morphology. Fukuyoa contains the new species Fukuyoa paulensis gen. et sp. nov., and F. yasumotoi comb. nov. and F. ruetzleri comb. nov.

Cyst–theca relationship and phylogenetic positions of the diplopsalioideans (Peridiniales, Dinophyceae), with description of Niea and Qia gen. nov.

:Nine genera have been assigned to the subfamily Diplopsalioideae, but since most have not been characterized molecularly and their cyst–theca relationships are largely unknown, the phylogenetic relationships among these genera are not well understood. Here we established the cyst–theca relationships of 11 species (Boreadinium breve, Diplopelta globula, Diplopsalis lenticula, Diplopsalopsis ovata, Lebouraia pusilla, Niea acanthocysta, Niea chinensis, Niea torta, Oblea rotunda, Preperidinium cf. meunieri and Qia lebouriae) belonging to nine genera by incubating cysts collected along the coast of China. In addition, we obtained 22 large-subunit ribosomal DNA sequences from the germinated motile cells of these 11 species by single-cell polymerase chain reaction. A new genus, Niea, was erected to encompass species with a plate formula identical to that of Oblea, that is, Po, X, 3′, 1a, 6′′, 3C+t, 5′′′, 2′′′′, but with an ortho 1′. Niea chinensis was described based on both theca and cyst morphology. The genus Oblea was emended to incorporate only species with a meta 1′. As a consequence, Oblea acanthocysta and O. torta were transferred to the newly erected genus Niea. A second new genus, Qia, was established to encompass Diplopsalis lebouriae, and the genus Diplopsalis was emended, differing from Qia in the shape of the anterior intercalary (1a) plate. Phylogenetic analyses were carried out using maximum likelihood and Bayesian inference. Molecular phylogeny revealed that the diplopsalioideans were not monophyletic and were subdivided into three clades. From our results, the shape of the first apical and anterior intercalary plates and the number of apical, anterior intercalary and antapical plates were useful characteristics to distinguish the diplopsalioideans at the genus level.

Cyst–theca relationship and phylogenetic positions of Protoperidinium (Peridiniales, Dinophyceae) species of the sections Conica and Tabulata, with description of Protoperidinium shanghaiense sp. nov.

:The genus Protoperidinium has been divided into several sections based on the shape of the first apical plate, the number/shape of anterior intercalary plates and the presence/absence of antapical horns/spines; however, phylogenetic relationships among these sections have not been fully explored. We examined the cyst–theca relationships of seven Protoperidinium species isolated from sediments along the Chinese coast. Ten partial nuclear-encoded large subunit ribosomal DNA (LSU rDNA) sequences were obtained by single-cell polymerase chain reaction (PCR) for seven species belonging to the Conica and Tabulata sections of the genus. New cyst–theca relationships were established for Protoperidinium biconicum and Protoperidinium humile, and the former was restricted to warmer waters. Brigantedinium majusculum was identified as the cyst of Protoperidinium pentagonum; whereas, Trinovantedinium applanatum corresponded to Protoperidinium shanghaiense sp. nov. Phylogenetic analyses based on LSU rDNA sequences were carried out using maximum likelihood and Bayesian inference and revealed that the theca-based section Conica was polyphyletic, and Tabulata was monophyletic. Surprisingly, some cyst-based genera (e.g. Brigantedinium, Selenopemphix) proved to be polyphyletic.

Genetic diversity of Clavispora lusitaniae isolated from Agave fourcroydes Lem, as revealed by DNA fingerprinting.

This study characterized Clavispora lusitaniae strains isolated from different stages of the processing and early fermentation of a henequen (Agave fourcroydes) spirit produced in Yucatan, Mexico using a molecular technique. Sixteen strains identified based on morphological features, obtained from different substrates, were typed molecularly. Nine different versions of the divergent D1/D2 domain of the large-subunit ribosomal DNA sequence were identified among the C. lusitaniae strains. The greatest degree of polymorphism was found in the 90-bp structural motif of the D2 domain. The MSP-PCR technique was able to differentiate 100% of the isolates. This study provides significant insight into the genetic diversity of the mycobiota present during the henequen fermentation process, especially that of C. lusitaniae, for which only a few studies in plants have been published. The applied MSP-PCR markers were very efficient in revealing olymorphisms between isolates of this species.

AS2077715: a novel antifungal antibiotic produced by Capnodium sp. 339855.

