Open Access Repository

The diatom genus pseudo-nitzschia (bacillariophyceae)in New South Wales, Australia: Morphotaxonomy, molecular phylogeny, toxicity, and distribution


Downloads per month over past year

Ajani, P, Murray, S, Hallegraeff, GM, Lundholm, N, Gillings, M, Brett, S and Armand, L 2013 , 'The diatom genus pseudo-nitzschia (bacillariophyceae)in New South Wales, Australia: Morphotaxonomy, molecular phylogeny, toxicity, and distribution' , Journal of Phycology, vol. 49 , pp. 765-785 , doi: 10.1111/jpy.12087.

[img] PDF
jpy_20AJANI_201...pdf | Request a copy
Full text restricted
Available under University of Tasmania Standard License.


Species belonging to the potentially harmful
diatom genus Pseudo-nitzschia, isolated from 16
localities (31 sampling events) in the coastal waters
of south-eastern Australia, were examined. Clonal
isolates were characterized by (i) light and
transmission electron microscopy; (ii) phylogenies,
based on sequencing of nuclear-encoded ribosomal
deoxyribonucleic acid (rDNA) regions and, (iii)
domoic acid (DA) production as measured by liquid
chromatography–mass spectrometry (LC-MS/MS).
Ten taxa were unequivocally confirmed as Pseudonitzschia
americana, P. arenysensis, P. calliantha,
P. cuspidata, P. fraudulenta, P. hasleana, P. micropora,
P. multiseries, P. multistriata, and P. pungens. An
updated taxonomic key for south-eastern Australian
Pseudo-nitzschia is presented. The occurrence of two
toxigenic species, P. multistriata (maximum
concentration 11 pg DA per cell) and P. cuspidata
(25.4 pg DA per cell), was documented for the first
time in Australia. The Australian strains of
P. multiseries, a consistent producer of DA in strains
throughout the world, were nontoxic. Data from
5,888 water samples, collected from 31 oystergrowing
estuaries (2,000 km coastline) from 2005 to
2009, revealed 310 regulatory exceedances for
“Total Pseudo-nitzschia,” resulting in six toxic
episodes. Further examination of high-risk estuaries
revealed that the “P. seriata group” had highest cell
densities in the austral summer, autumn, or spring
(species dependent), and lowest cell densities in the
austral winter, while the “P. delicatissima group” had
highest in winter and spring.

Item Type: Article
Authors/Creators:Ajani, P and Murray, S and Hallegraeff, GM and Lundholm, N and Gillings, M and Brett, S and Armand, L
Journal or Publication Title: Journal of Phycology
ISSN: 0022-3646
DOI / ID Number: 10.1111/jpy.12087
Additional Information:

2013 Phycological Society of America

Item Statistics: View statistics for this item

Actions (login required)

Item Control Page Item Control Page