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Nina Lundholm - One of the best experts on this subject based on the ideXlab platform.
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MOESM1 of Transcriptomic responses to grazing reveal the metabolic pathway leading to the biosynthesis of Domoic Acid and highlight different defense strategies in diatoms
2019Co-Authors: Sara Harรฐardรณttir, Sylke Wohlrab, Uwe John, Bernd Krock, Ditte Hjort, Torkel Nielsen, Nina LundholmAbstract:Additional file 1: Figure S1. An overview of the proposed cellular metabolic pathways for Domoic Acid. Figure S2. Venn diagram showing a comparison of differently expressed genes in Pseudo-nitzschia seriata inducing Domoic Acid (DA) production in response to grazers with data from P. multistriata producing DA during phosphate limitation and pCO2 elevation and to Skeletonema marinoi exposed to copepod grazers. Figure S3. Graphical overview of the sequence similarities of the genes commonly identified to respond to copepod grazing
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Can Domoic Acid affect escape response in copepods
Harmful Algae, 2018Co-Authors: Sara Harðardóttir, Torkel Gissel Nielsen, Sylke Wohlrab, Uwe John, Bernd Krock, Nina LundholmAbstract:Abstract Copepods are important grazers on toxic phytoplankton and serve as vectors for algal toxins up the marine food web. Success of phytoplankton depends among other factors on protection against grazers like copepods, and same way copepod survival and population resilience relies on their ability to escape predators. Little is, however, known about the effect of toxins on the escape response of copepods. In this study we experimentally tested the hypothesis that the neurotoxin Domoic Acid (DA) produced by the diatom Pseudo-nitzschia affects escape responses of planktonic copepods. We found that the arctic copepods Calanus hyperboreus and C. glacialis reduced their escape response after feeding on a DA-producing diatom. The two species were not affected the same way; C. hyperboreus was affected after shorter exposure and less intake of DA. The negative effect on escape response was not related to the amount of DA accumulated in the copepods. Our results suggest that further research on the effects of DA on copepod behavior and DA toxicity mechanisms is required to evaluate the anti-grazing function of DA.
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Induction of Domoic Acid production in diatoms-Types of grazers and diatoms are important.
Harmful Algae, 2018Co-Authors: Nina Lundholm, Torkel Gissel Nielsen, Sylke Wohlrab, Uwe John, Bernd Krock, Jette Skov, Jinfeng Cheng, Marina Pančić, Kristie Rigby, Erik SelanderAbstract:Abstract Grazers can induce toxin (Domoic Acid, DA) production in diatoms. The toxic response has been observed in two species of Pseudo-nitzschia and was induced by Calanus copepods. In this study, interactions between diatoms and copepods were further explored using different species of diatoms and copepods. All herbivorous copepods induced toxin production, whereas exposure to carnivorous copepods did not. In line with this, increasing the number of herbivorous copepods resulted in even higher toxin production. The induced response is thus only elicited by copepods that pose a real threat to the responding cells, which supports that the induced toxin production in diatoms evolved as an inducible defense. The cellular toxin content in Pseudo-nitzschia was positively correlated to the concentration of a group of specific polar lipids called copepodamides that are excreted by the copepods. This suggests that copepodamides are the chemical cues responsible for triggering the toxin production. Carnivorous copepods were found to produce less or no copepodamides. Among the diatoms exposed to grazing herbivorous copepods, only two of six species of Pseudo-nitzschia and none of the Nitzschia or Fragilariopsis strains responded by producing DA, indicating that not all Pseudo-nitzschia species/strains are able to produce DA, and that different diatom species might have different strategies for coping with grazing pressure. Growth rate was negatively correlated to cellular Domoic Acid content indicating an allocation cost associated with toxin production. Long-term grazing experiments showed higher mortality rates of grazers fed toxic diatoms, supporting the hypothesis that DA production is an induced defense mechanism.
