Barramundi heads and bones were hydrolysed by using enzyme Flavourzyme. After the enzymatic hydrolysis, four products were generated which were protein hydrolysate powder, fish oil, insoluble protein powder and fish bone powder. The weight and nutritional composition of these products were determined. The study results showed that the protein hydrolysate powder had high content of proteins (81.5%), low content of lipids (1.80%), and ash content of 7.40%. The insoluble protein powder had protein content of 67.3%, lipid content of 16.5% and ash content of 6.90%. The protein hydrolysate powder and insoluble protein powder had a high nutritional value with essential amino acids. The fish oil from barramundi heads and bones was rich in omega-3 fatty acids (26.2%), especially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Fatty acids with high contents in fish oil were palmitic acid, oleic acid, arachidonic acid, DHA and EPA. The products were generated from hydrolysis of barramundi heads and bones can be applied in food for human or feed for aquaculture.

The study was conducted to determine the lipid requirement and the effects on the growth rate and fish carcass composition by the ratio of fish oil and soybean oil in mudskipper (Pseudapocryptes elongatus) diet. The study had two experiments. In the first one, mudskipper fingerlings (mean initial weight: 6.86g) were fed to triplicate groups of five iso-nitrogenous (35%) and iso-energy (17.2 kJ/g) diets, which contained different lipid levels (1.5%, 4.5%, 7.5%, 10.5% and 13.5%) for eight weeks. The results showed that survival rates in all treatments were not affected by different lipid levels. The highest specific growth rate (SGR) was recorded in fish fed 7.5% (1.41%/day) lipid diet, which was not significantly different (p>0.05) from 10.5% lipid diet but others. Results also showed that lipid efficiency ratio (LER) and lipid retention (LR) decreased with the increase of lipid levels in experimental diets. The quadratic regression curve of daily weight gain indicated that the optimal dietary lipid level for mudskipper was 9.05%. In the second experiment, fish fingerlings (mean initial weigh: 6.58g) were fed to triplicate groups of five isonitrogenus (35%) and isoenergy (17.2 KJ/g) and lipid (7.5%) diets containing five different ratios of fish oil and soybean oil (100%:0%, 75%:25%, 50%:50%, 25%:75% and 0%:100%). After eight experimental weeks, results showed that survival rates in all treatments were not affected by different tested diets. There was no significant difference (p>0.05) in SGR of treatments group containing 0%, 25% and 50% soybean oil (1.37, 1.39 and 1.41%/day), which were significantly different (p

Study on determination of dietary protein requirement of goby fingerling (Pseudapocryptes elongatus, Cuvier 1816) at two different energy levels was conducted. This can provide the basis information on manufacture of industrial feed for goby. Experiment was set up consisting of 8 feeding treatments with 4 levels of dietary protein (30%, 35%, 40% and 45%) and combined with 2 levels of energy (20 kJ/g and 18 kJ/g). Each treatment had 3 replications and complete random design. Experimental fish with average weight of 3.55 g were stocked in the 70-L tank with density of 14 fish/tank at salinity of 10 ppt. After 45 days of culture, survival rate of experimental fish ranged from 85.7% and 92.9%, and was not affected by the experimental feeds containing different protein and energy levels. The lowest FCR (1.00) in the treatment of 35% protein - 20KJ/g and 45% - 18KJ/g. The most effective protein efficiency (PER) was in treatments 30-35% protein feed - 20 kJ/g and 30% protein - 18 kJ/g. The crude protein content in the fish carcass (from 61.0 to 64.1%) increased with the increasing of dietary protein content, and it was in conversed for lipid content in fish carcass. The moisture and crude ash content in fish carcass didn?t show the interaction with dietary protein and energy content. The requirement of protein and energy levels for the goby 3-4g growth was 35.4% - 20 kJ/g.

This study aimed to evaluate growth and reproductive parameters of freshwater prawn originated from 4 provinces Ca Mau, Can Tho, Long An, and Dong Nai in order to provide basic information for selecting broodstock source for artificial reproduction. Thirty pairs (male and female) from each prawn source were selected and cultured at DongThapAquacultureSeedCenter. Each pair was stocked separately in a hapa (1x1x1.5 m) and all hapas were placed in a pond of 3000 m2. After three months of culture, results showed that pond water quality were suitable for maturation of freshwater prawn. Daily weight gain (DWG) of Dong Nai prawn was highest (0.25 g/day for males and 0.22 g/day for females), in which female?s DWG was significantly different from that of Can Tho and Ca Mau prawn. Survival rates of four prawn sources were above 86%. Reproductive parameters including maturation time, spawning rate, hatching rate, egg size, and fecundity of Dong Nai prawn were higher than those of the other prawn sources. The results indicated that Dong Nai prawn is the best source for domestication of freshwater prawn for reproduction.

The tank goby (Glossogobius giuris) is one of gobiid fishes (Gobiidae) distributing in Mekong Delta, especially in Soc Trang, and is commercial fish in this area. The study on length-weight relationship and growth parameter (e.g., slope value or b) of this species lasted for six month, from September 2013 to February 2014, in Cu Lao Dung, Soc Trang. A total 325 individuals were collected using gill-net at Con Tron river. After sexing based on external morphology of genital papilla, fish was measured total length (cm) and weighed (g). The results indicated that sex ratio of this species was nearly 1:1. This goby showed isometric growth because b value was nearly three. The regression value of male and female fish was not significant different, while this value was higher in wet than dry season.

The research aimed at determination of alone and combined effect of lactic acid and hot water treatment on catfish filet (Pangasius hypophthalamus). Hot water treatment at 75oC during 15 s combined with acetic acid treatment at concentrations 2% during 120 s showed the most efficacy for their decontamination effect on E. coli and bacterial total of contaminated catfish filet. Especially, combined treatment of hot water and acid acetic were synergistic. Right after treatment, the reduction of E. coli was 3.05 log cfu/g in comparison with the control. Especially, after 7 days storage at 4oC, the reduction of E. coli was 3.65 log cfu/g compared with the control. Similarly, right after the combined treatment, the reduction of bacterial total was 4.55 log cfu/g and after 7 days storage at 4oC, the reduction was 5.65 log cfu/g in comparison with the control.  This study suggested that acetic acid and hot water treatment can be used in combination to reduce E. coli and bacterial total in order to assure the safety of catfish filet, especially for exportation.

The guppy progenies from separately kept gravid females had been masculinized by dietary adding spironolactone (SP) treatment of the last 5 ? 14 days prior to parturition or by immersion of newborn alevins in the same steroid water. The contents of SP were 500 and 700 ppm in composed feed consisted of 1. fine fish or shrimp meal, 2. rice bran or wheat flour and 3. chicken egg yolk in following proportion: 5g : 15 g: 1 egg respectively. The SP concentrations in immersion treatments during two hours were 8 and 10 ppm. The sexing test was performed at 90th day of age. The fish with gonopodium and other male sex secondary characteristics were considered to be the males, meanwhile the other ones without such above mentioned properties were counted as the females. The results showed that the survival rates were 81.58 ± 3.60 and 88.78 ± 2.68% the differences from the control and those treated with methytestosterone (in dietary experiments at contents of 325 and 350 ppm and in immersion treatments at concentrations of 4 and 5 ppm) were not statisticaly significant. The masculinization rates ([(male proportion in the study) ? (male proportion in control)] x (female proportion in control)-1) were 64.25 ữ 71.00 %. The masculinizing efficiencies (equal survival rate multiplified by male ratio) were 66.55 ữ 73.27 %. The way to identify the neomales (the males with XX sex chromosome set) was discussed.

The morphological characteristic, anatomical venom duct, structure of radular teeth, a.a sequence of toxin and three-dimensional structure of Conus tessulatus?s (vermivorous feeding mode) toxin protein in Nha Trang Bay, Khanh Hoa Province were studied. The results showed that venom buld of C. tessulatus has a sickle milky white shape, venom duct has pale yellow, radular sac has reddish, radular teeth of C. tessulatus are soft structure and small size, have serration, one bard. Results of ?-conotoxin protein sequencing were used to construct deduced a.a sequence of the toxin protein from C. tessulatus. From this a.a sequence, framework of CC-C-C specific to ?-conotoxin be determined and three dimensional of C. tessulatus? s toxin protein structure be modeled to understand the functions of ?-conotoxin from C. tessulatus based on homological proteins known in the database. This study provides a protein database for applications in the production of drugs used in the treatment for neurological diseases.

This study was conducted at Faculty of Applied Biology - Tay Do University from March to April on 2013.  The study aims to determine the effects of stocking density and water salinity on the development and survival of Litopenaeus vannamei under biofloc culture conditions. The experiment was conducted with 36 60-L plastic tanks, containing 50L of water. The triplicate experiment was randomly designed with 2 factors of 3 density treatments (100, 300 and 500 shrimp/m3) and 4 salinity treatments (5?, 10?, 15?, 20?). Results shown that when the stocking density increased, parameters such as suspended solids TSS, TAN, NO2-, FVI and  productivity of shrimp increases, but pH, the size of biofloc and survival decreased. When salinity increased, TSS increased and the diversity of microorganisms decreased.  The experimental results showed that culturing white leg shrimp applying biofloc technology at 15? salinity and stocking density of 100-300 shrimp/m3 gave the best results in survival rates (79,1-100%).

