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Lesley L. Rhodes
Cawthron Institute, Private Bag 2, Nelson 7042, New Zealand

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Journal article
Published: 05 May 2021 in Toxins
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Understanding the toxicity and production rates of the various secondary metabolites produced by Gambierdiscus and cohabitating benthic dinoflagellates is essential to unravelling the complexities associated with ciguatera poisoning. In the present study, a sulphated cyclic polyether, gambierone, was purified from Gambierdiscus cheloniae CAWD232 and its acute toxicity was determined using intraperitoneal injection into mice. It was shown to be of low toxicity with an LD50 of 2.4 mg/kg, 9600 times less toxic than the commonly implicated Pacific ciguatoxin-1B, indicating it is unlikely to play a role in ciguatera poisoning. In addition, the production of gambierone and 44-methylgambierone was assessed from 20 isolates of ten Gambierdiscus, two Coolia and two Fukuyoa species using quantitative liquid chromatography–tandem mass spectrometry. Gambierone was produced by seven Gambierdiscus species, ranging from 1 to 87 pg/cell, and one species from each of the genera Coolia and Fukuyoa, ranging from 2 to 17 pg/cell. The production of 44-methylgambierone ranged from 5 to 270 pg/cell and was ubiquitous to all Gambierdiscus species tested, as well as both species of Coolia and Fukuyoa. The relative production ratio of these two secondary metabolites revealed that only two species produced more gambierone, G. carpenteri CAWD237 and G. cheloniae CAWD232. This represents the first report of gambierone acute toxicity and production by these cohabitating benthic dinoflagellate species. While these results demonstrate that gambierones are unlikely to pose a risk to human health, further research is required to understand if they bioaccumulate in the marine food web.

ACS Style

J. Murray; Sarah Finch; Jonathan Puddick; Lesley Rhodes; D. Harwood; Roel van Ginkel; Michèle Prinsep. Acute Toxicity of Gambierone and Quantitative Analysis of Gambierones Produced by Cohabitating Benthic Dinoflagellates. Toxins 2021, 13, 333 .

AMA Style

J. Murray, Sarah Finch, Jonathan Puddick, Lesley Rhodes, D. Harwood, Roel van Ginkel, Michèle Prinsep. Acute Toxicity of Gambierone and Quantitative Analysis of Gambierones Produced by Cohabitating Benthic Dinoflagellates. Toxins. 2021; 13 (5):333.

Chicago/Turabian Style

J. Murray; Sarah Finch; Jonathan Puddick; Lesley Rhodes; D. Harwood; Roel van Ginkel; Michèle Prinsep. 2021. "Acute Toxicity of Gambierone and Quantitative Analysis of Gambierones Produced by Cohabitating Benthic Dinoflagellates." Toxins 13, no. 5: 333.

Review
Published: 15 January 2020 in Toxins
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Gambierdiscus and Fukuyoa species have been identified in Aotearoa/New Zealand’s coastal waters and G. polynesiensis, a known producer of ciguatoxins, has been isolated from Rangitāhua/Kermadec Islands (a New Zealand territory). The warming of the Tasman Sea and the waters around New Zealand’s northern subtropical coastline heighten the risk of Gambierdiscus proliferating in New Zealand. If this occurs, the risk of ciguatera fish poisoning due to consumption of locally caught fish will increase. Research, including the development and testing of sampling methods, molecular assays, and chemical and toxicity tests, will continue. Reliable monitoring strategies are important to manage and mitigate the risk posed by this emerging threat. The research approaches that have been made, many of which will continue, are summarised in this review.

ACS Style

Lesley L. Rhodes; Kirsty F. Smith; J. Sam Murray; Tomohiro Nishimura; Sarah C. Finch. Ciguatera Fish Poisoning: The Risk from an Aotearoa/New Zealand Perspective. Toxins 2020, 12, 50 .

AMA Style

Lesley L. Rhodes, Kirsty F. Smith, J. Sam Murray, Tomohiro Nishimura, Sarah C. Finch. Ciguatera Fish Poisoning: The Risk from an Aotearoa/New Zealand Perspective. Toxins. 2020; 12 (1):50.

Chicago/Turabian Style

Lesley L. Rhodes; Kirsty F. Smith; J. Sam Murray; Tomohiro Nishimura; Sarah C. Finch. 2020. "Ciguatera Fish Poisoning: The Risk from an Aotearoa/New Zealand Perspective." Toxins 12, no. 1: 50.

Research article
Published: 19 June 2019 in New Zealand Journal of Marine and Freshwater Research
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Planktonic dinoflagellate records for New Zealand are substantial due to intense monitoring programmes that have taken place on behalf of New Zealand’s biotoxin regulators and the shellfish industry since 1993. At that time a Karenia bloom caused human illnesses and shellfish harvesting ceased until monitoring was instigated. Phytoplankton records are based on morphological identification using light microscopy but are backed up by government funded research programmes which implement techniques such as electron microscopy, DNA sequencing, molecular detection assays and high throughput sequencing of environmental DNA. This checklist will support management of aquaculture industries, recreational shellfish harvests and environmental health initiatives. Somegenera are considered benthic or epiphytic, but have lengthy planktonic life stages. Forty-five genera in the class Dinophyceae Fritsch are reported: Akashiwo, Alexandrium, Amphidinium, Amylax, Azadinium, Biecheleria, Bysmatrum, Cachonina, Cochlodinium (synonym: Margalefidinium), Coolia, Dicroerisma, Dinophysis, Diploneis, Diplopsalis, Fragilidium, Glenodinium, Gonyaulax, Gymnodinium, Gyrodinium, Heterocapsa, Karenia, Karlodinium, Lepidodinium, Lingulodinium, Margalefidinium, Ostreopsis, Oxyphysis, Pelagodinium, Pentapharsodinium, Phalacroma, Podolampas, Polarella, Polykrikos, Prorocentrum, Protodinium, Protoodinium, Protoperidinium, Pseliodinium, Scrippsiella, Takayama, Togula, Torodinium, Tripos, Vulcanodinium, Wolosynska. Other genera belonging to the Infraphylum Dinoflagellata also occur in New Zealand waters. They are not in the list but include Noctiluca, Pronoctiluca and Spatulodinium (Class: Noctilucophyceae) and Oxyrrhis (Class: Oxyrrhidophyceae).