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pseudo nitzschia simulans sp nov bacillariophyceae the first Domoic Acid producer from chinese waters
Harmful Algae, 2017Co-Authors: Chun Xiu Huang, Nina Lundholm, Sing Tung Teng, Zhijun TanAbstract:The genus Pseudo-nitzschia has attracted attention because of production of the toxin, Domoic Acid (DA), causing Amnesic Shellfish Poisoning (ASP). Pseudo-nitzschia blooms occur frequently in Chinese coastal waters, and DA has been detected in several marine organisms, but so far no Pseudo-nitzschia strains from Chinese waters have been shown to produce DA. In this study, monoclonal Pseudo-nitzschia strains were established from Chinese coastal waters and examined using light microscopy, electron microscopy and molecular markers. Five strains, sharing distinct morphological and molecular features differentiating them from other Pseudo-nitzschia species, represent a new species, Pseudo-nitzschia simulans sp. nov. Morphologically, the taxon belongs to the P. pseudodelicatissima group, cells possessing a central nodule and each stria comprising one row of poroids. The new species is characterized by the poroid structure, which typically comprises two sectors, each sector located near opposite margins of the poroid. The production of DA was examined by liquid chromatography tandem mass spectrometry (LC-MS/MS) analyses of cells in stationary growth phase. Domoic Acid was detected in one of the five strains, with concentrations around 1.05-1.54 fg cell-1. This is the first toxigenic diatom species reported from Chinese waters.
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Pseudo-nitzschia simulans sp. nov. (Bacillariophyceae), the first Domoic Acid producer from Chinese waters
'Elsevier BV', 2017Co-Authors: Li Yang, Nina Lundholm, Chun Xiu Huang, Sing Tung Teng, Shuang Xu Guo, Wu Haiyan, Zhijun TanAbstract:The genus Pseudo-nitzschia has attracted attention because of production of the toxin, Domoic Acid (DA), causing Amnesic Shellfish Poisoning (ASP). Pseudo-nitzschia blooms occur frequently in Chinese coastal waters, and DA has been detected in several marine organisms, but so far no Pseudo-nitzschia strains from Chinese waters have been shown to produce DA. In this study, monoclonal Pseudo-nitzschia strains were established from Chinese coastal waters and examined using light microscopy, electron microscopy and molecular markers. Five strains, sharing distinct morphological and molecular features differentiating them from other Pseudo-nitzschia species, represent a new species, Pseudo-nitzschia simulans sp. nov. Morphologically, the taxon belongs to the P. pseudodelicatissima group, cells possessing a central nodule and each stria comprising one row of poroids. The new species is characterized by the poroid structure, which typically comprises two sectors, each sector located near opposite margins of the poroid. The production of DA was examined by liquid chromatography tandem mass spectrometry (LC–MS/MS) analyses of cells in stationary growth phase. Domoic Acid was detected in one of the five strains, with concentrations around 1.05–1.54 fg cell�1. This is the first toxigenic diatom species reported from Chinese waters
T Zabka - One of the best experts on this subject based on the ideXlab platform.
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the role of Domoic Acid in abortion and premature parturition of california sea lions zalophus californianus on san miguel island california
Journal of Wildlife Diseases, 2009Co-Authors: T Zabka, Mary W. Silver, Sibel Bargu, Tracey Goldstein, Robert L Delong, Elizabeth Wheeler, Gina M Ylitalo, Tod A LeighfieldAbstract:Domoic Acid is a glutaminergic neurotoxin produced by marine algae such as Pseudo-nitzschia australis. California sea lions (Zalophus californianus) ingest the toxin when foraging on planktivorous fish. Adult females comprise 60% of stranded animals admitted for rehabilitation due to acute Domoic Acid toxicosis and commonly suffer from reproductive failure, including abortions and premature live births. Domoic Acid has been shown to cross the placenta exposing the fetus to the toxin. To determine whether Domoic Acid was playing a role in reproductive failure in sea lion rookeries, 67 aborted and live-born premature pups were sampled on San Miguel Island in 2005 and 2006 to investigate the causes for reproductive failure. Analyses included Domoic Acid, contaminant and infectious disease testing, and histologic examination. Pseudo-nitzschia spp. were present both in the environment and in sea lion feces, and Domoic Acid was detected in the sea lion feces and in 17% of pup samples tested. Histopathologic fin...