Study on pathogens in Giant mottled eel (Anguilla marmorata) rearing in tanks aimed to investigate the pathogen diversification which support to better management of marble diseases. Disease and normal marble ell (4-5 fish/tank) and rearing water were collected in all of 12 experimental tanks. Water samples were collected for total viable bacteria. Disease ells were isolated for pathogenic bacteria, pathogen identification and antimicrobial susceptibility testing as well as parasites identification. The total viable bacteria in rearing water accounted for 0.024-0.391x106 CFU/mL. Twenty phenotype bacteria belonged toAeromonas spp., which fully resistant to ampicillin, amoxycillin/clavulanic acid, cephalexin and flumequine. They were highly susceptible toflorfenicol (75%), ciprofloxacin (70%), cefotaxime (70%), tetracycline (65%). Two identified parasites included Trichodina and Dactylogyrus.

The objective of this study was to determine the diversity of zooplankton on HauRiverat Hau Giang and Soc Trang province to serve as database for development of a biomonitoring program in the HauRiver. The study was conducted in the period of December, 2013 to March, 2014. Zooplankton samples were collected at 9 sites including 4 sites on the main stream and 5 sites on its tributaries. The results showed that a total of 97 zooplankton species was recorded. Among them, Rotifera was the most abundant group with 45 species (47%), followed by Cladocera with 16 species (17%) and the others ranging from 8-14 species (8-14%). Densities of zooplankton on the main stream and its tributaries was from 8,071-36,289 ind.m-3 and 4,687-33,067 ind.m-3, respectively. Sorencen?s similarly index was recorded quite high and varied from 0.63 to 0.71. The Shannon-Wiener diversity index (H?) was varying from 2.03 to 2.73, the results indicated that pollution level of the study area on theHauRiver was slight to average.

In order to verify ?paradoxical masculinization in fish? (according to words of Howell et al., 1994) by spironolactone (SP), tilapias at 7 days post haching (DPH) were exposed in SP waters at concentrations of 2.5 ; 5.0 ; 12.5 ppm during 2 hours in polyethylene bags filled up with oxygen. The results showed that survival rates at 28 DHP were not statisticaly significant among treatments with values of 96.7, 95,7, 94.7, 96.3and 97.5% % in control treatment and MT2.5, SP2.5, SP5.0, SP12.5, respectively. Male proportion and masculinizing efficiencies [(survival rate) x (male proportion)] were 63.30 ± 3.30 ữ 82.20 ± 1.90 % and 59.60 ± 4.10 ữ 80.30 ± 3.10 % respectively. Thus, SP, an aldosterone antagonist, a human hypertension drug with antiandrogenic or feminizing side effects (including for mammalian models) has been proven to have the clear masculinizing effect in tilapia.

The study on reproductive biology of dwarf snakehead (Channa gachua) was studied on 117 fish samples, which were collected from February to October, 2013. The results showed that the development of gonad undergoing 6 phases with different histological structures. The fecundity of C. gachua is 1,709.52 ± 886.01 eggs/fish. The relationship between absolute fecundity with total weight and total length is quite hight and in proportion, the value of the correlation coefficient R2 is respectively 0.8771 and 0.8484. The Fulton ranged from 1.65 to1.96%; Clark ranged 1.49-1.87% and conditional factor (CF) ranged 0.009-0.012. The value of  Fulton and Clark was highest from February to May, and lowest in August (1.65% and 1.49%). Conditional factor (CF) was highest from February to September, and lowest October (0.009). The high GSI (Gonado somatic index) was from June to October (2.22-2.61%) and highest value on July (2.61%) and March (0.53%). Thus, over a period of the study, the sexual maturity of Channa gachua in the wild is from June to October.

This study aims to find the suitable salinity for growth of freshwater shark catfish (Wallago attu Bloch & Schneider, 1801). Fingerlings of Wallago attu at 30 days after hatching out (5.35 ± 0.93 g; 11.03 ± 0.25 cm) was determined the tolerance of salinity by increasing 1? every 30 minutes. The fish were acclimated to different salinities (0?, 3?, 6?, 9?, 12? and 15?) to evaluate the plasma osmotic and ionic regulation of the fish during 14 days of the experiment. Another experiment on the growth and survival of fish exposed to different salinities (0?, 3?, 6?, 9?, 12?) was conducted for 6 weeks. The result showed that salinity tolerance of Wallago attu fingerlings was 18?. The plasma osmolality levels and ion Na+, K+ concentrations of fish were relatively stable in the water environment of 0 ? 9?. At salinity level of 9?, the fish plasma osmolality (286.5 ± 21.4 mOsm/kg) was equivalent to environmental osmolality (272.3 mOsm/kg). The highest growth of fish was in the treatment 0?, but it was not significantly different with the treatment 3? (p>0.05). The survival rate was significantly highest in the treatment 3? and lowest in the treatment 9? (p

Analysing on technical and financial aspects of intensive shrimp farming on impacted climate change areas were needed. This study was conducted from January to March 2012 by interviews 93 farmers in Soc Trang, Bac Lieu and Ca Mau. The result showed that: Total areas farming was not significant differeces in three provinces. However, average culture area was different, lowest in Bac Lieu (0,30 ha/pond) and biggest in Soc Trang (0,41 ha/pond). Pond water depth in Soc Trang was 1,30 m smaller than in Bac Lieu (1,40 m) and Ca Mau (1,54 m). Stocking density in Ca Mau (24,87 ind/m2) higher than in Soc Trang (23,33 ind/m2) and in Bac Lieu (17,68 ind/m2). Food consumption rate (FCR) in Ca Mau (1,45) was not significantly different with Soc Trang (1,51) but significant with in Bac Lieu (1,62) (p < 0,05). Yield in Soc Trang (2,43 tons/ha/crop) was lower than significant Bac Lieu (4,12 tons/ha/crop) and Ca Mau (4,87 tons/ha/crop). Total production cost and profit in Soc Trang (206,01 mil./ha/crop and 134,98 mil./ha/crop) was lower than in Bac Lieu (334,27 mil./ha/crop and 289,06 mil./ha/crop), Ca Mau  (340,58  mil./ha/crop and 392,89 mil./ha/crop). Some of the many factors impacted to yield and profit were analysed and discussed in this study.

This study was conducted from April 2013 to March 2014 to identify species composition and population dynamics of the Sailfin Catfish in Can Tho City. The population parameters were estimated by using FiSAT II software to analysis the leght-frequency data. The results showed that two species namely Pterygoplichthys disjunctivus and Pterygoplichthys pardalis were identified. The population parameters of P. disjunctivus were also estimated from length-frequency data such as L? = 45 (cm), K = 0.89/ year, t0 = 0.20 year; total mortality Z = 1.86/year, nature mortality M = 1.49/year, fishing mortality F = 0.37/year. The resuts also indicated that there are two recruitment peaks with a distance between two peaks about 5 months. The results also showed that high nature mortality as compared with low fishing mortality of P. disjunctivus population.

Assessment of striped catfish fillet quality at different rearing area was done by sampling harvest fish (0.8-1kg, 10 fish/pond) at nine ponds located in Can Tho province, Vietnam. Fish ponds were classified into three groups such as closed to Mekong river (group 1), closed to Mekong tributaries (group 2) and in inland area (internal channel water supply, group 3). Collected fish was killed, filleted and evaluated fillet color as well as calculated for fillet ratio. Fillet was then stored in ice and transfer to laboratory for chemical composition analysis as moisture, protein, lipid, ash and amino acid content. Results showed that significant lowest organic matter content of sediment was found in group I. The highest percentage of ?white? fillet (93.3%) was found in group II and it was significant different to group III (53.3%). The fillet ratio was not significant difference between groups, varied 2.14 to 2.17. Results from linear regression showed that there was no correlation between organic matter content of sediment and fillet color (R2=0.074; p=0.479). Chemical compositions such as protein, lipid, moisture and ash between groups were not significant difference.

The Mekong Delta in Vietnam is known as a very rich area supplied with rich alluvial deposits from the Mekong flows, known in high biodiversity of fishes. Our study focuses on identification of freshwater fish species in this area. Based on morphological characteristics, this study found 22 species belonging to 17 genus, 15 families, 8 orders. Sequences of 16S rRNA in mitochondrial DNA were used to test the reliability of classification as well as examine phylogenetic relationships among species. The phylogram showed the monophyly of studied fish genera, however, genetic difference of 16S rRNA sequences has been found between current species and species reported in genbank. These data can be used as data sources for studies on biodiversity and management of fisheries resources in the Mekong Delta in Vietnam.

Mangro snail (Nerita balteata) is a potential aquaculture species but having a bottle neck on commercial seed production. A research on embryo development was conducted to determine better condition for incubating eggs and rearing larvae. Besides recording the development of eggs, there were 2 experiments designed with 3 treatments and 6 replicates each. The results showed that, mangrovesnail has long-time embryo development. It take 25-40 days for eggs to reach the trochophora stage, 50-70 days to veliger stage, 70-90 days to spat stage and about 100-120 days to become baby-snail. Optimal salinity for incubating eggs was 25pptthat resulted in a hatching rate of 80.6 ± 2.30% and lowest rate of deformation (3.6 ± 0.25%). Optimal incubating density was 5 egg-sacs per liter that resulted in a hatching rate of75.1 ± 0.53% and lowest rate of deformation (3.4 ± 0.25%).

The study aims to determine the differences in farming practice and water quality between intensive tiger shrimp (3 ponds) and white-leg shrimp farms (3 ponds). Record keeping of shrimp pondswere selected to record information related to farming practice. Water, sidement and harvested shrimp and feed samples in the tiger and white-leg shrimp ponds were collected to analyze the water/sediment quality and total nitrogen and phosphorus in the harvested shrimp and feeds. Results of survey showed that the stocking density and yield in tiger shrimp farms (26.47 shrimp/m2, 6.63 ton/ha/crop) were significantly lowerthan those in white-leg shrimp farms (80.67 shrimp/m2, 12.90 ton/ha/crop; p0,05). Feed conversion ratio in white-leg shrimp farms was significantly lower than that intiger shrimp farms.Generally, temperature, salinity, total organic matter in the white leg shrimp ponds were higher than those of the tiger shrimp ponds. Dissolved oxygen, nitrite, nitrate, total nitrogen and total phosphorus in the white-leg shrimp ponds were also higher than those of tiger shrimp ponds. The percentage of nitrogen assimilated from feed to white-leg shrimp bodies (20.6±1.79%) was significantly higher than that in tiger shrimp (14.72±1.26%) (p0.05).

