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Malaysia is one of the countries in Asia with higher scarcity of Clarias batrachus. Consequently, to arrive at better ways of handling the situation the reproductive endocrinology of the species was investigated. Testosterone (T), 11-ketotestosterone (11KT) and 17β-estradiol (E2) were the plasma sex steroid hormones monitored monthly throughout the reproductive cycles. Several peak levels were observed in the annual profiles of all the steroid hormones, implying that C. batrachus is a non-seasonal breeder, signifying that the species could spawn several times during the reproductive cycle. Most of the scholars who earlier worked on the breeding of this fish concentrated on a particular period (May to August) assuming that was the only season successful induced breeding of the species could be achieved. The present study has enhanced the understanding of the reproduction of C. batrachus. It has provided a platform for the optimization of reproduction and breeding program of the species.

Tor tambroides is an important and highly valued freshwater fish. In Malaysia, wild populations of this species has undergone declines in range and abundance due to degradation of their natural habitat. Due to economic important and concerns about their conservation, a culture artificial propagation programme was established to produced seed-stock for aquaculture and conservation purposes. The effectiveness of selected synthetic and non-synthetic commercial hormones was tested on filial 1 generation (F1) of Tor tambroides (Bleeker 1854) females in captivity. A total of 144 matured females were given intramuscular implantation of slow release hormone, Ovaplant (38.6-53.6 μg kg-1 b.wt.), for 5-6 weeks prior to induction. Selected commercial hormones were compared for the induction. The effect of these hormones on breeding performance and larval quality of F1 Tor tambroides were evaluated. The results showed that Ovatide (0.5 mL kg-1 BW) was the most reliable hormone in inducing ovulation of F1 T. tambroides females overshadowed the other tested hormones. Ovaprim (0.5 mL kg-1 b.wt.) was the next best tested hormone followed by a synthetic analogue of salmon gonadotropin releasing hormone (sGnRHa/OvaRH) (10 μg kg-1 b.wt.). No ovulation occurred in the groups treated with Luteinizing Hormone Releasing Hormone Analogue (LHRHa) (10 μg kg-1 b.wt.), Human Chorionic Gonadotropin (HCG) (1000 μg kg-1 b.wt.) and Carp Pituitary Extract (CPE) (10 mg kg-1 b.wt.). Ovatide was further chosen to test its effectiveness at various dosage levels in inducing ovulation of T. tambroides. Thus, concentration of 0.5 mL kg-1 b.wt. of Ovatide was found to be the optimum dosage for inducing ovulation of F1 T. tambroides in captivity.

Tidal variations in coastal waters have been often related to nutrients. However, few attempts have been made to investigate the difference in conditions between high and low tides and predict the responses in coastal waters related to nutrients and physicochemical properties. This study covered an area of 18 km from north Tanjung Gemuk to south Tanjung Tuan in Port Dickson, facing the Strait of Malacca, one of the busiest shipping routes in the world. This research investigated the relation between tides, nutrients, and physicochemical properties of water in order to provide the basis to describe the effects of tides in the coastal waters of Port Dickson, a central attraction of the Strait of Malacca. Relatively all of the studied parameters (physicochemical properties and nutrients concentration) showed higher values at low tide than at high tide, except for salinity and electrical conductivity. Relationships between nutrients and physicochemical properties at high and low tides were studied using Spearman correlation analysis. It may be noted that the relationship between nutrients and physicochemical properties at high and low tides varies from weak (r = 0.400) to moderate (r = 0.558). The multivariate statistical technique principal components analysis (PCA) was employed to better interpret information about the interaction between nutrients and physicochemical properties at high and low tides. The current study determined that there is an anthropogenic impact at increased levels of nutrient concentration, primarily for ammonia and phosphate. This study has provided new updated baseline data for the coastal waters of Port Dickson related physicochemical properties and nutrient concentration. The new updated baseline data will be used to identify and prioritize future studies and regulatory plans in Port Dickson as well as the Strait of Malacca. This data is also relevant to forensic investigations of potential future pollution events in the area.

The present study was carried out to investigate the embryonic and larval development of the endangered Temoleh, Probarbus jullieni in lab-rearing condition. The matured egg and sperm were collected by stripping the bloodstock of Temoleh fish after injecting with ovaprim hormone extract. The samples were collected from hatching tank at every 10 min interval for the first hour, 20 min for the second hour, 30 min for the third hour and then hourly interval up to hatching. After hatching, larvae were observed daily until the complete disappearance of the yolk sacs. The fertilized eggs were spherical, demersal, adhesive and brownish-yellow in colour with a mean diameter of 2316 μm. First cleavage occurred within 10 min post-fertilization at temperature ranged from 26.0 to 28.0°C. Hatching started 22 h post-fertilization and completed within 25 h at the same temperature. The yolk sac was completely absorbed 61 h after hatching. At the same time, the larvae started to swim actively and feed exogenously. This marks the first description on the early life history of P. jullieni. The present study will provide some valuable information on the ontogeny, breeding biology and early larval rearing protocol of P. jullieni which will ultimately be helpful towards the establishment of large scale seed production technique for conservation and aquaculture production.