A novel antifungal agent, AS2077715, was isolated from the fermentation broth of a fungal strain (339855) identified as a new Capnodium species based on morphological characteristics and large-subunit ribosomal DNA sequencing. AS2077715 was isolated as a white powder via solvent extraction, HP-20 and ODS-B column chromatography and crystallization, and was determined to have the molecular formula C25H41NO7. AS2077715 has a structure related to that of funiculosin, an inhibitor of mitochondrial cytochrome bc1 complex (complex III), and showed antifungal activity against Trichophyton species.

Epiphytic dinoflagellates in sub-tropical New Zealand, in particular the genus Coolia Meunier

Macroalgae growing in New Zealand's sub-tropical waters were sampled for epiphytic microalgae, in particular dinoflagellates. Four new Coolia isolates collected from sites throughout Northland in January/February 2013 were all identified as C. malayensis as determined by large subunit ribosomal DNA (LSU rDNA) sequence analysis and scanning electron microscopy. C. malayensis, a common dinoflagellate species in New Zealand, was previously reported as C. monotis and isolates held in the Cawthron Institute Culture Collection of Microalgae have now been reclassified based on the DNA sequence data. Toxicity studies of the New Zealand C. malayensis isolates (as determined by intraperitoneal (i.p.) injection of mice) resulted in an LD50 of 80.0mg/kg for isolate NLD 12 (95% CI: 63.8–101.0mg/kg) compared to a Malaysian isolate which exhibited low toxicity, with transient effects at 900mg/kg, but which resulted in the enlargement of the test animal's spleen. Ostreopsis siamensis, a common epiphytic bloom former in northern New Zealand, was found in association with Coolia at sites across Northland. Densest cell concentrations were collected from macroalgae throughout the Bay of Islands. Four new isolates of O. siamensis all produced palytoxin-like compounds (LC–MS analysis). Also isolated from Northland macroalgae were Amphidinium thermaeum (non-toxic by i.p. injection of mice) and Gambierdiscus cf. yasumotoi, with the latter producing a putative maitotoxin analogue (MTX-3) as determined by LC–MS.

New dinoflagellate species Protoperidinium haizhouense sp. nov. (Peridiniales, Dinophyceae), its cyst‐theca relationship and phylogenetic position within the Monovela group

SummaryThe number of cingular plates has been used to differentiate Protoperidinium from Peridinium and related genera. Protoperidinium is characterized by the presence of three cingular plates plus a transitional plate (3C+t). However, many Protoperidinium species have been described that exhibit different cingular plate tabulations. How these species should be classified within the genus remains unclear. To address this question, the phylogenetic relationship of four Protoperidinium species, with three or four cingular plates and lacking a transitional plate, were examined in relationship to other Protoperidinium species. These four species were germinated from cysts deposited in surface sediments collected from the East China Sea, the Bohai Sea and the Yellow Sea. Three of the isolated species, P. tricingulatum, P. americanum and P. parthenopes, were described previously. The fourth is here described as P. haizhouense sp. nov. with the plate formula Po, X, 4′, 3a, 7′′, 3C, 6S, 5′′′, 2′′′′. Differences in the cyst stages of these four species, which can be taxonomically informative, were compared. Partial large subunit ribosomal DNA sequences were obtained by single‐cell polymerase chain reaction. Maximum‐likelihood and Bayesian inference showed that these four species, P. fukuyoi and Islandinium minutum form a monophyletic clade with maximal support. The genus as a whole, however, appeared polyphyletic. Our results suggest that the presence/absence of a transitional plate is significant in the phylogeny of Protoperidinium.

New Species of the Genus Metschnikowia Isolated from Flowers in Indonesia, Metschnikowia cibodasensis sp. nov.