ACS Style

Lesley L. Rhodes; Kirsty F. Smith; Lincoln MacKenzie; Catherine Moisan. Checklist of the planktonic marine dinoflagellates of New Zealand. New Zealand Journal of Marine and Freshwater Research 2019, 54, 86 -101.

AMA Style

Lesley L. Rhodes, Kirsty F. Smith, Lincoln MacKenzie, Catherine Moisan. Checklist of the planktonic marine dinoflagellates of New Zealand. New Zealand Journal of Marine and Freshwater Research. 2019; 54 (1):86-101.

Chicago/Turabian Style

Lesley L. Rhodes; Kirsty F. Smith; Lincoln MacKenzie; Catherine Moisan. 2019. "Checklist of the planktonic marine dinoflagellates of New Zealand." New Zealand Journal of Marine and Freshwater Research 54, no. 1: 86-101.

Short communication
Published: 05 July 2018 in New Zealand Journal of Marine and Freshwater Research
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New Zealand benthic and epiphytic dinoflagellate records increased in recent years as harmful algal bloom research increased. This was largely due to risk assessments of micro-algal biotoxins for the seafood industry and concerns regarding ciguatera fish poisoning in humans from toxic finfish. High-throughput sequencing enabled the detection of dinoflagellate species that were previously overlooked by microscopy, particularly where diatoms or sediments obscured visual identification. This checklist includes new species records for New Zealand and species usually considered planktonic, but which have benthic life stages. Thirty-one dinoflagellate genera were recorded from isolations and descriptions of living cells: Alexandrium, Amphidinium, Archaeperidinium, Azadinium, Biecheleria, Blastodinium, Bysmatrum, Coolia, Crypthecodinium, Cryptoperidiniopsis, Durinskia, Ensiculifera, Fukuyoa, Gambierdiscus, Gymnodinium, Gyrodinium, Heterocapsa, Karenia, Kryptoperidinium, Ostreopsis, Pelagodinium, Pentapharsodinium, Pfiesteria, Polarella, Prorocentrum, Protodinium, Protoperidinium, Pseudopfiesteria, Scrippsiella, Togula and Vulcanodinium. A further nine genera were detected by high-throughput sequencing: Cachonina, Dinophysis, Fragilidium, Gonyaulax, Karlodinium, Lepidodinium, Protodinium, Symbiodinium and Woloszynskia.

ACS Style

Lesley Rhodes; Kirsty F. Smith. A checklist of the benthic and epiphytic marine dinoflagellates of New Zealand, including Rangitāhua/Kermadec Islands. New Zealand Journal of Marine and Freshwater Research 2018, 53, 258 -277.

AMA Style

Lesley Rhodes, Kirsty F. Smith. A checklist of the benthic and epiphytic marine dinoflagellates of New Zealand, including Rangitāhua/Kermadec Islands. New Zealand Journal of Marine and Freshwater Research. 2018; 53 (2):258-277.

Chicago/Turabian Style

Lesley Rhodes; Kirsty F. Smith. 2018. "A checklist of the benthic and epiphytic marine dinoflagellates of New Zealand, including Rangitāhua/Kermadec Islands." New Zealand Journal of Marine and Freshwater Research 53, no. 2: 258-277.

Short note
Published: 02 August 2017 in Marine Drugs
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Ciguatera Fish Poisoning (CFP) is increasing across the Pacific and the distribution of the causative dinoflagellates appears to be expanding. Subtle differences in thecal plate morphology are used to distinguish dinoflagellate species, which are difficult to determine using light microscopy. For these reasons we sought to develop a Quantitative PCR assay that would detect all species from both Gambierdiscus and Fukuyoa genera in order to rapidly screen environmental samples for potentially toxic species. Additionally, a specific assay for F. paulensis was developed as this species is of concern in New Zealand coastal waters. Using the assays we analyzed 31 samples from three locations around New Zealand and the Kingdom of Tonga. Fourteen samples in total were positive for Gambierdiscus/Fukuyoa and two samples were also positive using the F. paulensis assay. Samples from the Kermadec Islands were further characterized using high-throughput sequencing metabarcoding. The majority of reads corresponded to Gambierdiscus species with three species identified at all sites (G. australes, G. honu and G. polynesiensis). This is the first confirmed identification of G. polynesiensis, a known ciguatoxin producer, in New Zealand waters. Other known toxin-producing genera were also detected, included Alexandrium, Amphidinium, Azadinium, Dinophysis, Ostreopsis, and Prorocentrum.

ACS Style

Kirsty F. Smith; Laura Biessy; Phoebe A. Argyle; Tom Trnski; Tuikolongahau Halafihi; Lesley L. Rhodes. Molecular Identification of Gambierdiscus and Fukuyoa (Dinophyceae) from Environmental Samples. Marine Drugs 2017, 15, 243 .

