Farmed greenlip abalone Haliotis laevigata were fed commercial seaweed-based food pellets or feed... more Farmed greenlip abalone Haliotis laevigata were fed commercial seaweed-based food pellets or feed pellets supplemented with 8 Â 10 5 Alexandrium minutum dinoflagellate cells g À1 (containing 12 AE 3.0 mg STX-equivalent 100 g À1 , which was mainly GTX-1,4) every second day for 50 days. Exposure of abalone to PST supplemented feed for 50 days did not affect behaviour or survival but saw accumulation of up to 1.6 mg STX-equivalent 100 g À1 in the abalone foot tissue (muscle, mouth without oesophagus and epipodial fringe), which is w50 times lower than the maximum permissible limit (80 mg 100 g À1 tissue) for PSTs in molluscan shellfish. The PST levels in the foot were reduced to 0.48 mg STX-equivalent 100 g À1 after scrubbing and removal of the pigment surrounding the epithelium of the epipodial fringe (confirmed by both HPLC and LC-MS/MS). Thus, scrubbing the epipodial fringe, a common procedure during commercial abalone canning, reduced PST levels by w70%. Only trace levels of PSTs were detected in the viscera (stomach, gut, heart, gonad, gills and mantle) of the abalone. A toxin reduction of approximately 73% was observed in STX-contaminated abalone held in clean water and fed uncontaminated food over 50 days. The low level of PST uptake when abalone were exposed to high numbers of A. minutum cells over a prolonged period may indicate a low risk of PSP poisoning to humans from the consumption of H. laevigata that has been exposed to a bloom of potentially toxic A. minutum in Australia. Further research is required to establish if non-dietary accumulation can result in significant levels of PSTs in abalone. Crown
For the first time wild-caught Tasmanian abalone, Haliotis rubra, have been reported to contain p... more For the first time wild-caught Tasmanian abalone, Haliotis rubra, have been reported to contain paralytic shellfish toxins (PSTs). This observation followed blooms of the toxic dinoflagellate Gymnodinium catenatum. No illnesses were reported, but harvesting restrictions were enforced in commercial areas. Abalone were assayed using HPLC-FLD methodology based on AOAC official method 2005.06. An uncommon congener, deoxydecarbamoyl-STX (doSTX), was observed in addition to regulated PSTs as unassigned chromatographic peaks. A quantitative reference material was prepared from contaminated Tasmanian abalone viscera and ampouled at 54.2 mmol/L. The LD 50 of doSTX via intraperitoneal injection was 1069 nmol/kg (95% confidence limits 983e1100 nmol/kg), indicating it is nearly 40 times less toxic than STX. A toxicity equivalence factor of 0.042 was generated using the mouse bioassay. Levels of PSTs varied among individuals from the same site, although the toxin profile remained relatively consistent. In the foot tissue, STX, decarbamoyl-STX and doSTX were identified. On a molar basis doSTX was the dominant congener in both foot and viscera samples. The viscera toxin profile was more complex, with other less toxic PST congeners observed and was similar to mussels from the same site. This finding implicates localised dinoflagellate blooms as the PST source in Tasmanian abalone.