Study on nutritional characteristic of Oxyeleotris urophthalmus that distributed along the Hau river was conducted from August 2012 to July 2013. Results showed that O. urophthalmus is upper, large and stretching mouth, smooth and sharp teeth, short esophagus, stomach and intestines short, thick-walled and multiple lines than on the inside. O. urophthalmus was omnivorous and mainly eat animals (RLG

The results showed that the broodstock of orange-fin loach matured when they used tiny shrimp, trash fish or to combine between trash fish and pellets for feeding, especially tiny shrimp treatment. The maturation rate of orange-fin loach was 38.9 % in April and 67.8 % in May. The fecundities of fish were 3,773 ± 426 egg/fish. The GSI parameter was relatively low; the highest value was 3.26 ± 1.40. In reproduction, orange-fin loach was injected by only hypophysis (3; 5 and 7 mg hypophysis/kg female) or HCG (1,500; 2,000 and 2,500 UI/kg female so that they have not yet ovulated. On the other hand, fish was spawned by LHRH-a + Dom (150 àg/kg + 5 mg Dom) so that ovulation rate was 100 %. The time effects were 6 hours 15 munites, the hatching rate fluctuated from 73 to 83 %. The hormone combination in using was carried out between 2 mg hypophysis and 100 ?g LHRH-a + 5 mg DOM/kg female so that orange-fin loach ovulated eggs. The spawning time were about 8 ± 0.8 hours, ovulation, fertilization and hatching rates were 80 %, 64.3 ± 22.8 % and 5.9 ± 12.7 %, respectively. At temperature from 26 to 27 0C, eggs of orange-fin loach will hatch after 17 hours 50 munites. The artificial propagation of orange-fin loach is to provide for farmers, using of LHRH-a + Dom (150 àg + 5 mg Dom/kg female) could be introduced for fish spawning at high efficiency.

A study on the reproductive biology of Bigeye Scad (Selar crumenophthamus) distributed in the Soc Trang-Bac Lieu coastal areas" was conducted from January to December, 2013. Results of the study showed that the condition factors (CF) of fish ranged from 0.00979 to 0.01082 with the highest CF was observed in May and November and those of lowest in February and March and August. Highest values of the gonad somatic index (GSI) of fish was observed in May and November while the lowest one in February and March. The highest percentages of fish those possessing stage IV gonads found from May and November. Based on CF and GSI, spawning season of Bigeye Scad may occur from May and November. The absolute fecundity of Bigeye Scad ranged from 14,571 to 128,278 eggs, the relative fecundity was 310 eggs/g of female fish. The relationship between body weight and absolute fecundity of fish very closely follow the regression equation: F = 33.44 W1.4378 (R2 = 0.9844) with body weight ranged from 69.01 to 296.91 g / individual.

The purpose of this study was to assess the antibiotic resistance in 60 Edwardsiella ictaluri and Aeromonas hydrophila isolates. All bacteria were isolated from diseased striped catfish in the Mekong Delta during January 1013 to March 2014. The isolates were screened against 15 antibiotics by disk diffusion method. The results showed that E. ictaluri isolates were still sensitive to ampicillin and amoxicillin; highly resistant to tetracyclin, enrofloxacin, streptomycin, fenicol group antibiotics; and  completely resistant to trimethoprim/sulfamethoxazole. On the contrary, A. hydrophila isolates were sensitive to doxycycline, cefotaxime and ciprofloxacin; highly resistant to tetracycline, florfenicol and all A. hydrophila isolates were completely resistant to trimethoprim/ sulfamethoxazole, cefalexin, penicillin group antibiotics. In particular, all 60 isolates in this study displayed multi-drug resistance. Besides, tetracyclin and florfenicol antibiotics were also used to determine minimal inhibitory concentration (MIC) by using dilution method.

In the globalization stage, the requirements for fish safety and quality products and traceabilty are more highly and strictly; hence, it creates more dificulties for Pangasius producers and processors/exporters. To access market and develop sustainability of Pangasius industry in Mekong River Delta (MRD), it is necessary to increase the high quality Pangasius products in order to creeate a major source of foreign currency, employment, and higher income for farmers; the solutions for sustainable development of Pangasius industry are more concerned of Vietnamese governments. Three provinces in the Mekong River Delta (MRD), namely: Can Tho, An Giang, and Dong Thap were conducted for this research. Survey results indicated that the gaps in Pangasius production and export; then, the solutions for re-organization this sector are drawn to develop sustainability Pangasius Vietnamin the World integration.

This study was carried out in order to determine the TAN absorption ability of yucca at different yucca concentrations including 0 ppm, 0.25 ppm, 0.5 ppm and 1 ppm, in freshwater. The study was designed with 2 experiments. The first experiment was conducted during 12 hours in 60 liter tanks without fish. The second experiment was implemented in 500 liter tanks for 60 days. One hundred tilapia (Oreochromis niloticus) of 3-5 g in size were stocked in each tank. The tanks were treated with yucca every 14 days. TAN concentration was measured at before and after 6, 9, 12 hours of treatment. All experiments were set up following completely randomized design (CRD) with three replications. The results showed that yucca absorbed TAN efficiently in freshwater, each gram of yucca absorbed 0.415, 0.545 and 0.527 g of TAN after 6, 9 and 12 hours of treatment, respectively.

Protein plays an important role to the lives of humans and animals. The red meat tuna contains lagre protein which has high nutritive value. Besides the tuna dark muscle contains the large histamin, pigments, lipid. that production technologies surimi or fish ball can?t remove. This paper reseached about somes factors which effect to extraction productivity of protein from red meat tuna by means of pH adjustment. This paper showed that extracting by pH 12,13; after 1h and 30oC, with solution: material ration 1: 10, protein extracting productivity is maximum. However, pH = 13, after 1h and 30oC, with solution: material ratio 1: 10 is selected to extract protein from red meat tuna.

This study aimed to compare growth and survival rates of hybrids between two strains of climbing perch parents including wild strain sampled in Ca Mau (CM) and square ? head (DV) strain collected in Hau Giang. Four fish treatments including 2 reciprocal hybrids and 2 parent strains were reared in two completely randomized design experiments. First, fish were reared from fry to fingerling stage for 14 days in 12 tanks (200 L) with the density of 425 individuals/tank. They were fed live food (Rotifera, moina, and red worm) combined with commercial pellet (10 days after stocking). In the second experiment (15 to 55 days old), fish were stocked 140 individuals/200-L tank with 4 replicates, and fed commercial pellet  containing 42% protein. After 14 days, CM and CMxDV hybrid had insinificantly higher length (19.5 and 19.3 mm , respectively) and higher survival rates (64.7 and 81.9%, respectively) compared to DV and DVxCM hybrid (length:17.2 and 17.9 mm; survival:52.1 and 52.9%, respectively). After 55 days, growth and survival rates of 2 reciprocal hybrids were not significantly different from  2 parent strains (p>0.05). Weight and lenght of  4 treatments of fish averaged 1.51 ? 1.94 g and 40.2 ? 45.4 mm, respectively. Survival rates of fish ranged 40.8 ? 61.9%. Therefore, growth and survival of two hybrids from fry to juvenile stages were similar to those of two parent strains.

In Vietnam, the giant freshwater prawn (Macrobrachium rosenbergii) is reared mainly in the Mekong Delta, especially in ponds, garden canals and paddy fields including low pH areas; and is potential species of the freshwater aquaculture. The effects of pH on the giant freshwater prawn was carried out to determine the upper and lower pH threshold of this species. In addition, hemolymphosmolality and glucose concentration; molting cycle, growth and survival rate of the prawns were also investigated at different pH water levels. The results of the studies showed that the upper and lower pH threshold of this species in three hours of exposure were 3 and 11; the hemolymph osmolality fluctuated from 370 mOsm/kg to 430 mOsm/kg; while the glucose concentrations peaked at pH=5.5 (12.1-31.6 mg/mL) and pH=6.0 (8.43-29.1 mg/mL). After 70 days of rearing, the growth of prawns was fastest at pH=8.0 (15.2±0.05g), the daily weight gain was 0.08±0.00 mg/day; the molting cycle at pH=7.0 and 8.0 was 12 days; and the survival rate was 100% at pH=8.0. The results of this experiment indicated that the giant frshwater prawn grows well in the water environment with a range of pH from 7.0 to 9.0; if the pH out of this range the physiology and growth are affected.

The experiment was carried out in a 260-litter recirculation system. Snakehead fish (6.80±0.02 g/fish) was stocked at different densities of 10, 20, 30, 40, 50 fish/100L. Fish was fed with 45% protein pellet (Grobest) for the first 3 weeks and then 40% protein pellet (Master) in the following weeks. Changes of water parameters, growth and survival of fish were observed during 110 days of experimental period. Results in the change of water quality showed that pH in all treatments ranged from 6.4 ? 7.35 and tended to reduce while TAN, NO3-, NO2-increase when fish grew up. At the end of experiment, the highest) TAN concentration of 5.74 and 5.72 mg/L were observed in treatments of 40 and 50 fish/100L at p

Water quality in rotation rice-shrimp (Penaeus monodon) farming system in Tan Phu Dong, Tien Giang province was evaluated from Dec, 2012 to Oct, 2013 at Phu Tan commune. The water sampling was carried out in three farms and three sites of inlet. Farms? area varied from 0.4 to 3 ha with 3 sampling times in rice crop and 5 sampling times in shrimp crop. Results found that COD, TP in water, TN and TP in sediment in the inlet were higher limit standard. In general, water quality in the inlets and the farms were not much difference betwen the dry and the rainy season in the region.

