The enigmatic nucleus of the marine dinoflagellate .

The marine, bloom-forming dinoflagellate CCMP 1329 (formerly ) has a genome atypical of eukaryotes, with a large size of ~4.15 Gbp, organized in plentiful, highly condensed chromosomes and packed in a dinoflagellate-specific nucleus (dinokaryon). Here, we apply microscopic and proteogenomic approaches to obtain new insights into this enigmatic nucleus of axenic .

Morphological and Phylogenetic Characterisation of , sp. nov. (Prorocentrales, Dinophyceae), a Small Spiny Species from the North Atlantic.

comprises dinophytes with several unique traits, including the presence of two large thecal plates and apical insertion of flagella. Species delimitation for many small and similar planktonic species is challenging, as SEM analyses and DNA sequence information of type material are rarely available. Based on a strain from the North Atlantic sp.

Morphology and molecular phylogeny of the benthic dinoflagellates (Dinophyceae, Peridiniales) Amphidiniopsis crumena n. sp. and Amphidiniopsis nileribanjensis n. sp.

Amphidiniopsis is a benthic, heterotrophic and thecate dinoflagellate genus that has a smaller epitheca and larger hypotheca. The genus contains 24 described species, but is considered to be polyphyletic based on morphological characters and molecular phylogenetics. In this study, two new species were discovered from two distant sampling localities, Amphidiniopsis crumena sp.

Temporal and spatial distribution of epibenthic dinoflagellates in the Kattegat-Skagerrak, NE Atlantic-Focus on Prorocentrum lima and Coolia monotis.

Epibenthic dinoflagellates occur globally and include many toxin-producing species of concern to human health and benthic ecosystem function. Such benthic harmful algal blooms (BHABs) have been well described from tropical and sub-tropical coastal environments, but assessments from north temperate waters, e.g.

Molecular phylogeny and morphology of Carinadinium gen. nov. (Dinophyceae, Gonyaulacales), including marine sand-dwelling dinoflagellate species formerly classified within Thecadinium.

Thecadinium is a morphologically heterogenous marine benthic genus. Its polyphyly has been discussed. After redefinition of the sensu stricto genus, sensu lato taxa now need reclassification.

Morphological and phylogenetic data do not support the split of Alexandrium into four genera.

A recently published study analyzed the phylogenetic relationship between the genera Centrodinium and Alexandrium, confirming an earlier publication showing the genus Alexandrium as paraphyletic. This most recent manuscript retained the genus Alexandrium, introduced a new genus Episemicolon, resurrected two genera, Gessnerium and Protogonyaulax, and stated that: "The polyphyly [sic] of Alexandrium is solved with the split into four genera". However, these reintroduced taxa were not based on monophyletic groups.

First Detection of Paralytic Shellfish Toxins from above the Regulatory Limit in Blue Mussels () in New South Wales, Australia.

In 2016, 2017 and 2018, elevated levels of the species were detected within a blue mussel ( aquaculture area at Twofold Bay on the south coast of New South Wales, Australia. In 2016, the bloom persisted for at least eight weeks and maximum cell concentrations of 89,000 cells L of were reported. The identity of was confirmed using molecular genetic tools (qPCR and amplicon sequencing) and complemented by light and scanning electron microscopy of cultured strains.

Morphology and Molecular Phylogeny of a New Marine, Sand-dwelling Dinoflagellate Genus, Pachena (Dinophyceae), with Descriptions of Three New Species.

Marine benthic dinoflagellates are interesting not only because some epiphytic genera can cause harmful algal blooms but also for understanding dinoflagellate evolution and diversification. Our understanding of their biodiversity is far from complete, and many thecate genera have unusual tabulation patterns that are difficult to relate to the diverse known phytoplankton taxa. A new sand-dwelling genus, Pachena gen.

Characterisation of Two Toxic Gambierdiscus spp. (Gonyaulacales, Dinophyceae) from the Great Barrier Reef (Australia): G. lewisii sp. nov. and G. holmesii sp. nov.

Ciguatera fish poisoning (CFP) is a human illness caused via consumption of seafood contaminated with neurotoxins produced by some species from the epiphytic dinoflagellate genus Gambierdiscus. In this study, we describe two new species of Gambierdiscus isolated from Heron Island in the Southern Great Barrier Reef, Queensland, Australia. These new species were analysed using light microscopy, scanning electron microscopy, and phylogenetic analyses of nuclear encoded ribosomal ITS, SSU as well as D1-D3 and D8-D10 of the LSU gene regions.

Re-evaluation of Amphidiniopsis (Dinophyceae) Morphogroups Based On Phylogenetic Relationships, and Description of Three New Sand-dwelling Species From the NW Mediterranean.

Amphidiniopsis is a diverse genus of thecate heterotrophic dinoflagellates within the benthic, sand-dwelling species, with more than 20 currently described. Although molecular information about members of this genus is still scarce, morphological heterogeneity suggests the genus is paraphyletic. We investigated the diversity of Amphidiniopsis species in the NW Mediterranean Sea by morphological and molecular approaches, which led to the description of three new species, A.

Morphology and Phylogenetics of Benthic Species (Dinophyceae) from Tropical Northwestern Australia.

Approximately 70 species of are known, of which around 30 species are associated with benthic habitats. Some produce okadaic acid (OA), dinophysistoxin (DTX) and their derivatives, which are involved in diarrhetic shellfish poisoning. In this study, we isolated and characterized and from Broome in north Western Australia using light and scanning electron microscopy as well as molecular sequences of large subunit regions of ribosomal DNA, marking the first record of these species from Australian waters.

