Striped Catfish Pangasianodon Hypophthalmus Research Articles

Abiotic and biotic stress alleviating effects of the medicinal and aromatic plant-derived product on striped catfish Pangasianodonhypophthalmus

Intensification of aquaculture production leads to abiotic and biotic stresses, which are further induced by the impact of climate change. Thus, it is important to explore a combined strategy to alleviate multiple stresses in fish. In the present investigation, the removal of nitrogenous metabolites from aquaponics water was studied using products derived from five different locally available medicinal and aromatic plants (MAPs) namely banana stem (Musa Accuminata), Aloe vera, Mint (Minata sepicata), Indian beech/Pongameoil-tree/Karanj (Pongamia pinnatum), and Coat Button/Mexican daisy/Dagadipala (Tridax procrumbens) in the batch experiment for 24 h. A reduction of 91–94% in the ammonia level and 75–80% removal of nitrite-N in the treatments with products derived from mint, banana stem, and aloe vera has been observed. Mint product was also found to be bactericidal against fish pathogenic bacteria. Based on this dual function of mint, further study was conducted under wet-lab conditions to evaluate the possible protective role of the mint-based product in dry powder form against abiotic stresses caused by nitrogenous toxicants for 24 h and 45 days multiple stresses caused by nitrogenous toxicants in freshwater stocked with eight fingerlings of Pangasianodon hypophthalmus of the initial weight of 8 ± 0.5g for 24 h and 8.82 ± 0.75g for 45 days. The results revealed that mint-derived plant product has better anti-stress properties in terms of their bioremediation effectiveness in lowering ammonia and nitrite. Mint also improved the fish growth performance with better physiological responses and anti-oxidative status and reduced the cellular metabolic stress in fish reared under ammonia, as further indicated by reduced oxidative stress parameters, and tissue biochemical indices. Overall, mint showed its main properties as a growth promoter, and immune enhancer, where this medicinal plant product acts as a bioremediation and antibacterial agent to the host immune system. This has potential applications in the environmental and health management of aquaculture.

Effects of common full-sib families on accuracy of genomic prediction for tagging weight in striped catfish Pangasianodon hypophthalmus.

Common full-sib families (c 2 ) make up a substantial proportion of total phenotypic variation in traits of commercial importance in aquaculture species and omission or inclusion of the c 2 resulted in possible changes in genetic parameter estimates and re-ranking of estimated breeding values. However, the impacts of common full-sib families on accuracy of genomic prediction for commercial traits of economic importance are not well known in many species, including aquatic animals. This research explored the impacts of common full-sib families on accuracy of genomic prediction for tagging weight in a population of striped catfish comprising 11,918 fish traced back to the base population (four generations), in which 560 individuals had genotype records of 14,154 SNPs. Our single step genomic best linear unbiased prediction (ssGLBUP) showed that the accuracy of genomic prediction for tagging weight was reduced by 96.5%-130.3% when the common full-sib families were included in statistical models. The reduction in the prediction accuracy was to a smaller extent in multivariate analysis than in univariate models. Imputation of missing genotypes somewhat reduced the upward biases in the prediction accuracy for tagging weight. It is therefore suggested that genomic evaluation models for traits recorded during the early phase of growth development should account for the common full-sib families to minimise possible biases in the accuracy of genomic prediction and hence, selection response.

Monitoring of reproductive health in the striped catfish Pangasianodon hypophthalmus (Sauvage, 1878) from the Saen Saep Canal, Thailand

Khlong Saen Saep is one of the most important and large canal systems in Bangkok, Thailand. However, the emergence of heavily polluted water has occasionally been reported due to the domestic sewage and industrial effluents discharged into the system. This situation may affect the reproductive status of aquatic lives residing in this canal. To evaluate the reproductive status of the canal inhabitant, the striped catfish Pangasianodon hypophthalmus (Sauvage, 1878)—a common dweller of the Saen Saep Canal—was collected from two selected stations, the Bumpen Nua Temple and the Kamalun Islam Mosque. The fish gonads were then anatomically and histologically examined. The results indicated that neither parasites nor ovary with external abnormality were found. Nevertheless, several histological alterations were detected, including vacuolar degeneration of previtellogenic oocytes, accumulation of melanomacrophage centers (MMCs), and atretic oocytes. Moreover, severe histopathological changes, such as the eosinophilic cytoplasm of spermatogonia, MMCs, blood congestion, and syncytium of spermatozoa, were observed in the fish testis. Our study suggested that the environmental stress and pollutions previously reported from the Saen Saep Canal possibly underpin the gonadal impairments of P. hypophthalmus examined and may have adverse impact on the reproductive health of others living in this canal system

