Parasites (Monogenea) of tilapias Oreochromis niloticus and Coptodon rendalli (Cichlidae) in a river spring in Brazil

In the present study, we examined 30 individuals of introduced African cichlids, Oreochromis niloticus and Coptodon rendalli, collected in a river spring of the Pardo River, Paranapanema River basin, southeastern Brazil. Based on morphological and molecular analyses of the partial LSU rDNA gene, we identified four species of monogeneans, Cichlidogyrus tilapiae, C. thurstonae, C. mbirizei, and Scutogyrus longicornis on the gills of O. niloticus, whereas individuals of C. rendalli were infested only with C. papernastrema. This is the first record of C. mbirizei and C. papernastrema in tilapias from Brazil. The ecological consequences of the introduction of exotic species of tilapia such as O. niloticus and C. rendalli along with their monogenean parasites in a wild environment represented by a river spring are discussed. Our new molecular data on Cichlidogyrus and Scutogyrus contribute to the investigation of the phylogenetic interrelationships of these widely distributed genera of monogeneans since their species composition is still unsettled.

Single-cell DNA from West Greenland marine sediments suggests presence of Protoperidinium tricingulatum in the Arctic

Spiny brown dinoflagellate cysts are commonly used as sea-ice indicators in the Arctic, but their biological affinities are not well known. We present the first indication of hitherto temperate Protoperidinium tricingulatum in the Arctic based on single-cell LSU rDNA sequencing from sediments of the Disko Bay-Vaigat Sound, West Greenland. The morphological similarity of the sequenced cyst morphotype to the sea-ice indicator Islandinium? cezare morphotype 1 is striking. The morphology of the isolated cysts, as well as those observed in the total cyst assemblage following standard palynological preparation, both resemble either I.? cezare morphotype 1 or P. tricingulatum, suggesting that the specimens may in fact be close morphological variants of the same species. In addition, nine LSU rDNA sequences were obtained from morphological variants assigned to Islandinium minutum s.l.: including both subspecies minutum and subspecies barbatum. The two subspecies could not be differentiated based on partial LSU rDNA sequencing. Overall, Arctic spiny brown dinoflagellate cyst species may be morphologically more diverse and taxonomically more complex than shown earlier and further genetic and morphological studies are needed. Importantly, the value of cysts as palaeoecological indicators depends on a sound understanding of their biological affinity and taxonomy.

A new freshwater Ceratomyxa species (Myxozoa: Ceratomyxidae) parasitizing a sciaenid fish from the Amazon Basin, Brazil

Myxozoans of Ceratomyxidae Doflein, 1899 are common coelozoic parasites of marine life, and are also found less frequently in freshwater fish. The present study describes Ceratomyxa ranunculiformis n. sp. as a new freshwater myxosporean species infecting the gall bladder of the Amazonian sciaenid Plagioscion squamosissimus. The new Ceratomyxa was described based on its host, myxospore morphology, ribosomal rDNA gene sequencing, parasite distribution, and phylogenetic analysis. Immature and mature plasmodia were tadpole-shaped or pyriform, and exhibited slow undulatory motility. The myxospores were elongated and crescent-shaped in the frontal view, with a sutural line between two valves, which had rounded ends. The measurements of the formalin-fixed myxospores were: average length 4.9 (4.0-6.6) μm, average thickness 37.6 (32.4-43.9) μm, average posterior angle 165° (154°-173°). Two ovoid polar capsules of equal size, average length 2.0 (1.4-3.0) μm and average width 1.9 (1.4-2.4) μm, were located adjacent to the suture and contained polar filaments with 2-3 coils. The integrated comparative analysis of the morphological characteristics and molecular analyses of the ribosomal rDNA genes supported the identification of a new species of coelozoic Ceratomyxa. Maximum likelihood analyses showed the new species clustering within a well-supported clade, together with all the other Amazonian freshwater ceratomyxids.

New evidence of consistency between phylogeny and morphology for two taxa in ciliated protists, the subclasses Oligotrichia and Choreotrichia (Protista, Ciliophora)

Marine planktonic ciliates are largely oligotrichs and choreotrichs, which are two subclasses of the class Spirotrichea. The current phylogenetic assignments of oligotrichs and choreotrichs are inconsistent with previous results based on morphological features, probably hindered by the limited information from a single gene locus. Here we provide 53 new sequences from small subunit ribosomal RNA (SSU rDNA), ITS1-5.8S rDNA-ITS2, and large subunit ribosomal RNA (LSU rDNA) gene loci in 25 oligotrich and choreotrich species. We also predict RNA secondary structures for the ITS2 regions in 55 species, 48 species of which are reported for the first time. Based on these novel data, we make a more comprehensive phylogenetic reconstruction, revealing consistency between morphological taxonomy and an updated phylogenetic system for oligotrichs and choreotrichs. With the addition of data from ciliature patterns and genes, the phylogenetic analysis of the subclass Oligotrichia suggests three evolutionary trajectories, among which: 1) Novistrombidium asserts an ancestral ciliary pattern in Oligotrichia; 2) the subgenera division of Novistrombidium and Parallelostrombidium are fully supported; 3) the three families (Tontoniidae, Pelagostrombidiidae and Cyrtostrombidiidae) all evolved from the most diverse family Strombidiidae, which explains why strombidiids consistently form polyphyletic clades. In the subclass Choreotrichia, Strombidinopsis likely possesses an ancestral position to other choreotrichs, and both phylogenetic analysis and RNA secondary structure prediction support the hypothesis that tintinnids may have evolved from Strombidinopsis. The results presented here offer an updated hypothesis for the evolutionary history of oligotrichs and choreotrichs based on new evidence obtained by expanding sampling of molecular information across multiple gene loci.

First report of epiphytic dinoflagellate Coolia malayensis (Dinophyceae) in the southeastern Pacific Ocean

Coolia species are epiphytic and benthic dinoflagellates with a cosmopolitan distribution in tropical and subtropical areas. In the austral summer of 2016, during a survey in Bahía Calderilla, a dinoflagellate of the genus Coolia was detected in macroalgae samples, and a clonal culture was established. Subsequently, the cultured cells were observed by scanning electron microscopy (SEM) and identified as C. malayensis based on their morphological characteristics. Phylogenetic analyses based on the LSU rDNA D1/D2 regions confirmed that strain D005-1 corresponded to C. malayensis and clustered with strains isolated from New Zealand, Mexico, and Asia Pacific countries. Although the strain D005-1 culture did not contain yessotoxin (YTX), cooliatoxin, 44-methyl gambierone, or its analogs in detectable amounts by LC-MS/MS, more research is needed to evaluate its toxicity and to determine the possible impact of C. malayensis in northern Chilean waters.

Gambierdiscus (Gonyaulacales, Dinophyceae) diversity in Vietnamese waters with description of G. vietnamensis sp. nov

Viet Nam has a coastline of 3200 km with thousands of islands providing diverse habitats for benthic harmful algal species including species of Gambierdiscus. Some of these species produce ciguatera toxins, which may accumulate in large carnivore fish potentially posing major threats to public health. This study reports five species of Gambierdiscus from Vietnamese waters, notably G. australes, G. caribaeus, G. carpenteri, G. pacificus, and G. vietnamensis sp. nov. All species are identified morphologically by LM and SEM, and identifications are supported by molecular analyses of nuclear rDNA (D1-D3 and D8-D10 domains of LSU, SSU, and ITS1-5.8S-ITS2 region) based on cultured material collected during 2010-2021. Statistical analyses of morphometric measurements may be used to differentiate some species if a sufficiently large number of cells are examined. Gambierdiscus vietnamensis sp. nov. is morphologically similar to other strongly reticulated species, such as G. belizeanus and possibly G. pacificus; the latter species is morphologically indistinguishable from G. vietnamensis sp. nov., but they are genetically distinct, and molecular analysis is deemed necessary for proper identification of the new species. This study also revealed that strains denoted G. pacificus from Hainan Island (China) should be included in G. vietnamensis sp. nov.

Phylogeny and taxonomy of the genera of Erysiphaceae, part 3: Cystotheca

This contribution is part of a series devoted to the phylogeny and taxonomy of powdery mildews, with an emphasis on North American taxa. An overview of Cystotheca species is given, including references to ex-type sequences or, if unavailable, proposals for representative reference sequences for phylogenetic-taxonomic purposes. The new species C. mexicana is described, based on Mexican collections on Quercus glaucoides × Quercus microphylla and Quercus liebmannii × Q. microphylla. Cystotheca lanestris is reported for the first time worldwide on Quercus laceyi (Collected in Mexico) and on Q. toumeyi (collected in Arizona, USA). Cystotheca lanestris on Q. agrifolia and on Q. cerris is reported for the first time in Mexico. Epitypes with ex-epitype sequences are designated for Cystotheca wrightii, Lanomyces tjibodensis (= C. tjibodensis), Sphaerotheca kusanoi, and S. lanestris (C. lanestris).

