72 research outputs found

    A new species of genus Ephemeroporus Frey, 1982 (Cladocera: Anomopoda: Chydoridae) from Peninsular Malaysia

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    Study of Ephemeroporus Frey, 1982 populations from Peninsular Malaysia revealed a new species. Ephemeroporus malaysiaensis sp. nov. is characterized by the presence of four-five large denticles on anal margin of postabdomen instead of two-three, and five distinctive pigmented spots on each valve. Pigmented spots on the valves were never recorded for any species of family Chydoridae. E. malaysiaensis sp. nov. seems to be another endemic Chydoridae species of South- East Asia. E. malaysiaensis sp. nov. is a rare species, associated with emergent macrophytes in the littoral zone of shallow lake. Most of Ephemeroporus populations from Peninsular Malaysia belong to eurybiotic Paleotropical species Ephemeroporus barroisi (Richard, 1984)

    Trends, prospects and utilizations of sea cucumber fisheries in Malaysia

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    The holothurian or sea cucumber is one of the marine resources, which has been used not only as luxury food for certain countries but also as medicines. Because of its’ higher nutraceutical and pharmaceutical values, sea cucumber has become one of the most important products and it has high price in international market and thus provide an important employment and income source to the coastal communities in many Pacific island countries including Malaysia. They have been harvested for hundreds of years for trade with Asia and were probably one of the worthy exports from the Indo-Pacific islands. Unfortunately, the increase in demand and price, combined with the development of cash economies and growing coastal populations in many islands, has led to widespread overfishing of the resource across much of this region. There is a high level of interest in adoption of aquaculture and stock enhancement techniques to restore production phases,but different capacity levels require implementation of different techniques.Some Pacific island countries and territories have completed successful research trials of hatchery, nursery and release techniques,and now have capacity to scale up this activity but such types of research are still in the initial stage in Malaysia. Factors that work in favor of successful aquaculture include pristine marine environments,long familiarity with sea cucumbers as a commodity,and traditional marine tenure systems that in some places can provide a basis for management of released sea cucumbers.Currently,the exploitation of sea cucumber turns out to be excessive and disrupts its sustainability. Aquaculture is the best way to prevent this severe problem. The success of sea cucumber culture is very depending on broodstock management,seed availability and suitable food for larvae as well as juvenile along with appropriate grow-out culture techniques under controlled rearing protocols

    Continental copepod biodiversity in North-Eastern Borneo, Malaysia

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    To obtain a relevant information on copepod biodiversity/distribution in continental Borneo water bodies in June 2011 about 30 different sites in Malaysian state Sabah were visited and more than 50 alcohol and formalin preserved samples in nine rivers, 10 ponds, and six near-road ditches and canals, rice fields and forest leaf litter environment were collected. In literature 16 copepod species were referred for Borneo and 10 other species for Kalimantan (Indonesean) states. After the Sabah sample analyses, the copepodspecies richnessin the Borneo island increased more than twice. The most abundant with species number genera were ranged as: Mesocyclops (13), Elaphoidella (6), Microcyclops (5), Eucyclops (4), Thermocyclops (4), Halicyclops (3) and Paracyclops (3). Species biodiversity in different sites plotted against type of water body and several environment parameters revealed significant positive correlations for number of species and both for depth and temperature in sampling site (Pearson non-parametric tests 0.6 and 0.5 respectively at p < 0.05). One way Kruscal-Walise dispersal analysis confirmed significant relationship between copepod biodiversity and water transparence/ turbidity (p < 0.05). The highest copepod biodiversity values were found in ponds (23 species), near road ditches (15), rivers with transparent water (12), lowland or swamp areas related with rivers (9). The lowest number of species were found in rivers with turbid water colored in orange with soil-erosive matter where the average number of copepod species (0.2 ± 0.08 species per site) was about 20 times less than in waters without silt particles (3.8 ± 2.8 species per site). This indicates a strong negative effect of soil erosion resulting water land-used activities and deforestation in the watershed on the biodiversity of aquatic organisms in Borneo. In one sub-urban population of Mesocyclops cf. thermocyclopoides, a trans-sexual mutation of female-sized but constructed as male armed with genicu late antennule organisms was found that possibly reflect a negative result of wide artificial hormone-based pesticide usage in this area. Keys for Harpacticoida species for Borneo and for Eucyclops species known for SEAsia, Australia and India are provided. Within practically each copepod genus studied in Borneo there are forms with problems on species identification by existing faunistic keys. This possibly indicates a necessity of new species description from this area in the nearest future