Transcriptomic analysis of the immune response against A. hydrophila infection in striped catfish Pangasianodon hypophthalmus

As an emergent bacterial pathogen in aquaculture, A. hydrophila has caused considerable losses to the striped catfish aquaculture industry. Efficient transcriptome research has been widely used to study the immune response of fish against pathogens. This study firstly reported the effect of A. hydrophila infection at 0, 4, 12, 24, 36, and 48 h on Pangasianodon hypophthalmus at the transcriptome level. The changes in multiple immune indices indicated that the earlier stages, including 4, 12, and 24 h, were key time points during A. hydrophila infection. Accordingly, 6824, 2674, and 1571 differentially expressed genes (DEGs) were identified between each key infection time (4, 12, and 24 h) versus 0 h. Most of the DEGs were enriched in the functional categories of positive regulation of response to stimulus, positive regulation of immune system process, activation of immune response, positive regulation of immune response, and defense response. Further analysis based on the short time-series expression miner methods indicated that the genes significantly fluctuated in response to A. hydrophila infection and were enriched in cytokine-related pathways, including cytokine-cytokine interaction, the interleukin 17 signaling pathway, Th cell differentiation, and the chemokine signaling pathway. Weighted co-expression network analysis was applied to identify 14 hub genes involved in the immune response against A. hydrophila infection, and a corresponding gene regulatory network was constructed. The findings in this study provide further in-depth insights into the immune response of P. hypophthalmus against A. hydrophila infection, which could be implicated in the future prevention and treatment of infectious diseases in aquaculture.

Protective efficacy of phage PVN02 against haemorrhagic septicaemia in striped catfish Pangasianodon hypophthalmus via oral administration.

Haemorrhagic septicaemia caused by Aeromonas hydrophila in striped catfish (Pangasianodon hypophthalmus) is one of the most important aquatic diseases in the Mekong Delta, Vietnam. However, antibiotic-resistant A.hydrophila strains have become popular and resulted in inadequate control of the disease in striped catfish farms. This study investigates the protective efficacy of bacteriophage PVN02 against haemorrhagic septicaemia in striped catfish via oral administration. The phage-containing pellets were prepared by spraying the phage solution on food pellets at 20ml/kg. The rate of phage desorption from the food pellets into the water was very low; the phage titres in the water were approximately log 1.0 PFU/ml or undetectable. The in vivo experiment evaluating the protective efficacy of PVN02 against haemorrhagic septicaemia in striped catfish was conducted using 21 groups of 1,260 fish in 50-L plastic tanks in triplicate. The catfish were fed twice daily with phage-sprayed pellets. Different densities of bacterial suspensions were added into the tanks for 24hr. Without the existence of the phage, the highest mortality rate was 68.3±2.9% at the highest density of bacterial suspension. In contrast, the mortality rate at the highest density of bacterial suspension was significantly reduced to 8.33±2.9% or 16.67±2.9% at the phage dose of log 6.2±0.09 or log 4.2±0.09 PFU/g. This study provides a very practical manner of applying phage therapy to prevent disease in large-scale striped catfish farms.

Chromium Exposure Causes Structural Aberrations of Erythrocytes, Gills, Liver, Kidney, and Genetic Damage in Striped Catfish Pangasianodon hypophthalmus.