Six marine thecate Heterocapsa (Dinophyceae) from Malaysia, including the description of three novel species and their cytotoxicity potential

Thirty-four strains of Heterocapsa were established from Malaysian waters and their morphologies were examined by light, scanning, and transmission electron microscopy. Three species, H. bohaiensis, H. huensis, and H. rotundata, and three new species, H. borneoensis sp. nov., H. limii sp. nov., and H. iwatakii sp. nov. were described in this study. The three species were differentiated morphologically by unique characteristics of cell size, shape, displacement of the cingulum, shape and position of nucleus, the number and position of pyrenoids, and body scale ultrastructure. The species delimitations were robustly supported by the molecular data. A light-microscopy-based key to species of Heterocapsa is established, with two major groups, i.e., species with a single pyrenoid, and species with multiple pyrenoids. Bioassays were conducted by exposing Artemia nauplii to Heterocapsa densities of 1-5 × 10⁵ cells mL^-1, and treatments exposed to H. borneoensis showed naupliar mortality, while no naupliar death was observed in the treatments exposed to cells of H. bohaiensis, H. huensis, H. limii, and H. iwatakii. Naupliar death was observed during the initial 24 h for both tested H. borneoensis strains, and mortality rates increased up to 50% after 72-h exposure. This study documented for the first time the diversity and cytotoxic potency of Heterocapsa species from Malaysian waters.

Description of two new species Chattonella tenuiplastida sp. nov. and Chattonella malayana sp. nov. (Raphidophyceae) from South China Sea, with a report of wild fish mortality

Fisheries damage caused by Chattonella red tide has been recorded in Southeast Asia. Molecular studies have clarified the presence of two species, Chattonella marina complex and Chattonella subsalsa in the region, unlike East Asia that had only C. marina complex. To elucidate the phylogeography of Chattonella in Asia, further phylogenetic and morphological examinations were carried out with 33 additional culture strains, including the strains isolated during a bloom of Chattonella sp. (up to 142 cells mL^-1) that was associated with a wild fish mortality along the northeastern coast of Peninsular Malaysia in 2016, and those from Yellow Sea, where the Chattonella genotypes have not been determined. LSU rDNA and ITS2 trees showed five intrageneric clades in the genus Chattonella, which were clades I and II (C. subsalsa), clade III (C. marina complex) and two new clades, namely clade IV from Thailand and Malaysia, and clade V from Peninsular Malaysia. The positions of the two new clades were different in LSU rDNA and ITS2 trees. LSU rDNA divergences of clades IV and V from the other clades were ≥ 4.01% and ≥ 5.70%, while their ITS2 divergences were ≥ 7.44% and ≥ 16.43%, respectively. Three and five compensatory base changes (CBCs) were observed in the clades IV and V, respectively, when compared to each of their closest clade. Cells from clades IV and V showed similar morphology to C. marina complex and C. subsalsa clade II, including the presence of button-like granules on cell surface and oboe-shaped mucocysts. However, cell size, the number and shape of chloroplasts in Chattonella clades IV and V, and the non-stacked thylakoids penetrated the pyrenoid in C. subsalsa clade II, were distinctive. Based on the diagnostic chloroplast shape, we proposed the designation of clades IV and V to two new species, Chattonella tenuiplastida sp. nov. and Chattonella malayana sp. nov.

Two New Species of Backusella (Mucorales, Mucoromycota) from Soil in an Upland Forest in Northeastern Brazil with an Identification Key of Backusella from the Americas

During a survey of Mucorales from a forest located in Pernambuco state, Brazil, two new Backusella species were discovered and described based on morphological and molecular data (internal transcribed spacer and large subunit ribosomal DNA sequences). Both species were characterized as unbranched sporangiophores and sporangia with columellae of varied shapes forming. Multispored sporangiola were frequent, whereas unispored sporangiola were rare. URM 8395 forms sporangiophores that may support hyaline, slightly curved or circinate pedicels with multispored sporangiola at their apical portion, and abundant giant cells and chlamydospores. Columellae of sporangia are hyaline, conical (majority), or ellipsoidal with a truncate base, globose to subglobose or subglobose to conical, and, rarely, with slight medial constriction. URM 8427 does not form sporangiola from pedicels, giant cells are not observed, and columellae of sporangia are globose to subglobose, cylindrical with a truncate base, some with a slight constriction, applanate, obovoid, ellipsoidal, or, rarely, conical. Some columellae may have one side more swollen than the other and some are arranged obliquely on the sporangiophores. Sterile sporangia may or may not be formed on short sporophores. The detailed description and illustration of both novel species as well as an identification key for Backusella from the Americas are provided.

Exploring LSU and ITS rDNA Sequences for Acanthamoeba Identification and Phylogeny

The identification and classification of strains of Acanthamoeba, a potentially pathogenic ubiquitous free-living amoeba, are largely based on the analysis of 18S rDNA sequences, currently delineating 23 genotypes, T1 to T23. In this study, the sequences of the ITS region, i.e., the 5.8S rDNA and the two internal transcribed spacers (ITS-1 and ITS-2), and those of the large subunit (LSU) rDNA of Acanthamoeba were recovered from amoeba genomes; the sequences are available in GenBank. The complete ITS–LSU sequences could be obtained for 15 strains belonging to 7 distinct lineages (T4A, T4D, T4F, T4G, T2, T5, and T18), and the site of the hidden break producing the 26Sα and 26Sβ was identified. For the other lines, either the LSU is partial (T2/T6, T7) or the ITS is fragmentary (T7, T10, T22). It is noteworthy that a number of sequences assigned to fungi turned out to actually be Acanthamoeba, only some of which could be affiliated with known genotypes. Analysis of the obtained sequences indicates that both ITS and LSU are promising for diagnostic and phylogenetic purposes.

First record of the diatom Nitzschia navis-varingica (Bacillariophyceae) producing amnesic shellfish poisoning-toxins from Papua New Guinea

To determine the species distribution of an amnesic shellfish poisoning (ASP) toxins-producing diatom Nitzschia navis-varingica outside its current restricted geographical distribution range in Asian coastal waters, samples were collected from two sites of Bootless Bay, located on southwest coast of Papua New Guinea near Port Moresby. A total of twenty-one strains of N. navis-varingica were isolated and the clonal cultures established. The species identity was confirmed by molecular characterization based on the ribosomal DNA markers. The LSU rDNA phylogenetic inference revealed a monophyletic clade of all strains, clustered with N. navis-varingica with high bootstrap supports. ASP toxin production in the strains was investigated by HPLC with fluorescence detection and subsequently confirmed for the representative isolates by LC-MS/MS with multiple reaction monitoring (MRM) mode. All eleven strains from site A showed presence of domoic acid (DA) and isodomoic acid (IB); the toxin quota ranged from 0.70 to 4.63 pg cell^-1 (average 2.75 ± 1.26 pg cell^-1, n = 11), with the composition of DA and IB of 21 DA: 79 IB. While for strains from site B, four out of ten strains showed presence of DA and IB, with the toxin quota ranged from 1.40 to 3.84 (average 2.57 ± 1.17 pg cell^-1, n = 4); the composition was 52 DA: 48 IB. The strains examined in this study were divided into toxic and probably non-toxic groups in ITS2 phylogeny. This represents the first record of domoic acid-producing Nitzschia navis-varingica from Papua New Guinea.

Deciphering phylogenetic relationships in class Karyorelictea (Protista, Ciliophora) based on updated multi-gene information with establishment of a new order Wilbertomorphida n. ord

The class Karyorelictea, a unique assemblage of ciliates, is a key group in deciphering ciliate evolution history. However, the systematic relationships among members of this class remain poorly understood. Here we newly obtained eight small subunit (SSU) rDNA, 24 large subunit (LSU) rDNA, and 25 ITS1-5.8S-ITS2 sequences (covering 25 species, 10 genera and 4 out of 6 families) to analyze the phylogenetic relationships within Karyorelictea. Our results indicate that: (1) considering its unique morphology and early branching position in the SSU rDNA-based tree, the family Wilbertomorphidae represents a new taxon at order level, hence the new order Wilbertomorphida n. ord. is established; (2) all five families with available molecular information are monophyletic, as expected, and the orders Loxodida and Protostomatida show a closer relationship than with Protoheterotrichida; (3) in Trachelocercidae, the compound circumoral kineties is believed to be a plesiomorphic feature while the single circumoral kinety is synapomorphic; and (4) the freshwater genus Loxodes could be derived from the marine Remanella and both share most morphological features. Taken together, these muti-gene analyses provide further insights into the phylogeny of the diverse clades in Karyorelictea.