AMA Style

Kirsty F. Smith, Laura Biessy, Phoebe A. Argyle, Tom Trnski, Tuikolongahau Halafihi, Lesley L. Rhodes. Molecular Identification of Gambierdiscus and Fukuyoa (Dinophyceae) from Environmental Samples. Marine Drugs. 2017; 15 (8):243.

Chicago/Turabian Style

Kirsty F. Smith; Laura Biessy; Phoebe A. Argyle; Tom Trnski; Tuikolongahau Halafihi; Lesley L. Rhodes. 2017. "Molecular Identification of Gambierdiscus and Fukuyoa (Dinophyceae) from Environmental Samples." Marine Drugs 15, no. 8: 243.

Journal article
Published: 11 July 2017 in Marine Drugs
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Species in the genus Gambierdiscus produce ciguatoxins (CTXs) and/or maitotoxins (MTXs), which may cause ciguatera fish poisoning (CFP) in humans if contaminated fish are consumed. Species of Gambierdiscus have previously been isolated from macroalgae at Rangitahua (Raoul Island and North Meyer Islands, northern Kermadec Islands), and the opportunity was taken to sample for Gambierdiscus at the more southerly Macauley Island during an expedition in 2016. Gambierdiscus cells were isolated, cultured, and DNA extracted and sequenced to determine the species present. Bulk cultures were tested for CTXs and MTXs by liquid chromatography-mass spectrometry (LC-MS/MS). The species isolated were G. australes, which produced MTX-1 (ranging from 3 to 36 pg/cell), and G. polynesiensis, which produced neither MTX-1 nor, unusually, any known CTXs. Isolates of both species produced putative MTX-3. The risk of fish, particularly herbivorous fish, causing CFP in the Zealandia and Kermadec Islands region is real, although in mainland New Zealand the risk is currently low. Both Gambierdiscus and Fukuyoa have been recorded in the sub-tropical northern region of New Zealand, and so the risk may increase with warming seas and shift in the distribution of Gambierdiscus species.

ACS Style

Lesley L. Rhodes; Kirsty F. Smith; Sam Murray; D. Tim Harwood; Tom Trnski; Rex Munday. The Epiphytic Genus Gambierdiscus (Dinophyceae) in the Kermadec Islands and Zealandia Regions of the Southwestern Pacific and the Associated Risk of Ciguatera Fish Poisoning. Marine Drugs 2017, 15, 219 .

AMA Style

Lesley L. Rhodes, Kirsty F. Smith, Sam Murray, D. Tim Harwood, Tom Trnski, Rex Munday. The Epiphytic Genus Gambierdiscus (Dinophyceae) in the Kermadec Islands and Zealandia Regions of the Southwestern Pacific and the Associated Risk of Ciguatera Fish Poisoning. Marine Drugs. 2017; 15 (7):219.

Chicago/Turabian Style

Lesley L. Rhodes; Kirsty F. Smith; Sam Murray; D. Tim Harwood; Tom Trnski; Rex Munday. 2017. "The Epiphytic Genus Gambierdiscus (Dinophyceae) in the Kermadec Islands and Zealandia Regions of the Southwestern Pacific and the Associated Risk of Ciguatera Fish Poisoning." Marine Drugs 15, no. 7: 219.

Comparative study
Published: 30 June 2017 in Marine Drugs
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Ciguatoxins (CTXs), and possibly maitotoxins (MTXs), are responsible for Ciguatera Fish Poisoning, an important health problem for consumers of reef fish (such as inhabitants of islands in the South Pacific Ocean). The habitational range of the Gambierdiscus species is expanding, and new species are being discovered. In order to provide information on the potential health risk of the Gambierdiscus species, and one Fukuyoa species (found in the Cook Islands, the Kermadec Islands, mainland New Zealand, and New South Wales, Australia), 17 microalgae isolates were collected from these areas. Unialgal cultures were grown and extracts of the culture isolates were analysed for CTXs and MTXs by liquid chromatography tandem mass spectrometry (LC-MS/MS), and their toxicity to mice was determined by intraperitoneal and oral administration. An isolate of G. carpenteri contained neither CTXs nor MTXs, while 15 other isolates (including G. australes, G. cheloniae, G. pacificus, G. honu, and F. paulensis) contained only MTX-1 and/or MTX-3. An isolate of G. polynesiensis contained both CTXs and MTX-3. All the extracts were toxic to mice by intraperitoneal injection, but those containing only MTX-1 and/or -3 were much less toxic by oral administration. The extract of G. polynesiensis was highly toxic by both routes of administration.

ACS Style

Rex Munday; Sam Murray; Lesley L. Rhodes; Michaela E. Larsson; D. Tim Harwood. Ciguatoxins and Maitotoxins in Extracts of Sixteen Gambierdiscus Isolates and One Fukuyoa Isolate from the South Pacific and Their Toxicity to Mice by Intraperitoneal and Oral Administration. Marine Drugs 2017, 15, 208 .

AMA Style

Rex Munday, Sam Murray, Lesley L. Rhodes, Michaela E. Larsson, D. Tim Harwood. Ciguatoxins and Maitotoxins in Extracts of Sixteen Gambierdiscus Isolates and One Fukuyoa Isolate from the South Pacific and Their Toxicity to Mice by Intraperitoneal and Oral Administration. Marine Drugs. 2017; 15 (7):208.

Chicago/Turabian Style

Rex Munday; Sam Murray; Lesley L. Rhodes; Michaela E. Larsson; D. Tim Harwood. 2017. "Ciguatoxins and Maitotoxins in Extracts of Sixteen Gambierdiscus Isolates and One Fukuyoa Isolate from the South Pacific and Their Toxicity to Mice by Intraperitoneal and Oral Administration." Marine Drugs 15, no. 7: 208.

