Microbiological quality analysis of freshwater prawns from three sampling sites in Peninsular Malaysia viz: Site 1- Kg. Jumbang, Negri Sembilan; Site 2- Kg. Cangkat Tin, Perak and Site 3- Kg. Cenderiang, Perak for total mesophilic and psychrophilic aerobic counts, proteolytic bacterial counts, histamine producing bacteria, cadaverine producing bacteria and putrescine producing bacteria in the prawns and pond water for the three sites showed that the microbiological quality of freshwater prawns is related to the microflora of pond water in which they were grown. The initial bacterial counts indicated the values were in the range of log 4+ CFU/g for all samples. Total mesophilic and psychrophilic counts of the head regions were higher than that of the body regions for all prawn samples and types of growth media tested. All samples showed an increase in counts with time and temperature of storage up to log 7+ CFU/g for mesophilic counts after 12 hours at ambient, 6 days at 10 ± 2°C and 12 days at iced storage. The samples from Site 2 had relatively higher counts compared to the other two sites which correlated well with the levels determined in the pond water. Similar trends were observed for psychrophilic counts but at lower values for the different types of media studied.
Effects of preservatives on quality changes and shelf life of shrimp during iced storage indicated that boric acid, lactic acid and sodium metabisulphite managed to inhibit psychrophilic bacteria and biogenic amines formation in prawns while maintaining the mesophilic counts at lower levels during iced storage.
The aim of this work is to investigate the effect of exposure of heavy metals such as Ni, Fe and Mn on the growth of the cyanobacteria Anabaena flos-aquae, which can be found in fresh water environment. Results of the experiments showed that exposure of A. flos-aquae to Ni caused the most toxic effect as compared to exposure with Fe and Mn. The 96 hr LC50 value for Ni exposure was 0.321 mg/mL (approximately 30% inhibition), whereas Mn was the second most toxic metal followed by Fe with the 96 hr LC50 values of 0.684 mg/mL and 3.020 mg/mL respectively. This study demonstrated that even though Fe and Mn are essential micronutrients for A. flos-aquae, both show toxic effects at high concentrations. The difference in the toxicity value between Fe and Mn for A. flos-aquae is five times and this indicates that Mn was five times more toxic to A. flos-aquae than Fe suggesting that the Cyanobacteria is more tolerant to Fe when compared with Mn.
Ovitrap surveillance was initiated for eight continuous weeks to determine the distribution and abundance of Aedes sp. mosquitoes in the University of Malaya campus, Kuala Lumpur, and the impact of meteorological conditions on the Aedes populations. Two study areas within the campus were selected: Varsity Lake and Seventh Residential College. The abundance of Aedes populations in Varsity Lake was indicated by ovitrap index (OI) which ranged from 60.00%-90.00%. The mean number of larvae per ovitrap of Aedes albopictus in Varsity Lake ranged from 11.23+/-2.42-43.80+/-6.22. On the other hand, the outdoor OI for Seventh Residential College ranged from 73.33%-93.33%, respectively, while the mean number larvae per ovitrap for this area ranged from 19.33+/-4.55-35.27+/-5.46, respectively. In addition, the indoor OI of Seventh Residential College ranged from 0.00%-30.00%, while the mean number of larvae per ovitrap for Ae. albopictus ranged from 0-5.90+/-3.55. There was no significant difference (p>0.05) of Ae. albopictus population between Varsity Lake and Seventh Residential College. The studies showed a correlation between OI and mean number of larvae per ovitrap for outdoor Ae. albopictus populations in Varsity Lake and Seventh Residential College (r=0.794). There was also a correlation between the mean larvae number per ovitrap of Ae. albopictus obtained from eight weeks indoor ovitrap surveillance in Seventh Residential College with rainfall (r=0.584). However, there was no correlation between the mean larvae number per ovitrap of Ae. albopictus in both study areas with temperature and relative humidity. Aedes aegypti mosquitoes were found neither indoor nor outdoor in both study areas. This study indicated that the principal dengue vector in the university campus was most likely Ae. albopictus.