Morphological and molecular characters of Scutellonema brachyurus () from South Africa

During a survey on plant-parasitic nematodes from South Africa, Scutellonema brachyurus was recovered from soil samples collected around the rhizosphere of wild grass in the North West and Limpopo provinces. This species characterized by a hemispherical lip region with four to six annuli, basal lip's annuli with longitudinal incisures, body length 696-904 µm (a = 25.1-33.5; b = 5.0-7.2; c = 48.9-75.3; c' = 0.5-0.9; V = 55-60), stylet 21-27 µm length, tail rounded with 10-19 µm length and spermatheca nonfunctional and male absent. The nblast analysis based on the D2-D3 segment of 28 S rDNA placed South African populations of S. brachyurus with 98% similarity to Greece (KU059494) and 99% similarity to South African (JX472052) S. brachyurus. Besides, nblast of COI of mtDNA showed 98% similarity of the test species with South African populations of S. brachyurus (JX472096; JX472097). The phylogenetic analysis put the South African populations of S. brachyurus together with other S. brachyurus with a 100 posterior probability support. Besides, the measurements, line illustration, and scanning electron microscopy photographs are provided for S. brachyurus from South Africa.

Detection of Prorocentrum minimum by hyperbranched rolling circle amplification coupled with lateral flow dipstick

A novel method referred to as hyperbranched rolling circle amplification (HRCA) coupled with lateral flow dipstick (LFD) (HRCA-LFD) here was developed for specific, sensitive, rapid, and simple detection of Prorocentrum minimum. HRCA-LFD relies on a padlock probe (PLP) consisting of a common ligation sequence, two terminal sequences that complement the target DNA, and a manually designed detection probe (LFD probe). The two terminal sequences of the PLP were designed against the species-specific sites of the large subunit ribosomal DNA (LSU rDNA) D1-D2 region of P. minimum. The optimum parameters for HRCA were as follows: PLP concentration of 20 pM, ligation time of 30 min, ligation temperature of 59 °C, enzymic digestion time of 105 min, amplification time of 45 min, and amplification temperature of 58 °C. The HRCA-LFD displaying high specificity could accurately distinguish P. minimum from other microalgae. The detection limit of HRCA-LFD was as low as 1.42 × 10^-7 ng μL^-1 for genomic DNA, 1.03 × 10^-7 ng μL^-1 (approximately 27 copies) for recombinant plasmid containing the inserted LSU rDNA D1-D2, and 0.17 cells for crude DNA extract of P. minimum, which was consistently 100 times more sensitive than regular PCR. Interfering test suggested that the performance of HRCA-LFD is stable and would not be affected by other non-target species. The HRCA-LFD results of field samples that are comparable with microscopic examination confirmed that the developed method is competent for detection of target cells in field samples. In conclusion, the developed HRCA-LFD exhibiting stable performance is specific, sensitive, and rapid, which provides a good alternative to traditional microscopic examination for the detection of P. minimum cells in field samples.

Taxonomy and toxicity of a bloom-forming Ostreopsis species (Dinophyceae, Gonyaulacales) in Tahiti island (South Pacific Ocean): one step further towards resolving the identity of O. siamensis

Among dinoflagellates responsible for benthic harmful algal blooms, the genus Ostreopsis primarily described from tropical areas has been increasingly reported from subtropical and temperate areas worldwide. Several species of this toxigenic genus produce analogs of palytoxin, thus representing a major threat to human and environmental health. The taxonomy of several species needs to be clarified as it was based mostly on morphological descriptions leading in some cases to ambiguous interpretations and misidentifications. The present study aims at reporting a benthic bloom that occurred in April 2019 in Tahiti island, French Polynesia. A complete taxonomic investigation of the blooming Ostreopsis species was realized using light, epifluorescence and field emission electron microscopy and phylogenetic analyses inferred from LSU rDNA and ITS-5.8S rDNA regions. Toxicity of a natural sample and strains isolated from the bloom was assessed using both neuroblastoma cell-based assay and LC-MS/MS analyses. Morphological observations showed that cells were round to oval, large, 58.0-82.5 µm deep (dorso-ventral length) and 45.7-61.2 µm wide. The cingulum was conspicuously undulated, forming a 'V' in ventral view. Thecal plates possessed large pores in depressions, with a collar rim. Detailed observation also revealed the presence of small thecal pores invisible in LM. Phylogenetic analyses were congruent and all sequences clustered within the genotype Ostreopsis sp. 6, in a subclade closely related to sequences from the Gulf of Thailand and Malaysia. No toxicity was found on the field sample but all the strains isolated from the bloom were found to be cytotoxic and produced ostreocin D, a lower amount of ostreocins A and B and putatively other compounds. Phylogenetic data demonstrate the presence of this species in the Gulf of Thailand, at the type locality of O. siamensis, and morphological data are congruent with the original description and support this identification.

An assessment on the intrapopulational and intraindividual genetic diversity in LSU rDNA in the harmful algal blooms-forming dinoflagellate Margalefidinium (= Cochlodinium) fulvescens based on clonal cultures and bloom samples from Jiaozhou Bay, China

Large subunit ribosomal DNA (LSU rDNA) sequences have been increasingly used to infer the phylogeny and species identity of organisms, a few previous studies, however, have observed high intraspecific and even intraindividual variability in LSU rDNA in some dinoflagellate species due to, assumably, large copy numbers of rDNA in dinoflagellates. Since the copy number of LSU rDNA varies tremendously among dinoflagellate species, the intraspecific and intraindividual diversity for a species of particular interest thus needs to be investigated individually. As a toxic and HABs-forming dinoflagellate, Margalefidinium (= Cochlodinium) fulvescens has been observed to approach blooming density in Jiaozhou Bay, China since 2015 after numerous blooms having been reported from other countries. In trying to identify the source of this newly observed HABs-forming species in China by sequencing the LSU rDNA for both field samples and clonal cultures, we noticed and thus further investigated high intrapopulational and intraindividual genetic diversities of the dinoflagellate. The D1-D6 region of the LSU rDNA (1,435 bases) was amplified from 7 field samples (pooled cells) and 11 clonal cultures, cloned, sequenced, and analyzed phylogenetically for 2,341 sequences obtained. All the numbers of sequences obtained from each clonal culture were far less than the estimated rDNA copy number in M. fulvescens. In the clone library, only one unique sequence was contained in all samples as the most dominant sequence. We found high intrapopulational and intraindividual genetic diversity in M. fulvescens as reflected in the number of polymorphic sites and unique sequences in the clone library for different field samples and clonal cultures in comparison to other species. The mean number of nucleotide differences of each sequence from different field samples and clonal cultures were 6.43 and 4.42 bases, respectively, with the highest being 132 bases, nearly 10%. The sequences with highest variability may be easily annotated as different species if they were obtained from environmental genomic studies because sequence-based species identification in meta-barcoding studies often use "97% identity" threshold. Based on that the mean and overall intrapopulational genetic diversity calculated for 7 field samples was equivalent to the mean and overall intraindividual variability for 11 clonal cultures in indices of genetic diversity, together with the result of AMOVA analysis, we infer that the variability within individual cells (i.e. variability among LSU rDNA polymorphic copies) caused both the intraindividual and intrapopulational genetic diversities observed in the M. fulvescens population, and a higher interpopulational diversity may exist among different geographic populations. The results provide an insightful basis for such a comprehensive interpopulational comparison and important implications for identifying species and establishing new taxa based on the similarity comparison to reference sequences deposited in databases.

Morphological and molecular data on a new species of Plagiorhynchus Lühe, 1911 (Acanthocephala: Plagiorhynchidae) from the long-billed curlew (Numenius americanus) from northern Mexico

A new species of the genus Plagiorhynchus Lühe, 1911 from the intestine of the long-billed curlew (Numenius americanus) from northern Mexico is described. Plagiorhynchus (Plagiorhynchus) aznari n. sp. is morphologically distinguished from other congeneric species from the Americas by having a trunk expanded anteriorly and a cylindrical proboscis, armed with 19 longitudinal rows of hooks, with 14-15 hooks each row. Nearly complete sequences of the small subunit and large subunit of the nuclear ribosomal DNA of the new species were determined and compared with available sequences from GenBank. Phylogenetic analyses inferred from the two molecular markers consistently showed that P. (Plagiorhynchus) aznari n. sp. is closely related to P. (Plagiorhynchus) allisonae, and this clade is sister to a clade formed by P. (Prosthorhynchus) transversus and P. (Prosthorhynchus) cylindraceus from Plagiorhynchidae. The new species represents the second record of the genus in Mexico and the fourth species in the Americas. The phylogenetic relationships among the members of the order Polymorphida in this study provide significant insights into the evolution of ecological associations between parasites and their definitive hosts. Our analyses suggest that the colonization of marine mammals, fish-eating birds and waterfowl in Polymorphidae might have occurred independently, from a common ancestor of Centrorhynchidae and Plagiorhynchidae that colonized terrestrial birds and mammals.