Heavy metal pollution due to anthropogenic activities poses a great threat to aquatic organisms. The present study was conducted to evaluate the cytotoxic and genotoxic effects of hexavalent chromium (potassium dichromate) on hemato-biochemical, histo-pathological, and genetical changes in striped catfish Pangasianodon hypophthalmus. Three sub-lethal doses (0.8, 1.6, and 3.2 mg/L) of chromium (Cr) were selected and fish were exposed in vivo contrasting with a control (0 mg/L) for 30 days. The study revealed that various hemato-biochemical parameters showed a significant decrease in hemoglobin (Hb), red blood cells (RBCs), and blood glucose content, whereas white blood cells (WBCs) significantly increased in Cr exposed fish. Frequencies of all forms of structural abnormalities of erythrocytes (erythrocytic cellular abnormalities; ECA, erythrocytic nuclear abnormalities; ENA and erythroblasts; Ebs) were significantly increased in higher two test concentrations (1.6 and 3.2 mg/L) when compared to control. Differential leucocyte count exhibited significant increase in neutrophil and decrease in lymphocytes in the highest Cr treated group. The severity of various histo-pathological changes in the gills, liver, and kidney were increased considerably with the increase of Cr concentrations. Similarly, the amount of DNA (ng/μl) decreased significantly in blood and tissues of different vital organs where the liver showed the highest decline compared to control in a concentration-dependent manner. Taken altogether, P. hypophthalmus is susceptible to Cr and can be used as a bio-indicator to assess aquatic metal pollution.

Effect of different carbohydrate-to-lipid ratios elicits growth, feed utilization, lipid deposition and lipogenic enzyme activity in striped catfish (Pangasianodon hypophthalmus, Sauvage, 1878) fingerlings

This study evaluated the effects of diets containing various carbohydrate-to-lipid (CHO L-1) ratios on growth performance, nutrient utilization body indices and hepatic lipogenic enzyme (malic enzyme, 6-phosphogluconate dehydrogenase and fatty acid synthase) activities. Triplicate groups of Pangasianodon hypophthalmus fingerlings were fed eight isoenergetic and isonitrogenous diets with different carbohydrate-to-lipid ratios (0.51, 0.79, 1.12, 1.79, 2.41, 3.24, 4.43 and 7.62). Higher body fat deposition and lower growth performance were observed in P. hypophthalmus fingerlings fed with high-lipid diet than those fed with high-carbohydrate diet. The fish fed the diet with 7.62 CHO L-1 ratio exhibited significantly (p<0.05) higher hepatosomatic index compared to those fed higher lipid diets (0.51 and 0.79). High dietary carbohydrate level significantly increased (p<0.05) the activities of malic, 6-phosphogluconate dehydrogenase and fatty acid synthase enzyme. Based on the second-order polynomial regression analysis of weight gain, the optimal dietary carbohydrate and lipid contents for P. hypophthalmus fingerling were 304 and 103 g kg−1, respectively, which correspond to a dietary CHO L-1 ratio of 2.95.

Evaluation of health status of the striped catfish Pangasianodon hypophthalmus (Sauvage, 1878) from Khlong Saen Saep, Thailand: The use of integrated biomarkers

Khlong Saen Saep in Bangkok is a polluted canal whose water quality fails to meet standard criteria in many areas. We hence assessed the effects of pollution on the striped catfish Pangasianodon hypophthalmus (Sauvage, 1878) commonly found in polluted areas of the canal. Fish were sampled from two stations in Khlong Saen Saep: Masjid Kamalulislam and Wat Bumpennue. Dissolved oxygen (DO) and biochemical oxygen demand (BOD) indicated that the water quality of the former was better compared to the latter. Accordingly, total length, total weight, and condition factor were all higher in fish caught from Masjid Kamalulislam than in those from Wat Bumpennue. The hematologic profiling showed no significant difference between fish from the two stations, but the presence of some leucocytes suggested the existence of inflammation in fish from both stations. Importantly, fish from Wat Bumpennue showed higher prevalence of histopathological alterations, such as aneurysm, edema, hyperplasia, and fusion of filaments in gills; blood congestion and granuloma formation in the liver; renal degeneration and karyolysis in the renal tubule; and melanomacrophage centers (MMCS) in the liver and kidney. The use of integrated biomarkers thus illustrated the ongoing detrimental effects of pollution on the striped catfish, emphasizing the importance of conserving water resources.

The effect of herbal supplement feeding and different stocking density on the growth rate of striped catfish, Pangasianodon hypophthalmus (Sauvage, 1878)