Journal article
Published: 01 May 2017 in Harmful Algae
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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.

ACS Style

Lesley Rhodes; Kirsty F. Smith; Arjun Verma; Belinda G. Curley; D. Tim Harwood; Sam Murray; Gurjeet S. Kohli; Dorothy Solomona; Teina Rongo; Rex Munday; Shauna A. Murray. A new species of Gambierdiscus (Dinophyceae) from the south-west Pacific: Gambierdiscus honu sp. nov. Harmful Algae 2017, 65, 61 -70.

AMA Style

Lesley Rhodes, Kirsty F. Smith, Arjun Verma, Belinda G. Curley, D. Tim Harwood, Sam Murray, Gurjeet S. Kohli, Dorothy Solomona, Teina Rongo, Rex Munday, Shauna A. Murray. A new species of Gambierdiscus (Dinophyceae) from the south-west Pacific: Gambierdiscus honu sp. nov. Harmful Algae. 2017; 65 ():61-70.

Chicago/Turabian Style

Lesley Rhodes; Kirsty F. Smith; Arjun Verma; Belinda G. Curley; D. Tim Harwood; Sam Murray; Gurjeet S. Kohli; Dorothy Solomona; Teina Rongo; Rex Munday; Shauna A. Murray. 2017. "A new species of Gambierdiscus (Dinophyceae) from the south-west Pacific: Gambierdiscus honu sp. nov." Harmful Algae 65, no. : 61-70.

Journal article
Published: 15 March 2017 in New Zealand Journal of Marine and Freshwater Research
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In this study, we assessed the use of DNA metabarcoding as a method for biodiversity assessment of benthic-epiphytic dinoflagellate communities and for detecting rare, toxin-producing taxa. Mock communities and three primer pairs were used to establish the recovery of species signal and quantitative representation of species in the samples, as well as to determine primer biases, bioinformatic filtering steps, and threshold levels. Samples were analysed using high-throughput sequencing Illumina™ MiSeq technology. We did not find a relationship between read number and cell abundance for all treatments. However, the method was extremely sensitive, with two of the primer pairs detecting a single cell representing less than 0.001% of the cells in the sample. Benthic and epiphytic dinoflagellate communities were also collected from the Bay of Islands (Northland, New Zealand). Dinophyceae species richness was much higher when samples were analysed using metabarcoding than when analysed by microscopy, and we detected several new taxonomic records for New Zealand.

ACS Style

Kirsty F. Smith; Gurjeet S Kohli; Shauna A. Murray; Lesley L. Rhodes. Assessment of the metabarcoding approach for community analysis of benthic-epiphytic dinoflagellates using mock communities. New Zealand Journal of Marine and Freshwater Research 2017, 51, 555 -576.

AMA Style

Kirsty F. Smith, Gurjeet S Kohli, Shauna A. Murray, Lesley L. Rhodes. Assessment of the metabarcoding approach for community analysis of benthic-epiphytic dinoflagellates using mock communities. New Zealand Journal of Marine and Freshwater Research. 2017; 51 (4):555-576.

Chicago/Turabian Style

Kirsty F. Smith; Gurjeet S Kohli; Shauna A. Murray; Lesley L. Rhodes. 2017. "Assessment of the metabarcoding approach for community analysis of benthic-epiphytic dinoflagellates using mock communities." New Zealand Journal of Marine and Freshwater Research 51, no. 4: 555-576.

Journal article
Published: 21 February 2017 in Toxins
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Paralytic shellfish poisoning results from consumption of seafood naturally contaminated by saxitoxin and its congeners, the paralytic shellfish toxins (PSTs). The levels of such toxins are regulated internationally, and maximum permitted concentrations in seafood have been established in many countries. A mouse bioassay is an approved method for estimating the levels of PSTs in seafood, but this is now being superseded in many countries by instrumental methods of analysis. Such analyses provide data on the levels of many PSTs in seafood, but for risk assessment, knowledge of the relative toxicities of the congeners is required. These are expressed as “Toxicity Equivalence Factors” (TEFs). At present, TEFs are largely based on relative specific activities following intraperitoneal injection in a mouse bioassay rather than on acute toxicity determinations. A more relevant parameter for comparison would be median lethal doses via oral administration, since this is the route through which humans are exposed to PSTs. In the present study, the median lethal doses of gonyautoxin 5, gonyautoxin 6, decarbamoyl neosaxitoxin and of equilibrium mixtures of decarbamoyl gonyautoxins 2&3, C1&2 and C3&4 by oral administration to mice have been determined and compared with toxicities via intraperitoneal injection. The results indicate that the TEFs of several of these substances require revision in order to more accurately reflect the risk these toxins present to human health.

ACS Style

Andrew I. Selwood; Craig Waugh; David T. Harwood; Lesley L. Rhodes; John Reeve; Jim Sim; Rex Munday. Acute Toxicities of the Saxitoxin Congeners Gonyautoxin 5, Gonyautoxin 6, Decarbamoyl Gonyautoxin 2&3, Decarbamoyl Neosaxitoxin, C-1&2 and C-3&4 to Mice by Various Routes of Administration. Toxins 2017, 9, 73 .

AMA Style

Andrew I. Selwood, Craig Waugh, David T. Harwood, Lesley L. Rhodes, John Reeve, Jim Sim, Rex Munday. Acute Toxicities of the Saxitoxin Congeners Gonyautoxin 5, Gonyautoxin 6, Decarbamoyl Gonyautoxin 2&3, Decarbamoyl Neosaxitoxin, C-1&2 and C-3&4 to Mice by Various Routes of Administration. Toxins. 2017; 9 (2):73.