Fungal, Bacterial, and Archaeal Diversity in Soils Beneath Native and Introduced Plants in Fiji, South Pacific

The Fiji Islands is an archipelago of more than 330 islands located in the tropics of the South Pacific Ocean. Microbial diversity and biogeography in this region is still not understood. Here, we present the first molecular characterization of fungal, bacterial, and archaeal communities in soils from different habitats within the largest Fijian island, Viti Levu. Soil samples were collected from under native vegetation in maritime-, forest-, stream-, grassland-, and casuarina-dominated habitats, as well as from under the introduced agricultural crops sugarcane, cassava, pine, and mahogany. Soil microbial diversity was analyzed through MiSeq amplicon sequencing of 16S (for prokaryotes), ITS, LSU ribosomal DNA (for fungi). Prokaryotic communities were dominated by Proteobacteria (~ 25%), Acidobacteria (~ 19%), and Actinobacteria (~ 17%), and there were no indicator species associated with particular habitats. ITS and LSU were congruent in β-diversity patterns of fungi, and fungal communities were dominated by Ascomycota (~ 57-64%), followed by Basidiomycota (~ 20-23%) and Mucoromycota (~ 10%) according to ITS, or Chytridiomycota (~ 9%) according to LSU. Indicator species analysis of fungi found statistical associations of Cenococcum, Wilcoxina, and Rhizopogon to Pinus caribaea. We hypothesize these obligate biotrophic fungi were co-introduced with their host plant. Entoloma was statistically associated with grassland soils, and Fusarium and Lecythophora with soils under cassava. Observed richness varied from 65 (casuarina) to 404 OTUs (cassava) for fungi according to ITS region, and from 1268 (pine) to 2931 OTUs (cassava) for bacteria and archaea. A major finding of this research is that nearly 25% of the fungal OTUs are poorly classified, indicative of novel biodiversity in this region. This preliminary survey provides important baseline data on fungal, bacterial, and archaeal diversity and biogeography in the Fiji Islands.

Establishment and application of hyperbranched rolling circle amplification coupled with lateral flow dipstick for the sensitive detection of Karenia mikimotoi

The dinoflagellate Karenia mikimotoi is a noxious and harmful algal bloom (HAB)-forming microalga. Establishing a rapid, accurate, and sensitive method of detecting this harmful alga is necessary to provide warnings of imminent HABs through field monitoring. Here, an isothermal amplification technique combined with a rapid analytical method for nucleic acid-based amplified products, i.e., hyperbranched rolling circle amplification (HRCA) coupled with lateral flow dipstick (LFD), hereafter denoted as HRCA-LFD, was established to detect K. mikimotoi. The HRCA-LFD assay relied on a padlock probe (PLP) targeting DNA template and an LFD probe targeting PLP. The sequenced internal transcribed spacer of K. mikimotoi through molecular cloning was used as the target of PLP. The optimized HRCA conditions was determined to be as follows: PLP concentration, 20 pM; ligation temperature, 65 °C; ligation time, 10 min; amplification temperature, 61 °C; and amplification time, 30 min. The developed HRCA-LFD assay was specific for K. mikimotoi, displaying no cross-reactivity with other common microalgae. Sensitivity-comparison tests indicated that HRCA-LFD assay was 100-fold more sensitive than PCR, with a detection limit of 0.1 cell mL^-1 when used to analyze spiked field samples. The analysis with field samples also indicated that HRCA-LFD assay was suitable for samples with a target cell density range of 1-1000 cells mL^-1. All of these results suggested that HRCA-LFD assay is an alternative method for the sensitive and reliable detection of K. mikimotoi from marine water samples.

Ostreopsis lenticularis Y. Fukuyo (Dinophyceae, Gonyaulacales) from French Polynesia (South Pacific Ocean): A revisit of its morphology, molecular phylogeny and toxicity

To date, the genus Ostreopsis comprises eleven described species, of which seven are toxigenic and produce various compounds presenting a major threat to human and environmental health. The taxonomy of several of these species however remains controversial, as it was based mostly on morphological descriptions leading, in some cases, to ambiguous interpretations and even possible misidentifications. The species Ostreopsis lenticularis was first described by Y. Fukuyo from French Polynesia using light microscopy observations, but without genetic information associated. The present study aims at revisiting the morphology, molecular phylogeny and toxicity of O. lenticularis based on the analysis of 47 strains isolated from 4 distinct locales of French Polynesia, namely the Society, Australes, Marquesas and Gambier archipelagos. Observations in light, epifluorescence and field emission scanning electron microscopy of several of these strains analyzed revealed morphological features in perfect agreement with the original description of O. lenticularis. Cells were oval, not undulated, 60.5-94.4 μm in dorso-ventral length, 56.1-78.2 μm in width, and possessed a typical plate pattern with thecal plates showing two sizes of pores. Phylogenetic analyses inferred from the LSU rDNA and ITS-5.8S sequences revealed that the 47 strains correspond to a single genotype, clustering with a strong support with sequences previously ascribed to Ostreopsis sp. 5. Clonal cultures of O. lenticularis were also established and further tested for their toxicity using the neuroblastoma cell-based assay and LCMS/MS analyses. None of the 19 strains tested showed toxic activity on neuroblastoma cells, while LCMS/MS analyses performed on the strains from Tahiti Island (i.e. type locality) confirmed that palytoxin and related structural analogs were below the detection limit. These findings allow to clarify unambiguously the genetic identity of O. lenticularis while confirming previous results from the Western Pacific which indicate that this species shows no toxicity, thus stressing the need to reconsider its current classification within the group of toxic species.

Extensive Cryptic Diversity in the Terrestrial Diatom Pinnularia borealis (Bacillariophyceae)

With the increasing application of molecular techniques for diatom species discovery and identification, it is important both from a taxonomic as well as an ecological and applied perspective, to understand in which groups morphological species delimitation is congruent with molecular approaches, or needs reconsideration. Moreover, such studies can improve our understanding of morphological trait evolution in this important group of microalgae. In this study, we used morphometric analysis on light microscopy (LM) micrographs in SHERPA, detailed scanning electron microscopy (SEM), and cytological observations in LM to examine 70 clones belonging to eight distinct molecular lineages of the cosmopolitan terrestrial diatom Pinnularia borealis. Due to high within-lineage variation, no conclusive morphological separation in LM nor SEM could be detected. Morphological stasis due to the "low-morphology" problem or stabilizing selection, as well as parallel/convergent evolution, phenotypic plasticity and structural inheritance are discussed as potential drivers for the observations. Altogether, P. borealis is truly cryptic, in contrast to the majority of other diatom species complexes which turned out to be pseudo-cryptic following detailed morphological analysis.

Morphological and molecular diversity of arbuscular mycorrhizal fungi in revegetated iron-mining site has the same magnitude of adjacent pristine ecosystems

Arbuscular mycorrhizal fungi (AMF) are important during revegetation of mining sites, but few studies compared AMF community in revegetated sites with pristine adjacent ecosystems. The aim of this study was to assess AMF species richness in a revegetated iron-mining site and adjacent ecosystems and to relate AMF occurrence to soil chemical parameters. Soil samples were collected in dry and rainy seasons in a revegetated iron-mining site (RA) and compared with pristine ecosystems of forest (FL), canga (NG), and Cerrado (CE). AMF species were identified by spore morphology from field and trap cultures and by LSU rDNA sequencing using Illumina. A total of 62 AMF species were recovered, pertaining to 18 genera and nine families of Glomeromycota. The largest number of species and families were detected in RA, and Acaulospora mellea and Glomus sp1 were the most frequent species. Species belonging to Glomeraceae and Acaulosporaceae accounted for 42%-48% of total species richness. Total number of spores and mycorrhizal inoculum potential tended to be higher in the dry than in the rainy season, except in RA. Sequences of uncultured Glomerales were dominant in all sites and seasons and five species were detected exclusively by DNA-based identification. Redundancy analysis evidenced soil pH, organic matter, aluminum, and iron as main factors influencing AMF presence. In conclusion, revegetation of the iron-mining site seems to be effective in maintaining a diverse AMF community and different approaches are complementary to reveal AMF species, despite the larger number of species being identified by traditional identification of field spores.

Comparison of loop-mediated isothermal amplification with hyperbranched rolling circle amplification as a simple detection method for Heterosigma akashiwo

The fish-killing alga Heterosigma akashiwo is a globally distributed, toxic, and bloom-forming raphidophyte that has caused great losses to the fishing industry in many coastal countries. Therefore, rapid and sensitive detection methods should be developed to present timely warning of harmful algal blooms. In this study, hyperbranched rolling circle amplification (HRCA) was established for the detection of H. akashiwo and compared with loop-mediated isothermal amplification (LAMP) in terms of specificity and sensitivity. The partial D1-D2 sequence of the large subunit (LSU) of rDNA of H. akashiwo was used to design a specific padlock probe for HRCA and two pairs of specific primers for LAMP. The parameters for HRCA were optimized. Cross-reactivity tests showed that the specificity of the developed HRCA for H. akashiwo was greater than that of LAMP in this study. The sensitivities of HRCA and LAMP were comparable and were 10-fold higher than that of regular PCR. These methods also yielded a detection limit of 20 fg/μL for the recombinant plasmid containing the target LSU D1-D2 and 1 cell for target species. The test with the simulated field samples indicated that the developed HRCA obtained a detection limit of 5 cells mL^-1, which was lower than the warning cell density (100 cells mL^-1) of H. akashiwo. The visual detection of positive HRCA could be achieved via coloration reaction with the addition of fluorescent SYBR Green I dye to the amplification products. The developed HRCA was also efficient for field samples with target cell densities ranging from 10 cells mL^-1 to 1000 cells mL^-1. Therefore, the proposed HRCA detection protocols are possibly applicable to the field monitoring of H. akashiwo.