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characterization of a degenerative cardiomyopathy associated with Domoic Acid toxicity in california sea lions zalophus californianus
Veterinary Pathology, 2009Co-Authors: T Zabka, Tracey Goldstein, C Cross, Rudi Mueller, C Kreuderjohnson, Santokh GillAbstract:Domoic Acid, produced by marine algae, can cause acute and chronic neurologic sequela in California sea lions (Zalophus californianus) from acute toxicity or sublethal exposure. Eight sea lions, representing acute and chronic cases, both sexes, and all age classes, were selected to demonstrate a concurrent degenerative cardiomyopathy. Critical aspects of characterizing the cardiomyopathy by lesion distribution and morphology were the development of a heart dissection and tissue-trimming protocol and the delineation of the cardiac conducting system by histomorphology and immunohis- tochemistry for neuron-specific protein gene product 9.5. Histopathologic features and progression of the cardiomyopathy are described, varying from acute to chronic active and mild to severe. The cardiomyopathy is distinguished from other heart lesions in pinnipeds. Based on histopathologic features, immunopositive staining for cleaved caspase-3, and comparison with known, similar-appearing cardiomyopathies, the proposed pathogenesis for the degenerative cardiomyopathy is the primary or at least initial direct interaction of Domoic Acid with receptors that are suspected to exist in the heart. L- Carnitine, measured in the heart and skeletal muscle, and troponin-I, measured in serum collected at the time of death from additional animals (n 5 58), were not predictive of the Domoic Acid-associated cardiomyopathy. This degenerative cardiomyopathy in California sea lions represents another syndrome beyond central neurologic disease associated with exposure to Domoic Acid and may contribute to morbidity and mortality.
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in utero Domoic Acid toxicity a fetal basis to adult disease in the california sea lion zalophus californianus
Marine Drugs, 2008Co-Authors: John S Ramsdell, T ZabkaAbstract:California sea lions have been a repeated subject of investigation for early life toxicity, which has been documented to occur with increasing frequency from late February through mid-May in association with organochlorine (PCB and DDT) poisoning and infectious disease in the 1970's and Domoic Acid poisoning in the last decade. The mass early life mortality events result from the concentrated breeding grounds and synchronization of reproduction over a 28 day post partum estrus cycle and 11 month in utero phase. This physiological synchronization is triggered by a decreasing photoperiod of 11.48 h/day that occurs approximately 90 days after conception at the major California breeding grounds. The photoperiod trigger activates implantation of embryos to proceed with development for the next 242 days until birth. Embryonic diapause is a selectable trait thought to optimize timing for food utilization and male migratory patterns; yet from the toxicological perspective presented here also serves to synchronize developmental toxicity of pulsed environmental events such as Domoic Acid poisoning. Research studies in laboratory animals have defined age-dependent neurotoxic effects during development and windows of susceptibility to Domoic Acid exposure. This review will evaluate experimental Domoic Acid neurotoxicity in developing rodents and, aided by comparative allometric projections, will analyze potential prenatal toxicity and exposure susceptibility in the California sea lion. This analysis should provide a useful tool to forecast fetal toxicity and understand the impact of fetal toxicity on adult disease of the California sea lion.
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novel symptomatology and changing epidemiology of Domoic Acid toxicosis in california sea lions zalophus californianus an increasing risk to marine mammal health
Proceedings of The Royal Society B: Biological Sciences, 2008Co-Authors: T Zabka, Jonna A K Mazet, Mary W. Silver, Sibel Bargu, Tracey Goldstein, Kathleen M. Colegrove, Gregg W Langlois, F Van DolahAbstract:Harmful algal blooms are increasing worldwide, including those of Pseudo-nitzschia spp. producing Domoic Acid off the California coast. This neurotoxin was first shown to cause mortality of marine mammals in 1998. A decade of monitoring California sea lion (Zalophus californianus) health since then has indicated that changes in the symptomatology and epidemiology of Domoic Acid toxicosis in this species are associated with the increase in toxigenic blooms. Two separate clinical syndromes now exist: acute Domoic Acid toxicosis as has been previously documented, and a second novel neurological syndrome characterized by epilepsy described here associated with chronic consequences of previous sub-lethal exposure to the toxin. This study indicates that Domoic Acid causes chronic damage to California sea lions and that these health effects are increasing.