    Effect of hydrogen sulphide on liver somatic index and Fulton's condition factor in Mystus nemurus

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    The growth rate and liver somatic index were significantly (P0.05) in Fulton's condition factor were detected between the exposed fish and the controls. The results revealed that liver somatic index is a more sensitive indicator of hydrogen sulphide toxicity compared to Fulton's condition factor

    Growth and nutritional value of a Tropical Green Alga, Ankistrodesmus convolutus corda, in Agro-industrialeffluents

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    Use of agro-industrial effluents for microalgal culture was investigated using a tropical freshwater green alga, Ankistrodesmus convolutus cultured in various dilutions of latex concentrate effluent (LCRE), standard Malaysian rubber effluent (SMRE) and digested palm oil mill effluent (POMED). Ankistrodesmus convolutus grown in 40%and 60%LCRE, 60%SMRE and 10% POMED showed significantly higher (P < 0.05) specific growth rate in terms of cell number and chlorophyll a than that grown in other effluent media and inorganic fertiliser (N:P:K = 1:1:0.5) as control. Total biomass of this microalgae grown in 60%LCRE, 60%SMRE and 10% POMED was significantly higher (P < 0.05) than that cultured in other effluent media and the control. Ankistrodesmus convolutus cultured in 40% and 60% LCRE, 60% SMRE and 10% POMED showed significantly (P < 0.05) higher amount of crude protein and lipid than that grown in other effluent media and the control. Significantly higher (P < 0.05) amount of most of the essential amino acids (EAAs) except a few were found in A. convolutus cultured in 60% LCRE and 60% SMRE than that grown in other effluent media and control. Ankistrodesmus convolutus cultured in 10% POMED resulted in significantly higher (P < 0.05) amount of all the EAAs except threonine and tyrosine that were grown in other POMED media and control. Ankistrodesmus convolutus grown in 40% and 60% LCRE, contained significantly higher (P < 0.05) amounts of all the C18 and C20 polyunsaturated fatty acids (PDFAs) than that cultured in other SMRE media and control, except eicosadienoic acid (20: 2n-11). A similar trend of PUFAs was recorded in A. convolutus cultured in 60% SMRE except eicosatrienoic acid (20:3n-6) and arachidonic acid (20:4n-6). It was found that A. convolutus contained significantly (P < 0.05) higher amount of PUFAs such as linoleic acid (l8:2n-6), linolenic acid (18:3n-3) and arachidonic acid (20:4n-6) when grown in 10% POMED than that cultured in other POMED media and control. This study showed that A. convolutus grown in 40-60% rubber and 10% POMED has higher nutritional value that that cultured in other effluent media and inogranic fertilizer

    Nutritional values of chironomid larvae grown in palm oil mill effluent and algal culture

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    Chironomid larvae were grown in nine 70-1 tanks containing palm oil mill effluent (POME) and algol culture. The algol culture was obtained by inoculating 200 ml pure culture of Chlorella vulgaris Beijerinck initially in 20-1 tap water containing inorganic fertilizer N:P:K (1:0.2:0.2). Each treatment was done in triplicate. Dissolved oxygen, pH, total nitrogen, total ammonia nitrogen, ortho-phosphate, chemical oxygen demand (COD), total suspended solids and total dissolved solids of the media in each tank were analyzed. Protein, lipid ash, amino acids, fatty acids, total carotene and minerals were determined for POME, chironomid larvae, and algae. The culture was terminated after 25 days and chironomid production was determined. The production of chironomid larvae was significantly (P < 0.01) higher in POME tanks (580 g/20 1 POME) than in algal culture (35 g/20 1 algal culture). Raw palm oil mill effluents contained significantly higher (P < 0.05) arginine, methionine, isoleucine and phenylalanine than algae grown in fertilizer. The essential amino acids of chironomid larvae grown in POME such as histidine, arginine, methionine, isoleucine, phenylalanine and lysine were significantly (P < 0.05) higher than in chironomid larvae grown on algal culture. The polyunsaturated fatty acids (PUFA) with the exception of Υ-linolenic acid (18:3n - 6), were higher in chironomid larvae grown in POME than those grown on algal culture. Twenty seven minerals were detected by electron microscope but 23 minerals were analyzed and quantified in POME, algae, and chironomid larvae grown in POME and algol culture. The quantity of sulfur was significantly higher (P < 0.05) in POME than algae, which probably induced the synthesis of methionine, a S-containing essential amino acid in chironomid larvae cultured in POME. Experiments showed that POME did not only induce high production of chironomid larvae, but also produced high quality live food for the aquaculture industry