Striped catfish Pangasianodon hypophthalmus (Sauvage, 1878) has a high economic value and relatively fast growth, so that optimum stocking density and supplement of natural ingredients, such as Curcuma domestica Val., Kaempferia galanga Linn., and Curcuma xanthorriza Robx. can increase growth and immunity. This study aimed to obtain the optimum stocking density and herbal supplement dosage in feed to increase the growth and survival rates of striped catfish. An experimental method by applying factorial design was used, i.e. the dose and stocking density factors. The dosage of herbal supplements used were 100 mL kg-1 feed (D1), 200 mL kg-1 (D2) and 300 mL kg-1 (D3). Stocking density used was 50 m-3 (P1) and 75 m-3 (P2). The fish used were 8.5±0.5 cm long and weighed 7.5±0.3 g, kept in floating cages of 1 m x 1.5 m x 1 m. Fish maintenance was carried out for 60 days with feeding frequency of three times a day, as much as 10% of body weight. The results showed that the treatment of 200 mL kg-1 dosage and 75 m-3 stocking densities was the best treatment. This treatment showed that specific growth rate, absolute weight, absolute length and feed efficiency were 4.86%, 119.07 g, 15.45 cm, 82.93%, respectively. A supplement dose of 200 mL kg-1 in feed and stocking densities of 75 m-3 could increase growth rates, survival, and feed utilization efficiency of striped catfish.

Single or Combined Dietary Supply of Psidium guajava and Phyllanthus amarus Extracts Differentially Modulate Immune Responses and Liver Proteome in Striped Catfish (Pangasianodon hyphophthalmus).

Guava Psidium guajava L (Pg) and bhumi amla Phyllanthus amarus Schum. et Thonn (Pa) are well-known plants in traditional medicine. However, the capacity of these plants for improving the immune system of aquatic species has received less attention so far. This study aimed to investigate the effects of single supply or mixture of Pg and Pa extracts on immune responses, disease resistance and liver proteome profiles in striped catfish Pangasianodon hypophthalmus. Fish were fed diets including basal diet 0% or one of three doses of each plant extract, either alone or in mixture, 0.08, 0.2, or 0.5% Pg, Pa or mixture (Pg:Pa, v/v) for 6 weeks. The immune parameters (respiratory burst activity (RBA); nitric oxide synthase (NOS), total immunoglobulin, lysozyme, and complement activities) were examined at W3, W6 post-feeding, and after challenge test. The growth parameters and the challenge test with Edwardsiella ictaluri were done at W6. The liver proteome profiles were analyzed in W6 at 0.08 and 0.5% of each extract. The results showed that extract-based diets significantly improved growth parameters in the Pg0.2 group compared to control. The cellular immune responses in spleen and the humoral immune responses in plasma were significantly improved in a dose and time-dependent manner. Diets supplemented with single Pg and Pa extracts, and to lesser extent to combined extracts, could significantly decrease the mortality of striped catfish following bacterial infection compared to control. The proteomic results indicated that some pathways related to immune responses, antioxidant and lipid metabolism were enriched in liver at W6. Several proteins (i.e., CD8B, HSP90AA1, HSP90AB1, PDIA3, CASP8, TUBA1C, CCKAR, GNAS, GRIN2D, PLCG1, PRKCA, SLC25A5, VDAC2, ACTN4, GNAI2, LCK, CARD9, NLRP12, and NLRP3) were synergistically upregulated in mixture of Pg and Pa-based diets compared to control and single dietary treatments. Taken together, the results revealed that single Pg and Pa extracts at 0.2 and 0.5% and their mixture at 0.08 and 0.5% have the potential to modulate the immune mechanisms and disease resistance of striped catfish. Moreover, the combination of Pg and Pa in diets suggested positive synergistic effects liver proteome profile related to immune system processes.

Acute effects of chromium on hemato-biochemical parameters and morphology of erythrocytes in striped catfish Pangasianodon hypophthalmus

Chromium is considered the most detrimental pollutant to the aquatic organisms. The present experiment was conducted to determine the acute toxicity of chromium in view of its effects on hemato-biochemical parameters and the structure of erythrocytes in striped catfish, Pangasianodon hypophthalmus. Fish were exposed to seven different concentrations (0, 10, 20, 30, 40, 50 and 60 mg/L) of chromium, each with three replications for 96 h. After 96 h of exposure, the survived fish were sacrificed to measure hemato-biochemical parameters (hemoglobin, Hb; red blood cell, RBC; white blood cell, WBC; packed cell volume, PCV; mean corpuscular volume, MCV; the mean corpuscular hemoglobin, MCH and blood glucose). In addition, erythrocytic cellular abnormalities (ECA) and erythrocytic nuclear abnormalities (ENA) of peripheral erythrocytes were assayed. No mortality was observed up to 10 mg/L, but 90% and 100% mortality was observed at 50 mg/L and 60 mg/L, respectively after a 96 h exposure period. The 96 h LC50 value through probit analysis was 32.47 mg/L. Hb (%), RBC (×106/mm3) and PCV (%) significantly decreased at 20, 30 and 40 mg/L of chromium, whereas WBC (×103/mm3), MCV (μm3) and MCH (pg) showed the opposite scenario. Blood glucose (mg/dL) levels significantly increased at 10, 20, 30 and 40 mg/L of chromium compared to 0 mg/L. Frequencies of ECA and ENA significantly increased with increasing chromium concentrations. This study indicates that chromium is highly toxic to striped catfish.