Chicago/Turabian Style

Andrew I. Selwood; Craig Waugh; David T. Harwood; Lesley L. Rhodes; John Reeve; Jim Sim; Rex Munday. 2017. "Acute Toxicities of the Saxitoxin Congeners Gonyautoxin 5, Gonyautoxin 6, Decarbamoyl Gonyautoxin 2&3, Decarbamoyl Neosaxitoxin, C-1&2 and C-3&4 to Mice by Various Routes of Administration." Toxins 9, no. 2: 73.

Original article
Published: 17 February 2017 in Journal of Eukaryotic Microbiology
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Gambierdiscus, a benthic dinoflagellate, produces ciguatoxins that cause the human illness Ciguatera. Ciguatoxins are polyether ladder compounds that have a polyketide origin, indicating that polyketide synthases (PKS) are involved in their production. We sequenced transcriptomes of Gambierdiscus excentricus and Gambierdiscus polynesiensis and found 264 contigs encoding single domain ketoacyl synthases (KS; G. excentricus: 106, G. polynesiensis: 143) and ketoreductases (KR; G. excentricus: 7, G. polynesiensis: 8) with sequence similarity to type I PKSs, as reported in other dinoflagellates. In addition, 24 contigs (G. excentricus: 3, G. polynesiensis: 21) encoding multiple PKS domains (forming typical type I PKSs modules) were found. The proposed structure produced by one of these megasynthases resembles a partial carbon backbone of a polyether ladder compound. Seventeen contigs encoding single domain KS, KR, s‐malonyltransacylase, dehydratase and enoyl reductase with sequence similarity to type II fatty acid synthases (FAS) in plants were found. Type I PKS and type II FAS genes were distinguished based on the arrangement of domains on the contigs and their sequence similarity and phylogenetic clustering with known PKS/FAS genes in other organisms. This differentiation of PKS and FAS pathways in Gambierdiscus is important, as it will facilitate approaches to investigating toxin biosynthesis pathways in dinoflagellates.

ACS Style

Gurjeet S. Kohli; Katrina Campbell; Uwe John; Kirsty F. Smith; Santiago Fraga; Lesley L. Rhodes; Shauna A. Murray. Role of Modular Polyketide Synthases in the Production of Polyether Ladder Compounds in Ciguatoxin‐Producing Gambierdiscus polynesiensis and G. excentricus (Dinophyceae). Journal of Eukaryotic Microbiology 2017, 64, 691 -706.

AMA Style

Gurjeet S. Kohli, Katrina Campbell, Uwe John, Kirsty F. Smith, Santiago Fraga, Lesley L. Rhodes, Shauna A. Murray. Role of Modular Polyketide Synthases in the Production of Polyether Ladder Compounds in Ciguatoxin‐Producing Gambierdiscus polynesiensis and G. excentricus (Dinophyceae). Journal of Eukaryotic Microbiology. 2017; 64 (5):691-706.

Chicago/Turabian Style

Gurjeet S. Kohli; Katrina Campbell; Uwe John; Kirsty F. Smith; Santiago Fraga; Lesley L. Rhodes; Shauna A. Murray. 2017. "Role of Modular Polyketide Synthases in the Production of Polyether Ladder Compounds in Ciguatoxin‐Producing Gambierdiscus polynesiensis and G. excentricus (Dinophyceae)." Journal of Eukaryotic Microbiology 64, no. 5: 691-706.

Research articles
Published: 05 January 2017 in New Zealand Journal of Marine and Freshwater Research
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An expedition to North Meyer Island, Kermadec Islands, in November 2015, resulted in the isolation of two Gambierdiscus species, G. australes and a previously unknown Gambierdiscus species maintained in the Cawthron Institute Culture Collection of Micro-algae as CAWD242. Identifications were based on morphology and DNA sequence data analysis. Nine isolates of G. australes produced maitotoxin-1 (MTX-1) ranging from present (detectable but below the confidence level) to 36.6 pg per cell. One further isolate did not produce MTX-1, but all G. australes isolates produced putative MTX-3. Isolate CAWD242 was negative for MTX-1 but produced MTX-3. Ostreopsis sp. 3 isolated from samples collected during an earlier expedition in 2013 produced low concentrations of palytoxin (PLTX)-like compounds (0.013 pg per cell), but an isolate of the same species from samples collected in 2015 was non-toxic. Other dinoflagellates isolated and identified were Coolia malayensis, Amphidinium carterae and Prorocentrum hoffmannianum.

ACS Style

Lesley L. Rhodes; Kirsty F. Smith; Arjun Verma; Sam Murray; D. Tim Harwood; Tom Trnski. The dinoflagellate genera Gambierdiscus and Ostreopsis from subtropical Raoul Island and North Meyer Island, Kermadec Islands. New Zealand Journal of Marine and Freshwater Research 2017, 51, 490 -504.

AMA Style

Lesley L. Rhodes, Kirsty F. Smith, Arjun Verma, Sam Murray, D. Tim Harwood, Tom Trnski. The dinoflagellate genera Gambierdiscus and Ostreopsis from subtropical Raoul Island and North Meyer Island, Kermadec Islands. New Zealand Journal of Marine and Freshwater Research. 2017; 51 (4):490-504.

Chicago/Turabian Style

Lesley L. Rhodes; Kirsty F. Smith; Arjun Verma; Sam Murray; D. Tim Harwood; Tom Trnski. 2017. "The dinoflagellate genera Gambierdiscus and Ostreopsis from subtropical Raoul Island and North Meyer Island, Kermadec Islands." New Zealand Journal of Marine and Freshwater Research 51, no. 4: 490-504.