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Domoic Acid toxicity in Californian sea lions (Zalophus californianus): clinical signs, treatment and survival
The Veterinary record, 2002Co-Authors: Martin Haulena, T Zabka, Deborah A. Fauquier, G. Langlois, Michelle E. Lander, R. DuerrAbstract:Eighty-one Californian sea lions (Zalophus californianus) with signs of Domoic Acid toxicity stranded along the coast of California in 1998 when there were blooms of the Domoic Acid-producing alga Pseudonitzschia australis off-shore. In 2000, a further 184 sea lions stranded with similar clinical signs, but the strandings occurred both during detectable algal blooms and after the blooms had subsided. The clinical signs in these 265 Californian sea lions included seizures, ataxia, head weaving, decreased responsiveness to stimuli and scratching behaviour. Affected animals had high haematocrits, and eosinophil counts, and high activities of serum creatine kinase. They were treated supportively by using fluid therapy, diazepam, lorazepam and phenobarbitone. Fifty-five of the 81 sea lions (68 per cent) affected in 1998 and 81 of the 184 (44 per cent) affected in 2000 died despite the treatment. Three of the 23 sea lions which survived in 1998 were tracked with satellite and radiotransmitters; they travelled as far south as San Miguel Island, California, and survived for at least three months. Eleven of the 129 animals which were released stranded within four months of being released.
Tracey Goldstein - One of the best experts on this subject based on the ideXlab platform.
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characterization of a degenerative cardiomyopathy associated with Domoic Acid toxicity in california sea lions zalophus californianus
Veterinary Pathology, 2009Co-Authors: T Zabka, Tracey Goldstein, C Cross, Rudi Mueller, C Kreuderjohnson, Santokh GillAbstract:Domoic Acid, produced by marine algae, can cause acute and chronic neurologic sequela in California sea lions (Zalophus californianus) from acute toxicity or sublethal exposure. Eight sea lions, representing acute and chronic cases, both sexes, and all age classes, were selected to demonstrate a concurrent degenerative cardiomyopathy. Critical aspects of characterizing the cardiomyopathy by lesion distribution and morphology were the development of a heart dissection and tissue-trimming protocol and the delineation of the cardiac conducting system by histomorphology and immunohis- tochemistry for neuron-specific protein gene product 9.5. Histopathologic features and progression of the cardiomyopathy are described, varying from acute to chronic active and mild to severe. The cardiomyopathy is distinguished from other heart lesions in pinnipeds. Based on histopathologic features, immunopositive staining for cleaved caspase-3, and comparison with known, similar-appearing cardiomyopathies, the proposed pathogenesis for the degenerative cardiomyopathy is the primary or at least initial direct interaction of Domoic Acid with receptors that are suspected to exist in the heart. L- Carnitine, measured in the heart and skeletal muscle, and troponin-I, measured in serum collected at the time of death from additional animals (n 5 58), were not predictive of the Domoic Acid-associated cardiomyopathy. This degenerative cardiomyopathy in California sea lions represents another syndrome beyond central neurologic disease associated with exposure to Domoic Acid and may contribute to morbidity and mortality.