First application in Turkey of the European Non‐native Species in Aquaculture Risk Analysis Scheme to evaluate the farmed non‐native fish, striped catfish Pangasianodon hypophthalmus

AbstractThe European Non‐native Species in Aquaculture Risk Analysis Scheme (ENSARS) was used to assess one of the most popular aquaculture species in the world, the striped catfish Pangasianodon hypophthalmus (Sauvage, 1878), in two locations of southern Anatolia (Turkey). The overall mean risk score generated for P. hypophthalmus by the ENSARS Organism module (which assesses the risks of introduction, establishment, dispersal and impact) indicated that the species poses a medium risk under current climatic conditions. All other ENSARS modules rendered scores that indicated a moderately low risk under current climatic conditions. However, the risks of introducing novel diseases and the actual use (e.g. deliberate introduction to the natural habitats or food market) of the species both attracted scores indicating a medium risk. Confidence levels were medium or high for all modules except the Socio‐economic, with low confidence values also attributed to the risks for farming process of the organism, and its overall risk of spread into the wild during farming procedures and to marketing impacts. Recommendations are provided for further use of the ENSARS scheme, especially for a a priori assessment of potential aquaculture species in Turkey, where the sector has been remarkably developing in the last decades.

Antibiotic Use by Small-Scale Farmers for Freshwater Aquaculture in the Upper Mekong Delta, Vietnam.

This study describes antibiotic use by small-scale freshwater aquaculture farmers in the upper Mekong Delta in southwestern Vietnam and the knowledge and practices surrounding the cause and prevention of aquaculture disease in that region. Forty five farmers were included in the study, of which 19 (42%) cultivated tilapia Oreochromis spp., 13 (29%) Striped Catfish Pangasianodon hypophthalmus and 13 (29%) giant river prawns Macrobrachium rosenbergii. Antibiotics were used by farmers of tilapia and Striped Catfish (84% and 69% of farmers, respectively), but not by any of the prawn farmers. Most farmers (72%) used antibiotics for around 3d when treating diseases, depending on the farmers' economic means and whether the fish recovered, as judged by the farmer. If farmers perceived that the antibiotic treatment had failed, the most common response was to change to another type of antibiotic. Some farmers also used antibiotics in the absence of clinical symptoms as a preventive measure. In the absence of rapid, cost-effective diagnostics, the likelihood for the incorrect use of antibiotics is high, which has implications for antibiotic resistance. Moreover, the sequential use of different antibiotics following therapeutic failure is a risk factor for the emergence of resistance. All farmers that were surveyed were aware of the risks associated with antibiotic use. This may lead to successful intervention toward reduced antibiotic use in freshwater fish farming in Vietnam.

Performance of Pregnant Mare Serum Gonadotropin and Vitamin Mix in Inducing Striped Catfish Pangasianodon hypophthalmus Rematuration

The research aimed to assess the performance of Pregnant Mare Serum Gonadotropin (PMSG) and Human Chorionic Gonadotropin (HCG) hormone injection combined with vitamin mix to induce the rematuration of Striped catfish Pangasianodon hypophthalmus broodstock. Three PMSG and HCG treatments of 5 and 2,5 IU; 10 and 5 IU;also 20 and 10 IU/kg of broodstock body weight dosage combined with vitamin mix addition to fish feed and one control was used with four replications. The broodstock was reared for four weeks and weekly sampling for GR and SGR as well as hormone injection were performed. For the following two weeks, the broodstock was observed for maturation. Artificial spawning was conducted for broodstock reaching gonadal maturity. Statistic analysis of observed variables showed insignificant differences among the three treatments in rematuration parameters. The rematuration rate resulted in a 100% pregnancy. Broodstock treated with 10 IU PMSG and 5 IU HCG/kg of spawner body weight was able to reach maturity and spawned with the larval survival rate on the fourth day at 84,81%, thus it can be concluded that 10 IU PMSG and 5 IU HCG/kg of body weight as the best dosage.