A novel species, Metschnikowia cibodasensis, is proposed to accommodate eight strains (ID03- 0093(T), ID03-0094, ID03-0095, ID03-0096, ID03-0097, ID03-0098, ID03-0099, and ID03-0109) isolated from flowers of Saurauia pendula, Berberis nepalensis, and Brunfelsia americana in Cibodas Botanical Garden, West Java, Indonesia. The type strain of M. cibodasensis is ID03- 0093(T) (= NBRC 101693(T) =UICC Y-335(T) = BTCC-Y25(T)). The common features of M. cibodasensis are a spherical to ellipsoidopedunculate shaped ascus, which contains one or two needleshaped ascospores, and lyse at maturity. Asci generally develop directly from vegetative cells but sometimes from chlamydospores. The neighbor-joining tree based on the D1/D2 domain of nuclear large subunit (nLSU) ribosomal DNA sequences strongly supports that M. cibodasensis (eight strains) and its closest teleomorphic species, M. reukaufii, are different species by a 100% bootstrap value. The type strain of M. cibodasensis, ID03-0093(T), differed from M. reukaufii NBRC 1679(T) by six nt (five substitutions and one deletion) in their D1/D2 region of nLSU rDNA, and by 18 nt (five deletions, four insertions, and nine substitutions) in their internal transcribed spacer regions of rDNA, respectively. Four strains representative of M. cibodasensis (ID03-0093(T), ID03-0095, ID03-0096, and ID03-0099) showed a mol% G+C content of 44.05 ± 0.25%, whereas that of M. reukaufii NBRC 1679(T) was 41.3%. The low value of DNADNA homology (5-16%) in four strains of M. cibodasensis and M. reukaufii NBRC 1679(T) strongly supported that these strains represent a distinct species.

Identification of Medically Relevant Species of Arthroconidial Yeasts by Use of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was used for an extensive identification study of arthroconidial yeasts, using 85 reference strains from the CBS-KNAW yeast collection and 134 clinical isolates collected from medical centers in Qatar, Greece, and Romania. The test set included 72 strains of ascomycetous yeasts (Galactomyces, Geotrichum, Saprochaete, and Magnusiomyces spp.) and 147 strains of basidiomycetous yeasts (Trichosporon and Guehomyces spp.). With minimal preparation time, MALDI-TOF MS proved to be an excellent diagnostic tool that provided reliable identification of most (98%) of the tested strains to the species level, with good discriminatory power. The majority of strains were correctly identified at the species level with good scores (>2.0) and seven of the tested strains with log score values between 1.7 and 2.0. The MALDI-TOF MS results obtained were consistent with validated internal transcribed spacer (ITS) and/or large subunit (LSU) ribosomal DNA sequencing results. Expanding the mass spectrum database by increasing the number of reference strains for closely related species, including those of nonclinical origin, should enhance the usefulness of MALDI-TOF MS-based diagnostic analysis of these arthroconidial fungi in medical and other laboratories.

Morphology, ultrastructure and phylogeny of Takayama xiamenensis sp. nov. (Gymnodiniales, Dinophyceae) from the East China Sea

Gu H., Luo Z., Zhang X., Xu B. and Fang Q. 2013. Morphology, ultrastructure and phylogeny of Takayama xiamenensis sp. nov. (Gymnodiniales, Dinophyceae) from the East China Sea. Phycologia 52: 256–265. DOI: 10.2216/12-090.1A new species, Takayama xiamenensis (Kareniaceae, Dinophyceae), was isolated from Xiamen Harbor, East China Sea, and its morphology was examined using light microscopy, scanning electron microscopy, and transmission electron microscopy (TEM). The vegetative cells of T. xiamenensis were 20.0–27.0 μm long, 18.0–23.0 μm wide and 17.0–20.5 μm thick. The apical groove was deeply sigmoid, and the sulcus extended into the epicone as a distinctive finger-like protrusion. Epifluorescence microscopy revealed a large, cup-shaped nucleus, filling most of the epicone. TEM showed that the chloroplasts were enveloped by two membranes and that some chloroplasts possessed large, bulging pyrenoids. Partial large subunit ribosomal DNA sequences of two strains of T. xiamenensis were identical to the putative T. acrotrocha strains from Italy, suggesting these strains might be conspecific. The original description of T. acrotrocha from Australia does not include a finger-like protrusion, thus justifying the new species description.