New Zealand Journal of Marine and Freshwater Research, 2003
The larval development of the New Zealand geoduck, Panopea zelandica, grown under culture conditi... more The larval development of the New Zealand geoduck, Panopea zelandica, grown under culture conditions, was described through measurements of shell morphometry using video image analysis, photomicrographs, and scanning electron microscopy (SEM). Gametes were stripped from ripe broodstock and eggs fertilised with a dilute sperm solution. Developing larvae were maintained at 17 ± 1°C. Fertilised eggs developed into trochophores within 12
New Zealand Journal of Marine and Freshwater Research, 1986
The accumulation and release of virus by the Pacific oyster, Crassostrea gigas, was studied by au... more The accumulation and release of virus by the Pacific oyster, Crassostrea gigas, was studied by autoradiographic methods. An insect picornavirus, cricket paralysis virus, was used as a model because of its taxonomic similarity to the human enteroviruses that might be encountered in effluent contaminated sea water. High concentrations of label accumulated in the mucus in the digestive tract when oysters
New Zealand Journal of Marine and Freshwater Research, 2000
Three species of epiphytic dino‐flagellates—Ostreopsis siamensis, O. lenticularis, and O. ovata h... more Three species of epiphytic dino‐flagellates—Ostreopsis siamensis, O. lenticularis, and O. ovata have recently been found on both the east and west coasts of the upper North Island, New Zealand. The morphological differences of all three Ostreopsis spp. have been studied with both light and scanning electron microscopes. Detailed studies of the inner face of the thecal wall of Ostreopsis siamensis
Toxicon : official journal of the International Society on Toxinology, 2014
For the first time wild-caught Tasmanian abalone, Haliotis rubra, have been reported to contain p... more For the first time wild-caught Tasmanian abalone, Haliotis rubra, have been reported to contain paralytic shellfish toxins (PSTs). This observation followed blooms of the toxic dinoflagellate Gymnodinium catenatum. No illnesses were reported, but harvesting restrictions were enforced in commercial areas. Abalone were assayed using HPLC-FLD methodology based on AOAC official method 2005.06. An uncommon congener, deoxydecarbamoyl-STX (doSTX), was observed in addition to regulated PSTs as unassigned chromatographic peaks. A quantitative reference material was prepared from contaminated Tasmanian abalone viscera and ampouled at 54.2 μmol/L. The LD50 of doSTX via intraperitoneal injection was 1069 nmol/kg (95% confidence limits 983-1100 nmol/kg), indicating it is nearly 40 times less toxic than STX. A toxicity equivalence factor of 0.042 was generated using the mouse bioassay. Levels of PSTs varied among individuals from the same site, although the toxin profile remained relatively consi...
Farmed greenlip abalone Haliotis laevigata were fed commercial seaweed-based food pellets or feed... more Farmed greenlip abalone Haliotis laevigata were fed commercial seaweed-based food pellets or feed pellets supplemented with 8 Â 10 5 Alexandrium minutum dinoflagellate cells g À1 (containing 12 AE 3.0 mg STX-equivalent 100 g À1 , which was mainly GTX-1,4) every second day for 50 days. Exposure of abalone to PST supplemented feed for 50 days did not affect behaviour or survival but saw accumulation of up to 1.6 mg STX-equivalent 100 g À1 in the abalone foot tissue (muscle, mouth without oesophagus and epipodial fringe), which is w50 times lower than the maximum permissible limit (80 mg 100 g À1 tissue) for PSTs in molluscan shellfish. The PST levels in the foot were reduced to 0.48 mg STX-equivalent 100 g À1 after scrubbing and removal of the pigment surrounding the epithelium of the epipodial fringe (confirmed by both HPLC and LC-MS/MS). Thus, scrubbing the epipodial fringe, a common procedure during commercial abalone canning, reduced PST levels by w70%. Only trace levels of PSTs were detected in the viscera (stomach, gut, heart, gonad, gills and mantle) of the abalone. A toxin reduction of approximately 73% was observed in STX-contaminated abalone held in clean water and fed uncontaminated food over 50 days. The low level of PST uptake when abalone were exposed to high numbers of A. minutum cells over a prolonged period may indicate a low risk of PSP poisoning to humans from the consumption of H. laevigata that has been exposed to a bloom of potentially toxic A. minutum in Australia. Further research is required to establish if non-dietary accumulation can result in significant levels of PSTs in abalone. Crown