Journal article
Published: 01 December 2016 in Harmful Algae
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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.

ACS Style

Kirsty F. Smith; Lesley Rhodes; Arjun Verma; Belinda G. Curley; D.Tim Harwood; Gurjeet S Kohli; Dorothy Solomona; Teina Rongo; Rex Munday; Shauna A. Murray. A new Gambierdiscus species (Dinophyceae) from Rarotonga, Cook Islands: Gambierdiscus cheloniae sp. nov. Harmful Algae 2016, 60, 45 -56.

AMA Style

Kirsty F. Smith, Lesley Rhodes, Arjun Verma, Belinda G. Curley, D.Tim Harwood, Gurjeet S Kohli, Dorothy Solomona, Teina Rongo, Rex Munday, Shauna A. Murray. A new Gambierdiscus species (Dinophyceae) from Rarotonga, Cook Islands: Gambierdiscus cheloniae sp. nov. Harmful Algae. 2016; 60 ():45-56.

Chicago/Turabian Style

Kirsty F. Smith; Lesley Rhodes; Arjun Verma; Belinda G. Curley; D.Tim Harwood; Gurjeet S Kohli; Dorothy Solomona; Teina Rongo; Rex Munday; Shauna A. Murray. 2016. "A new Gambierdiscus species (Dinophyceae) from Rarotonga, Cook Islands: Gambierdiscus cheloniae sp. nov." Harmful Algae 60, no. : 45-56.

Journal article
Published: 01 May 2016 in Harmful Algae
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ACS Style

Lesley Rhodes; Tim Harwood; Kirsty Smith; Phoebe Argyle; Rex Munday. Corrigendum to ‘Production of ciguatoxin and maitotoxin by strains of Gambierdiscus australes, G. pacificus and G. polynesiensis (Dinophyceae) isolated from Rarotonga, Cook Islands’ [Harmful Algae 39 (2014) 185–190]. Harmful Algae 2016, 55, 295 .

AMA Style

Lesley Rhodes, Tim Harwood, Kirsty Smith, Phoebe Argyle, Rex Munday. Corrigendum to ‘Production of ciguatoxin and maitotoxin by strains of Gambierdiscus australes, G. pacificus and G. polynesiensis (Dinophyceae) isolated from Rarotonga, Cook Islands’ [Harmful Algae 39 (2014) 185–190]. Harmful Algae. 2016; 55 ():295.

Chicago/Turabian Style

Lesley Rhodes; Tim Harwood; Kirsty Smith; Phoebe Argyle; Rex Munday. 2016. "Corrigendum to ‘Production of ciguatoxin and maitotoxin by strains of Gambierdiscus australes, G. pacificus and G. polynesiensis (Dinophyceae) isolated from Rarotonga, Cook Islands’ [Harmful Algae 39 (2014) 185–190]." Harmful Algae 55, no. : 295.

Journal article
Published: 01 May 2016 in Harmful Algae
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In this study, inter- and intraspecific genetic diversity within the marine harmful dinoflagellate genus Coolia Meunier was evaluated using isolates obtained from the tropics to subtropics in both Pacific and Atlantic Ocean basins. The aim was to assess the phylogeographic history of the genus and to clarify the validity of established species including Coolia malayensis. Phylogenetic analysis of the D1-D2 LSU rDNA sequences identified six major lineages (L1–L6) corresponding to the morphospecies Coolia malayensis (L1), C. monotis (L2), C. santacroce (L3), C. palmyrensis (L4), C. tropicalis (L5), and C. canariensis (L6). A median joining network (MJN) of C. malayensis ITS2 rDNA sequences revealed a total of 16 haplotypes; however, no spatial genetic differentiation among populations was observed. These MJN results in conjunction with CBC analysis, rDNA phylogenies and geographical distribution analyses confirm C. malayensis as a distinct species which is globally distributed in the tropical to warm-temperate regions. A molecular clock analysis using ITS2 rDNA revealed the evolutionary history of Coolia dated back to the Mesozoic, and supports the hypothesis that historical vicariant events in the early Cenozoic drove the allopatric differentiation of C. malayensis and C. monotis.

ACS Style

Chui Pin Leaw; Toh Hii Tan; Hong Chang Lim; Sing Tung Teng; Hwa Lin Yong; Kirsty F. Smith; Lesley Rhodes; Matthias Wolf; William C. Holland; Mark W. Vandersea; R. Wayne Litaker; Patricia A. Tester; Haifeng Gu; Gires Usup; Po Teen Lim. New scenario for speciation in the benthic dinoflagellate genus Coolia (Dinophyceae). Harmful Algae 2016, 55, 137 -149.

AMA Style

Chui Pin Leaw, Toh Hii Tan, Hong Chang Lim, Sing Tung Teng, Hwa Lin Yong, Kirsty F. Smith, Lesley Rhodes, Matthias Wolf, William C. Holland, Mark W. Vandersea, R. Wayne Litaker, Patricia A. Tester, Haifeng Gu, Gires Usup, Po Teen Lim. New scenario for speciation in the benthic dinoflagellate genus Coolia (Dinophyceae). Harmful Algae. 2016; 55 ():137-149.

Chicago/Turabian Style

Chui Pin Leaw; Toh Hii Tan; Hong Chang Lim; Sing Tung Teng; Hwa Lin Yong; Kirsty F. Smith; Lesley Rhodes; Matthias Wolf; William C. Holland; Mark W. Vandersea; R. Wayne Litaker; Patricia A. Tester; Haifeng Gu; Gires Usup; Po Teen Lim. 2016. "New scenario for speciation in the benthic dinoflagellate genus Coolia (Dinophyceae)." Harmful Algae 55, no. : 137-149.