This study was conducted to evaluate the effects of different stocking densities on the growth and survival rate of black apple snail, Pila polita. There were 4 stocking densities and 3 replicates were run per each treatment as follow: 300, 600, 900, 1200 ind/m2. Snails with initial weight (0.03 g) and shell height (4.25 mm) were reared in the composite tanks and fed with pellet (18% protein). After 35 days, the survival rate at 300 ind./m2 (97.1%) was higher than at 600 ind./m2 (90.1%), 900 ind./m2 (85.4%) and 1200 ind/m2 (83.4%) and there was significant difference (p

The halophytic green micro algae Dunaliella salina has an important economic value because it contains ?-carotene, glycerol and other accessory pigments, which have pharmaceutical application. In this study, Dunaliella salina NT6 was isolated from 30 water samples collected in salt fields along the coast of Khanh Hoa province and assessed the role of cultural medium, temperature, light and sanity concentration to the growth and ?-carotene production of this strain. As the result, after 7 days enrichment on J/l 8,8% Dunaliella salina NT6 strain were isolated by transplanting on agar plates, diluting samples and morphological observation on optical microscope. The J/l medium comforted the growth of the algae when compared with Walne and F/2 medium.Furthermore, D.salina NT6 grew the best in NaCl 2M, 14.000lux and 28oC. Under high salt concentration (2M NaCl) and strong light energy constantly 14.000lux, ?-carotene concentration was accumulated up to 2.94 pg/cell in this strain. These findings contribute into studying on diversity of Dunaliella species in Khanh Hoa and further their applications in functional drugs and fish aquaculture.

Intensive shrimp farming, compounded by climate change, has complicated the outbreak pattern and control of shrimp diseases, whose pathogen is mainly due to virus and bacteria groups belonging to Vibrio genus. In consequence, the infected shrimp had mass mortality within few days. Therefore, a rapid and highly specific diagnostic method is needed for early and accurate detection of the pathogen. A good candidate for such a method is the multiplex PCR procedure, which allows simultaneous detection of luminous bacteria (Vibrio harveyi) and white spot syndrome virus (WSSV) in shrimp farming. The procedure is based on the one-step PCR protocol, in which: primers F6, R4 designed from vhh gene, a specific gene of Vibrio harveyi (Sun et al., 2009) and primers P1, P2, P3, P4 of WSSV (Kimura et al., 1996). Experiment results showed that the total amplification time is approximately 3 hours, demonstrating that the mPCR procedure can be applied to simultaneously detect WSSV and luminous bacteria in infected shrimp in a time-effective manner.

This study was conducted to evaluate the development of bio-flocs at different salinities in laboratory conditions for 21 days. Four salinity treatments consisted of 35, 60, 80 and 100 ppt were set up in a 10-L glass bottles with continuous aeration. Tapioca powder combined with chicken manure were used as a carbon source (C:N of 10:1) to stimulate formation of bio-floc. Results showed that concentrations of nitrogen compounds (NH4, NO2, NO3 and TN) increased after 7 days of experiment, and then tended to gradually decline until termination of experiment at day 21. The contents of TSS and VSS increased with increasing in salinity and those in all the treatments had enhancement with time. Similarly, the bio-floc volume and densities of total bacteria increased during experimental period, total bacteria in the 35 and 60 ppt treatments were 5 to 10 times higher than two other treatments. The proximate composition of bio-floc was not different among salinity treatments and reached the highest values at day 14. It is suggested from this study that bio-floc can be developed in high salinity for aquaculture, especially high saline species.

Threadfin fish (Polynemus paradiseus) is a wild fish species which belongs to family Polynemidae, order Perciformes. That is a commercial valuable and high potential candidate for aquaculture. Therefore, the study nutritional characteristic of threadfin fish (P. paradiseus) inHau River,Vietnamwas carried out from July 2012 to June 2013. Specimens were monthly collected from fishermen and local market at four locations onHauRiverincluding Thot Not and Ninh Kieu (Can Tho city), Dai Ngai and Tran De (Soc Trang province). The samples were kept in cold condition and transported to the lab ofCollegeofAquacultureand Fisheries,CanthoUniversityfor analysis. The results showed that P. paradiseus is zoophagous with RLG (Relative length of gut) = 0,56 ± 0,11. Their fry (Wt = 0.014 - 1.431g) mainly fed small size aquatic animals including zooplankton (100%), mollusks (92.81%), crustaceans (2.69%), and worms (0.9%). The component of larger than sized fish (Wt = 2 g - ?20 g) were crustaceans (54.89%), zooplankton (40.43%), worms (2.34%), and fish (0.43%). Fed spectrums of the adult fish (Wt > 20 ? 175.1 g) also consist of crustaceans, zooplanktons, worms, and fish; in which crustaceans had the highest rate (> 80%).

The effects of using some food additives includes gelatin: corn flour, gluten: corn flour, gelatin: gluten to the textural characteristic of shrimp paste as well as types and rate of natural extracts from plants such as pandan’s leaf, citronella’s leaf and garlic; the rate of Nobashi shrimp:batter coating mixture on quality of batter coating Nobashi shrimp product were studied. The results showed that shrimp paste obtained good texture in cutting force and gel strength in addition of 1.2% gelatin: 6% corn flour. Adding extract from pandan’s leaf with the rate of 20% to batter coating mixture and soaking with the rate 1:1.5 of Nobashishrimp: batter coating mixture which produces high sensory and suitable batter coating thickness of batter coating Nobashi shrimp product.

The study was carried out to evaluate the use of gut weed (Enteromorpha sp.) and blanket weed (Cladophoraceae) as protein source to substitute soybean meal protein in practical diets for postlarval white leg shrimp (Litopenaeus vannamei). A diet without seaweed meal served as a control was compared with six experimental diets in which soybean meal protein was replaced by increasing levels of gut weed or blanket weed protein (20%, 40% and 60%) in practical diets (35% protein and 7% lipid). The experiment was set up in 100 L plastic tanks filled with water at a salinity of 10 ppt. Thirty shrimp postlarvae with mean initial weight of 0.012g were stocked in each tank and fed the tested diets for 45 days. The results showed that survival of the shrimp was not influenced by the feeding treatments, ranging from 81.1 to 87.8%. Growth rates of the shrimp fed 20% and 40% replacement levels of gut weed or blanket weed protein in the diets were better or similar to those fed the control diet. Shrimp fed the diet containing 60% substitution level had poorer growth. However, significant differences were not observed between the control and the other feeding treatments (p>0.05). Additionally, the feed conversion ratio and protein efficiency ratio exhibited the similar trend as observed for growth performance. Data indicated that gut weed and blanket weed could be replaced up to 40% of soybean meal protein in practical diets for white leg shrimp postlarvae.

The effects of temperature on physiological parameters and growth rate of catfish (Pangasianodon hypophthalmus) (25-27 g) was performed. The study included two experiments in which the fish were designed in different temperatures as 24°C, 30°C, 32°C, 34°C, 36°C, and control with 3 times replication. The first experiments was carried out to investigate the effects of temperatures on the amount of cortisol, glucose and IGF-I in blood samples of the fish observed. Particularly, fish were designed in different 300-L tanks during 14 days. After 0, 1, 4, 7, 14 days, respectively, 0,3 ? 0,5 mL blood of three fish per each experiment was sampled. The second part of study was conducted to investigate effects of the different temperatures on fish growth after 56 days of culturing in 300L tanks. The survival rate, growth rate, and feed conversion ratio of the experimented fish were observed. The results showed that at 24°C and 36°C, fish were stressful and then their growth was considerably affected. For temperatures from 30°C to 34°C, the amount of cortisol, glucose, and IGF-I in experimented fish increased and higher than those of control group on the first days of experiments; however, after 14 days, the amount of those parameters decreased gradually to normal levels. The growth rate of fish observed was highest at 34°C (with p0,05). Therefore, it can be concluded that temperature directly affected on fish health and growth. The fish growth rate was low at the low temperatures, while it was high when the temperatures increased.

The study on male selection of giant freshwater prawn (Macrobrachium rosenbergii) culture in rotation rice - prawn rotational system was conducted in Thoai Son district, An Giang province. Postlarvae at 15 days were stocked in the connected pond in the rice fields at density of 50 PL/m2. After 2.5 months, only male prawns were selected and restocked in the rice fields (treatment I). In the control treatment (treatment II), mixed sex of prawns were culture in the rice fields. After 6 months, the final mean weight of prawns in the treatment II (54.4 g/prawn) was smaller than that in the treatment I (69.4 g/prawn). The survival rate of both two treatments was not significantly different (p>0.05). The yield profit and benefit cost ratio in the male selection treatment were not significantly higher than those of the treatment II (p>0.05).