Morphology and phylogeny of Prorocentrum caipirignum sp. nov. (Dinophyceae), a new tropical toxic benthic dinoflagellate

A new species of toxic benthic dinoflagellate is described based on laboratory cultures isolated from two locations from Brazil, Rio de Janeiro and Bahia. The morphology was studied with SEM and LM. Cells are elliptical in right thecal view and flat. They are 37-44μm long and 29-36μm wide. The right thecal plate has a V shaped indentation where six platelets can be identified. The thecal surface of both thecal plates is smooth and has round or kidney shaped and uniformly distributed pores except in the central area of the cell, and a line of marginal pores. Some cells present an elongated depression on the central area of the apical part of the right thecal plate. Prorocentrum caipirignum is similar to Prorocentrum lima in its morphology, but can be differentiated by the general cell shape, being elliptical while P. lima is ovoid. In the phylogenetic trees based on ITS and LSU rDNA sequences, the P. caipirignum clade appears close to the clades of P. lima and Prorocentrum hoffmannianum. The Brazilian strains of P. caipirignum formed a clade with strains from Cuba, Hainan Island and Malaysia and it is therefore likely that this new species has a broad tropical distribution. Prorocentrum caipirignum is a toxic species that produces okadaic acid and the fast acting toxin prorocentrolide.

Taxonomic assignment of the benthic toxigenic dinoflagellate Gambierdiscus sp. type 6 as Gambierdiscus balechii (Dinophyceae), including its distribution and ciguatoxicity

Recent molecular phylogenetic studies of Gambierdiscus species flagged several new species and genotypes, thus leading to revitalizing its systematics. The inter-relationships of clades revealed by the primary sequence information of nuclear ribosomal genes (rDNA), however, can sometimes be equivocal, and therefore, in this study, the taxonomic status of a ribotype, Gambierdiscus sp. type 6, was evaluated using specimens collected from the original locality, Marakei Island, Republic of Kiribati; and specimens found in Rawa Island, Peninsular Malaysia, were further used for comparison. Morphologically, the ribotype cells resembled G. scabrosus, G. belizeanus, G. balechii, G. cheloniae and G. lapillus in thecal ornamentation, where the thecal surfaces are reticulate-foveated, but differed from G. scabrosus by its hatchet-shaped Plate 2', and G. belizeanus by the asymmetrical Plate 3'. To identify the phylogenetic relationship of this ribotype, a large dataset of the large subunit (LSU) and small subunit (SSU) rDNAs were compiled, and performed comprehensive analyses, using Bayesian-inference, maximum-parsimony, and maximum-likelihood, for the latter two incorporating the sequence-structure information of the SSU rDNA. Both the LSU and SSU rDNA phylogenetic trees displayed an identical topology and supported the hypothesis that the relationship between Gambierdiscus sp. type 6 and G. balechii was monophyletic. As a result, the taxonomic status of Gambierdiscus sp. type 6 was revised, and assigned as Gambierdiscus balechii. Toxicity analysis using neuroblastoma N2A assay confirmed that the Central Pacific strains were toxic, ranging from 1.1 to 19.9 fg P-CTX-1 eq cell^-1, but no toxicity was detected in a Western Pacific strain. This suggested that the species might be one of the species contributing to the high incidence rate of ciguatera fish poisoning in Marakei Island.

LSU rDNA based RFLP assays for the routine identification of Gambierdiscus species

The Gambierdiscus genus is a group of benthic dinoflagellates commonly associated with ciguatera fish poisoning (CFP), which is generally found in tropical or sub-tropical regions around the world. Morphologically similar species within the genus can vary in toxicity; however, species identifications are difficult or sometimes impossible using light microscopy. DNA sequencing of ribosomal RNA genes (rDNA) is thus often used to identify and describe Gambierdiscus species and ribotypes, but the expense and time can be prohibitive for routine culture screening and/or large-scale monitoring programs. This study describes a restriction fragment length polymorphism (RFLP) typing method based on analysis of the large subunit rDNA that can successfully identify at least nine of the described Gambierdiscus species and two Fukuyoa species. The software programs DNAMAN 6.0 and Restriction Enzyme Picker were used to identify a set of restriction enzymes (SpeI, HpyCH4IV, and TaqαI) capable of distinguishing most of the known Gambierdiscus species for which DNA sequences were available. This assay was tested using in silico analysis and cultured isolates, and species identifications of isolates assigned by RFLP typing were confirmed by DNA sequencing. To verify the assay and assess intra-specific heterogeneity in RFLP patterns, identifications of 63 Gambierdiscus isolates comprising ten Gambierdiscus species, one ribotype, and two Fukuyoa species were confirmed using RFLP typing, and this method was subsequently employed in the routine identification of isolates collected from the Caribbean Sea. The RFLP assay presented here reduces the time and cost associated with morphological identification via scanning electron microscopy and/or DNA sequencing, and provides a phylogenetically sensitive method for routine Gambierdiscus species assignment.

A new species of Gambierdiscus (Dinophyceae) from the south-west Pacific: Gambierdiscus honu sp. nov

Two isolates of a new tropical, epiphytic dinoflagellate species, Gambierdiscus honu sp. nov., were obtained from macroalgae sampled in Rarotonga, Cook Islands, and from North Meyer Island, Kermadec Islands. Gambierdiscus honu sp. nov. had the common Gambierdiscus Kofoidian plate formula: Po, 3', 6″, 6C?, 6 or 7S, 5‴, 1p and 2⁗. The characteristic morphological features of this species were its relatively small short dorsoventral length and width and the shape of individual plates, in particular the combination of the hatchet-shaped 2' and pentagonal 3' plates and the length to width ratio of the antapical 1p plate. The combination of these characteristics plus the smooth thecal surface and equal sized 1⁗ and 2⁗ plates differentiated this species from other Gambierdiscus species. The phylogenetic analyses supported the unique description. Both isolates of G. honu produced the putative maitotoxin (MTX)-3 analogue, but neither produced ciguatoxin (CTX) or MTX. Extracts of G. honu were shown to be highly toxic to mice by intraperitoneal injection (0.2mg/kg), although less toxic by gavage. It is possible that toxins other than putative MTX-3 are produced.

Molecular Characterization and Phylogenetic Congruence of Hydropsyche sciligra (Tricoptera: Hydropsychidae) Using Mitochondrial and Nuclear Markers

BACKGROUND

Caddisflies have significant roles in freshwater ecosystems. Morphological identification is the major impediment in accurate species identification of Hydropsychids. Mitochondrial and nuclear markers are suitable for molecular systematics of these group of arthropods.

METHODS

Trichopteran specimens of Lavasan District in northeastern Tehran, Iran were collected in 2012, and described using the morphological and molecular characters of mitochondrial cytochrome c oxidase subunit I (mt-COI) and three expansion fragments of large subunit (LSU) nuclear ribosomal DNA (28S rDNA) D1, D2, and D3. The resemblance of the specimen sequences was obtained by conducting BLAST searches against the GenBank database and by using simple maximum likelihood clustering using COI, D1, D2, D3, and combination of D1-D2-D3 sequence data sets.

RESULTS

Based on morphological traits the specimens were resembled to Hydropsyche sciligra however there were no its counterpart sequences in the GenBank. Due to lack of unique group of data set for each gene fragment, the specimens were associated with different taxa on molecular phylograms. The sequence contents of the COI, D1, D2, D3, and D1-D3 regions clustered H. sciligra with H. brevis, H. angustipennis, H. occidentalis, H. hedini, H. grahami, and H. longifurca/H. naumanni, respectively.

CONCLUSION

Phylogenies obtained from combination of D1-D3 showed the highest bootstrap values for most of clades suggesting that long LSU-rDNA potentially is more useful for understanding phylogenetic relationships of caddisflies. A large-scale molecular and zoogeographic study on trichopteran species is suggested to revise and to develop the current knowledge of the caddisfly fauna and distributions in the country.