Breeding for improved resistance to Edwardsiella ictaluri in striped catfish (Pangasianodon hypophthalmus): Quantitative genetic parameters.

Bacillary necrosis of Pangasius (BNP), caused by Edwardsiella ictaluri, is one of the most devastating diseases in stripedcatfish farming. To date, quantitative genetic inheritance of BNP resistance is not known in striped catfish Pangasianodon hypophthalmus. The main aim of this study was to estimate genetic parameters for BNP resistance in a breeding population of striped catfish undergoing four generations of selection for high growth. Specifically, the study examined whether BNP resistance is heritable to enable family selection and whether genetic improvement for enhanced BNP resistance may have detrimental effects on growth and survival rate. To test these hypotheses, 720 full- and half-sib families were challenged with E.ictaluri pathogen using injection and cohabitation methods over four years, from 2010 to 2012 and 2015. In total, the data included 398,234 animals in the pedigree, from which 18,849 animals had disease challenge test records and 39,103 siblings had growth performance. Both univariate and bivariate sire-dam linear and threshold mixed models were used to estimate (co)variance components for BNP resistance, survivals and growth traits. The estimates of heritability for the BNP resistance recorded as death or survival were low regardless of models used (0.10-0.16), whereas survival time (days post-challenge test) showed moderate heritability (0.35). The survival rate during hapa rearing had medium heritability (0.33-0.52). The genetic correlations of BNP resistance with body weight and survival were all positive (0.03-0.53), suggesting that selection of increased BNP resistance may have positive impacts on growth and survival traits, and these traits could be easily improved simultaneously in the selective breeding programme for striped catfish.

Impact and tissue metabolism of nitrite at two acclimation temperatures in striped catfish (Pangasianodon hypophthalmus)

Elevated concentrations of nitrite develop occasionally in various aquatic habitats and aquaculture facilities, providing a potential danger for freshwater fish that take up nitrite via the gill chloride uptake mechanism. We studied the uptake, effects and metabolism of nitrite in blood, heart and skeletal muscle at two temperatures in striped catfish Pangasianodon hypophthalmus, a facultative air-breathing fish that is heavily cultivated in Southeast Asia. Exposure to 0.8 mM ambient nitrite increased blood [nitrite] and [methaemoglobin] (metHb) to high values at day 1, but values subsequently decreased towards controls at day 7. Blood [nitrite] and metHb content were unexpectedly higher at 27 °C (∼1.2 mM; 69% at day 1) than at 33 °C (∼0.9 mM; 55%), reflecting a lower nitrite uptake at the highest temperature, possibly via an increased reliance on air-breathing relative to water-breathing with temperature increase. A large fraction of the nitrite taken up was effectively eliminated by being detoxified to nitrate. Further, erythrocyte metHb reductase activity was increased during nitrite exposure, efficiently reducing metHb to functional haemoglobin. The uptake of nitrite into white skeletal musculature (main part of the fish) was much lower than into heart tissue. While heart [nitrite] was close to blood plasma levels, muscle [nitrite] peaked at ∼0.2 mM at day 1 and subsequently declined to ∼0.05 mM at day 7, which is below levels reported in various commercial cured meat products. Nitrite was partly metabolized to iron-nitrosyl, S-nitroso and N-nitroso compounds. The increase in nitros(yl)ated compounds was marginal in skeletal muscle and more pronounced in heart tissue.

GROWTH AND MEAT QUALITY ENHANCEMENT OF STRIPED CATFISH (Pangasianodon hypophthalmus) USING RECOMBINANT GROWTH HORMONE