The presence of Asian catfish, Clarias batrachus in Malaysia is at a deteriorating state. It is hardly a cultured species since the supply of seed is unavailable. This species is found in lowland streams, swamp and rice fields. Therefore, they are greatly exposed to factors such as intermittent periods of drought, devastation of the natural habitat and agro-chemicals. Presently, fish farmers are more into the culture of Clarias gariepinus. This threatened the mere existence of this indigenous C. batrachus. Hardiness, good growth, efficient food conversion and excellent nutritional profile guarantee C. batrachus as a suitable aquaculture candidate. Some conservation efforts were looked into in order to prevent the extinction of this potentially important catfish.

Induced ovulation of captive Malaysian mahseer (Tor tambroides) often encounters low reproductive performances. The present study was conducted to gain insight to problems associated with poor breeding performance of Malaysian mahseer in captivity. In this study, sex steroid hormone levels and ovulation performance in filial 1 (F1) generation of Malaysian mahseer (Tor tambroides) were investigated. Fishes were injected with ovatide, combination of Salmon Gonadotropin Releasing Hormone Analogue (sGnRHa), DOM, sGnRHa+DOM and 0.9% NaCl. A total of 30 matured females T. tambroides with weight ranged from 2.01-3.80 kg were used in this study. The females were given ovaplant (39.5-37.3 μg kg-1) pretreatment for 6 weeks prior to hormones injection. Females were given a single intramuscular injection of ovatide (0.5 mL kg-1 b.wt.), sGnRHa (10 μg kg-1 b.wt.), DOM (5 mg kg-1 b.wt.), sGnRHa+DOM (10 μg kg-1 b.wt.+5 mg kg-1 b.wt.) or 0.9% NaCl. Blood samples were collected at 0, 6, 12 and 24 h (s) after injection. The effect of these treatments on sex steroids level (Testosterone (T) and 17β-Estradiol (E2) and ovulation performance of F1 Tor tambroides were evaluated. Result showed that higher ovulatory response was observed in the group treated with positive control ovatide (0.5 mL kg-1 b.wt.). Interestingly, it was observed that sGnRHa and Domperidone (DOM) produce highest egg and larval qualities compared to ovatide and sGnRHa alone. No ovulation occurred in the group treated with DOM alone. Sex steroids plasma concentration of T and E2 increased significantly in association with ovulation. The levels fluctuated and reached a peak at 12 h, then dropped dramatically at 24 Post Injection (PI). In contrast the non-ovulated groups, the sex steroids hormone concentration showed little increment after injection and rose at 12 h PI, then slowly dropped at 24 h pi. These results provide evidence for a strong dopamine inhibition on GtH secretion in captive mahseer.

The aim of this study was to characterize embryonic and larval developmental stages of the river catfish, Hemibagrus nemurus. Fertilized eggs were spherical, adhesive and demersal with a mean egg diameter of 1.5±0.3 mm. Seven embryonic periods were characterized for timing and features: zygote, cleavage, blastula, gastrula, segmentation, pharyngula and hatching. Mean hatch was 23±1 h post fertilization at 27°C. The newly hatched larvae measured 3.0±0.2 mm in total length. Morphogenesis was completed in a day. The yolk sac was completely absorbed in three days. H. nemurus has a short embryonic developmental period in comparison with other catfish species. The information obtained from this study will be useful for egg incubation and larval rearing during the culture of H. nemurus.

The river catfish Mystus nemurus is an important fresh water species for aquaculture in Malaysia. We report the first genetic linkage map of M. nemurus based on segregation analysis and a linkage map using newly developed microsatellite markers of M. nemurus. A total of 70 of the newly developed polymorphic DNA microsatellite markers were analyzed on pedigrees generated using a pseudo-testcross strategy from 2 mapping families. In the first mapping family, 100 offspring were produced from randomly selected dams of the same populations; dams of the second family were selected from 2 different populations, and this family had 50 offspring. Thirty-one of the 70 markers segregated according to the Mendelian segregation ratio. Linkage analysis revealed that 17 microsatellite markers belonging to 7 linkage groups were obtained at a logarithm of the odds score of 1.2 spanning 584 cM by the Kosambi mapping function, whereas the other 14 remained unlinked. The results from this study will act as primer to a more extensive genetic mapping study aimed towards identifying genetic loci involved in determining economically important traits.

Reproductive cycle, growth, mortality and exploitation rate of Acetes indicus were examined in the coastal waters of Malacca, Malaysia between February 2005 and March 2007. Monthly length frequency data were analyzed using FiSAT software for estimating population parameters of A. indicus, including asymptotic length (L∝), growth co-efficient (K) and exploitation rate (E) to assess the status of the stock. The annual mean L∝ and K for males were estimated at 29.93 mm and 1.60 yr−1, and for the females were 40.95 mm and 1.20 yr−1. Mean growth performance index (φ′) was calculated as 3.15 and 3.31 for males and females, respectively. Maximum life span (tmax) of males and females was 1.88 and 2.50 years. Total mortality (Z) by length converted catch curve was estimated at 4.30 yr−1 for males and 3.62 yr−1 for females. The rate of natural mortality (M) for males and females was calculated as 2.54 yr−1 and 1.93 yr−1, and the fishing mortality (F) was 1.77 yr−1 for males and 1.70 yr−1 for females. Recruitment pattern of A. indicus was continuous throughout the year with two major peaks. The exploitation rate (E) of males was 0.41 and that of females was 0.47, though the exploitation rates were slightly less than the optimum level of exploitation (E = 0.50). Thus, the stock of A. indicus is under pressure in the coastal waters of Malacca, Malaysia.