A new Gambierdiscus species (Dinophyceae) from Rarotonga, Cook Islands: Gambierdiscus cheloniae sp. nov

Ciguatera fish poisoning (CFP) has been reported for many years in Rarotonga, Cook Islands, and has had the world's highest reported incidence of this illness for the last 20 years. Following intensive sampling to understand the distribution of the causative organisms of CFP, an undescribed Gambierdiscus species was isolated from the Rarotongan lagoon. Gambierdiscus cheloniae sp. nov. has the common Gambierdiscus Kofoidian plate formula (except for a variability in the number of precingular plates in aberrant cells): Po, 3', 6″ (7″), 6C?, 6 or 7S, 5'″, 1p and 2″″. The 2' plate is hatchet shaped and the dorsal end of 1p is pointed and the relatively narrow 1p plate. Morphologically G. cheloniae is similar to the genetically closely related species G. pacificus, G. toxicus and G. belizeanus, although smaller (depth and length) than G. toxicus. The apical pore plate varies from those of G. belizeanus and G. pacificus, which are shorter and narrower, and from G. toxicus, which is larger. G. cheloniae also differs from G. pacificus in the shape of the 2' plate. The description of this new species is supported by phylogenetic analyses using three different gene regions. G. cheloniae produced the putative maitotoxin-3 analogue, MTX-3, but neither maitotoxin or monitored ciguatoxin. Extracts of G. cheloniae were shown to be highly toxic to mice by intraperitoneal (i.p.) injection, although they were less toxic by gavage. It is possible that this species produces toxins other than putative MTX-3.

Diatom Nitzschia navis-varingica (Bacillariophyceae) and its domoic acid production from the mangrove environments of Malaysia

The distribution of the toxic pennate diatom Nitzschia was investigated at four mangrove areas along the coastal brackish waters of Peninsular Malaysia. Eighty-two strains of N. navis-varingica were isolated and established, and their identity confirmed morphologically and molecularly. Frustule morphological characteristics of the strains examined are identical to previously identified N. navis-varingica, but with a sightly higher density of the number of areolae per 1μm (4-7 areolae). Both LSU and ITS rDNAs phylogenetic trees clustered all strains in the N. navis-varingica clade, with high sequence homogeneity in the LSU rDNA (0-0.3%), while the intraspecific divergences in the ITS2 data set reached up to 7.4%. Domoic acid (DA) and its geometrical isomers, isodomoic A (IA) and isodomoic B (IB), were detected in cultures of N. navis-varingica by FMOC-LC-FLD, and subsequently confirmed by LC-MS/MS, with selected ion monitoring (SIM) and multiple reaction monitoring (MRM) runs. DA contents ranged between 0.37 and 11.06pgcell^-1. This study demonstrated that the toxigenic euryhaline diatom N. navis-varingica is widely distributed in Malaysian mangrove swamps, suggesting the risk of amnesic shellfish poisoning and the possibility of DA contamination in the mangrove-related fisheries products.

The Large Subunit rDNA Sequence of Plasmodiophora brassicae Does not Contain Intra-species Polymorphism

Clubroot disease caused by Plasmodiophora brassicae is one of the most important diseases of cultivated brassicas. P. brassicae occurs in pathotypes which differ in the aggressiveness towards their Brassica host plants. To date no DNA based method to distinguish these pathotypes has been described. In 2011 polymorphism within the 28S rDNA of P. brassicae was reported which potentially could allow to distinguish pathotypes without the need of time-consuming bioassays. However, isolates of P. brassicae from around the world analysed in this study do not show polymorphism in their LSU rDNA sequences. The previously described polymorphism most likely derived from soil inhabiting Cercozoa more specifically Neoheteromita-like glissomonads. Here we correct the LSU rDNA sequence of P. brassicae. By using FISH we demonstrate that our newly generated sequence belongs to the causal agent of clubroot disease.

Morphology, molecular phylogeny and azaspiracid profile of Azadinium poporum (Dinophyceae) from the Gulf of Mexico

Azadinium poporum produces a variety of azaspiracids and consists of several ribotypes, but information on its biogeography is limited. A strain of A. poporum (GM29) was incubated from a Gulf of Mexico sediment sample. Strain GM29 was characterized by a plate pattern of po, cp, x, 4', 3a, 6″, 6C, 5S, 6‴, 2⁗, a distinct ventral pore at the junction of po and the first two apical plates, and a lack of an antapical spine, thus fitting the original description of A. poporum. The genus Azadinium has not been reported in waters of the United States of America before this study. Molecular phylogeny, based on large subunit ribosomal DNA (LSU rDNA) and internal transcribed spacer (ITS) sequences, reveals that strain GM29 is nested within the well-resolved A. poporum complex, but forms a sister clade either to ribotype B (ITS) or ribotype C (LSU). It is, therefore, designated as a new ribotype, termed as ribotype D. LSU and ITS sequences similarity among different ribotypes of A. poporum ranges from 95.4% to 98.2%, and from 97.1% to 99.2% respectively, suggesting that the LSU fragment is a better candidate for molecular discrimination. Azaspiracid profiles were analyzed using LC-MS/MS and demonstrate that strain GM29 produces predominantly AZA-2 with an amount of 45fg/cell. The results suggest that A. poporum has a wide distribution and highlights the risk potential of azaspiracid intoxication in the United States.

Toxigenic algae and associated phycotoxins in two coastal embayments in the Ebro Delta (NW Mediterranean)

Harmful Algal Bloom (HAB) surveillance is complicated by high diversity of species and associated phycotoxins. Such species-level information on taxonomic affiliations and on cell abundance and toxin content is, however, crucial for effective monitoring, especially of aquaculture and fisheries areas. The aim addressed in this study was to determine putative HAB taxa and related phycotoxins in plankton from aquaculture sites in the Ebro Delta, NW Mediterranean. The comparative geographical distribution of potentially harmful plankton taxa was established by weekly field sampling throughout the water column during late spring-early summer over two years at key stations in Alfacs and Fangar embayments within the Ebro Delta. Core results included not only confirmed identification of HAB taxa that are common for the time period and geographical area, but also provided evidence of potentially new taxa. At least 25 HAB taxa were identified to species level, and an additional six genera were confirmed, by morphological criteria under light microscopy and/or by molecular genetics approaches involving qPCR and next generation DNA pyrosequencing. In particular, new insights were gained by the inclusion of molecular techniques, which focused attention on the HAB genera Alexandrium, Karlodinium, and Pseudo-nitzschia. Noteworthy is the discovery of Azadinium sp., a potentially new HAB species for this area, and Gymnodinium catenatum or Gymnodinium impudicum by means of light microscopy. In addition, significant amounts of the neurotoxin domoic acid (DA) were found for the first time in phytoplankton samples in the Ebro Delta. While the presence of the known DA-producing diatom genus Pseudo-nitzschia was confirmed in corresponding samples, the maximal toxin concentration did not coincide with highest cell abundances of the genus and the responsible species could not be identified. Combined findings of microscopic and molecular detection approaches underline the need for a synoptic strategy for HAB monitoring, which integrates the respective advantages and compensates for limitations of individual methods.

Etheliaceae fam. nov. (Gigartinales, Rhodophyta), with a clarification of the generitype of Ethelia and the addition of six novel species from warm waters

Based upon COI-5P, LSU rDNA, and rbcL sequence data and morphological characteristics, six new members of the noncalcified crustose genus of red algae Ethelia are described in a new family, Etheliaceae (Gigartinales), sister to the recently described Ptilocladiopsidaceae. The novel species are described from subtropical to tropical Atlantic and Indo-Pacific Ocean basins; E. mucronata sp. nov. and E. denizotii sp. nov. from southern and northern Western Australia respectively, E. wilcei sp. nov. from the Cocos (Keeling) Islands of Australia, E. suluensis sp. nov. from the Philippines, E. umbricola sp. nov. from Bermuda and E. kraftii sp. nov. from Lord Howe Island, Australia. The generitype, Ethelia biradiata, originally reported from the Seychelles, Indian Ocean, is added to the Western Australian flora.

Cyst-motile stage relationship, morphology, ultrastructure, and molecular phylogeny of the gymnodinioid dinoflagellate Barrufeta resplendens comb. nov., formerly known as Gyrodinium 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.

Ailadinium reticulatum gen. et sp. nov. (Dinophyceae), a New Thecate, Marine, Sand-Dwelling Dinoflagellate from the Northern Red Sea

A new photosynthetic, sand-dwelling marine dinoflagellate, Ailadinium reticulatum gen. et sp. nov., is described from the Jordanian coast in the Gulf of Aqaba, northern Red Sea, based on detailed morphological and molecular data. A. reticulatum is a large (53-61 μm long and 38-48 μm wide), dorsoventrally compressed species, with the epitheca smaller than the hypotheca. The theca of this new species is thick and peculiarly ornamented with round to polygonal depressions forming a foveate-reticulate thecal surface structure. The Kofoidian thecal tabulation is APC (Po, cp), 4', 2a, 6'', 6c, 4s, 6''', 1p, 1'''' or alternatively it can be interpreted as APC, 4', 2a, 6'', 6c, 4s, 6''', 2''''. The plate pattern of A. reticulatum is noticeably different from described dinoflagellate genera. Phylogenetic analyses based on the SSU and LSU rDNA genes did not show any supported affinities with currently known thecate dinoflagellates.