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the role of Domoic Acid in abortion and premature parturition of california sea lions zalophus californianus on san miguel island california
Journal of Wildlife Diseases, 2009Co-Authors: T Zabka, Mary W. Silver, Sibel Bargu, Tracey Goldstein, Robert L Delong, Elizabeth Wheeler, Gina M Ylitalo, Tod A LeighfieldAbstract:Domoic Acid is a glutaminergic neurotoxin produced by marine algae such as Pseudo-nitzschia australis. California sea lions (Zalophus californianus) ingest the toxin when foraging on planktivorous fish. Adult females comprise 60% of stranded animals admitted for rehabilitation due to acute Domoic Acid toxicosis and commonly suffer from reproductive failure, including abortions and premature live births. Domoic Acid has been shown to cross the placenta exposing the fetus to the toxin. To determine whether Domoic Acid was playing a role in reproductive failure in sea lion rookeries, 67 aborted and live-born premature pups were sampled on San Miguel Island in 2005 and 2006 to investigate the causes for reproductive failure. Analyses included Domoic Acid, contaminant and infectious disease testing, and histologic examination. Pseudo-nitzschia spp. were present both in the environment and in sea lion feces, and Domoic Acid was detected in the sea lion feces and in 17% of pup samples tested. Histopathologic fin...
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demographics and spatio temporal signature of the biotoxin Domoic Acid in california sea lion zalophus californianus stranding records
Marine Mammal Science, 2008Co-Authors: Adriana C Bejarano, Tracey Goldstein, Frances M. D. Gulland, Judy St Leger, Michele Hunter, Lori H Schwacke, Frances M Vandolah, Teri RowlesAbstract:California sea lions (Zalophus californianus) in otherwise good nutritional condition have been consistently affected by the marine biotoxin Domoic Acid since the late 1990s. In this study we evaluated the temporal and spatial stranding patterns of suspected and confirmed cases of Domoic Acid intoxicated sea lions from 1998 to 2006, using records of strandings along the California coast obtained from members of the California Marine Mammal Stranding Network. The majority of Domoic Acid cases were adult females (47%-82% of the total annual Domoic Acid cases), a contrast to strandings that were not related to Domoic Acid, which were generally dominated by juveniles and pups. Exposure to this biotoxin led to a 6.67-fold increase in adult female strandings in 2000, and a 5.44-fold increase in adult female deaths in 2006, relative to strandings and deaths of adult female not affected by Domoic Acid. Domoic Acid cases have occurred annually since 1998 (except for 1999) between April and August, with clusters centered primarily at Pismo Beach (San Luis Obispo County), as well as at other beaches in San Luis Obispo, Monterey, Santa Cruz, Santa Barbara, Orange, and San Diego counties. The larger ecological and population level implications of increased Domoic Acid strandings and deaths, particularly among adult female sea lions, warrant further attention and need to be investigated.
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novel symptomatology and changing epidemiology of Domoic Acid toxicosis in california sea lions zalophus californianus an increasing risk to marine mammal health
Proceedings of The Royal Society B: Biological Sciences, 2008Co-Authors: T Zabka, Jonna A K Mazet, Mary W. Silver, Sibel Bargu, Tracey Goldstein, Kathleen M. Colegrove, Gregg W Langlois, F Van DolahAbstract:Harmful algal blooms are increasing worldwide, including those of Pseudo-nitzschia spp. producing Domoic Acid off the California coast. This neurotoxin was first shown to cause mortality of marine mammals in 1998. A decade of monitoring California sea lion (Zalophus californianus) health since then has indicated that changes in the symptomatology and epidemiology of Domoic Acid toxicosis in this species are associated with the increase in toxigenic blooms. Two separate clinical syndromes now exist: acute Domoic Acid toxicosis as has been previously documented, and a second novel neurological syndrome characterized by epilepsy described here associated with chronic consequences of previous sub-lethal exposure to the toxin. This study indicates that Domoic Acid causes chronic damage to California sea lions and that these health effects are increasing.
Zhijun Tan - One of the best experts on this subject based on the ideXlab platform.