Mangrove snail (Nerita balteata) is a marine species with full of nutrition and high commercial value, therefore, they are over exploiting.  A research based on surveys method was conducted in order to give good advice for sustainable exploitation of this species. The result showed that, in Quang Ninh they were mainly distributed in offshore island and mangrove forests. The mangrove snail had highest yield in Van Don with production of 2842 ± 125 kg/year, density of 10.5 ind./m2 and biomassof 25 g/m2. The exploitation season took place from April to Novenber in which they were exploited based on monthly tidal cycle. Mangrove snail (Nerita balteata) is a marine species with full of nutrition and high commercial value, therefore, they are over exploiting.  A research based on surveys method was conducted in order to give good advice for sustainable exploitation of this species. The result showed that, in Quang Ninh they were mainly distributed in offshore island and mangrove forests. The mangrove snail had highest yield in Van Don with production of 2842 ± 125 kg/year, density of 10.5 ind./m2 and biomassof 25 g/m2. The exploitation season took place from April to Novenber in which they were exploited based on monthly tidal cycle.

Genetic diversity of freshwater fish species in the wild can be negatively affected by overexploitation and aquaculture activities, while that of cultured populations can be reduced due to evolutionary changes associated in captive conditions. In this study, we evaluated genetic diversity of climbing perch (Anabas testudineus), an important species in aquaculture and fisheries, in one cultured (called square-head, in Hau Giang province) and 3 wild populations (sampled in Ca Mau, Hau Giang and Dong Thap provinces) using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) techniques. Total 83 specimens were amplified using 7 primers (1 RAPD and 6 ISSR primers). All populations showed moderate levels of genetic diversity, evidenced by the percentage of polymorphism (ranged 78.9% - 85.9%) and heterozygosity (averaged 0.192 - 0.258). Wild fish population in Ca Mau had the highest genetic diversity. Results also revealed that a high portion of total genetic variation existed within populations (92%), while genetic differentiation among populations was low (Gst=0.0648), indicating a high level of gene flow (Nm = 7.2) among populations. Low genetic difference among climbing perch populations could be affected by anthropogenic activities and geographic feature such as river/canal systems of the Mekong delta.

Two experiments in this study were conducted to evaluate the effects of adding different supplements into the diet during larval rearing of oyster Crassostrea sp.  In Experiment 1, D larvae were reared at stocking density of 5,000 ind./L with algal mixture of Nannochloropsis oculata and Chaetoceros muelleri, adding Lansy or DHA emulsions. After 10 days of experiment, larvae in treatment adding DHA obtained highest shell length (85.87 àm), survival rate (8.67%), metamorphosis rate (84.72%) and significantly higher than those from other treatments (p

The study aims to investigate the technical and cost-benefit of three shrimp culture systems such as (1) added organic carbon system of white-leg shrimp (S1), traditional culture system of white-leg shrimp (without adding organic carbon) (S2) and traditional culture system of tiger shrimp (S3). The secondary data were collected from Fisheries Department of Ninh Thuan province. One hundred and fourteen shrimp farmers were randomly interviewed using a structured questionnaire to determine the pond size (ha), stocking density (shrimp/m2), survival rate (5), shrimp yield, FCR, net income and ratio of net loss farms.The S1, S2 and S3 had pond size of 0.25±0.07, 0.29±0.09 and 0.32±0.07 ha, respectively. The stocking density of S1 (152±13 shrimp/m2) was higher than that of S2 (87±10 shrimp/m2) and S3 (23±4 shrimp/m2). The yield of S1, S2 and S3 was 15.97, 9.14 and S3 4.22 ton/ha/crop, respectively. The average net income of S1 was 689 VND/ha, S2 was 225 VND/ha, and S3 was 112 VND/ha. The ratio of net income per the total production of S1, S2 and S3 was 0.57, 0.32 and 0.27, respectively. The percentages of net?loss farmers S1 was 22% lower than that of S2 (53%) and S3 (64%).

A study on reproductive biological characteristics of Golden tank goby (Glossogobius aureus Akihito & Meguro, 1975)was carried out in Ben Tre coastal areas from January to December 2013. Thirty fish were sampled monthly in the researched areas by using bag net. The results indicated that the lowest conditions factor (CF)was observed in October, while the highest one was in January. Meanwhile the highest gonadosomatic index (GSI)found in October and the lowest was in January. However, the lowest hepatosomatic index (HSI)was in October, while the highest HIS value was in January. The result also indicated that spawning season of G.aureus occur from September to December. Absolute fecundity of Golden tank gopy G. giuris fluctuated from 30,848 to 276,457 eggs/female. Golden tank goby eggs are oval and small, but the eegs can be observed when the ovaries reached stage IV, the diameter of egg was 0.77±0.07 mm in length and the diameter of egg was 0.20±0.02 mm in width. The length at first maturity (Lm) of G. aureus was Lm= 13.02 cm.

In order to assess the situation of chemical use in rice-fish, stripped catfish cultured in eath ponds and red tilapia cultured in cages systems, in 2013, a survey was conducted on 30 rice-fish fields, 15 stripped catfish ponds and 22 red tilapoa cages in provinces of Mekong Delta. The result showed that all surveyed systems used chemicals in culturing process. The number of chemicals used in rice-fish system was 37 most of them (30 types) was used for rice production. Nineteen chemicals were used in stripped catfish system, the chemicals included 10 types of water quality treatment and antiparasite agents, 7 types of antibiotics and 2 diet supplement elements. In red tilapia, 18 types of chemicalswas used which belonged to antibiotic, water treatment and antiparasite groups. Generally, the antibiotics used in these systems were similar, and all of used chemicals were approved by Government of Vietnam, but, most of antibiotics were listed in limited use list of Ministry of Fisheries. This may lead to the propability of residue of these compounds in aquatic products with concentration higher than maximum residue levels (MRLs) which will affect on consumer health and exported activities.

The study on artificial propagation and nursing of Osteochilus melanopleura was conducted at the NationalBreedingCenterfor Southern Fresh-water Aquaculture. Results indicated that brood fish matured after 5 months conditioning in earthen pond. Conditioning density was 17 kg-1m2consisting 12 kg Osteochilus melanopleura and 5 kg of Cirrhinus jullieni. Formulated feed containing 70% of rice bran and 30% of fish meal was fed to broodstock. Dissolved oxygen, water temperature and pH levels were 4,2-7,5 ppm, 28-32oC, 6,9-8,0 respectively. Result also shown that maturation rates of male and female were 73.33% and 59.60 % respectively. Male got mature one month earlier than female in the same environment condition. The combinations of pituitary gland and/or HCG, LH-RHa were designed as treatments for artificial induced spawning. The combination of pituitary gland 2 mg and HCG 2,000 IU caused ovulation rate 33.33%. The dosage of LH-RHa 150 àg + DOM 10 mg reflected the similar patterns of the first treatment 33,33%. The third treatment was pituitary gland 2 mg + LH-RHa 80 mg + DOM 10 mg gave higher ovulation and fertilization rate 66.67 %. The combination of pituitary gland 2 mg + LH-RHa 100 mg + DOM 10 mg resulted highest ovulation, fertilization and hatching rates, which were 100%. The embryo development took 12 hours at 28-30oC.

Plasma cortisol levels have been used to evaluate the stress response in a variety of cultured fish species. In the Mekong Delta region, striped catfish (Pangasianodon hypophthalmus) are normally transported from nursing ponds to grow-out ponds by boats. Fish are highly stressed depending on transportation duration. In this study, stress indicators such as plasma cortisol and glucose concentration were examed from three groups of practical and laboratoty transportation duration including 2 hrs. 4 hrs. and 6 hrs. Blood samples were collected at different points of time during the transportation process including before transportation (in hapa installed in pond); in carrying basket (from hapa to boat); 1 hrs., 3 hrs. and 5 hrs. of transportation in boat; and in carrying basket (from boat to grow-out pond). Plasma cortisol and glucose concentrations changed from 170 ng/mL to 249 ng/mL and 60 mg/100 mL to 110 mg/100mL, respectively. The plasma cortisol increased while fish held in the carrying baskets. However, significant differences of plasma cortisol and glucose levels were only found in the groups of 4 hrs. and 6 hrs. transportation. In laboratory condition, plasma cortisol levels of fish at density 4.000 fish/ m3 was significantly higher than those at 3.000 fish/m3 at 4 hrs. and 6 hrs. After restocked 1 day, the cortisol level of fish was still high leading to the fish are still stress and do not recover after 24 hours.

The study was conducted to determine the appropriate replacing of fish meal (FM) protein by three type?s soybean meal: defatted soybean meal (SB), fermented soybean meal (FSB) and soy protein concentrate (SPC) in snakehead (Channa striata) diet. Four isonitrogenous (45%) and isocaloric (4.6 Kcal/g) diets were formulated. The control diet was prepared with 100% FM protein. Three other diets was replaced 40% FM protein by three type?s soybean meal protein. Results showed that there was no significant difference in survival rate between feeding treatments. Fish growth performance in control diet and diet replaced SPC were significantly higher than the diets replaced SB and FSB. Food intake observed in diet replaced SPC treatment was not significant difference compared to control treatment. There was no significant difference between treatments in Feed Conversion Ratio, Protein Efficiency Ratio and hematological parameters (red blood cells and white blood cells). Hepatosomatic Index calculated in control treatment was significantly higher than those of others. Thus, it can be replaced 40% fish meal (FM) protein by soy protein concentrate (SPC) in snakehead (Channa striata) diet.

