Salinity effect on growth and toxin production of four tropical Alexandrium species (Dinophyceae)
Four tropical PSP toxins-producing dinoflagellates, Alexandrium minutum, Alexandrium tamiyavanichii, Alexandrium tamarense and Alexandrium peruvianum from Malaysian waters were studied to investigate the influences of salinity on growth and toxin production. Experiments were conducted on constant...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier Ltd.
2005
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| Subjects: | |
| Online Access: | http://ir.unimas.my/id/eprint/17594/ http://ir.unimas.my/id/eprint/17594/1/Salinity.pdf |
| Summary: | Four tropical PSP toxins-producing dinoflagellates, Alexandrium minutum, Alexandrium tamiyavanichii, Alexandrium
tamarense and Alexandrium peruvianum from Malaysian waters were studied to investigate the influences of salinity on growth
and toxin production. Experiments were conducted on constant temperature 25 8C, 140 mE mol mK2 sK1 and under
14:10 light:dark photo-cycle with salinity ranged from 2 to 30 psu. The PSP-toxin congeners, GTX 1–6, STX, dcSTX, NEO and
C1–C2 were analysed by high performance liquid chromatography. Salinity tolerance of the four species in decreasing order is
A. minutumOA. peruvianumOA. tamarenseOA. tamiyavanichii. Specific growth rates and maximum densities varied among
these species with A. minutum recorded as the highest, 0.5 dayK1 and 6!104 cells mLK1. Toxin content decreased with
elevated salinities in A. minutum, the highest toxin content was about 12 fmole cellK1 at 5 psu. In A. tamiyavanichii, toxin
content peaked at optimal growth salinity (20 and 25 psu). Toxin content of A. tamarense, somehow peaked at sub-optimal
growth salinity (15 and 30 psu). Results of this study implied that salinity fluctuation not only influenced the growth physiology
but also toxin production of these species. |
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