Phylogenetic relationships of five uncommon species of Lasiosphaeria and three new species in the Helminthosphaeriaceae (Sordariomycetes)

In an ongoing effort to monograph the genus Lasiosphaeria, it is desirable to obtain estimates of the phylogenetic relationships for five uncommon species, L. coacta, L. munkii, L. punctata, L. sphagnorum and L. stuppea. Three additional species previously placed in Lasiosphaeria, Echinosphaeria canescens, Hilberina caudata and Ruzenia spermoides, also were included in this study as well as three undescribed species. These species were believed to have relations elsewhere based on various ambiguous morphological characters, so an independent dataset from one or more genes was used to resolve their phylogenetic affinities. Sequences from the nuclear ribosomal 28S large subunit (LSU) and β-tubulin genes were generated for these taxa. Maximum likelihood and Bayesian analyses indicated these taxa form a well supported monophyletic group with members of the Helminthosphaeriaceae and therefore, should be transferred out of Lasiosphaeria. Except for Helminthosphaeria gibberosa, Hilberina elegans, Ruzenia spermoides and Synaptospora plumbea, all taxa within this clade possess ascomata with distinct thick-walled setae. Based on a combination of morphological and molecular data, Helminthosphaeria tomaculum, Helminthosphaeria triseptata and Hilberina robusta are described as new and four new combinations are proposed: Helminthosphaeria ludens, Hel. stuppea, Hilberina punctata and H. sphagnorum. Ten new combinations are proposed based on morphological data: Echinosphaeria heterostoma, Helminthosphaeria flavocompta, Hel. gibberosa, Hel. heterotricha, Hilberina breviseta, H. elegans, H. foliicola, H. meznaensis, H. moseri and H. rhynchospora. Lasiosphaeria coacta is placed in synonymy with Hel. ludens and the previous transfer of Hilberina munkii is accepted. Synaptospora plumbea was found to belong in the family. Illustrations are provided for most Helminthosphaeriaceae taxa seen in this study.

The monospecific genus Meredithia (Kallymeniaceae, Gigartinales) is species rich and geographically widespread with species from temperate Atlantic, Pacific, and Indian Oceans

Using sequences of 5' region of the cytochrome oxidase subunit 1 gene, large subunit rDNA, and ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit gene as genetic markers to elucidate their phylogenetic positions, six unknown species from Western Australia, Tasmania, Lord Howe Is., and Norfolk Is. cluster with Meredithia in the Kallymeniaceae (Gigartinales), and are described as new members of this previously monospecific genus. Specimens from Bermuda referable to Kallymenia limminghei Mont. in the 20th century also clustered with this genetic grouping, not with the generitype of Kallymenia. The Bermudian specimens are further shown to be morphologically distinct from the type of K. limminghei (Guadeloupe, Caribbean Sea) and are described as a new species, Meredithia crenata. Using these Indo-Pacific and Bermudian collections, our analyses further show that Psaromenia is closely related to Meredithia, and that Cirrulicarpus nanus sensu stricto should be returned to Meredithia.

On the species status of the root-knot nematode Meloidogyne ulmi Palmisano & Ambrogioni, 2000 (Nematoda, Meloidogynidae)

The root-knot nematode Meloidogyne ulmi is synonymised with Meloidogyne mali based on morphological and morphometric similarities, common hosts, as well as biochemical similarities at both protein and DNA levels. M. mali was first described in Japan on Malus prunifolia Borkh.; and M. ulmi in Italy on Ulmus chenmoui W.C. Cheng. Morphological and morphometric studies of their holo- and paratypes revealed important similarities in the major characters as well as some general variability in a few others. Host test also showed that besides the two species being able to parasitize the type hosts of the other, they share some other common hosts. Our study of the esterase and malate dehydrogenase isozyme phenotypes of some M. ulmi populations gave a perfectly comparable result to that already known for M. mali. Finally, phylogenetic studies of their SSU and LSU rDNA sequence data revealed that the two are not distinguishable at DNA level. All these put together, leave strong evidences to support the fact that M. ulmi is not a valid species, but a junior synonym of M. mali. Brief discussion on the biology and life cycle of M. mali is given. An overview of all known hosts and the possible distribution of M. mali in Europe are also presented.

Three novel species in the Pseudo-nitzschia pseudodelicatissima complex: P. batesiana sp. nov., P. lundholmiae sp. nov., and P. fukuyoi sp. nov. (Bacillariophyceae) from the Strait of Malacca, Malaysia

A study on the morphology and phylogeny of 18 strains of Pseudo-nitzschia established from the Strait of Malacca, Peninsular Malaysia, was undertaken. Morphological data combined with molecular evidence show that they constitute three new species, for which the names, P. batesiana sp. nov., P. lundholmiae sp. nov., and P. fukuyoi sp. nov., are proposed. The three new species closely resemble species in the P. pseudodelicatissima complex sensu lato. Morphologically, P. batesiana differs from other species in the complex by having a smaller part of cell overlapping in the chain, whereas P. lundholmiae differs by having fewer poroid sectors and P. fukuyoi by having a distinct type of poroid sectors. Nucleotide sequences of the LSU rDNA (D1-D3) of the three new species reveal significant nucleotide sequence divergence (0.1%-9.3%) from each other and from other species in the P. pseudodelicatissima complex s.l. The three species are phylogenetically closely related to species in the P. pseudodelicatissima complex, with P. batesiana appearing as a sister taxon to P. circumpora, P. caciantha, and P. subpacifica; whereas P. lundholmiae and P. fukuyoi are more closely related to P. pseudodelicatissima and P. cuspidata. The three species show 2-3 compensatory base changes (CBCs) in their ITS2 transcripts when compared to the closely related species. The ITS2 with its structural information has proven its robustness in constructing a better resolved phylogenetic framework for Pseudo-nitzschia.

Identification, molecular characterization, and evolution of group I introns at the expansion segment D11 of 28S rDNA in Rhizoctonia species

The nuclear ribosomal DNA of Rhizoctonia species is polymorphic in terms of the nucleotide composition and length. Insertions of 349-410 nucleotides in length with characteristics of group I introns were detected at a single insertion point at the expansion segment D11 of 28S rDNA in 12 out of 64 isolates. Eleven corresponded to Rhizoctonia solani (teleomorph: Thanatephorous) and one (AG-Q) to Rhizoctonia spp. (teleomorph: Ceratobasidium). Sequence data showed that all but AG-Q contained conserved DNA catalytic core regions (P, Q, R, and S) essential for selfsplicing. The predicted secondary structure revealed that base-paired helices corresponded to subgroup IC1. Isolates from same anastomosis group and even subgroups within R. solani were variable with regard to possession of introns. Phylogenetic analyses indicated that introns were vertically transmitted. Unfortunately, sequence data from the conserved region from all 64 isolates were not useful for delimiting species. Analyses with IC1 introns at same insertion point, of both Ascomycota and Basidiomycota indicated the possibility of horizontal transfer at this site. The present study uncovered new questions on evolutionary pattern of change of these introns within Rhizoctonia species.

MORPHOLOGY AND MOLECULAR PHYLOGENY OF ANKISTRODINIUM GEN. NOV. (DINOPHYCEAE), A NEW GENUS OF MARINE SAND-DWELLING DINOFLAGELLATES FORMERLY CLASSIFIED WITHIN AMPHIDINIUM(1)

The classical athecate dinoflagellate genera (Amphidinium, Gymnodinium, Gyrodinium) have long been recognized to be polyphyletic. Amphidinium sensu lato is the most diverse of all marine benthic dinoflagellate genera; however, following the redefinition of this genus ∼100 species remain now of uncertain or unknown generic affiliation. In an effort to improve our taxonomic and phylogenetic understanding of one of these species, namely Amphidinium semilunatum, we re-investigated organisms from several distant sites around the world using light and scanning electron microscopy and molecular phylogenetic methods. Our results enabled us to describe this species within a new heterotrophic genus, Ankistrodinium. Cells of A. semilunatum were strongly laterally flattened, rounded-quadrangular to oval in lateral view, and possessed a small asymmetrical epicone. The sulcus was wide and characteristically deeply incised on the hypocone running around the antapex and reaching the dorsal side. The straight acrobase with hook-shaped end started at the sulcal extension and continued onto the epicone. The molecular phylogenetic results clearly showed that A. semilunatum is a distinct taxon and is only distantly related to species within the genus Amphidinium sensu stricto. The nearest sister group to Ankistrodinium could not be reliably determined.

Mariannaea samuelsii Isolated from a Bark Beetle-Infested Elm Tree in Korea

During an investigation of fungi from an elm tree infested with bark beetles in Korea, one isolate, DUCC401, was isolated from elm wood. Based on morphological characteristics and phylogenetic analysis of the internal transcribed spacer and 28S rDNA (large subunit) sequences, the isolate, DUCC401, was identified as Mariannaea samuelsii. Mycelia of the fungus grew faster on malt extract agar than on potato dextrose agar and oatmeal agar media. Temperature and pH for optimal growth of fungal mycelia were 25℃ and pH 7.0, respectively. The fungus demonstrated the capacity to degrade cellobiose, starch, and xylan. This is the first report on isolation of Mariannaea samuelsii in Korea.