We used a combined microscopy-molecular approach to determine the occurrence and identities of waterborne Giardia sp. cysts isolated from 18 separate, 10l grab samples collected from a Malaysian zoo. Microscopy revealed that 17 of 18 samples were Giardia cyst positive with concentrations ranging from 1 to 120 cysts/l. Nine (52.9%) of the 17 cyst positive samples produced amplicons of which 7 (77.8%) could be sequenced. Giardia duodenalis assemblage A (6 of 7) and assemblage B (1 of 7), both infectious to humans, were identified at all sampling sites at the zoo. The presence of human infectious cysts raises public health issues, and their occurrence, abundance and sources should be investigated further. In this zoo setting, our data highlight the importance of incorporating environmental sampling (monitoring) in addition to routine faecal examinations to determine veterinary and public health risks, and water monitoring should be considered for inclusion as a separate element in hazard analysis, as it often has a historical (accumulative) connotation.
Nine 50-l surface water samples from a Malaysian recreational lake were examined microscopically using an immunomagnetisable separation-immunofluorescent method. No Cryptosporidium oocysts were detected, but 77.8% of samples contained low numbers of Giardia cysts (range, 0.17-1.1 cysts/l), which were genetically characterised by SSU rRNA gene sequencing. Genotype analyses indicated the presence of Giardia duodenalis assemblage A suggesting potential risk to public health. The present study represents the first contribution to our knowledge of G. duodenalis assemblages in Malaysian recreational water.
The world’s biodiversity is not distributed uniformly throughout the globe. Some areas such as the tropical rainforests, seas and coral reefs teem with the varieties of life whereas others such as some deserts and polar regions are almost devoid of them (Gaston, 2000). Malaysia, with her tropical jungles and seas, is rich with biodiversity. She is fortunate to have had eminent pioneers such as Ridley (1967), Corner (1972), Soepadmo (1972) and Whitmore (1983) to study her flora and Medway (1968) and Lim (1991) to study her fauna taxonomy. Other pioneers in Malaysian biology included Berry, Dhaliwal and Mohsin. These pioneers are then ably followed by workers such as Latiff, Kiew, Go, Khoo, Davidson, Saberi, Omar, Jambari, Idris, Zekri, Teo, Marziah, Tan, Mukherjee, Shapor, Yusoff, Azmi and many others studying the various subdisciplines of biology. In addition to the more obvious large plants and animals, microorganisms and aquatic organisms had not been neglected either. Workers such as Nawawi, Verghese, Ho and Faridah are known
for their work on fungi while Fatimah, Phang, Japar and Anton had studied algae, seaweeds, diatoms and seagrasses. However, some of these workers have now either retired or are soon going to attain retirement age and the worrying part is that there are not many younger
workers keen to pursue research in taxonomy and biosystematics, a prerequisite to further studies in ecology, genetics, biotechnology which in turn are prerequisites for rational conservation, management and sustainable utilization of our rich biological resources. With each passing day species are becoming extinct sometimes without us even knowing that they had ever existed. Even in a developed country such as the USA, one third of her plant and animal species are at risk of extinction (McCann, 2000). Hence, taxonomic and biosystematic studies of our plants, animals and microbes whether terrestrial or aquatic, freshwater and marine, should be priority areas. So should studies on their reproductive biology, life cycles, physiology, feeding habits, migration patterns, predators and their sensitivities to environmental changes.
Groundwater is the prime source of freshwater in most small islands. A detailed groundwater and seawater chemistry study was undertaken from March 2006 to January 2007 to examine the evolution of groundwater in the shallow aquifer of Manukan Island, Sabah, Malaysia. Coastal groundwater aquifers especially for small islands are often exposed to heavy pumping and consequently to risks of seawater intrusion. Major ion chemistry analysis showed that the groundwater quality of the island experienced changes attributed to seawater intrusion. The groundwater has undergone a compositional change from Ca-rich to Na-rich which can be explained mostly by simple mixing process and cation exchange process. From the PHREEQC simulation model, calcite, dolomite and aragonite solubility showed positive mean values (0.65; 1.11; 0.51, respectively) of the saturation indices (SI) indicating supersaturation which attributed from the simple mixing and eventually cation exchange process. This information is important in protecting and remediating the disturbed aquifer situation.