The freshwater fish, Probarbus jullieni (Sauvage), locally referred to as "Temoleh", is a high-valued freshwater fish in Malaysia and has both cultural and conservational significance. It is widely distributed in the North-east Asian countries such as Thailand, Cambodia, Vietnam and Malaysia. During the recent past, the natural stocks of P. jullieni have been decreased severely due to habitat degradation and man-induced hazards in aquatic ecosystem. Despite the vast research that has been conducted on various carp species, little attention has been given to P. jullieni. This study reviewed the published information on the status, distribution, reproduction and biodiversity of this commercially important fish species. The findings would greatly be helpful towards the species conservation and aquaculture development of the highly endangered P. jullieni.

Port Dickson is the only coastal district in Negeri Sembilan, Malaysia which is a favourite weekend getaway for people from Malaysia as well as Singapore. Impacts of tourism activities, shipping, refineries, land reclaiming activities, coastal zone management construction and insufficient sewage water treatment are the most pressing environmental problems that have caused deterioration of water quality in Port Dickson. Thus, bearing in mind all the impacts towards water quality of Port Dickson, water quality studies related to Port Dickson are briefly reviewed. This is to provide an overall viewpoint of current situation of water quality status, identify and prioritize future studies and regulatory plans in Port Dickson. Extensive Port Dickson water quality studies were done from 1999 to 2002 so far, Port Dickson waters have been analyzed in terms of physico-chemical parameters, nutrients, organic carbon, microbiological and heavy metals to indicate environmental pollution. However, limited studies were available on heavy metal concentration in coastal waters of Port Dickson. After 2002, fewer studies were conducted in terms of water quality in Port Dickson. This review output showed that water quality related studies in Port Dickson are clearly needed to be increased and strategized in terms of research objectives. Looking into pollution factors in Port Dickson, accumulation of heavy metals in water, sediment and biomonitors studies are crucial at this point of time. Future studies on heavy metals are crucial to understand impacts of different ecological compartments from various anthropogenic sources. Future studies in Port Dickson should also give a focus in utilization of this resource in order fill in the knowledge gap and provide clear direction in sustainable development of this precious resource. Amid these findings, real extent of contamination in Port Dickson will give direction helpful recommendations on environmental management and pollution control in this area.

Five species of sergestid shrimps viz., Acetes indicus, Acetes japonicus, Acetes intermedius, Acetes vulgaris and Acetes serrulatus were identified from the different coastal region of Peninsular Malaysia and East Malaysia. Acetes indicus was recorded from the coastal waters of Klebang Besar in the state of Malacca and also in Kuala Gula Perak. The widely distributed shrimp A. japonicus was identified from the coastal waters of Klebang Besar (Malacca), Kuala Gula (Perak), Bagan Ajam (Pulau Pinang), Kuala Sala (Kedah) and Sungai Berembang (Perlis). Acetes intermedius was collected from the coastal waters of Klebang Besar (Malacca), Seberang Takir (Terengganu) and Bintulu (Sarawak). Acetes vulgaris and A. serrulatus were restricted to the coastal waters of Pontian and Kukup in southwestern Johor.

Natural spawning ground of most Malaysian streams are undergoing extreme changes as a result of human activities, pollution and climate change (extreme temperature fluctuation) which lead to dramatic decrease in mahseer (Tor tambroides, Cyprinidae) populations. An experiment was conducted to evaluate the effectiveness of salmon gonadotropin releasing hormone analogue (sGnRHa) alone or in combination with dopamine antagonist domperidone (DOM) on breeding performances of female breeders. Sixty females T. tambroides ranging in weight 2.01 to 3.96 kg while thirty males with average weight 1.38 to 1.72 kg were used in this study. The females were given pretreatment with Ovaplant (23.4-44.9 μg kg-1) for 6 weeks prior to induction. Females were tested with various treatments such as Ovatide, sGnRHa, sGnRHa+DOM and DOM. SGnRH analogue alone does not contain dopamine antagonist to block dopaminergic inhibition action. Females were given single intramuscular injection of Ovatide (0.5 mL kg-1 BW), sGnRHa (10 μg kg-1 BW), sGnRHa+DOM (10 μg kg-1 BW+5 mg kg-1 BW) or DOM (5 mg kg-1 BW). The control group was administered with 0.9% NaCl. The fish did not spawn spontaneously but through hand stripping to release eggs. Results showed that Ovatide significantly produced highest ovulation rate, total stripped eggs and stripped fecundity. Interestingly, we observed that broodstock groups injected with sGnRHa+DOM produced highest fertilization, hatching and survival rates compared to other treatments. Good egg and larval quality were recorded in the group treated with sGnRHa+DOM. No females ovulated in the group receiving DOM alone and saline solution. The combination treatment was found to be more potent in inducing ovulation as compared to sGnRHa alone or DOM alone. Our results suggest that dopaminergic inhibition is a major barrier in inducing spontaneous spawning in captive mahseer and we successful produced progeny generation of T. tambroides larvae.