Taxonomy, DNA barcoding and phylogeny of three new species of Pythium from Canada

Three new species of Pythium, namely, P. oopapillum, P. emineosum and P. camurandrum are presented in this paper based on morphological descriptions and molecular phylogenetic characterisation. These new species were isolated from various ecological regions in Canada. They have unique morphological features in the genus Pythium, and form distinct clades in maximum parsimony analyses, which are also supported by maximum likelihood phylogeny using general time reversible model (GTR), and Bayesian inference (BI) phylogeny using Markov Chain Monte Carlo (MCMC) analysis methods. A comparative study of the new species with closely related taxa, their clade positions, and morphological features are described in this paper.

NOV.(1)

The name Peridinium palatinum Lauterborn currently designates a freshwater peridinioid with 13 epithecal and six cingular plates, and no apical pore complex. Freshwater dinoflagellate floras classify it in Peridinium group palatinum together with P. pseudolaeve M. Lefèvre. General ultrastructure, flagellar apparatus, and pusular components of P. palatinum were examined by serial section TEM and compared to P. cinctum (O. F. Müll.) Ehrenb. and Peridiniopsis borgei Lemmerm., respectively, types of Peridinium and Peridiniopsis. Partial LSU rDNA sequences from P. palatinum, P. pseudolaeve and several peridinioids, woloszynskioids, gymnodinioids, and other dinoflagellates were used for a phylogenetic analysis. General morphology and tabulation of taxa in group palatinum were characterized by SEM. Differences in plate numbers, affecting both the epitheca and the cingulum, combine with differences in plate ornamentation and a suite of internal cell features to suggest a generic-level distinction between Peridinium group palatinum and typical Peridinium. The branching pattern of the phylogenetic tree is compatible with this conclusion, although with low support from bootstrap values and posterior probabilities, as are sequence divergences estimated between species in group palatinum, and typical Peridinium and Peridiniopsis. Palatinus nov. gen. is proposed with the new combinations Palatinus apiculatus nov. comb. (type species; syn. Peridinium palatinum), P. apiculatus var. laevis nov. comb., and P. pseudolaevis nov. comb. Distinctive characters for Palatinus include a smooth or slightly granulate, but not areolate, plate surface, a large central pyrenoid penetrated by cytoplasmic channels and radiating into chloroplast lobes, and the presence of a peduncle-homologous microtubular strand. Palatinus cells exit the theca through the antapical-postcingular area.

GYMNODINIUM COROLLARIUM SP. NOV. (DINOPHYCEAE)-A NEW COLD-WATER DINOFLAGELLATE RESPONSIBLE FOR CYST SEDIMENTATION EVENTS IN THE BALTIC SEA(1)

A naked dinoflagellate with a unique arrangement of chloroplasts in the center of the cell was isolated from the northern Baltic proper during a spring dinoflagellate bloom (March 2005). Morphological, ultrastructural, and molecular analyses revealed this dinoflagellate to be undescribed and belonging to the genus Gymnodinium F. Stein. Gymnodinium corollarium A. M. Sundström, Kremp et Daugbjerg sp. nov. possesses features typical of Gymnodinium sensu stricto, such as nuclear chambers and an apical groove running in a counterclockwise direction around the apex. Phylogenetic analyses based on partial nuclear-encoded LSU rDNA sequences place the species in close proximity to G. aureolum, but significant genetic distance, together with distinct morphological features, such as the position of chloroplasts, clearly justifies separation from this species. Temperature and salinity experiments revealed a preference of G. corollarium for low salinities and temperatures, confirming it to be a cold-water species well adapted to the brackish water conditions in the Baltic Sea. At nitrogen-deplete conditions, G. corollarium cultures produced small, slightly oval cysts resembling a previously unidentified cyst type commonly found in sediment trap samples collected from the northern and central open Baltic Sea. Based on LSU rDNA comparison, these cysts were assigned to G. corollarium. The cysts have been observed in many parts of the Baltic Sea, indicating the ecologic versatility of the species and its importance for the Baltic ecosystem.

MORPHOLOGICAL AND MOLECULAR CHARACTERIZATION OF SPECIES OF THE GENUS CENTROCERAS (CERAMIACEAE, CERAMIALES), INCLUDING TWO NEW SPECIES(1)

Centroceras clavulatum (C. Agardh) Montagne is widely reported as being a prime example of a cosmopolitan red algal species. Instead, C. clavulatum is here determined as restricted to northern Chile, Peru, southern California, southern Australia, and New Zealand. Specimens identified using the current species concept for "C. clavulatum" fall into nine morphological groups that correspond to highly supported clades in phylogenetic analyses. Three of these clades correspond to the resurrected species Centroceras gasparrinii (Meneghini) Kützing, C. hyalacanthum Kützing, and C. micracanthum Kützing. Two others are recognized as new species: Centroceras rodmanii sp. nov. from southern Chile, which is characterized by hooked spines arranged in a whorl at the node, a spine or flattened gland cell cut off from the first cortical initials, and a single acropetal cortical cell issued from the second cortical initials; and C. tetrachotomum sp. nov. from South Africa, which has a tetrachotomous branching pattern, straight spines in a whorl, an acropetal cortical cell and a spine or a flattened gland cell cut off from the first cortical initials, and a two-celled acropetal filament cut off from the second cortical initials. Three additional species from South Africa are also recognized as distinct species. All phylogenetic analyses of the rbcL gene, LSU rDNA, and SSU rDNA were consistent with the vegetative and tetrasporangial morphological distinctions, thus supporting the resurrection of three species and the description of two new species.

SYMBIODINIUM NATANS SP. NOV.: A "FREE-LIVING" DINOFLAGELLATE FROM TENERIFE (NORTHEAST-ATLANTIC OCEAN)(1)

We examined a free-living Symbiodinium species by light and electron microscopy and nuclear-encoded partial LSU rDNA sequence data. The strain was isolated from a net plankton sample collected in near-shore waters at Tenerife, the Canary Islands. Comparing the thecal plate tabulation of the free-living Symbiodinium to that of S. microadriaticum Freud., it became clear that a few but significant differences could be noted. The isolate possessed two rather than three antapical plates, six rather than seven to eight postcingular plates, and finally four rather than five apical plates. The electron microscopic study also revealed the presence of an eyespot with brick-shaped contents in the sulcal region and a narrow anterior plate with small knob-like structures. Bayesian analysis revealed the free-living Symbiodinium to be a member of the earliest diverging clade A. However, it did not group within subclade AI (=temperate A) or any other subclades within clade A. Rather, it occupied an isolated position, and this was also supported by sequence divergence estimates. On the basis of comparative analysis of the thecal plate tabulation and the inferred phylogeny, we propose that the Symbiodinium isolate from Tenerife is a new species (viz. S. natans). To elucidate further the species diversity of Symbiodinium, particularly those inhabiting coral reefs, we suggest combining morphological features of the thecal plate pattern with gene sequence data. Indeed, future examination of motile stages originating from symbiont isolates will demonstrate if this proves a feasible way to identify and characterize additional species of Symbiodinium and thus match ribotypes or clusters of ribotypes to species.

GAYLIELLA GEN. NOV. IN THE TRIBE CERAMIEAE (CERAMIACEAE, RHODOPHYTA) BASED ON MOLECULAR AND MORPHOLOGICAL EVIDENCE(1)

On the basis of comparative morphology and phylogenetic analyses of rbcL and LSU rDNA sequence data, a new genus, Gayliella gen. nov., is proposed to accommodate the Ceramium flaccidum complex (C. flaccidum, C. byssoideum, C. gracillimum var. byssoideum, and C. taylorii), C. fimbriatum, and a previously undescribed species from Australia. C. transversale is reinstated and recognized as a distinct species. Through this study, G. flaccida (Kützing) comb. nov., G. transversalis (Collins et Hervey) comb. nov., G. fimbriata (Setchell et N. L. Gardner) comb. nov., G. taylorii comb. nov., G. mazoyerae sp. nov., and G. womersleyi sp. nov. are based on detailed comparative morphology. The species referred to as C. flaccidum and C. dawsonii from Brazil also belong to the new genus. Comparison of Gayliella with Ceramium shows that it differs from the latter by having an alternate branching pattern; three cortical initials per periaxial cell, of which the third is directed basipetally and divides horizontally; and unicellular rhizoids produced from periaxial cells. Our phylogenetic analyses of rbcL and LSU rDNA gene sequence data confirm that Gayliella gen. nov. represents a monophyletic clade distinct from most Ceramium species including the type species, C. virgatum. We also transfer C. recticorticum to the new genus Gayliella.