Morphology And Molecular Characterization Of Alexandrium Tamutum In Sarawak Water

Alexandrium tamutum is a solitary, small single cell that is known to not produce paralytic shellfish poisoning toxins. Despite the increased frequency of algal bloom episodes observed in Malaysia, which have been linked to negative environmental and health repercussions, there is a lack of research on Alexandrium tamutum that can help with species identification and future plankton monitoring. A study was done to characterize the A. tamutum species based on their morphology and molecular characterization in Sarawak waters. Four strains of Alexandrium were collected and established from Santubong Beach, Kuching was maintained in L1 medium under light intensity 12:12 hour light-dark photoperiod. The detailed morphological observation was carried out by using a compound and scanning electron microscope. The morphotype such as the the anterior sulcal plate (Sa), ventral pore (vp), first antapical plate (1’), sixth precingular plate (6’’), apical pore complex (APC), and the posterior sulcal plate (Sp) was similar to Alexandrium tamuntum. A Bayesian Inference (BI) and Maximum Likelihood (ML) tree were constructed by DNA amplification and sequencing of Large Subunit (LSU) of length 580bp. Based on the BI and ML phylogeny tree, Alexandrium in this study were cladded together with A.tamutum with a supported bootstrap value of (0.95/100%)