Information on the genetic diversity of Penaeus monodon throughout its natural range in Malaysia is still Hmited even though it is a highly exploited species, thus this study was undertaken to genetically characterize the prawn populations. The P. monodon samples were randomly collected from Malaysian waters and were characterized using thirty polymorphic primer pairs which showed high level of polymorphism. The total number of alleles per locus ranged from 3 to 36 with allele size ranging from 100 to 275 base pairs. The mean observed heterozygosity (0.5166) was less than the expected (0.5552), highly significant deficiencies in heterozygotes were detected in total inbreeding (F IS = 0.5500) and pair-wise genetic differentiation (F ST = 0.6308) among the populations. Both the (χ 2) chi-square and (G 2) likelihood ratio tests detected significant differences (p

The study described the Length-Weight Relationship (LWR) of commercially important and indigenous freshwater catfishes from Peninsular Malaysia. Seven species of freshwater catfishes from three families (Bagriidae, Clariidae and Pangasidae) were collected from various rivers in Peninsular Malaysia. Allometric coefficient, b in LWR varied between 2.19 and 3.20. The LWR with high correlation coefficient (r2) is significant for all species except P. nasutus. The present study also documented first reference for Pangasius nasutus and Pseudomystus siamensis.

A study was conducted to develop and validate a competitive enzyme-linked immunosorbent assay (ELISA) for detection of plasmatic vtg in Asian sea bass, Lates calcarifer. Highly specific polyclonal antibodies against purified vtg (antigen) were employed for quantifying the concentration of plasma vtg. The working ranges of the assay were 31.2 to 1000 ng mL-1 with the sensitivity of 6.9 ng mL-1. Antigen concentration of 250 ng mL-1 and antibody dilution of 1:1000 were selected as a workable ELISA after several preliminary test. The ELISA demonstrated precision with intra-and inter-assay Coefficient of Variations (CVs) at 90, 80 and 50% of binding were less than 8.4 (n = 9) and 12.1% (n = 5), respectively. Serial plasma dilutions from natural vitellogenic females and E2 treated were paralleled to the vtg standard curve (purified vtg) as analyzed by ANCOVA (p

Annual gonad hormonal profile of wild, matured mahseer (29 males and 23 female) averaging in weight between 0.95 ± 0.26 and 1.19 ± 0.23 kg for males and females, respectively, were investigated from November 2007 to November 2008 using enzyme-linked immunosorbent assay (ELISA) technique. Blood was collected from caudal vein, monthly and plasma separation by centrifugation was done to measure reproductive hormones: 17β-estradiol (E2), testosterone (T), and 11-keto-testosterone (11KT). Gonads were sampled for histology processing to observe their maturity. Highest T level in females and males was recorded at 0.22 ± 0.016 and 0.88 ± 0.014 ng/ml, respectively. The 11KT showed several peaks and the highest value was noted at 0.7 ± 0.018 ng/ml in November 2008. The female E2 initially was at 1.48 ± 0.16 ng/ml and significantly increased (P < 0.05) to 1.53 ± 0.39 ng/ml in November 2008. Ovaries were laden with oocytes in several stages in all the samples while testes gonad showed a high level of spermatids throughout the year. Changes in plasma level of the gonadal hormones were correlated with the ovarian and testes maturities. In conclusion, the study suggests that mahseer can be categorized as asynchronized and multiple spawner. The information gathered is important for appropriate breeding and conservation programs of the Malaysian mahseer.

Research in developmental biology has led to the discovery of different types of stem cells (totipotent, pluripotent and multipotent stem cells) that can give rise to multiple tissue types. This review summarizes a description about the stem cell concept, different type of stem cells and their potential applications. The face of extraordinary advances in the prevention, diagnosis and treatment of human diseases, devastating illnesses such as heart disease, diabetes, cancer and diseases of the nervous system, continue to deprive people of health, independence and well-being has been reviewed in this study. Stem cell research leading to prospective therapies in reparative medicine has the potential to affect the lives of millions of people around the world and there is a good reason to be optimistic. The road towards the development of an effective cell-based therapy for widespread use is long and involves overcoming numerous technical, legislative, ethical and safety issues. © 2011 Asian Network for Scientific Information.

Two sympatric populations of brown planthopper (BPH), one from rice and the other from Leersia hexandra were collected from each of five locations in Malaysia. All the tested malathion-resistant individuals of the rice BPH population and F1 generation (cross between malathion-resistant (usually caught on rice) and malathion- susceptible (usually caught on Leersia)) showed high esterase activity, while all malathion- susceptible individuals on L. hexandra showed low esterase activity. In the F2 generation, all the individuals tested against malathion were approximately 75% resistant and 25% susceptible and the inheritance pattern of esterase activity (high and low esterase activity) segregated in the same manner to a 3: 1 ratio. This confirms that resistance to malathion is mono-factorial and inheritance pattern of esterase activity is also linked to malathion resis- tance. Carboxylesterase or total esterase activity in BPH is inherited in a simple Mendelian fashion that is encoded by a single dominant gene. For the total esterase assay, average esterase activity levels in the rice-infesting population ranged from 17.64 to 19.37 nmoles 1-napthol/mg protein while that in the Leersia-infesting population ranged from 5.29 to 6.11 nmoles 1-napthol/mg protein. In terms of esterase activity, the two sympatric Ni- laparvata lugens populations separated into two distinct groups. Results based on the tube color intensity test showed 96% and 98% resistant and susceptible individuals were present in the rice- andLeersia-infesting populations, respectively. In a filter paper test, the rice-infesting population had 94% with high esterase activity while the Leersia-infesting population had 96% with low esterase activity.

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 6 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 as 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 is suitable for identification of closely related genotypes.