This study aimed to evaluate the effects of Promin in Macrobrachium rosenbergii larva rearing according to the close water system. The experiment was arranged in random with completed designs include 3 treatments. Three replicate each with 2 factors: doses of Promin (extracted from earthworm???) was supplied into the food (0, 1, 2, 3 ml / kg of feed) and cycles for larvae feed supplemented with Promin (no feeding, feeding every day, every another day (one day interval), two day interval). The experimental results that, using Promin has contributed to make the stability and improve better for the environmental parameters. TAN and N-NO2- decreased and they were lower than the control treatment, N-NO3-levels increased but remained in the suitable range for the development of larvae. The larval molting occurs simultaneously when supplemented Promin 3ml/kg per day, which improve the average survival of larvae in this experiment was and to be highest (90 ± 0,48%), significant difference (p

A study on stomach contents of Pterygoplichthys disjunctivus was carried out from 4/2013 to 3/2014 in natural water bodies of Can Tho City. The results showed that P. disjunctivus has an interior ventral sucking mouth and a muscular oral valve. Its jaw tooth is soft and thick-walled. Gill rakers are strong and thick to filter small kind of food; esophagus is long and thick. Stomach is greatly expanded with the posterior portion, forming as a long and thin sac and filled with air. The long intestine form as many circles. RLG (relative length of the gut) was determined to be 16.60 2.82, the result indicated that P. disjunctivus is omnivorous fish, mainly as herbivores. The results also indicated that the food spectrum of P. disjunctivus including zooplankton (Protozoa, Rotifera, Copepoda, Cladocera), phytoplankton (Bacillariophyta, Chlorophyta, Euglena, Cyanobacteria) and detritus, in which, organic material (88.36%), phytoplankton (11.2%) and zooplankton (0.44%).

Utilizing fishery by-products to process into food and bioactivity products will bring economic benefits and reduce waste into the environment. This study focused on investigating the effect of storage time in frozen black tiger shrimp (Penaeus monodon) head meat on the protease enzyme extracted from the flesh shrimp head meat as well as the optimum extraction conditions of protease enzyme. The result showed that the enzyme activity did not affect the protease extraction during 8 weeks frozen storage. Alkaline protease extract obtained from shrimp head meat have the highest overall activity was 13.48 U/g dry material in the ratio of sample and solvent ratio was 1: 4 (w/ v) at pH 9.0, 50°C during 40 minutes.

Study on reproductive biology of Eleotris melanosoma distributed along the Hau River was conducted from August 2012 to July 2013. Results showed that gonadosomatic index (GSI ) of E. melanosoma was low (from 0.23 to 8.89%) and less fluctuation than hepatosomatic index (HSI) (from 0.89 to 7.56 % ); conditional factor (CF) of them was also less fluctuation especially in male fish, in which CF reached the highest value in April and November. Fecundity of E. melanosoma ranged from 49 to 981 egg/g body weight (mean=433±357 egg/g) with total length was 7.0±0.8 cm and total weight was 4.8±2.2 g. Results also showed that during the study period of gonad development of E. melanosoma only reached to a stage IV in 6 stages of gonad development, which suggested that breeding season of E. melanosoma begins from January to December, in which main breeding season was from April to June.

Two Artemia populations originated from Artemia franciscana; SFB (San Francisco Bay) anh Vinh Chau were cultured in the same laboratory condition at different temperature levels of 25, 30 and 320C aiming to investigate the change on fatty acid profiles in their biomass when subjected to temperatures from nauplii to adult stage. After two weeks of culturing, despite of various variations in fatty acid content of Nauplii, results showed that there was no difference in fatty acid profiles as well as content of both populations at the same temperature, they both was very similar in FAs except saturated fatty acid 18:0. Results also confirmed that in Artemia fatty acid composition, food and temperature effect was more than strain-specificity. At 320C temperature, saturated fatty acid occurred a highest level (>25%) compared to other lower levels (24%), p

The two factorial experiment was designed randomly with the time hydrolyzed rice flour (12, 24, 48 hours) and supplementing rice flour to feed and TAN with C:N=15:1. The aim of the study is to find out the way to supplement effect rice flour to yield of white leg shrimp culture. The result showed that when plugin rice flour according to TAN for element TSS, TAN, NO2-, the size biofloc, lượng biofloc (FVI). Total bacteria increased and decreased alkalinity in water comparion supplement with feed. The time hydrolyzed rice flour was not effect to the environment; the longer time hydrolyzed leads to the environment  improved and bigger sizes of biofloc, but smaller volume of biofloc. Speed ??increase grow, survival rate or productivity in the experiment plugin carbohydrate with feed increaser comparion with experimentals plugin rice flour according to TAN. White leg shrimp culture following process biofloc by using the sources of rice flour with hydrolyzed in 48 hours and plugin according to feed has the best result.

Study the effect of supplementation selective Bacillus sp. on the growth of Artemia fanciscana to improve the efficiency of biomass production of natural food was conducted. The experiment included 4 treatments and 3 replications; in that (1) the control (no additional bacteria). (2) Additional mix of Bacillus B37 and B41, (3) additional Probiotic Pro ? W. (4): additional Probiotic Inter pro. The density of additional Bacillus sp was similar in all treatments (106 CFU/mL). Artemia density in culture bottle was 100L ind./500 mL. The results showed that the survival rate of Artemia in additional treatments B37+B41 obatained highest (88%) and was significant difference (p

The aims of this study were to determine (1) the filtration rate and feeding rate with three different algae species including Chaetoceros calcitrans, Dunaliella tertiolecta and Isochrysis albana; (2) the growth in length and time at different development stages; and (3) the reproductive characteristics of Schmackeria dubia. The study was implemented in laboratory condition containing 1 copepod in a small cup 3 mL with prepared sea water (15 ppt) and 10 replicates. The results showed that S. dubia obtained highest filtration and feeding rates when fed with Isochrysis albana but lowest for Chaetoceros calcitrans. Body length of S. dubia nauplius, copepodite and adult was 100 àm to 370 àm, 400 àm to 1010 àm, and 1010 - 1200 àm, respectively. The life cycle was lasting from 26.79 to 31.75 days. Mean maturation duration was 15.4±1.7 hours, embryonic development duration was, 24.2±2.32 hours, spawning interval was 36.22±8.31 hours and mean fecundity was 106±6 eggs.

Currently, the shrimp aquaculture in our country has been growing very fast, statistics show that each year tens of billions of post larvae shrimp are supplied to farmers. However, post larvae counting process at suppliers is usually done manually, it takes time and the accuracy of counting result is not high. Therefore, the objective of this research is to develop the first prototype to help the post larvae shrimp counting process, making it faster and more accurate. The device counts based on an optical sensor. Initial results showed that the shrimp counter yields 6000 units/hour and accuracy approximately 95%.

A tubificid worm Limnodrilus hoffmeisteri (Claparede, 1862) is one of the oligochaeta worm, fed on detritus, distributed high density in the bottom of freshwater bodies. They have been playing an important role in the decomposing the organic compounds, reducing the polluted matter in the environment. Therefore, the L.hoffmeisteri has been considered as an indicator organism. In aquaculture, L.hoffmeisteri is being fed for fish, crustaceans at their first feeding. The study was conducted to determine the suitable feed for propagation of L.hoffmeisteri. After 42 days of experiment, the biomass and density of L.hoffmeisteri were the best at the treatment with rice bran (the worms increased by 4,53±0,10 times and density increased 9,12 ± 0,62 times), and the worst results were shown in worms fed on chicken manure (the biomass and density were increased only 1,13±0,25 times and 1,42±0,31 times, respectively) and cow manure (the biomass and the density were increased 1,21±0,28 times and 1,02±0,15 times, respectively). To be concluded, rice bran was the most suitable feed that resulted in the best performance of the worm population.

The study tested two PCR procedures: (i) colony PCR procedure allows detection of luminous bacteria on black tiger shrimp (Vibrio harveyi) directly from the colony without DNA extraction stage. The first process uses primers F6, R4 designed from vhh gene, a specific gene of V. harveyi. Electrophoresis results gave a band of 159 bp, positive for V. harveyi; (ii) Another colony PCR procedure detect streptococcosis on red tilapia (Streptococcus agalactiae) directly from the colony without DNA extraction stage. The process uses primers F1, IMOD designed from 16S rRNA, gene sequences specific for S. agalactiae. Electrophoresis results gave a band of 220 bp, positive for S. agalactiae. The total amplification time was about 3 hours.

The purpose of this study is to select an appropriate method that is used to forecast the amount of export Pangasius during the first six months of 2014. The forecasting was based on the statistical data from 2008 to 2013 at the seafoods export company in Mekong Delta. This paper focused on 3 quantitative forecasting methods: decomposition model, Winters? exponential smoothing and combined forecast. Holdout Period method was used in processing data analysis. These forecasting methods were evaluated by mean of absolute deviation and tracking signal. The results of study showed that the combinational forecasting model was suitable with data characteristics.

The study of zoobenthos composition on the HauRiverwas conducted in the rainy season with two sampling periods (June, 2013 and September, 2013) at 22 sites in which 7 sites were in the main stream and 15 sites in its tributaries. The results showed that total of 61 species belonging to 6 groups were recorded. Among them, Gastropoda was the most diverse group (with 26 species, accounting for 43%), and the rest consisted of 3 to 16 species, accounting for 5-28%. Difference in species composition between the main stream and its tributaries was not found in both sampling periods. However, species number of zoobenthos in the first sampling period was higher than that in the second one in both main stream and its tributaries, whereas their density was in the inverse trend. Density ranged from 67 to 3,450 ind.m-2 in the main stream and from 67 to 13,187 ind.m-2 in its tributaries. The Shannon-Weaver (H?) and Margalef (d) indices were from 0.4 to 2.8 and from 0.3 to 3.2, respectively. Similarity of zoobenthos composition between the main stream and its tributaries was high. These parameters indicated that pollution level of the research sites onHauRiver was from average to very high. In addition, the results of this research would be used as database for development of a bioassessment program on the Hau River.

