| Summary: | The swamp eel, Monopterus albus is widely distributed in East and Southeast Asia. It
can be found in rice fields, ponds and rivers. It is a highly commercial food fish, and is
also used as traditional medicine especially in China and Malaysia. In Malaysia, the
wild stock of swamp eel is decreasing due to over fishing. Therefore, development of
mass seed production technology and aquaculture of swamp eel is highly needed, not
only to increase the yield for satisfying the high demand of consumers, but also to
conserve the wild swamp eel resource and increasing revenue generation. Broodstock
selection is one of the important aspects in broodstock management, which is also an
essential step in seed production for aquaculture. Population genetics study which is
derived from the mitochondrial DNA analysis is a useful tool to identify the
population structure of swamp eel for broodstock selection. However, there is
insufficient data for swamp eel population structure in Malaysia. East Coast of
Peninsular Malaysia (ECPM) is the second largest producing region of swamp eel in
Malaysia, with many paddy fields that favoured people in the region to engage in
farming of this fish species. The present study aimed to reveal the population structure
of swamp eel in ECPM. A total of sixty-one samples were collected from three states
(Kelantan, Terengganu and Pahang) from six different sampling sites. After DNA
extraction and PCR of 16S rRNA of mtDNA using universal primer L1567 and
H2196, successful sequencing (624 bp) were aligned and analyzed. Four haplotypes
were detected among all the samples. Hap-l was the most widespread haplotype
among the six sampling sites, comprising about 75.4% of all samples. The haplotypes
relationship as observed in phylogenetic analysis constructed by neighbor-joining tree
using Kimura-2 parameter distance, 1,000 bootstrap replication with Synbranchus
marmoratus as an outgroup; revealed that all four haplotypes clust~red into one
lineage with Hap-l more closely related to the ancestors. Both the non-significant
values of Tajima's D and Fu's Fs suggested that all populations were at genetic
equilibrium. Analysis of Molecular Variance (AMOV A) revealed a significant
differences among sampling sites (FST= 0.92401, P<0.05). In pairwise comparisons of
FST, the Kuala Terengganu population showed significant values between all
populations. This study suggested that it is genetically different from other
populations. Non significant FST values of Pasir Puteh, Tanah Merah, Rantau Panjang,
Kampung Raja and Pekan populations revealed that they are closely related
populations. Further study using larger sample sizes and longer mtDNA fragment is
recommended to reveal more genetic variation of these populations. Conservation
initiatives on Kuala Terengganu population should be carried out to prevent the loss of
these natural gene resources for future selection and cross-breeding program. Distinct
haplotypes could be used as DNA markers for their respective sampling location.
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