Rutilus frisii kutum (Kamensky 1901) is one of the economically important fishes that migrate for spawning to rivers in the Caspian Sea. However, the fish populations have slowly decreased in recent years. The declining of these resources has resulted from some activities by the Iranian Fisheries Organization (IFO is responsible for stock enhancement) to catch some broodstocks of Rutilus frisii kutum from their natural spawning rivers. The broodstocks are caught for artificial propagation of the fish. Artificial propagations are carried out every year to produce fingerlings to be released into the rivers in the Caspian Sea. In recent years, total catch of this fish have greatly fluctuated due to the disruption of the natural spawning grounds and over fishing. The substantial reduction to 1,298 metric tons, the lowest total catch reported in 1984–1985, could be due to over-exploitation of the fishery resources. However, the total catch has increased after the fingerlings release programs started in 1979. The total numbers of Rutilus frisii kutum fingerlings released had increased from 12 million to 225 million in 2002, to 155 million pieces in 2003, to 179 million pieces in 2004, 229 million pieces in 2005, 174 million pieces in 2006, 262 million pieces in 2007 and 187.1 in 2008. The total catch was also increased from 6,417 metric ton to 8,984 metric ton, to 7,036 metric ton, to 9,631 metric ton and 16,117, 17,196, 14,835 in years 2002, 2003, 2004, 2005, 2006, 2007 and 2008, respectively.

The distributions of Cu, Zn, and Pb concentrations in the selected soft tissues (foot, cephalic tentacle, mantle, muscle, gill, digestive caecum, and remaining soft tissues) and shells of the mud-flat snail Telescopium telescopium were determined in snails from eight geographical sites in the south-western intertidal area of Peninsular Malaysia. Generally, the digestive caecum compared with other selected soft tissues, accumulated higher concentration of Zn (214.35+/-14.56 microg/g dry weight), indicating that the digestive caecum has higher affinity for the essential Zn to bind to metallothionein. The shell demonstrated higher concentrations of Pb (41.23+/-1.20 microg/g dry weight) when compared to the selected soft tissues except gill from Kuala Sg. Ayam (95.76+/-5.32 microg/g dry weight). The use of different soft tissues also can solve the problem of defecation to reduce error in interpreting the bioavailability of heavy metals in the intertidal area.

The genetic variability within and among three deer species in Malaysia, namely Cervus nippon (sika), Cervus timorensis (rusa) and Cervus unicolor (sambar), were evaluated using the RAPD technique. The DNA extracted from the buffy coat of 34 sika, 38 rusa and 9 sambar were analysed using ten primers that gave bands which showed good resolution. The primers generated 164 RAPD markers in total, and these ranged in size from 150 to 900 bp. The percent of polymorphism of the bands generated per primer ranged from 66.66-93.33% for rusa, 36.84-61.14% for sambar and 52.38-100% for sika. The overall percent polymorphism observed for the 164 RAPD markers was 99.39%. The results revealed five exclusive, monomorphic markers for sambar and one exclusive, monomorphic marker for sika; none was observed for rusa. However, these cannot be declared as markers for the identification of the species without analysis of more samples, populations and species. The means of within population genetic distances, based on Dice's and Jaccard's similarity indices, were similar for the rusa (0.383 and 0.542, respectively) and sika (0.397 and 0.558, respectively) populations with the sambar population being the least variable (0.194 and 0.323, respectively). The Dice based genetic distances within the species ranged from 0.194 to 0.397 and the genetic distances among the species were 0.791-0.911. The genetic distances based on Dice's and Jaccard's similarity indices between the rusa and sambar were 0.556 and 0.713, between the rusa and sika populations were 0.552 and 0.710, and between sambar and sika were 0.622 and 0.766, respectively.

The inheritance of 31 amplicons from short and long primer RAPD was tested for segregating ratios in two families of the brown planthopper, Nilaparvata lugens, and they were found to be inherited in a simple Mendelian fashion. These markers could now be used in population genetics studies of N. lugens. Ten populations of N. lugens were collected from five locations in Malaysia. Each location had two sympatric populations. Cluster and principal coordinate analyses based on genetic distance along with AMOVA revealed that the rice-infesting populations (with high esterase activity) at five localities clustered together as a group, and Leersia-infesting populations (with low esterase activity) at the same localities formed another distinct cluster. Two amplicons from primers OPD03 (0.65 kb) and peh#6 (1.0 kb) could be considered diagnostic bands, which were fixed in the Leersia-infesting populations. These results represent evidence of a sibling species in the N. lugens complex.

Present research records for the first time, the occurrence of the sergestid shrimp Acetes intermedius in Peninsular Malaysia. A taxonomic account of this shrimp is provided. Notes on its habitat and population characteristics were examined based on 995 specimens collected from the Klebang Besar, coastal waters of Malacca, Peninsular Malaysia during February 2005 to January 2006. Size-frequency distribution revealed that the mean size of females consistently exceeded that of males throughout the year (TL range: 15-27.50 and 13.50-33 mm for males and females, respectively). The overall yearly and the monthly sex ratio were in favor of females. Asymptotic length (L4) and growth co-efficient (K) was estimated as 34.65 mm and 1.50 yearG1. The exponent b (2.979) of the length-weight relationship for males was found near to the isometric value (b = 3.0) and positive allometric growth was observed in females and combined sexes (b = 3.227 for females and b = 3.249 combined sexes). The asymptotic weight was calculated as 211.21 mg. The overall average growth rate of A. intermedius showed 2.10 (` 0.88) mm/month in the coastal waters of Malacca.