The application of fish recombinant growth hormone (rGH) has been known as one of the methods to improve the growth performance of cultured fishes, one of which is the striped catfish Pangasianodon hypophthalmus, a species that is becoming commercially attractive in Indonesia. Hence, this study was aimed to evaluate the effects of rGH supplementation in commercial diet on the growth, feed utilization and flesh quality in P. hypophthalmus grow out. The rGH was mixed with chicken egg yolk and sprayed on the commercial feeds with different protein levels (32, 28 and 23%). In the control, the feeds were also sprayed with chicken egg yolk but without rGH. Striped catfish with body weights of 110.66 ± 1.32 g ind-1 were fed on rGH-supplemented diets two times a week during the first and third months, and during the rest of the months they were fed on diet without rGH supplementation. The fishes were reared for 120 days in 18 hapa (2×1×1.5 m3) with initial density of 20 fishes per hapa. The result showed that the highest weight gain, specific growth rate (SGR), and lowest feed conversion ratio (FCR) were obtained by fishes fed on 32% protein content with rGH-supplemented diet. No significant difference was observed in the weight gain, SGR and FCR in rGH treated group with 28% protein content with rGH supplemented diet and non-rGH control group receiving 32% protein diet. Similar moisture content of meat, protein content of meat, belly fat and edible portion were observed in rGH-supplemented diet and their control. Except in the treatment 23% protein content rGH supplemented diet that has lower lipid content in fish body and meat. The highest SGR was obtained when the fishes were fed on the 32% protein feed combined with rGH. Enrichment with rGH depleted the fat content in the meat of fish fed on all levels of protein in which the lowest fat was found in the 23% protein feed.

Quantifying sustainability indicators in striped catfish Pangasianodon hypophthalmus downstream and upstream ponds

To assess the potential for improving sustainability and efficiency in an important Vietnamese finfish culture, we quantified sustainability indicators for 2 downstream and 2 upstream 3 to 4 m deep ponds for striped catfish Pangasianodon hypophthalmus (Sauvage, 1878) production along the Mekong River, Vietnam. The resources used per kg fish produced were (downstream vs. upstream): 2.8 vs. 7.1 m3 water, 0.04 vs. 0.14 kWh energy, 0.06 vs. 0.11 h human labour and 0.06 vs. 0.15 g antibiotics (p 0.05). Nitrogen and phosphorus utilization efficiencies were 44 vs. 40% for nitrogen (p 0.05). An advantage of production in deep ponds is the breakdown of organic matter through denitrification and fermentation. Based on the difference between feed input and monitored outputs and sinks, an estimated 29–37% of dry matter volatilized as CO2 and 30–34% of nitrogen was lost as N2. A major disadvantage of the deep pond production system is its dependency on water exchange with the Mekong River, resulting in low biosecurity, which is aggravated by the lack of availability of disease-free fingerlings. Dealing with disease caused farmers to apply suboptimal feeding rations and to lengthen the culture period. Developing (semi-)closed systems that adopt elements from recirculation technology could improve both culture performance and sustainability.

Salinity stress, enhancing basal and induced immune responses in striped catfish Pangasianodon hypophthalmus (Sauvage)

In the Mekong Delta, striped catfish are faced with chronic salinity stress related to saltwater intrusion induced by global climatic changes. In this study, striped catfish juveniles were submitted to a prolonged salinity stress (up to 10ppt) over three weeks followed by infection with a virulent bacterial strain, Edwardsiella ictaluri. Osmoregulatory parameters were investigated. In addition, a label free quantitative proteomics workflow was performed on kidneys. The workflow consisted of an initial global profiling of relative peptide abundances (by LC/MS, peak area quantification based on extracted ion currents), followed by identification (by MS/MS). The aim of the study was to highlight specific functional pathways modified during realistic salinity stress, particularly those involved in immunity. In kidney proteome, 2483 proteins were identified, of which 400 proteins were differentially expressed between the freshwater and the saline water conditions. Several pathways and functional categories were highlighted, mostly related to energy metabolism, protein metabolism, actin cytoskeleton, signaling, immunity, and detoxification. In particular, the responsiveness of proteins involved in small GTPases and Mitogen Activated Protein Kinase p38 signaling, phagolysosome maturation, and T-cells regulation is discussed. Statement of significanceIn the Mekong River Delta (Vietnam), striped catfish production is threatened by extensive sea water intrusion exacerbated by sea level rise. In fish, the effect of chronic exposure to salinity stress on immune capacities and response to disease has been poorly investigated. This study aims to highlight the main molecular changes occurring in the kidney during acclimation to salinity stress, particularly those involved in the immune defences of fish.