The most important waste material in shrimp processing industries is shrimp head comprise about 30ữ35% of whole shrimp weight. This part is rich in nutrients like protein and minerals are being wasted. Factors affect the drying process of shrimp head meat to producing shrimp meat powder which has low water activity (aw) value, good color associated with choosing the suitable package to prolong the storage time were the main investigations of this research. From the result, minced shrimp head meat was treated at 90ºC in 20 minutes before drying at 65ºC to reach 6% moisture was the suitable value to grind into powder, the rate of powder through sieve (1 x 1mm diameter) is over 90%, had the special color of dried shrimp and low water activity (0.48). In addition, shrimp head meat powder products were preserved in PA package with vacuum 85% during 4 weeks of shrimp meat showed the least fluctuation.

This study on induced spawning cobia was conducted by using different types and doses of HCG and LHRHa. Fish broodstocks (10 ? 12 kg/individual) were selected from maturation cage culture. Treatments of the experiment included (i) control (without hormone injection, natural spawning), (ii) HCG at doses of 250, 500, 750 UI/kg of female fish, and (iii) LHRH-a at doses of 20, 30 and 40 mg/kg of female cobia. Half dose of hormone injected for female was applied for male fish. Female and male fish were injected once at the same time. Each treatment comprised of three to five pairs of cobia. Results showed that the fish spawned from 36-62 hours after hormone injection and spawning rate ranged from 25-80%. Fish injected with LHRH-a at dose of 20 and 30 àg/kg performed the highest spawning rate, up to 80%. Fecundity ranged from 76,601 ? 91,058 eggs/kg. The control and the treatment injected 20-30 àg LHRH-a showed the better rate of fertilized egg (73.17 ? 84.44%) and the hatching rate (74.24 ? 83.58%) compared to other treatments. Thus, in induced spawning of cobia reproduction, injection of LHRH-a at dose of 20-30 àg/kg female are recommended.

The study on some biological characteristics of orange-fin loach (Botia modesta Bleeker, 1865) including external morphology of fish, nutritional and reproductive characteristics was conducted. Fish samples were monthly collected along Tien and Hau rivers (An Phu, Chau Doc and Long Xuyen and Thanh Binh) from September 2012 to October 2013. The total samples were 446 fishes from 2.62 to 32.4 g/fish in weight. Orange fin loach is slender body. Besides, this body was covered by a layer of smooth scales. The results showed that orange ? fin loach had short body.  Moreover, fish had long-head and slender. The highest feed ratio was molluse (60.8%), whereas the rates of insect larvae, crustacean and organic humus were 10.8%, 5.4% and 20%, respectively and 3% of undetermined components. The correlations between length and weight were very close with the equation of W = 0.0048 L3.4871, R2 = 0.9364. The gonado somatic index (GSI) increased gradually from May, June to July (0.27; 0.33 and 1.17%, respectively) and the highest GSI was found in August (2.51%). The relative fecundity fluctuated from 181,205 to 194,744 eggs/kg female. The reproductive season strated from May, June and lasted until September.

Outdoor culture of Nannochloropsis oculata was included two experiments to find out the simplest method with high production. The first experiment was performed for evaluation population growth in 50 L of deposited  plastic bag and composite tank. The second ones was conducted to culture algae in composite tank with 50 L, 500 L and 1 000 L in volume. N. oculata was inoculated with initial density of 2 ì 106 cells/mL; continuously aeration; salinity was maintained at 25 pp. Walne medium was used as nutrient supply. Highest density of algae in plastic bag was 38,85±1,28 ì 106  cells/mL at the day 7, whereas, culture of algae in composite tank was obtained this value at 20,70±1,01 ì 106 cells/mL in the day 9. There were no significantly differences of algal production in 50 L, 500 L and 1 000 L composite tank.

Greasyback shrimp (Metapenaeus ensis) is studied in My Thanh River, Soc Trang province in year of 2010. The aim of the study is to identify factors to have effects to yield and size of shrimp. Bagnet is the fishing gear is used in the study, 6 stations along the river were selected for sampling, environmental parameters and shrimp were collected on 36 km of the river from the estuary, the sampling was repeated 6 times on 12 months and distance among stations is 6km. Besides, survey fishermen for identifying the fishing status was also carried out in the study. Results found that shrimp occurs year around, but the highest peaks are June and August; yield of shrimp in rainy season is 45-85 kg/bagnet/month, whereas yield of shrimp in dry seasonal months is 15-30 kg/bagnet/month. Furthermore, it is also different yield in various days on the same month, the yield depends on tidal regime, the yield was not significant differences about various distances from the estuarine. Besides, size of shrimp was not affected by salinity, turbidity and depth.

Study on cobia fingerling rearing in recirculation system with different diets was conducted from March to May 2012 in College of Aquaculture and Fisheries, Can Tho University, Vietnam. The experiment has three treatments of feed types (i) commercial pellet; (ii) trash-fish and (iii) commercial pellet combined with trash-fish with triplication. Fish at initial size of 5.41 cm in length and 0.35g in weight were stocked at 40 fish/m3. After culturing 30 days, results showed that temperature, pH, nitrite, nitrate and TAN in all treatments were in a normal ranges for fish growth. The fish in all the treatments reach to total length and body weight of 11.42 ? 13.42 cm and 4.6 ? 11.52 g respectively. Fish fed with commercial pellets gave the highest growth rate and significantly different to the other treatments at p

This research identified effecting of nutrient medium AGP, initial density, salinity, light intensity on the growth of microalgae Thalassiosira weissflogii and studied biomass cultured. The study obtained results: (i) Microalgae T.weissflogii was in the best growth on the AGP 10% medium (306 x 104 cells/ml); (ii) After 12 days, microalgae T.weissflogii at density 200 x 104 cells/ml got highest density peaks, there were the significantly differences with other treatments (p

The metacercariae species were detected on 3 fish species: striped catfish (Pangasianodon hypophthalmus), climbing perch (Anabas testudineus) and mullet (Mugil cephalus) by morphological and genetic characters (using 28S gene of genomic ribosome).  474 metacercariae were obtained from three fish species, in which 159 metacercariae  on  striped catfish including 3 species (Clonorchis sinensis, Centrocestus formosanus, Haplorchis taichui), 181 metacercariae of 3 unidentified species of 3 different genera (Centrocestus, Haplorchis, Metagonimoides) were found on the climbing perch,  and 134 metacercariae of 3 genera (Procerovum, Stellantchasmus, Clonorchis) on the mullet. Prevalence fluctuates depending on the infected metacercariae and fish species, the lowest was 2.13% for Centrocestus formosanus on striped catfish and the highest is 83.33% for Procerovum sp. on mullet. Phylogenetic tree was constructed using 28S rDNA gene of ribosomal DNA. The phylogram showed the monophyly of studied metacerarian genera, except Haplorchis and Procerovum. Species of two different family (Heterophyidae and Opisthorchiidae) were placed in the same clade. Sequence differences of species rang from 2% to 9%. Research need to be conducted to species identification based on morphological and genetic characteristics.

This study was conducted by interviewing 64 snakehead farmers (pond culture) in An Giang and Tra Vinh provinces from February to April 2014. The results showed that farm scale in An Giang province was smaller than that in Tra Vinh province, the source of snakehead fingerling was mainly from hatcheries in An Giang. Pellet feed was used in snakehead farming with FCR: 1.32-1.33. Culture period, survival rate and yield were not significantly different between the two provinces; harvest size in Tra Vinh was larger than that in An Giang. Total cost of fish culture was rather high (4.9-5.8 VND billion/ha/crop), ratio of gained profit households in Tra Vinh and An Giang were 15.6% and 37.5%, respectively due to low farm gate price. Weather changes were effected snakehead pond culture such as (prolong hot and drought, hotter in dry season, large temperature variation between day and night, colder in cold season, irregular rain and sunshine and saline water intrusion caused more diseases, poorer water quality, reduced survival rate and yield. Farmers? adaptative solution was increase the cost of water plumbing and using chemical- drug 24.2 - 29.2 VND million/ha/year.

This study was carried out from May, 2012 to April, 2013 in An Giang University. The study focused on reproductive biology of Malayan leaffish (Pristolepis fasciata) such as sex ratio, ovarian development stages, gonadosomatic index (GSI), spawning season, fecundity and egg size. Fishes were collected once a month along Hau River, An Giang province. Total of 369 fishes were collected during study period. The results showed that, in nature, the ovary of P. fasciata developed through out 6 stages (I-VI). The highest gonadosomatic index of female and male Malayan leaffish were 14.68 and 4.75%, respectively. The spawning season was from December to September, dominated in May and August yearly. The relative average fecundity was 453,514 eggs per kilogram of female and the absolute average fecundity was 41,884 eggs per of female. The egg diameter was rather small, varying from 0.75 to 1.10 mm (fresh egg, stage IV).

This study aimed at investigating the types of products from snakehead fish and technological processes for manufacturing these products in An Giang province. It has three main contents including (i) production situation and technological processes for manufacturing the products; (ii) investigating types of products; (iii) trade situation in the markets and customer tastes for the products. The results showed that (i) relatively good technological processes and good quality products were almost from processing facilities that operated longer than 20 years. However, these facilities primarily produced by traditional methods which could only meet the requirement of domestic customers without reaching food safety and hygiene standards for export; (ii) products from snakehead fish primarily were dry salted snakehead fish and salty fermented snakehead fish; (iii) consumption of these products were at the medium level because of high price. Customers aged 30-40 liked eating salty fermented snakehead fish while customers aged 20-30 liked eating dry salted snakehead fish. When buying these products, customers payed attention to quality, safety, hygiene, brand name and price of the products.