Review articles
Published: 02 April 2016 in New Zealand Journal of Marine and Freshwater Research
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The Cawthron Institute Culture Collection of Micro-algae (CICCM) is a unique, nationally and internationally significant collection of 450 strains of approximately 100 micro-algae and 50 cyanobacteria species, both living and cryopreserved. The collection comprises 13 taxonomic classes and underpins research into the ecology and taxonomy of the isolates and the biotoxins they produce and their toxicity. The CICCM expanded significantly in the 1990s after a major harmful algae bloom event in the Hauraki Gulf, New Zealand. Since 2000, it has underpinned development of molecular detection tools and enabled development of new chemical testing methods for biotoxins in seafood. The tropical collection allows research into potential issues for New Zealand as the oceans warm, for example, the risks of ciguatera fish poisoning and palytoxins in seafood. Research results generated from isolates in the cyanobacterial collection have assisted national risk management regarding drinking water and informed the development of the New Zealand guidelines for managing cyanobacteria in recreational fresh waters. The actual living and cryopreserved micro-algae and cyanobacteria collection (without infrastructure) has a current estimated value of NZ$1.6 million.

ACS Style

L Rhodes; Kf Smith; L MacKenzie; Sa Wood; K Ponikla; Dt Harwood; Michael Packer; R Munday. The Cawthron Institute Culture Collection of Micro-algae: a significant national collection. New Zealand Journal of Marine and Freshwater Research 2016, 50, 291 -316.

AMA Style

L Rhodes, Kf Smith, L MacKenzie, Sa Wood, K Ponikla, Dt Harwood, Michael Packer, R Munday. The Cawthron Institute Culture Collection of Micro-algae: a significant national collection. New Zealand Journal of Marine and Freshwater Research. 2016; 50 (2):291-316.

Chicago/Turabian Style

L Rhodes; Kf Smith; L MacKenzie; Sa Wood; K Ponikla; Dt Harwood; Michael Packer; R Munday. 2016. "The Cawthron Institute Culture Collection of Micro-algae: a significant national collection." New Zealand Journal of Marine and Freshwater Research 50, no. 2: 291-316.

Book chapter
Published: 10 March 2016 in Smart and Sustainable Planning for Cities and Regions
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Microalgae are an important source of primary production in the oceans’ food webs and are therefore beneficial to humankind. Of the huge diversity of algae only 6 % are estimated to multiply to form harmful algae blooms (HABs) and less than 2 % of the described species produce potent biotoxins. This small number of algae can, however, have great economic impacts in terms of public health, commercial fisheries and recreation and tourism.

ACS Style

Lesley Rhodes; Rex Munday. Harmful Algae and Their Commercial Implications. Smart and Sustainable Planning for Cities and Regions 2016, 301 -315.

AMA Style

Lesley Rhodes, Rex Munday. Harmful Algae and Their Commercial Implications. Smart and Sustainable Planning for Cities and Regions. 2016; ():301-315.

Chicago/Turabian Style

Lesley Rhodes; Rex Munday. 2016. "Harmful Algae and Their Commercial Implications." Smart and Sustainable Planning for Cities and Regions , no. : 301-315.

Journal article
Published: 28 May 2015 in BMC Genomics
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Marine microbial protists, in particular, dinoflagellates, produce polyketide toxins with ecosystem-wide and human health impacts. Species of Gambierdiscus produce the polyether ladder compounds ciguatoxins and maitotoxins, which can lead to ciguatera fish poisoning, a serious human illness associated with reef fish consumption. Genes associated with the biosynthesis of polyether ladder compounds are yet to be elucidated, however, stable isotope feeding studies of such compounds consistently support their polyketide origin indicating that polyketide synthases are involved in their biosynthesis. Here, we report the toxicity, genome size, gene content and transcriptome of Gambierdiscus australes and G. belizeanus. G. australes produced maitotoxin-1 and maitotoxin-3, while G. belizeanus produced maitotoxin-3, for which cell extracts were toxic to mice by IP injection (LD50 = 3.8 mg kg-1). The gene catalogues comprised 83,353 and 84,870 unique contigs, with genome sizes of 32.5 ± 3.7 Gbp and 35 ± 0.88 Gbp, respectively, and are amongst the most comprehensive yet reported from a dinoflagellate. We found three hundred and six genes involved in polyketide biosynthesis, including one hundred and ninty-two ketoacyl synthase transcripts, which formed five unique phylogenetic clusters. Two clusters were unique to these maitotoxin-producing dinoflagellate species, suggesting that they may be associated with maitotoxin biosynthesis. This work represents a significant step forward in our understanding of the genetic basis of polyketide production in dinoflagellates, in particular, species responsible for ciguatera fish poisoning.

ACS Style

Gurjeet S. Kohli; Uwe John; Rosa Isabel Figueroa; Lesley L. Rhodes; D. Tim Harwood; Marco Groth; Christopher J. S. Bolch; Shauna A. Murray. Polyketide synthesis genes associated with toxin production in two species of Gambierdiscus (Dinophyceae). BMC Genomics 2015, 16, 1 -10.

AMA Style

Gurjeet S. Kohli, Uwe John, Rosa Isabel Figueroa, Lesley L. Rhodes, D. Tim Harwood, Marco Groth, Christopher J. S. Bolch, Shauna A. Murray. Polyketide synthesis genes associated with toxin production in two species of Gambierdiscus (Dinophyceae). BMC Genomics. 2015; 16 (1):1-10.