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pseudo nitzschia simulans sp nov bacillariophyceae the first Domoic Acid producer from chinese waters
Harmful Algae, 2017Co-Authors: Chun Xiu Huang, Nina Lundholm, Sing Tung Teng, Zhijun TanAbstract:The genus Pseudo-nitzschia has attracted attention because of production of the toxin, Domoic Acid (DA), causing Amnesic Shellfish Poisoning (ASP). Pseudo-nitzschia blooms occur frequently in Chinese coastal waters, and DA has been detected in several marine organisms, but so far no Pseudo-nitzschia strains from Chinese waters have been shown to produce DA. In this study, monoclonal Pseudo-nitzschia strains were established from Chinese coastal waters and examined using light microscopy, electron microscopy and molecular markers. Five strains, sharing distinct morphological and molecular features differentiating them from other Pseudo-nitzschia species, represent a new species, Pseudo-nitzschia simulans sp. nov. Morphologically, the taxon belongs to the P. pseudodelicatissima group, cells possessing a central nodule and each stria comprising one row of poroids. The new species is characterized by the poroid structure, which typically comprises two sectors, each sector located near opposite margins of the poroid. The production of DA was examined by liquid chromatography tandem mass spectrometry (LC-MS/MS) analyses of cells in stationary growth phase. Domoic Acid was detected in one of the five strains, with concentrations around 1.05-1.54 fg cell-1. This is the first toxigenic diatom species reported from Chinese waters.
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Pseudo-nitzschia simulans sp. nov. (Bacillariophyceae), the first Domoic Acid producer from Chinese waters
'Elsevier BV', 2017Co-Authors: Li Yang, Nina Lundholm, Chun Xiu Huang, Sing Tung Teng, Shuang Xu Guo, Wu Haiyan, Zhijun TanAbstract:The genus Pseudo-nitzschia has attracted attention because of production of the toxin, Domoic Acid (DA), causing Amnesic Shellfish Poisoning (ASP). Pseudo-nitzschia blooms occur frequently in Chinese coastal waters, and DA has been detected in several marine organisms, but so far no Pseudo-nitzschia strains from Chinese waters have been shown to produce DA. In this study, monoclonal Pseudo-nitzschia strains were established from Chinese coastal waters and examined using light microscopy, electron microscopy and molecular markers. Five strains, sharing distinct morphological and molecular features differentiating them from other Pseudo-nitzschia species, represent a new species, Pseudo-nitzschia simulans sp. nov. Morphologically, the taxon belongs to the P. pseudodelicatissima group, cells possessing a central nodule and each stria comprising one row of poroids. The new species is characterized by the poroid structure, which typically comprises two sectors, each sector located near opposite margins of the poroid. The production of DA was examined by liquid chromatography tandem mass spectrometry (LC–MS/MS) analyses of cells in stationary growth phase. Domoic Acid was detected in one of the five strains, with concentrations around 1.05–1.54 fg cell�1. This is the first toxigenic diatom species reported from Chinese waters
Juan Blanco - One of the best experts on this subject based on the ideXlab platform.
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RNA-Seq Transcriptome Profiling of the Queen Scallop (Aequipecten opercularis) Digestive Gland after Exposure to Domoic Acid-Producing Pseudo-nitzschia
MDPI AG, 2019Co-Authors: Pablo Ventoso, Juan Blanco, Antonio J. Pazos, Luz M. Pérez-parallé, Juan C. Triviño, José L. SánchezAbstract:Some species of the genus Pseudo-nitzschia produce the toxin Domoic Acid, which causes amnesic shellfish poisoning (ASP). Given that bivalve mollusks are filter feeders, they can accumulate these toxins in their tissues. To elucidate the transcriptional response of the queen scallop Aequipecten opercularis after exposure to Domoic Acid-producing Pseudo-nitzschia, the digestive gland transcriptome was de novo assembled using an Illumina HiSeq 2000 platform. Then, a differential gene expression analysis was performed. After the assembly, 142,137 unigenes were obtained, and a total of 10,144 genes were differentially expressed in the groups exposed to the toxin. Functional enrichment analysis found that 374 Pfam (protein families database) domains were significantly enriched. The C1q domain, the C-type lectin, the major facilitator superfamily, the immunoglobulin domain, and the cytochrome P450 were among the most enriched Pfam domains. Protein network analysis showed a small number of highly connected nodes involved in specific functions: proteasome components, mitochondrial ribosomal proteins, protein translocases of mitochondrial membranes, cytochromes P450, and glutathione S-transferases. The results suggest that exposure to Domoic Acid-producing organisms causes oxidative stress and mitochondrial dysfunction. The transcriptional response counteracts these effects with the up-regulation of genes coding for some mitochondrial proteins, proteasome components, and antioxidant enzymes (glutathione S-transferases, thioredoxins, glutaredoxins, and copper/zinc superoxide dismutases)