A total of 1951 species of freshwater and marine fishes belonging to 704 genera and 186 families are recorded in Malaysia. Almost half (48%) are currently threatened to some degree, while nearly one third (27%) mostly from the marine and coral habitats require urgent scientific studies to evaluate their status. Freshwater habitats encompass the highest percentage of threatened fish species (87%) followed by estuarine habitats (66%). Of the 32 species of highly threatened (HT) species, 16 are freshwater and 16 are largely marine-euryhaline species. Fish extinctions in Malaysia are confined to two freshwater species, but both freshwater and marine species are being increasingly threatened by largely habitat loss or modification (76%), overfishing (27%) and by-catch (23%). The most important threat to freshwater fishes is habitat modification and overfishing, while 35 species are threatened due to their endemism. Brackish-water, euryhaline and marine fishes are threatened mainly by overfishing, by-catch and habitat modification. Sedimentation (pollution) additionally threatens coral-reef fishes. The study provides recommendations to governments, fish managers, scientists and stakeholders to address the increasing and unabated extinction risks faced by the Malaysian fish fauna.
Gadilam river basin has gained its importance due to the presence of Neyveli Lignite open cast mines and other industrial complexes. It is also due to extensive depressurization of Cuddalore aquifer, and bore wells for New Veeranam Scheme are constructed downstream of the basin. Geochemical indicators of groundwater were used to identify the chemical processes that control hydrogeochemistry. Chemical parameters of groundwater such as pH, electrical conductivity, total dissolved solids, sodium (Na(+)), potassium (K(+)), calcium (Ca(+)), magnesium (Mg(+)), bicarbonate (HCO(-)(3)), sulfate (SO(-)(4)), phosphate (PO(-)(4)), and silica (H(4)SiO(4)) were determined. Interpretation of hydrogeochemical data suggests that leaching of ions followed by weathering and anthropogenic impact controls the chemistry of the groundwater. Isotopic study reveals that recharge from meteoric source in sedimentary terrain and rock-water interaction with significant evaporation prevails in hard rock region.
During several surveys made in the region of the lower Fly River and delta, Papua New Guinea, nine species of oxudercine gobies (Gobiidae: Oxudercinae) were recorded: Boleophthalmus caeruleomaculatus, Oxuderces wirzi, Periophthalmodon freycineti, Periophthalmus darwini, Periophthalmus novaeguineaensis, Periophthalmus takita, Periophthalmus weberi, Scartelaos histophorus and Zappa confluentus. An exploratory multivariate analysis of their habitat conditions discriminated five guilds, differentially distributed in habitats with different quantities of environmental water and three guilds corresponding to different levels of salinity. A partial correspondence between phylogenetic and ecological categories suggested the presence of parallel adaptive radiations within different genera. In particular, the species found in the most terrestrial habitats (P. weberi) was also found in the widest range of conditions, suggesting that colonization of extreme semi-terrestrial and freshwater habitats by this species was facilitated by eurytypy. It is proposed that these findings provide insight into convergent adaptations for the vertebrate eco-evolutionary transition from sea to land.
Surface sediments along the south of Caspian Sea were collected to evaluate the contamination of heavy metals. The result ranged (μg/g, Fe% dw): Pb(13.06-33.48); Ni(18.01-69.63); Cd(0.62-1.5); Zn(30.11-87.88); Cu(5.86-26.37) and Fe(1.8-4%) respectively. Cadmium showed higher EF when compared to other sites. Geoaccumulation Index value for Cd in most stations was classified as moderately contaminated and moderately to strongly contaminated, as well as the average of I(geo) of Cd (1.77 ± 0.35) suggested that surface sediments of Caspian coast were moderately polluted by this metal. The result of the Pearson correlation showed that there were significant positive associations between Ni, Cd and Zn (r = 0.44-0.76; p < 0.01).