Population parameters such as asymptotic length (L∞), growth coefficient (K), mortality rates (Z, F and M), exploitation level (E) and recruitment pattern of green mussel Perna viridis were estimated using length–frequency data from the coast of Malacca, Peninsular Malaysia. Asymptotic length (L∞) was 102.38 mm and growth coefficient (K) was estimated at 1.50 year−1. Total mortality (Z) for P. viridis was 2.48 year−1, while natural mortality (M) and fishing mortality (F) were 1.69 and 0.79 year−1, respectively. The growth performance index was (φ′) 4.197 and the exponent “b” of the length–weight relationship was 2.602 (±0.02) during the study period. The asymptotic wet weight estimated from length–weight relationship was 40.81 g. Exploitation level (E) of P. viridis was 0.32 while the maximum allowable limit of exploitation (Emax) was 0.43. The recruitment pattern was continuous with one major peak in the months of July–August. The exploitation level (0.32) and lower fishing mortality (0.79 year−1) indicate that the green mussel is under-exploited from Malacca coastal waters.

Green-lipped mussels, Perna viridis, were collected from the eastern and western parts of the Johore Straits in September 2004 and January 2005. Based on the heavy metal concentrations in the different soft tissues (gonad, foot, mantle, gills, muscle, and remaining soft tissues) of these mussel samples, the eastern part of the Johore Straits (which is divided into two portions by a causeway), recorded higher levels of bioavailability and contamination by Cd, Cu, Fe, Ni, and Zn when compared to the western part, while Kg. Pasir Puteh in the eastern part was found to record the highest bioavailability and contamination by heavy metals. The use of different soft tissues of P. viridis as biomonitors of bioavailability and contamination by Cd, Cu, Fe, Pb, Ni, and Zn in the semi-enclosed Johore Straits is proposed, since erroneous results due to spawning and the problem of defecation before dissection could be overcome. Hence, a more accurate interpretation of the bioavailability and contamination by heavy meta...

The work reported here is an attempt to explore the possibility of DNA microsatellite loci transfer (cross-species amplification) to other economically important aquacultured catfish species other than its source species. A total of 25 new microsatellite loci developed for riverine catfish, Mystus nemurus were successfully cross-amplified in two distantly related catfish species within the suborder Siluroidei. Five out of the 19 loci that successfully cross-amplified in Pangasius micronemus were polymorphic, while for Clarias batrachus, cross-amplification was successful using 17 polymorphic loci. The observed heterozygosities were high for all the three catfishes. The results indicated that microsatellite loci could be as polymorphic in non-source species as in the source species.

Yellow catfish, Mystus nemurus (Cuv. & Val.), is becoming one of the major freshwater species farmed by aquaculturists in Southeast Asia. It was of interest to examine levels of genetic subpopulation differentiation among samples of this species obtained from parts of its range, as well as to compare the genetics of wild and hatchery-bred fish. Horizontal starch gel electrophoresis and histochemical staining techniques were used to examine genetic variation within and among eight wild and one hatchery populations of M. nemurus from northern, northeastern, central and southern Thailand. Four tissues (heart, liver, kidney, and muscle) from individual specimens were used to analyze variations at 23 protein-coding loci. Fifteen of the 23 loci examined (65.22%), namely, ACP*, AAT-1*, EST-1*, EST-2*, GPI*, IDH-1*, IDH-2*, MDH-1*, MDH-2*, MDH-3*, ME*, PGM*, 6PGD*, SOD*, and HB*,were polymorphic at the 0.95 level. Observed heterozygosities ranged from 0.041 to 0.111, with an average of 0.068 ± 0.028. Genetic distances ranged from 0.005 to 0.164. The greatest genetic distance was found between the Chainat and the Suratthani populations (0.164), a level indicative of subspecific differentiation in M. nemurus from within Thailand.

This work represents the first application of the amplified fragment length polymorphism (AFLP) technique and the random amplified polymorphic DNA (RAPD) technique in the study of genetic variation within and among five geographical populations of M. nemurus. Four AFLP primer combinations and nine RAPD primers detected a total of 158 and 42 polymorphic markers, respectively. The results of AFLP and RAPD analysis provide similar conclusions as far as the population clustering analysis is concerned. The Sarawak population, which is located on Borneo Island, clustered by itself and was thus isolated from the rest of the populations located in Peninsular Malaysia. Both marker systems revealed high genetic variability within the Universiti Putra Malaysia (UPM) and Sarawak populations. Three subgroups each from the Kedah, Perak, and Sarawak populations were detected by AFLP but not by RAPD. Unique AFLP fingerprints were also observed in some unusual genotypes sampled in Sarawak. This indicates that AFLP may be a more efficient marker system than RAPD for identifying genotypes within populations.

Problem statement: In beef cattle production, of meat quality and carcass traits are important. Traditionally beef cattle breeding programs unfortunately are time consuming and also recording of carcass and growth traits need heavy cost, Approach: Marker Assisted Selection (MAS) should be utilized in beef herds, along with economically important phenotypic traits, for genetic progress to made with respect to improving the uniformity and consistency of beef. Blood samples were collected from 41 nelor cattle in Malaysia. Forward and reversed primers amplified a 1552 bp fragment from calpastatin gene. XmnI enzyme was used for restriction analysis of PCR products. Result: Overall, the frequency of alleles A and B in the studied breeds were estimated as 0.42 and 0.58, respectively. In this study we calculated genotype frequency AA, AB and BB 12.2, 58.53 and 29.27% respectively and also observed heterozygosity, expected heterozygosity and average value of heterozygosity were 0.58, 0.49 and 0.48 respectively. Highest frequency of allele was B (0.58) and lowest was A (0.42) This Nelor cattle population was in the Hardy-Weinberg equilibrium. Conclusion: Perhaps, this molecular genetic information helps breeders for designing the proper genetic selection program in the development direction of this breed.