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depuration and anatomical distribution of Domoic Acid in the surf clam mesodesma donacium
Toxicon, 2015Co-Authors: Gonzalo Alvarez, Eduardo Uribe, Helena Martín, Jorge Regueiro, Teresa Gajardo, Lorena Jara, Juan BlancoAbstract:Abstract In northern Chile, Domoic Acid (DA) has been detected in several bivalve species. In Mesodesma donacium , one of the most important commercial species for local fishermen, no information is available on depuration, or on the anatomical distribution of this toxin and its potential use as a palliative measure to minimize the consequences of ASP outbreaks. Deputation of DA is very fast in M. donacium , and can be adequately described by means of a two-compartment model. The estimated rates for the first and second compartments were 1.27 d −1 and 0.24 d −1 , respectively, with a transfer rate between compartments of 0.75. Having high depuration rates protects this species from being affected by Pseudo-nitzschia blooms for an extended period of time. Taking this into account, the time in which the bivalves are unsafe for consumers is very short, and therefore the economic losses that could result by the DA outbreaks in local fisheries should be moderate. In relation to anatomical distribution, at least during the uptake phase, the toxin was evenly distributed within the soft tissues, with a total toxin burden corresponding to 27%, 32% and 41% for Digestive Gland (DG), Foot (FT) and Other Body Fractions (OBF), respectively. Since the contribution of each organ to the toxin concentration is a function of both weight contribution and toxin burden, the pattern of toxin distribution showed the following trend: “all other body fractions” (OBF) > Foot (FT) > Digestive Gland (DG). Thus, the highest concentration of DA, with a contribution close to 72%, corresponds to the edible tissues (OBF + FT), while the DG (non-edible tissue) only contributes the remaining 28%. Consequently, in view of the anatomical distribution of Domoic Acid in M. donacium , the elimination of the digestive gland does not substantially reduce the toxicity of the final product and therefore selective evisceration would not improve their quality for human consumption.
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depuration and anatomical distribution of the amnesic shellfish poisoning asp toxin Domoic Acid in the king scallop pecten maximus
Aquatic Toxicology, 2002Co-Authors: Juan Blanco, C P Acosta, Bermudez M De La Puente, Covadonga SalgadoAbstract:The depuration kinetics of the Domoic Acid of four body fractions (digestive gland, adductor muscle, gonad+kidney and gills+mantle) of the scallop Pecten maximus was studied over 295 days. The scallops, which had acquired the toxins during a Pseudo-nitzschia australis episode that took place the week before the beginning of the experiment, were maintained in tanks with running seawater. All the body fractions, except the adductor muscle, decreased their Domoic Acid burden throughout the experiment. The amount of toxin in the muscle dropped sharply at the start of the experiment but increased again at the end, to levels that were higher than the initial ones. Several dynamic models of depuration kinetics, which included the depuration of each fraction (excluding the adductor muscle) and the transfers between them, were constructed, implemented and fitted to the data to obtain their parameters. The estimated depuration rates were very low, both considering and not considering the transfer of toxin between organs or the effect of weight loss. There were strong differences in the Domoic Acid burden of the body fractions studied but not between their depuration rates. No net transfer from the digestive gland, the tissue with highest Domoic Acid concentration, to the other fractions was found, as the inclusion of these processes in the models produced only a marginally better fit to the data. The depuration of Domoic Acid was slightly, but significantly, affected by biomass. Weight loss induced Domoic Acid loss, suggesting that part of the depuration may be produced by the direct loss of bivalve cells. The concentration or dilution effect, due to decreases or increases in biomass, documented for other species and toxins, has little importance in Pecten maximus.