As groundwater is a vital source of water for domestic and agricultural activities in Thanjavur city due to lack of surface water resources, groundwater quality and its suitability for drinking and agricultural usage were evaluated. In this study, 102 groundwater samples were collected from dug wells and bore wells during March 2008 and analyzed for pH, electrical conductivity, temperature, major ions, and nitrate. Results suggest that, in 90% of groundwater samples, sodium and chloride are predominant cation and anion, respectively, and NaCl and CaMgCl are major water types in the study area. The groundwater quality in the study site is impaired by surface contamination sources, mineral dissolution, ion exchange, and evaporation. Nitrate, chloride, and sulfate concentrations strongly express the impact of surface contamination sources such as agricultural and domestic activities, on groundwater quality, and 13% of samples have elevated nitrate content (>45 mg/l as NO(3)). PHREEQC code and Gibbs plots were employed to evaluate the contribution of mineral dissolution and suggest that mineral dissolution, especially carbonate minerals, regulates water chemistry. Groundwater suitability for drinking usage was evaluated by the World Health Organization and Indian standards and suggests that 34% of samples are not suitable for drinking. Integrated groundwater suitability map for drinking purposes was created using drinking water standards based on a concept that if the groundwater sample exceeds any one of the standards, it is not suitable for drinking. This map illustrates that wells in zones 1, 2, 3, and 4 are not fit for drinking purpose. Likewise, irrigational suitability of groundwater in the study region was evaluated, and results suggest that 20% samples are not fit for irrigation. Groundwater suitability map for irrigation was also produced based on salinity and sodium hazards and denotes that wells mostly situated in zones 2 and 3 are not suitable for irrigation. Both integrated suitability maps for drinking and irrigation usage provide overall scenario about the groundwater quality in the study area. Finally, the study concluded that groundwater quality is impaired by man-made activities, and proper management plan is necessary to protect valuable groundwater resources in Thanjavur city.
Rasbora tawarensis is an endemic freshwater fish in Lake Laut Tawar, Aceh Province, Indonesia. Unfortunately, its status is regarded as critical endangered with populations decreasing in recent years. To date no information on the spawning activities of the fish are available. Therefore, this study provides a contribution to the knowledge on reproductive biology of R. tawarensis especially on spawning seasons as well as basic information for conservation of the species.
A depth-averaged numerical model was developed to study tidal circulation and suspended sediment transport in the gulf of Khambhat along the west coast of India. The spatial resolution of the model is 750m x 750m. A 2-D fine resolution (150 m x 150 m) model for the lower part of the Narmada estuary is coupled with the coarser gulf model to simulate the flow features in the lower estuary. The model dynamics and basic formulation remain the same for both the gulf model and the estuary model. The models are barotropic, based on the shallow water equations and neglect horizontal diffusion and wind stress terms in the momentum equations. The models are fully non-linear and use a semi-explicit finite difference scheme to solve mass, momentum, and advection- diffusion equation for suspended sediments in a horizontal plane. The erosion and deposition have been computed by an empirically developed source and sink term in the suspended sediment equation. The tide in the gulf is mainly represented in the model by the semi-diurnal M2 constituent. Meanwhile, fresh water discharge from the rivers joining the gulf had also been considered. Numerical experiments were carried out to study the circulation and suspended sediment concentrations in the gulf and estuarine region.
The presence of 226 Ra in water is a great concern in human life since it can cause health risk to a certain extent. In the state of Kelantan, being known of its granitic area, there is a lack measurement of 226 Ra content in river water, since water is the major source of water supply. According to the INTERIM National Water Quality Standards for Malaysia (INWQS), 226 Ra activity concentration in water cannot exceed 0.1 Bq/L. For this reasons, this research was planned to carry out a systematic measurement of water along Sungai Kelantan. Liquid Scintillation Counting was used for measurement of 226 Ra in water samples from Sungai Kelantan mainly in district of Kuala Krai. In this paper, the results obtained is about 26 water samples, filtered and unfiltered, collected along Sungai Lebir, Sungai Sok and Bukit Sabah. Thus, the assessment activity concentration of 226 Ra in river water was obtained as well as annual effective dose for consumption of drinking water.
Tooth wear is the loss of tooth tissue and structures not due to caries. It can occur in various forms either attrition, abrasion, erosion, noncaries cervical lesion (NCCL) or a combination of two or more forms. The objective of this study was to determine the patterns and associated aetiologies of tooth wear among adults in Kelantan, Malaysia. This crosssectional study involved 81 adults with tooth wear which was visually assessed using the Smith and Knight Tooth Wear Index (TWI). A questionnaire was used to seek putative aetiologies of the wear. Data were analyzed and the results were expressed as frequencies and percentages. Six thousand three hundred and eighty four tooth surfaces were examined in 1596 teeth. 17.4% surfaces had tooth wear; 80% scored 1, 18% scored 2 and 2% scored 3. Among the 81 cases of tooth wear, 29 (35.8%) had abrasion; 25 (30.9%) had attrition; 1(1.2%) had erosion while 26 (32.1%) had the combined type. Among those with abrasion, majority had the habit of eating freshwater clams (Corbicula fluminea) as local delicacy where most of the times people use their teeth to pry open the clam shells. Erosion was related to the pooling of carbonated drinks or beverages in the mouth before swallowing. In conclusion, most adults experienced abrasion and the most common possible associated aetiology is the way of eating clams.