Molecular phylogeny of rhynchonellide articulate brachiopods (Brachiopoda, Rhynchonellida)

We present here the first report based on phylogenetic analyses of small subunit (SSU/18S) and large subunit (LSU/28S) ribosomal DNA (rDNA) sequences from a wider-than-token sample of rhynchonellide articulate brachiopods, with data from 11 of ∼20 extant genera (12 species) belonging to all four extant superfamilies. Data exploration by network and saturation analyses shows that the molecular sequence data are free from major aberrations and are suitable for phylogenetic reconstruction despite the presence of large deletions in four SSU rDNA sequences. Although molecular sequence analyses cannot directly illuminate the systematics of fossils, the independent, genealogical evidence and phylogenetic inferences about extant forms that they make possible are highly relevant to paleontological systematics because they highlight the limitations of evolutionary inference from morphology. Parsimony, distance, maximum likelihood (no clock) and Bayesian (relaxed-clock) analyses all find a tree topology that disagrees strongly with the existing superfamily classification. All tested phylogenetic reconstructions agree that the taxa analyzed fall into three clades designated A1, A2, and B that reflect two major divergence events. The relaxed-clock analysis indicates that clades A and B diverged in the Paleozoic, while clades A1 and A2 reflect Permo-Triassic (and later) events. Morphological homoplasy and possible gene co-option are suggested as the main sources for the discord between the morpho-classification, the results of cladistic analyses of morphology, and the relationships reconstructed from molecular sequences. The origin, function and evolutionary implications of the deletion-bearing rhynchonellide SSU rDNA sequences are briefly discussed in relation to pseudogenes and concerted evolution in the rDNA genomic region.

A new species of Lenzitopsis (Thelephorales, Basidiomycota) and its phylogenetic placement

Lenzitopsis (Thelephorales, Basidiomycota), typified by Lenzitopsis oxycedri, was monotypic before we described the second species of this genus, Lenzitopsis daii in this study. L. daii resembles L. oxycedri in producing lenzitoid hymenophore as well as brown hyphae and echinulate spores, but it differs from the type species by its annual basidiocarps, amyloid spores and growth exclusively on Juniperus chinensis (Cupressaceae). In the phylogenetic perspective inferred with nuclear large subunit ribosomal DNA sequences, the two species were separated from each other and formed a strongly supported clade in the Thelephorales. The two Lenzitopsis species showed a more than 5% difference in internal transcribed spacer sequences. Lenzitopsis species are wood-decaying fungi, and this is the second genus of the order where mycorrhizal life style is unknown, besides of Amaurodon.

Mortalities of sea-cage salmon ( Oncorhynchus tshawytscha) due to a bloom of Pseudochattonella verruculosa (Dictyochophyceae) in Queen Charlotte Sound, New Zealand

Over a 6 day period in mid winter (June) 2010 about 200 tonnes of Chinook salmon ( Oncorhynchus tshawytscha) on a sea-cage farm at Ruakaka Bay, Queen Charlotte Sound died as a result of exposure to a bloom of the dictyochophyte Pseudochattonella verruculosa. The alga was isolated and its identity confirmed by morphology and large subunit ribosomal DNA sequencing. Cells densities of P. verruculosa over several tens of thousands of cells per litre were sufficient to cause fish mortalities. The bloom originated in the inland reaches of the sound in the Grove Arm and the farm was located near its seaward extension. Fish were affected and recovered as the bloom front moved on and off the farm site under the influence of tidal currents. Before the bloom reached its peak (at about 1.0 × 10 5 cells L −1) the farm was relocated to a site outside the affected area where surviving fish quickly recovered. The bloom took place when day length and seawater temperatures were near their annual minimum (9 h and 12 °C respectively), and after its peak it was rapidly displaced by the in situ development of a diatom bloom dominated by Skeletonema costatum. The P. verruculosa bloom arose after several weeks of persistent rainfall. This may have assisted in the development of a circulation pattern that led to the movement of increasingly buoyant, relatively warm, nutrient-enriched bottom water into the Grove Arm, shoaling to shallow depths at the head of the inlet. The high productivity of waters in this area at the time is believed to have been largely driven by this mechanism. Larger size (∼3.5 kg) fish were mainly killed by the bloom and examination of affected salmon tissues showed pathologies in the liver and kidneys. There are ambitious plans for the expansion of sea cage fish farming in New Zealand and this event is a timely reminder of the hazard these events pose to sea cage fish farming operations.

Confirmation of the paraphyletic relationship between families Opisthorchiidae and Heterophyidae using small and large subunit ribosomal DNA sequences

Opisthorchiidae and Heterophyidae are classified into different families based on morphological identification. However, recent molecular phylogenetic studies suggested the possible paraphyletic relationship between these two families. In this study, the paraphyletic relationship between these two families was confirmed further by maximum likelihood and Bayesian inference analyses using the combined sequences of SSU and LSU rDNA.