Eight single locus microsatellite markers were developed to characterize the Malaysian giant freshwater prawn, Macrobrachium rosenbergii. These microsatellites were isolated from an enriched genomic library contained by using a 5'-anchored polymerase chain reaction technique. Primers were designed to flank the repeat sequences and subsequently used to characterize 30 unrelated individuals of the giant freshwater prawn. The polymerase chain reaction amplification products of these eight microsatellite loci were polymorphic with the number of alleles ranging from two to 10 alleles per locus while the levels of heterozygosity ranged from 0.6333 to 0.8667.

Twelve single-locus trinucleotide microsatellite markers were developed to characterize the Asian river catfish, Mystus nemurus, an important food fish in Southeast Asia. They were obtained by using a rapid method, namely, the 5′ anchored PCR enrichment protocol. The specific primers were designed to flank the repeat sequences and these were subsequently used to characterize 90 unrelated fish from Malaysia. The number of alleles per locus ranged from 2 (MnVj2-281) to 12 (MnBp8-4-43b) while the levels of heterozygosity ranged from 0.0444 (MnVj2-1-19) to 0.7458 (MnVj2-291).

A preliminary linkage map was constructed by applying backcross and testcross strategy using microsatellite (SSR) markers developed for Xiphophorus and Poecilia reticulata in ornamental fish, molly Poecilia sp. The linkage map having 18 SSR loci consisted of four linkage groups that spanned a map size of 516.1cM. Association between genotypes and phenotypes was tested in a random fashion and QTL for dorsal fin length was found to be linked to locus Msb069 on linkage group 2. Coincidentally, locus Msb069 was also reported as putative homologue primer pairs containing SSRs repeat motif which encoded hSMP-1, a sex determining locus. Dorsal fin length particularly in males of Poecilia latipinna is an important feature during courtship display. Therefore, we speculate that both dorsal fin length and putative hSMP-1 gene formed a close proximity to male sexual characteristics.

Summary A total of 143 microsatellites were isolated from Mystus nemurus using a 5′ anchored polymerase chain reaction technique or the random amplified hybridization microsatellite method, the first set of microsatellite markers developed for the Southeast Asian river catfish. Twenty polymorphic microsatellite loci were used as markers for population characterization of M. nemurus from six different geographical locations in Malaysia (Perak, Kedah, Johor, UPM, Sarawak and Terengganu). The number of alleles per locus ranged from 2 to 11 with 6.3 as the average number of alleles per locus. Characterization of the populations showed relatively high levels of genetic variation compared with previous studies using allozyme markers. The highest genetic similarity was found between Perak and Kedah, while the highest genetic distance was found between Terengganu and Kedah. The majority of clustering was in accordance with geographical locations and the histories of the populations. Microsatellite analysis indicated that the Sarawak population might be genetically closer to the Peninsular Malaysian populations than has been previously shown by other molecular marker studies.

Contamination of insect DNA for RAPD-PCR analysis can be a problem because many primers are non-specific and DNA from parasites or gut contents may be simultaneously extracted along with that of the insect. We measured the quantity of food ingested and assimilated by two sympatric populations of brown planthopper (BPH), Nilaparvata lugens, one from rice and the other from Leersia hexandra (Poaceae), a wetland forage grass, and we also investigated whether host plant DNA contaminates that of herbivore insects in extractions of whole insects. Ingestion and assimilation of food were reduced significantly when individuals derived from one host plant were caged on the other species. The bands, OPA3 (1.25), OPD3 (1.10), OPD3 (0.80), OPD3 (0.60), pUC/M13F (0.35), pUC/M13F (0.20), BOXAIR (0.50), peh#3 (0.50), and peh#3 (0.17) were found in both rice-infesting populations of brown planthopper and its host plant (rice). Similarly, the bands, OPA4 (1.00), OPB10 (0.70), OPD3 (0.90), OPD3 (0.80), OPD3 (0.60), pUC/ M13F (0.35), pUC/M13F (0.20), and BOXAIR (0.50) were found in both Leersia-infesting populations of brown planthopper and the host plant. So, it is clear that the DNA bands amplified in the host plants were also found in the extracts from the insects feeding on them.

Plasma sex steroid hormonal profile and gonad histology were correlated to study the annual reproductive cycle of Hemibagrus nemurus. Hormones were measured by Enzyme Linked Immunosorbent Assay. Gonad tissues were observed by using light microscopy. The highest testosterone (T) value for male was observed in November and that of female was in October. 11-ketotestosterone (11-KT) and 17β-estradiol (E2) levels were highest in June and November, respectively. Hormonal profiles of T, 11-KT and E2 showed several peaks which indicated a non-seasonal pattern. There were significant differences (p