The aim of the study was to investigate the pattern of food selection by spotted scat (Scatophagus argus) larvae fed on live foods in capture conditions. The study was based on the gut analysis of spotted scat larvae during the larval stage from hatching to 30 days old. Gut contents were compared to the natural food and electivity indexes were calculated. Three days after hatching, the larvae commenced feeding and fed mainly on zooplankton, especially on Branchionus plicatilis and nauplius of copepods. Phytoplankton and protozoa were selected on the 7th and 8th after hatching by the larvae,  while from 10th onwards copepods were chosen with the greatest percentage of the food of spotted scat, especially on Paracalanus parvus, Enterpe acutifrons, Corycaeus sp, Paracalanus aculeatus, Acartia negligenus, Acartia tonas  and Oithoina rigida. Prey selectivity was variable might be due to the moth size and the movement of the spotted scat larvae. Larvae showed as zooplankton feeder from newly hatched stage to 15?day old, and as phytoplankton feeder from 15 to day 30-day old.

A study on growth assessment of Serratia plymuthica RVH1 (causing chilled food spoilage) and the mutant TM1-S18 (a cold-defective mutant of S. plymuthica RVH1) at low temperatures was carried out. Growth parameter estimates of the wild type and mutant strain were determined by program Microfit 1.0. The results showed that in comparison to Tryptic Soy Broth (TSB), Luria Bertani(LB) performed better in supporting growth of the strain, Serratia plymuthica RVH1 budAB,- at low temperatures. Besides, the both cell number and OD measurements can be used interchangeably for growth assessment of Serratia plymuthica RVH1 budAB-. The linear relationship between log(OD) and log(cfu/ml) of Serratia plymuthica RVH1 budAB- in either LB or TSB at three differenttemperatures was also obtained. Although the grow at 30oC (àmax=0,15h1) was seen, the mutant TM1_S18 showed distinct growth from its wild type at low temperatures which was the defective growth at low temperature (4oC) (àmax, can?t be determined). Therefore, in this experiment, the gene plsC knocked out in mutant TM1_S18 is the one gene essential for cold adaptation of Serratia plymuthica. However, mutant and complement strains, the linear relationship between log(OD) and log(cfu/ml) of the mutant was unable to be constructed.

The survey on the current status of giant freshwater prawn (Macrobrachium rosenbergii de Man, 1879) cultured in coconut garden ditches was conducted and a trial on prawn culture was carried out with three different stocking densities (5, 7 and 9 PL15/m2) in Thanh Phu district, Ben Tre province, from June 2012 to February 2013. The area each ditch was 3,000 m2, kinds of feed were used pellet and live food. Prawns were harvested after 6 months. In the trial on freshwater prawn culture at different stocking densities, water quality parameters (temperature, DO, water pH, N-NH4 and chlorophyll-a) were in suitable ranges for growth of giant freshwater prawn. Daily weight gain of prawn in the treatment I (5 PL15/m2), II (7 PL/m2) and III (9 PL/m2) were 0.05 ? 0.42 g/day, 0.04 ? 0.33 g/day and 0.04 ? 0.30 g/day, respectively. The survival rate and yield of prawns in treatments I, II and III were 18,7% and 42.6 kg/1,000 m2; 15,1% and 45.8 kg/1,000 m2; and 16,5% and 60.1 kg/1,000 m2, respectively. The profit in treatment III (5.32 million VND/1,000 m2) was highest.  In conclusion, stocking 9 PL/m2 obtained high efficiency and could be applied for giant freshwater prawn farming in the coconut garden ditches.

Smallscale tonguesole (Cynoglossus microlepis) is studied on Hau river from June 2012 to May 2013 by trawl-net, there are 12 times of sampling on three main regions of the river. It includes An Giang Province (upstream), Can Tho City (midstream) and Soc Trang Province (downstream). The aims of the study is to monitor on population dynamics of the species. FISAT was applied to base on length frequency to analysis growth rate, coefficients. Results found that this species appears year around, but they are caught in early stages of the life, it is common from 0.5-22.5 cm in total length, asymptotic length L? = 44.33 cm, growth coefficient K = 1.02/year, age of fish at length t0 = 0.01/year, individuals have size larger 25 cm length often concentrate on estuarine and coastal region, whereas smaller individuals are found mainly in upstream and midstream.  It also found that only 1% individuals are larger than 24.5 cm from the research, whereas individuals from 0.5-12.5 cm  attained 81% about quantity, it has twice recrutiments per year, the first recruitment peak is diffrent among regions, but it is not different in the second recruitment peak for three regions.

This study aimed to investigate effects of broodstock age and sizes selected based on two cut-off values (5% and 25 % of the normal distribution of the G1 population?s weight) on offspring growth of climbing perch (Anabas estudineus) from fry to fingerling stages. Square-head climbing perch fry artificially produced from two selected G1 parents (G2-CL1 and G2-CL2, respectively) and from the first generation (G1-0) were compared growth and survival rates with the one from non-selected G1 parents (G2-NN) in two nursing stages. In the first experiment, fry fish were randomly stocked in 1-m3 tanks (3000 fish/tank, 4 replicates). Fish were fed by live food (rotifer, moina, red worm) combined with commercial feed (42% protein). After 21 days, length of fish in 2 selected groups (2.51±0.06 cm and 2.42±0.09 cm) was insignificantly higher than that of offspring in the control and treatment G1-0 (2.41±0.02 cm and 2.37±0.06 cm, respectively). However, fish weight in G2-CL1 was significatly highest (0.43±0.37g) compared to the other treatments (averaged 0.32-0.36 g). Survival rates were not significant among treatments (p>0.05), ranging from 14.0±1.8% to 18.6±3.6%. At fingerling to juvenile stages, fish were reared in 2 m2 -hapas (200 fish/hapa, 3 replciates) and fed commercial feed. After 30 days of rearing, growth of fish in G2-CL1 was significantly highest (6.5±1.6 cm and 6.3±4.8 g). Survival rates were similar among treatments (p>0,05), ranging 79.8 to 84.9%. Therefore, mass selection 5% of the highest population weight increases growth rate of squared head climbing perch from fry to juvenile stages.

The study was conducted in the fish hatchery of the College of Aquaculture and Fisheries, Cantho University. The objective of this study was to determine dietary protein requirement of whisker catfish (Micronema bleekeri) fingerling. The experiment was randomly set up with 7 treatments and 3 replications. Whisker catfish (269 mg) was nursed in 12L composite tanks with the density of 2.5 fish/L (30 fish/tank) for the duration of 6 weeks. Seven experiment diets were formulated containing different protein levels of 24%, 29%, 34%, 39%, 44%, 49%, and 54% with the same energy (4.36 Kcal/g) and lipid levels (10%). Result showed that the specific growth rates (SGR) of whisker catfish increased and feed conversion ratio (FCR) decreased with the increase of protein levels from 24% to 49% in diets. However, in the treamtnet of 54% protein, SGR of fish decreased and FCR increased. Dietary protein requirement of whisker catfish (269mg/fish) fingerling was 43,2% protein.

A study on histopathology in clown knifefish effected of Aeromonas hydrophila. A total of 22 fish samples was collected for bacterial identification and histological examination. Almost diseased fish, pure cultures of Aeromonas hydrophila were isolated from liver and kidney. The histopathology of gills, liver, kidney and spleen was displayed focal hyperaemic, haemorrhage and necrosis in tissues. The renal tubules were observed degeneration, and necrosis followed by tubular destruction. Haemorrhage sometimes occurred among damaged muscle fibers. Histological structure of gills was characterised by the oedematous secondary lamellae with a bacterial invasion into the primary lamellae and gill congestion. Giemsa staining method showed that markedly bacterial cells like as rod shape in these tissues.

The study of Phytoplankton community fluctuation in white shrimp ponds to determine the correlating of them with shrimp health status. The results will be used as a baseline for pond management and disease prevention. Phytoplankton was collected from 20 white shrimp Litopenaeus vannamei ponds with the densities varied from 25 to 140 inds.m-2 in Mekong delta region. 20 ponds were divided into 2 groups: infected and non-infected shrimp ponds. The results showed that 119 species were identified in which 87 of diatoms, 10 of dinoflagellates, 11 of euglenoid 6 of green algae and 5 of blue-green algae. Diatoms contributed with the highest proportion in the community in all ponds. The densities of blue-green algae and euglenoid were high showing the eutrophic and low salinity environment. The diversity of phytoplankton in infected shrimp ponds was lower than that of non-infected ponds while the density of them was opposite. It is found that the densities of dinoflagellates, euglenoid, and blue green algae in infected shrimp ponds were higher than that of non-effected shirmp ponds. Whereas, the density of diatom in non-effected shrimp ponds was 22 times higher than that of infected ponds. There was no bloom of toxic algae in all shrimp ponds during the survey.

The mantis shrimps (Stomatopoda) are marine, predatory species, characterized by the greatly developed second maxilliped modified as large powerful raptorial appendages. More than 450 described species are known, distributed in seven superfamilies and 17 families (Ahyong, 2008). Many species that inhabit soft bottoms and distributed from Indian ocean to the Pacific ocean. In coastal Mekong Delta, the mantis shrimp was captured from the nature. The research on species composition and distribution of the mantis shrimp are limited. Preliminary results were identified four species of Squillidae, namely: Erugosquilla woodmasoni (Kemp, 1911), Harpiosquilla harpax (De Haan, 1844), Miyakea nepa (Latreille, 1828), and Oratosquillina interrupta (Kemp, 1911). Four species of mantis shrimp were captured in shallow water wih a depth of 8-12 m and muddy sand substrates. In which, two species of mantis shrimp, including Oratosquillina interrupta and Harpiosquilla harpax were large sized with 24.0 cm and 19.0 cm in total length, respectively. These were an economic and potential species for seed production and commercial mantis shrimps farming in the future.