Triploid striped catfish Pangasianodon hypophthalmus: growth performance and gonadal development

&lt;p&gt;&lt;strong&gt;ABSTRACT &lt;/strong&gt;&lt;/p&gt;&lt;p&gt; &lt;/p&gt;&lt;p&gt;This study was aimed to evaluate the growth performance and gonadal development of diploid and triploid striped catfish &lt;em&gt;Pangasianodon hypophthalmus&lt;/em&gt;. Triploids were produced through a heat shock method at 42 °C for two minutes, at two minutes after fertilization. Before treatment performed, group of triploid and diploid were separated through nucleolus counting confirmed cromoseme counting. Five individual of each group at the age of nine months were tagged and reared for two months. Parameter of growth performance, feed conversion ratio, and survival rate were analysed using &lt;em&gt;independent-samples t-test &lt;/em&gt;at confidence interval 95%, while gonadosomatic index (GSI) and gonad histology were analysed descriptively. No significant differences were observed between diploid and triploid fish in terms of growth performance, feed conversion ratio, and survival rate (P&amp;gt;0.05) during the two months rearing period, while GSI was higher in diploid (P&amp;lt;0.05) compared to triploid females. Histological observations of triploid female gonads showed early development stage, indicating sterility through symptoms such as oocytes degradation and abnormal development. Meanwhile, male gonad developed faster compared to female as spermatids were found in several lobules. As conclusion, diploid and triploid striped catfish &lt;em&gt;P. hypophthalmus &lt;/em&gt;growth performance did not differ up to the age of 11 months, although some sterility symptoms were observed in both male and female.&lt;/p&gt;&lt;p&gt; &lt;/p&gt;&lt;p&gt;Keywords: diploid, triploid, growth, gonad, &lt;em&gt;Pangasianodon hypophthalmus &lt;/em&gt;&lt;/p&gt;&lt;p&gt;&lt;em&gt; &lt;/em&gt;&lt;/p&gt;&lt;p&gt; &lt;/p&gt;&lt;p&gt;&lt;strong&gt;ABSTRAK &lt;/strong&gt;&lt;/p&gt;&lt;p&gt; &lt;/p&gt;&lt;p&gt;Penelitian ini bertujuan untuk mengevaluasi performa pertumbuhan dan perkembangan gonad ikan patin siam &lt;em&gt;Pangasianodon hypophthalmus &lt;/em&gt;diploid dan triploid. Triploid diproduksi dengan kejut suhu panas pada suhu 42 °C selama dua menit, pada dua menit setelah fertilisasi. Sebelum pengujian, kelompok diploid dan triploid dipisahkan dengan menganalisis jumlah nukleolus yang dikonfirmasi dengan penghitungan jumlah kromosom. Masing-masing lima ekor ikan diploid dan triploid pada umur sembilan bulan ditandai dan dipelihara selama dua bulan. Parameter pertumbuhan, rasio konversi pakan, dan kelangsungan hidup dianalisis menggunakan &lt;em&gt;independent-samples t-test &lt;/em&gt;pada selang kepercayaan 95% sedangkan gonadosomatik indeks (GSI) dan histologi gonad dianalisis secara deskriptif. Pertumbuhan, rasio konversi pakan, dan kelangsungan hidup antara diploid dan triploid selama dua bulan pemeliharaan tidak menunjukkan perbedaan yang nyata (P&amp;gt;0,05). Nilai GSI diploid lebih tinggi (P&amp;lt;0,05) dibandingkan triploid, baik pada jantan maupun betina. Hasil histologi menunjukkan bahwa gonad ikan patin betina masih pada tahap perkembangan awal. Namun, indikasi steril terlihat dengan adanya degradasi oosit dan perkembangannya yang terganggu. Gonad jantan berkembang lebih cepat dibandingkan betina, dengan ditemukannya spermatid pada beberapa lobule. Gonad jantan triploid menunjukkan adanya gejala sterilitas tetapi tidak permanen, sebagian masih mampu berkembang hingga fase spermatid, namun jumlahnya lebih sedikit dibandingkan diploid. Berdasarkan penelitian, disimpulkan bahwa pertumbuhan antara ikan patin siam diploid dan triploid hingga umur 11 bulan tidak menunjukkan perbedaan, akan tetapi gejala sterilitas ditemukan baik pada jantan maupun betina triploid.&lt;/p&gt;&lt;p&gt; &lt;/p&gt;&lt;p&gt;Kata kunci: diploid, triploid, pertumbuhan, gonad, &lt;em&gt;Pangasianodon hypophthalmus&lt;/em&gt;&lt;/p&gt;