For the first time wild-caught Tasmanian abalone, Haliotis rubra, have been reported to contain p... more For the first time wild-caught Tasmanian abalone, Haliotis rubra, have been reported to contain paralytic shellfish toxins (PSTs). This observation followed blooms of the toxic dinoflagellate Gymnodinium catenatum. No illnesses were reported, but harvesting restrictions were enforced in commercial areas. Abalone were assayed using HPLC-FLD methodology based on AOAC official method 2005.06. An uncommon congener, deoxydecarbamoyl-STX (doSTX), was observed in addition to regulated PSTs as unassigned chromatographic peaks. A quantitative reference material was prepared from contaminated Tasmanian abalone viscera and ampouled at 54.2 mmol/L. The LD 50 of doSTX via intraperitoneal injection was 1069 nmol/kg (95% confidence limits 983e1100 nmol/kg), indicating it is nearly 40 times less toxic than STX. A toxicity equivalence factor of 0.042 was generated using the mouse bioassay. Levels of PSTs varied among individuals from the same site, although the toxin profile remained relatively consistent. In the foot tissue, STX, decarbamoyl-STX and doSTX were identified. On a molar basis doSTX was the dominant congener in both foot and viscera samples. The viscera toxin profile was more complex, with other less toxic PST congeners observed and was similar to mussels from the same site. This finding implicates localised dinoflagellate blooms as the PST source in Tasmanian abalone.
New Zealand Journal of Marine and Freshwater Research, 2003
The larval development of the New Zealand geoduck, Panopea zelandica, grown under culture conditi... more The larval development of the New Zealand geoduck, Panopea zelandica, grown under culture conditions, was described through measurements of shell morphometry using video image analysis, photomicrographs, and scanning electron microscopy (SEM). Gametes were stripped from ripe broodstock and eggs fertilised with a dilute sperm solution. Developing larvae were maintained at 17 ± 1°C. Fertilised eggs developed into trochophores within 12
New Zealand Journal of Marine and Freshwater Research, 1986
The accumulation and release of virus by the Pacific oyster, Crassostrea gigas, was studied by au... more The accumulation and release of virus by the Pacific oyster, Crassostrea gigas, was studied by autoradiographic methods. An insect picornavirus, cricket paralysis virus, was used as a model because of its taxonomic similarity to the human enteroviruses that might be encountered in effluent contaminated sea water. High concentrations of label accumulated in the mucus in the digestive tract when oysters
New Zealand Journal of Marine and Freshwater Research, 2000
Three species of epiphytic dino‐flagellates—Ostreopsis siamensis, O. lenticularis, and O. ovata h... more Three species of epiphytic dino‐flagellates—Ostreopsis siamensis, O. lenticularis, and O. ovata have recently been found on both the east and west coasts of the upper North Island, New Zealand. The morphological differences of all three Ostreopsis spp. have been studied with both light and scanning electron microscopes. Detailed studies of the inner face of the thecal wall of Ostreopsis siamensis
Toxicon : official journal of the International Society on Toxinology, 2014
For the first time wild-caught Tasmanian abalone, Haliotis rubra, have been reported to contain p... more For the first time wild-caught Tasmanian abalone, Haliotis rubra, have been reported to contain paralytic shellfish toxins (PSTs). This observation followed blooms of the toxic dinoflagellate Gymnodinium catenatum. No illnesses were reported, but harvesting restrictions were enforced in commercial areas. Abalone were assayed using HPLC-FLD methodology based on AOAC official method 2005.06. An uncommon congener, deoxydecarbamoyl-STX (doSTX), was observed in addition to regulated PSTs as unassigned chromatographic peaks. A quantitative reference material was prepared from contaminated Tasmanian abalone viscera and ampouled at 54.2 μmol/L. The LD50 of doSTX via intraperitoneal injection was 1069 nmol/kg (95% confidence limits 983-1100 nmol/kg), indicating it is nearly 40 times less toxic than STX. A toxicity equivalence factor of 0.042 was generated using the mouse bioassay. Levels of PSTs varied among individuals from the same site, although the toxin profile remained relatively consi...
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