Hong-Chang Lim's Page

Institution/Organization

Faculty of Resource Science and Technology, Universiti Malaysia Sarawak

Title/Position

Doctoral student

Website

http://www.ibec.unimas.my/hab/index.html

I’m involved in, or am interested in the following barcoding initiatives

Marine Barcode of Life (MarBOL)

I’m involved in or interested in the following iBOL Working Groups

WG4.1 Environmental Barcoding

Keywords about my barcoding projects (separate each choice with a comma)

Pseudo-nitzschia, Bacillariophyceae, marine diatom, ITS,

I’m involved in the following aspects of barcoding:

Fieldwork/specimen collecting, Labwork/generating barcode sequences, Analysis of barcode data, Using barcode data in taxonomy/systematic biology

Current Project(s)

My research interest is in occurrence, seasonal distribution to population dynamic, systematic and genetic diversity of amnesic shellfish toxin producing marine diatom, Pseudo-nitzschia species (Bacillariophyceae) in Malaysia. Amnesic shellfish poisoning (ASP) is a type of poisoning due to ingestion of contaminated shellfish by the neurotoxin, known as domoic acid (DA). There are about 36 of Pseudo-nitzschia species had been described with 14 were known to be toxic. This toxin were also produced by several species of diatom i.e. Nitzschia navis-varingica, Amphora coffeaeformis and a red algae (Chondria armata) but Pseudo-nitzschia were the most commonly reported species with more cases. Not only affected human but also marine mammals and seabird.

Various studies have been carried out using the clonal cultures established along the coast of Peninsula Malaysia and Malaysian Borneo since 2007. Studies were also carried out under jointly research with other agencies (National University of Malaysia, Fisheries Research Institute of Malaysia, Kitasato University, Tokyo University and University of Copenhagen). We used advanced microscopy (TEM & SEM) techniques in morphological characterization and species identification. At molecular level, we characterize the genetic information and investigated the genetic diversity of isolates from the waters with various genetic markers (LSU, ITS1-5.8S-ITS2, large subunit of RUBISCO and cytochrome oxidase subunit 1). The DNA barcoding of Pseudo-nitzschia were revealed by nuclear encoded gene of second internal transcribe spacer (ITS2). Toxicity of these species was examined by HPLC. So far, about 26 species of Pseudo-nitzschia were found in Malaysian waters, with one new species described (Journal of Phycology) and three new morphotypes (Journal in preparation).