New morphological data and molecular phylogeny of the benthic dinoflagellate Pseudothecadinium campbellii (Dinophyceae, Gonyaulacales).

Pseudothecadinium campbellii, a phototrophic, thecate, marine benthic species, has been found in the Sea of Japan, Russia. The morphological description of the species has been emended, and the thecal tabulation pattern is now APC 4' 2a 4″ 6c 6 s 5‴ 1⁗. Our study indicates that P.

Psammodinium inclinatum gen. nov. et comb. nov. (=Thecadinium inclinatum Balech) is the closest relative to the toxic dinoflagellate genera Gambierdiscus and Fukuyoa.

The heterotrophic sand-dwelling dinoflagellate Thecadinium inclinatum has been re-examined by light and scanning electron microscopy in order to resolve the discrepancies on its plate pattern from the literature, and to obtain its phylogenetic information single-cell PCR technique has been used. The comparison of morphological and molecular information available for other Thecadinium species confirms the genus is polyphyletic and T. inclinatum seems not related to other representatives of the genus sensu lato.

Revisions to the Classification, Nomenclature, and Diversity of Eukaryotes.

This revision of the classification of eukaryotes follows that of Adl et al., 2012 [J. Euk.

Pentaplacodinium saltonense gen. et sp. nov. (Dinophyceae) and its relationship to the cyst-defined genus Operculodinium and yessotoxin-producing Protoceratium reticulatum.

Strains of a dinoflagellate from the Salton Sea, previously identified as Protoceratium reticulatum and yessotoxin producing, have been reexamined morphologically and genetically and Pentaplacodinium saltonense n. gen. et sp.

Plate pattern clarification of the marine dinophyte Heterocapsa triquetra sensu Stein (Dinophyceae) collected at the Kiel Fjord (Germany).

One of the most common marine dinophytes is a species known as Heterocapsa triquetra. When Stein introduced the taxon Heterocapsa, he formally based the type species H. triquetra on the basionym Glenodinium triquetrum.

Molecular and phylogenetic characterization of Ostreopsis (Dinophyceae) and the description of a new species, Ostreopsis rhodesae sp. nov., from a subtropical Australian lagoon.

Cryptic and pseudo-cryptic species are common amongst marine phytoplankton, and may cause misleading inferences of ecological and physiological data of plankton community studies. Deciphering the diversity and distribution of species of the benthic dinoflagellate Ostreopsis is one example, as there are many morphologically indistinct clades that differ greatly genetically and toxicologically from one another. In this study, a new species, Ostreopsis rhodesae from the southern Great Barrier Reef was described.

Characterization of Gambierdiscus lapillus sp. nov. (Gonyaulacales, Dinophyceae): a new toxic dinoflagellate from the Great Barrier Reef (Australia).

Gambierdiscus is a genus of benthic dinoflagellates found worldwide. Some species produce neurotoxins (maitotoxins and ciguatoxins) that bioaccumulate and cause ciguatera fish poisoning (CFP), a potentially fatal food-borne illness that is common worldwide in tropical regions. The investigation of toxigenic species of Gambierdiscus in CFP endemic regions in Australia is necessary as a first step to determine which species of Gambierdiscus are related to CFP cases occurring in this region.

Molecular Phylogeny of the Benthic Dinoflagellate Genus Amphidiniopsis and its Relationships with the Family Protoperidiniaceae.

The genus Amphidiniopsis is a benthic (sand-dwelling) lineage of thecate dinoflagellates, containing 19 morphologically diverse species. Past work has shown that some Amphidiniopsis species form a clade with the sand-dwelling Herdmania litoralis as well as some planktonic species in the family Protoperidiniaceae (i.e.

Alexandrium diversaporum sp. nov., a new non-saxitoxin producing species: Phylogeny, morphology and sxtA genes.

Species of the PST producing planktonic marine dinoflagellate genus Alexandrium have been intensively scrutinised, and it is therefore surprising that new taxa can still be found. Here we report a new species, Alexandrium diversaporum nov. sp.

Cob gene pyrosequencing enables characterization of benthic dinoflagellate diversity and biogeography.

Dinoflagellates in marine benthic habitats living epiphytically on macroalgae are an important but highly understudied group of protists. Many produce toxins that can have severe economic impacts on marine-based economies, and improved monitoring tools are required to enhance the management of toxin-related hazards. We analysed the distribution and diversity of epibenthic dinoflagellates inhabiting eight sites in Cocos (Keeling) Islands, Papua New Guinea, and Broome and Exmouth, Western Australia.

Life Cycle of the pseudocolonial dinoflagellate Polykrikos kofoidii (Gymnodiniales, Dinoflagellata).

The athecate, pseudocolonial polykrikoid dinoflag-ellates show a greater morphological complexity than many other dinoflagellate cells and contain not only elaborate extrusomes but sulci, cinguli, flagellar pairs, and nuclei in multiple copies. Among polykrikoids, Polykrikos kofoidii is a common species that plays an important role as a grazer of toxic planktonic algae but whose life cycle is poorly known. In this study, the main life cycle stages of P.

The revised classification of eukaryotes.

This revision of the classification of eukaryotes, which updates that of Adl et al. [J. Eukaryot.

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.

Genetic diversity, morphological uniformity and polyketide production in dinoflagellates (Amphidinium, Dinoflagellata).

Dinoflagellates are an intriguing group of eukaryotes, showing many unusual morphological and genetic features. Some groups of dinoflagellates are morphologically highly uniform, despite indications of genetic diversity. The species Amphidinium carterae is abundant and cosmopolitan in marine environments, grows easily in culture, and has therefore been used as a 'model' dinoflagellate in research into dinoflagellate genetics, polyketide production and photosynthesis.