Fishes from five streams in Gunung Machinchang and six streams in Gunung Raya areas of Pulau Langkawi were surveyed with the aim to investigate their diversity and distribution. Fish samples were collected from 23rd to 29th November 2007. Samplings took place along the 50 m reach of each of the site using an electrofisher and scoop nets. A total of 619 individuals of fish comprising 27 species and 14 families were recorded. Sixty-six percent from the taxa listed were of the cyprinids and Puntius binotatus was the most abundant species. Carassius auratus auratus was recorded for the first time in Pulau Langkawi. Streams of the Gunung Machinchang area were dominated by secondary freshwater fish species, but in the Gunung Raya area the streams were dominated by primary freshwater fish species. The highest diversity of fish was recorded for Sg. Kubang Badak with Simpson Index Ds = 0.838 and the lowest was for Sg. Perangin with Ds = 0.450. The highest evenness index of fish species was detected for Sg. Temurun with Es = 0.684 and the lowest was for Sg. Perangin with Es = 0.299. Species overlapping between streams of the two areas was 9.6%.
In this project, several surrogate surfaces designed to directly measure Hg dry deposition were investigated. Static water surrogate surfaces (SWSS) containing deionized (DI), acidified water, or salt solutions, and a knife-edge surrogate surface (KSS) using quartz fiber filters (QFF), KCl-coated QFF and gold-coated QFF were evaluated as a means to directly measure mercury (Hg) dry deposition. The SWSS was hypothesized to collect deposited elemental mercury (Hg⁰), reactive gaseous/oxidized mercury (RGM), and mercury associated with particulate matter (Hg(p)) while the QFF, KCl-coated QFF, and gold-coated QFF on the KSS were hypothesized to collect Hg(p), RGM+Hg(p), and Hg⁰+RGM+Hg(p), respectively. The Hg flux measured by the DI water was significantly smaller than that captured by the acidified water, probably because Hg⁰ was oxidized to Hg²+ which stabilized the deposited Hg and decreased mass transfer resistance. Acidified BrCl, which efficiently oxidizes Hg⁰, captured significantly more Hg than other solutions. However, of all collection media, gold-coated QFFs captured 6 to 100 times greater Hg mass than the other surfaces, probably because there is no surface resistance for Hg⁰ deposition to gold surfaces. In addition, the Hg⁰ concentration is usually 100-1000 times higher than RGM and Hg(p). For all other media, co-located samples were not significantly different, and the combination of daytime plus nighttime results were comparable to 24-h samples, implying that Hg⁰, RGM and Hg(p) were not released after they deposited nor did the surfaces reach equilibrium with the atmosphere. Based on measured Hg ambient air concentrations and fluxes, dry deposition velocities of RGM and Hg⁰ to DI water and other surfaces were 5.6±5.4 and 0.005-0.68 cm s⁻¹ in this study, respectively. These results suggest surrogate surfaces can be used to measure Hg dry deposition; however, extrapolating the results to natural surface can be challenging.
Seven polymorphic microsatellite loci were isolated and characterized for the snakehead murrel, Channa striata (Channidae), a valuable tropical freshwater fish species. Among 25 specimens collected from Kedah state in Malaysia, the number of alleles per locus ranged from 2 to 7. Observed and expected heterozygosities ranged from 0.120 to 0.880 and 0.117 to 0.698, respectively. A single locus (CS1-C07) was significantly deviated from Hardy-Weinberg equilibrium after Bonferroni correction. These novel markers would be useful for population genetic studies of the C. striata.
Channa (C.) striatus (Malay-Haruan), is a fresh water snakehead fish, consumed as a rejuvenating diet in post-parturition period in local Malay population. The aqueous extract of C. striatus fillet (AECSF) was reported to act through serotonergic receptor system in a previous study. There is no scientific report on neuropharmacological effects of C. striatus. Based on these data, the antidepressant-like effect of C. striatus was evaluated in mice models of depression.