    Impacts of gamete concentration, age and contact time on the fertilization success in the tropical species of white sea urchin, Salmaciella dussumieri

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    The globoid sea urchin (Salmaciella dussumieri) occurs abundantly in the Indo-West Pacific from the Island of the West Indian Ocean, East Africa, Magdagascar, Red Sea, South-East Arabia, Ceylon, Bay of Bengal, North Australia, Philippine, China and South Japan and Australia, and also has significant biological, ecological, aquaculture, conservational and medicinal importance. An experiment was carried out to assess the influence of sperm dilution, egg concentration, sperm-egg exposure time, and gamete aging on fertilization success of S. dussumieri in a captive laboratory condition. It has been found that dilution, age and contact time of sperm to egg were successively the most dominant factors effecting the success of fertilization, but concentration of eggs did not significantly so over the range investigated. The sperms retained their competency for more than two hours only in relatively dense sperm concentrations (> 10-4 dilution of `dry' sperm), although they exhibited lower capability and potency with increasing dilutions and age. In the trials of the egg-sperm exposure time, >80% eggs were fertilized within 10 sec of contact time at lower dilutions (10-3-10-2) of concentrated sperm, while some longer times were required to get the higher rates of fertilization. On the contrary, eggs remained in good quality for up to a period of 3 h and no abnormality or any adverse effects in fertilization were observed. The findings obtained from the present experiment reveal that limited longevity of diluted sperm have an important effect on fertilization rate of sea urchin eggs during natural spawning seasons in the field. Hence, the globoid sea urchin (S. dussumieri) is under extensive selective pressures to breed synchronously with the purpose of producing high sperm concentrations and higher sperm-egg interactions to maximize the success of fertilization in the water column

    TaqMan real-time PCR assay for relative quantitation of white spot syndrome virus infection in Penaeus monodon Fabricius exposed to ammonia.

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    White spot disease is caused by a highly virulent pathogen, the white spot syndrome virus (WSSV). The disease is usually triggered by changes in environmental parameters causing severe losses to the shrimp industry. This study was undertaken to quantify the relative WSSV load in shrimp exposed to ammonia, using a TaqMan-based real-time PCR, and their subsequent susceptibility to WSSV. Shrimp were exposed to different levels of total ammonia nitrogen (TAN) (8.1, 3.8 and 1.1 mg L−1) for 10 days and challenged with WSSV by feeding WSSV-positive shrimp. WSSV was detected simultaneously in haemolymph, gills and pereopods at four hours post-infection. The TaqMan real-time PCR assay showed a highly dynamic detection limit that spanned over 6 log10 concentrations of DNA and high reproducibility (standard deviation 0.33–1.42) and small correlation of variability (CV) (1.89–3.85%). Shrimp exposed to ammonia had significantly higher (P < 0.01) WSSV load compared to the positive control, which was not exposed to ammonia. Shrimp exposed to 8.1 mg L−1 of TAN had the highest (P < 0.01) WSSV load in all three organs in comparison with those exposed to 3.8 and 1.1 mg L−1 of TAN. However, haemolymph had significantly higher (P < 0.01) viral load compared to the gills and pereopods. Results showed that shrimp exposed to ammonia levels as low as 1.1 mg L−1 (TAN) had increased susceptibility to WSSV

    Sex ratio, spawning season and the size at maturity of Parapenaeopsis sculptilis (Heller 1862) in the coastal waters of Perak, Peninsular Malaysia

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    Parapenaeopsis sculptilis (Heller, 1862) locally referred to as "udang kulit keras" in Malaysia has profound biological, ecological, aquacultural and conservational significance. The reproductive biology of this important penaeid from the coastal waters of Perak, Peninsular Malaysia, was studied during the period between February 2012 to January 2013. Females outnumbered males with a sex ratio of M: F= 1:3 (P < 0.05). Four maturity stages of female gonads viz., immature, maturing, mature and spent stages were distinguished. The first stage of sexual maturity was attained at a length of 9.3 cm, and female P. sculptilis showed a peak gonadosomatic index during the month of April, August and October, indicating that P. sculptilis potentially breeds throughout the year. The findings of this study would greatly contribute towards the understanding of gonadal maturation, spawning season and breeding biology, which could be important for the effective population management of this prawn species
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