BUKU ABSTRAK - Universiti Putra Malaysia

Shrimp Fishery: Genetic Structure of Planktonic Shrimp, Acetes japonicus
(Decapoda: Sergestidae) of the Straits of Malacca Waters
Prof. Dr. Siti Shapor Hj. Siraj
Dania Aziz
Faculty of Agriculture, University Putra Malaysia,
43400 UPM Serdang, Selangor, Malaysia.
+603-8946 4172; shaporsiraj@yahoo.com
Keywords: Acetes shrimp, population characteristic, peninsular Malaysia
Tracing of Phylogeny through Chromosomal Approaches in Malaysian Catfishes
Keywords: Malaysian catfishes, karyotyping
Prof. Dr. Siti Shapor Hj. Siraj
Siti Khalijah Daud, Ratiah Sukardi and Jothi Panandam
Faculty of Agriculture, University Putra Malaysia,
43400 UPM Serdang, Selangor, Malaysia.
+603-8946 4172; shaporsiraj@yahoo.com
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Agriculture
Genomic DNA of sergestid shrimp, Acetes japonicus was successfully extracted by using the Promega
Wizard Genomic DNA Purification Kit. Population genetic characterization of A. japonicus along the western
coast of Peninsular Malaysia (state of Perak, Malacca, and Kedah) was examined using the Random Amplified
Polymorphic DNA (RAPD) marker. Twenty oligonucleotides from operon a kit were used to screen the
populations, of which six were able to be amplified (OPA03, OPA04, OPA07, OPA09, OPA10, OPA16). The
percentages of polymorphic bands of the three populations investigated varied from 57.77% to 87.77%. Genetic
distances between populations and cluster analysis from UPGMA grouped the populations into two major
clusters. The Perak and Malacca populations were in one cluster, while the Kedah population was clustered by
itself, indicating a different population. The genetic distance was highest 0.0999 for the Kedah and the Malacca
populations while lowest value was 0.0413 for the Perak and the Malacca populations, which probably have a
closed ancestral relationship. The results of this study suggested that RAPD analysis, if carried out carefully and
accurately would give a good indication of the separation between individuals of different populations and are
suitable for identification of closely related genotypes.
Karyotyping is one of the useful tools in species identification, taxonomy, evolutionary and breeding
selection. The importance of this study is to provide documentation on the karyotypic structure of selected catfishes
and generates genetic marker for species identification. To date, little information on karyotyping of freshwater
catfishes were documented. The aims of this study were to determine and differentiate the karyotypic structure and
fundamental arm numbers of selected catfish families namely: Bagridae, Clariidae and Pangasiidae for species
identification. Five fishes of Family Bagridae (Pahang) and three to eighteen catfishes from Family Clariidae
(Kelantan, Pahang, Sarawak, Johor and Selangor) were used. Only four catfishes from Family Pangasiidae were
collected from Perak and Pahang. The fish samples ranging from 23 - 300 g in weight and 16 - 40 cm in standard
length were used to obtain the chromosomes from the first pair of gill filaments by subjecting to a combination
of colchicine and phytohaemagglutinin (m-form) for arresting a mitotic division. The slides were prepared by
flame drying technique and stained with giemsa solution for observation. The karyotype of each species was
arranged according to size, type and structure such as metacentric (M), submetacentric (SM), subtelocentric
(ST) and acrocentric/telocentric (A/T). The diploid chromosome numbers ranged from 2n equal to 52 (Clarias
nieuhofii); 54 (Clarias macrocephalus, Clarias batrachus); 56 (Hemibagrus nemurus and Clarias gariepinus)
and 60 (Pangasius pangasius and Pangasius sutchi). The fundamental arm numbers ranged from 92-100 (Clarias
macrocephalus; Clarias batrachus; Clarias gariepinus; and Clarias nieuhofii) in Clariidae; 103-104 in Bagridae
(Hemibagrus nemurus) and 96-102 in Pangasiidae (Pangasius pangasius and Pangasius sutchi).