Hemibagrus nemurus is a riverine catfish with high economic and nutritive values. Investigations on ovarian development of this fish were carried out to determine the mode of ovarian development and describe the oocyte developmental stages. Histological studies were done on ovaries using light microscopy and scanning electron microscopy. Fish were sampled monthly for a period of six months (August 2009 to January 2010). The mean oocyte diameter (OD) ranged from 871 ± 161.41 µm to 1,167 ± 26.77 µm and the highest OD was in November. Oocyte size-frequency distribution showed a polymodal distribution. The mean gonadosomatic index (GSI) ranged from 1.14 ± 0.87% to 7.06 ± 1.40% and highest GSI was in November. The ovaries exhibited three phases of oocyte growth, which were primary growth, secondary growth and maturation phases. Based on histological criteria, the oocyte developmental stages were divided into seven stages as chromatin nucleolar, early perinucleolar, late perinucleolar, cortical alveolar, vitellogenesis, mature oocyte and germinal vesicle migration stages. All the seven stages of oocyte development were observed in the ovaries. Oogonia were always present throughout the developmental stages. The ovaries had more than two stages of oocyte development. This is the first report on the mode of ovarian development of H. nemurus. These findings indicated that H. nemurus has asynchronous mode of ovarian development and is capable of spawning several times in a year under favourable conditions.

The effects of genetic manipulation of eggs and sperm on the yields of gynogenetic fry of Puntius gonionotus were investigated. Gynogenesis was achieved by cold-and heat-shocking eggs fertilized with ultraviolet irradiated sperm of P. schwanenfeldii at various times after fertilization and at different duration intervals. 66.6% viable, gynogenetic fry were obtained when eggs were inseminated with irradiated sperm and cold shocked at 2°C for 5 minutes duration 1 minute after fertilization. At warm water temperature shocks the fertilized eggs performed best at 42°C, with percent survival rates of 20.0% 1 minute after fertilization for 1.0 minute duration and 17.2% and 14.7% 13 and 23 minutes after fertilization respectively for a duration of 1.5 minutes.

A total of 26 simple sequence repeats were identified using a random amplified polymorphic DNA (RAPD) based technique in the Southeast Asian river catfish Mystus nemurus. We report on the characterization of five polymorphic microsatellite loci in M. nemurus. The average number of alleles per locus was 3.2. These are the first microsatellite loci that have been developed for this species. These markers should prove useful as tools for managing the brood stocks and for future aquacultural development of this species.

Termites of the genus Odontotermes are important decomposers in the Old World tropics and are sometimes important pests of crops, timber and trees. The species within the genus often have overlapping size ranges and are difficult to differentiate based on morphology. As a result, the taxonomy of Odontotermes in Peninsular Malaysia has not been adequately worked out. In this study, we examined the phylogeny of 40 samples of Odontotermes from Peninsular Malaysia using two mitochondrial DNA regions, that is, the 16S ribosomal RNA and cytochrome oxidase subunit I genes, to aid in elucidating the number of species in the peninsula. Phylogenies were reconstructed from the individual gene and combined gene data sets using parsimony and likelihood criteria. The phylogenies supported the presence of up to eleven species in Peninsular Malaysia, which were identified as O. escherichi, O. hainanensis, O. javanicus, O. longignathus, O. malaccensis, O. oblongatus, O. paraoblongatus, O. sarawakensis, and three possibly new species. Additionally, some of our taxa are thought to comprise a complex of two or more species. The number of species found in this study using DNA methods was more than the initial nine species thought to occur in Peninsular Malaysia. The support values for the clades and morphology of the soldiers provided further evidence for the existence of eleven or more species. Higher resolution genetic markers such as microsatellites would be required to confirm the presence of cryptic species in some taxa.

Studies on hybridization, inheritance, and population genetics of brown planthoppers that infest rice and weeds were undertaken using starch gel electrophoresis to determine whether the weed-infesting population represents a biological race or a species. F(1) and F(2) generations were produced by crosses between parental insects from the two populations with little indication of hybrid sterility. Gpi, Mdh, and Idh loci were inherited in a simple Mendelian fashion in families of two sympatric populations. Sixteen populations of Nilaparvata spp. from eight locations were collected. The Mdh, Idh, Pgm, Gpi, 6Pgd, and Acp loci were polymorphic. The N. lugens of rice with high esterase activity were clustered into a group and characterized by the presence of alleles Gpi (110) and Gpi (120), whereas N. lugens from weeds with low esterase activity were clustered into another group and characterized by Gpi (100) and Gpi (90) . There was a lack of heterozygotes between the common alleles of the two populations. This means that the two groups of individuals belong to different gene pools.

Prawns of the genus Macrobrachium Bate, 1868 (Crustacea: Palaemonidae), are a highly diverse, abundant, and widespread group of decapod crustaceans found in circumtropical marine, estuarine, and freshwater areas (de Bruyn et al. 2004). The giant freshwater prawn Macrobrachium rosenbergii is the largest species in the genus and is the most important culture species. It is being cultured in commercial quantities in many parts of the world, including Hawaii, Honduras, Mauritius, Taiwan, Thailand, Philippines, Costa Rica, Israel, Malaysia, and Mexico (New 2002). Overexploitation of M. rosenbergii, however, will eventually lead to the loss of genetic diversity.

The microsatellite markers for Mystus nemurus were isolated using the 5’ anchored PCR procedure. A degenerate primer was designed for the construction of the genomic library. Fourteen clones were sequenced and revealed a total of 45 microsatellite repeats. From these, 20 specific primer pairs were designed and employed to characterize unrelated fishes from six populations of M. nemurus. Thirteen loci were found to be polymorphic. The allelic frequencies ranged from 0.007 to 0.800, while the levels of heterozygosity ranged from 0.0563 (MnBp5-1-115b) to 0.8714 (MnBp5-1-12a).