Chicago/Turabian Style

Gurjeet S. Kohli; Uwe John; Rosa Isabel Figueroa; Lesley L. Rhodes; D. Tim Harwood; Marco Groth; Christopher J. S. Bolch; Shauna A. Murray. 2015. "Polyketide synthesis genes associated with toxin production in two species of Gambierdiscus (Dinophyceae)." BMC Genomics 16, no. 1: 1-10.

Short communication
Published: 08 September 2014 in New Zealand Journal of Marine and Freshwater Research
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Epiphytic dinoflagellates were isolated from samples collected from macroalgae and corals during an expedition to the Kermadec Islands group, led by the Auckland Museum in November 2013. Isolates included species of Gambierdiscus and Ostreopsis, genera included in the ciguatera fish poisoning complex. Cells of a compressed (apical to antapical) form of Gambierdiscus were isolated into growth media, but species identification was not possible as isolates failed to grow in culture. The Ostreopsis isolate was successfully cultured and appears to be a new species (a full description will be undertaken). Palytoxin production was determined by chemical analysis (LC-MS/MS) as 0.013 pg palytoxin equiv. per cell. Prorocentrum isolates were identified morphologically as P. cf. emarginatum and P. lima; both were non-toxic. Amphidinium cf. massartii and Coolia malayensis were identified by DNA sequence analysis. The suite of dinoflagellates isolated was typical of the co-occurring genera found throughout the Pacific region.

ACS Style

L Rhodes; K Smith; T Harwood; C Bedford. Novel and toxin-producing epiphytic dinoflagellates isolated from sub-tropical Raoul Island, Kermadec Islands group. New Zealand Journal of Marine and Freshwater Research 2014, 48, 594 -599.

AMA Style

L Rhodes, K Smith, T Harwood, C Bedford. Novel and toxin-producing epiphytic dinoflagellates isolated from sub-tropical Raoul Island, Kermadec Islands group. New Zealand Journal of Marine and Freshwater Research. 2014; 48 (4):594-599.

Chicago/Turabian Style

L Rhodes; K Smith; T Harwood; C Bedford. 2014. "Novel and toxin-producing epiphytic dinoflagellates isolated from sub-tropical Raoul Island, Kermadec Islands group." New Zealand Journal of Marine and Freshwater Research 48, no. 4: 594-599.

Journal article
Published: 31 July 2014 in Harmful Algae
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Species of the genus Gambierdiscus are epiphytic dinoflagellates well known from tropical coral reef areas at water temperatures from 24 to 29 °C. Gambierdiscus spp. are able to produce ciguatoxins (CTXs) known to bioaccumulate in fish, and the ingestion of tropical fish that accumulated CTXs and possibly also maitotoxins (MTXs) can cause ciguatera fish poisoning (CFP) in humans. In Australia, ciguatera poisonings have been reported in tropical parts of Queensland and the Northern Territory. Here, we report for the first time the seasonal abundance (April–May 2012/13) of Gambierdiscus spp. (up to 6565–8255 cells g−1 wet weight algae) from Merimbula and Wagonga Inlets in temperate southern New South Wales, Australia (37° S) at water temperatures of 16.5–17 °C. These are popular shellfish aquaculture and recreational fisheries areas with no reports of ciguatera poisoning. Sequencing of a region of the 28S rRNA gene led to the conclusive identification of Gambierdiscus carpenteri. The cells differed however from the Belize type description, including the absence of a thecal groove, dorsal rostrum and variable hatchet- to rectangular-shaped 2′ plate, and were morphologically more similar to Gambierdiscus toxicus. To study the dinoflagellate community structure in detail, a pyrosequencing approach based on the 18S rRNA gene was applied, which confirmed the presence of a single Gambierdiscus species only. Neither CTXs nor MTXs were detected in natural bloom material by LC–MS/MS; however, the extracts were found to be toxic via mouse-bioassay, with symptoms suggestive of poisoning by MTX-like compounds. Understanding the abundance of Gambierdiscus populations in areas with no apparent human health impacts is important towards defining the alternate conditions where sparse populations can create ciguatera problems.

ACS Style

Gurjeet S. Kohli; Shauna A. Murray; Brett A. Neilan; Lesley L. Rhodes; D. Tim Harwood; Kirsty F. Smith; Lauren Meyer; Angela Capper; Steve Brett; Gustaaf M. Hallegraeff. High abundance of the potentially maitotoxic dinoflagellate Gambierdiscus carpenteri in temperate waters of New South Wales, Australia. Harmful Algae 2014, 39, 134 -145.

AMA Style

Gurjeet S. Kohli, Shauna A. Murray, Brett A. Neilan, Lesley L. Rhodes, D. Tim Harwood, Kirsty F. Smith, Lauren Meyer, Angela Capper, Steve Brett, Gustaaf M. Hallegraeff. High abundance of the potentially maitotoxic dinoflagellate Gambierdiscus carpenteri in temperate waters of New South Wales, Australia. Harmful Algae. 2014; 39 ():134-145.

Chicago/Turabian Style

Gurjeet S. Kohli; Shauna A. Murray; Brett A. Neilan; Lesley L. Rhodes; D. Tim Harwood; Kirsty F. Smith; Lauren Meyer; Angela Capper; Steve Brett; Gustaaf M. Hallegraeff. 2014. "High abundance of the potentially maitotoxic dinoflagellate Gambierdiscus carpenteri in temperate waters of New South Wales, Australia." Harmful Algae 39, no. : 134-145.