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This study was designed to assess the influence of dietary supplementation with Gum Arabic at various levels in Nile tilapia fish, Oreochromis niloticus. For 56 days feeding period, a total of 200 juvenile fish were allocated into 20 aquariums and divided into four equal groups, five replicates each, with Gum Arabic (GA) dietary inclusion as follow; the fish group was given a basal diet (CTR 0%); fish group fed a diet supplemented with GA 0.25%; fish group fed a diet supplemented with GA 0.5%; and fish group fed a diet supplemented with GA 1%. Dietary supplementation with 0.5 or 1% GA significantly improves final fish biomass, weight gain, weight gain percent, consumed feed, feed conversion ratio, innate immune response and antioxidant status compared to other treatments. The fish fed elevated levels of GA (1% GA) exhibited higher lipase and amylase activities as well as total protein, albumin, and globulin levels and lower uric acid, AST, and ALT levels. Furthermore, 1% GA enriched tilapia diets significantly up-regulated IL-1β and IL10 , whereas downregulated TNFɑ mRNA expression in kidney and spleen tissues. Moreover, highly-AG enriched diets were associated with stronger antibacterial efficacy against pathogenic bacterial populations, together with increased counts of grown Bacillus in the mid gut. Overall, these findings suggest that dietary inclusion of 1% GA could be beneficial and should be explored as a functional feed supplement for Nile tilapia farming. • Arabic Gum (AG) dietary administration (0.25 to 1%) was studied in Oreochromis niloticus. • Enhanced growth performance was observed in the fish fed diet containing 0.5 and 1% AG. • High levels of AG boosts antioxidant, immune responses, and upregulated pro-inflammation gene transcription of tilapia. • AG significantly increased digestive enzymes activities of O. niloticus gastrointestinal tract. • AG showed a strong antibacterial activity against intestinal pathogens. [ABSTRACT FROM AUTHOR]

Summary: The present study is focused on the intensity distribution of rainfall in different classes and their contribution to the total seasonal rainfall. In addition, we studied the spatial and diurnal variation of the rainfall in the study areas. For the present study, we retrieved data from TRMM (Tropical Rain Measuring Mission) rain rate available in every 3h temporal and 25km spatial resolutions. Moreover, station rainfall data is used to validate the TRMM rain rate and found significant correlation between them (linear correlation coefficients are 0.96, 0.85, 0.75 and 0.63 for the stations Kota Bharu, Senai, Cameron highlands and KLIA, respectively). We selected four areas in the Peninsular Malaysia and they are south coastal, east coastal, west coastal and highland regions. Diurnal variation of frequency of rain occurrence is different for different locations. We noticed bimodal variation in the coastal areas in most of the seasons and unimodal variation in the highland/inland area. During the southwest monsoon period in the west coastal stations, there is no distinct diurnal variation. The distribution of different intensity classes during different seasons are explained in detail in the results. [Copyright &y& Elsevier]

The current work was planned to assess the effects of dietary microalga, Nannochloropsis oculata (NP) on the growth indices, serum biochemistry, non-specific immunity, and resistance of Nile tilapia (Oreochromis niloticus) juveniles against challenge with pathogenic Aeromonas veronii. Fish (10.21 ± 0.28 g) were randomly divided into four treatments in triplicates and were fed on diets supplemented with different levels of NP (0, 5, 10, and 15%) for eight weeks. The results showed that the dietary 5% NP significantly improved the growth parameters (final body weight, weight gain, specific growth rate, and total feed intake) (P < 0.05). Meanwhile, the feed conversion ratio was significantly decreased in NP-supplemented groups with respect to the control group. The serum protein profile (total protein, albumin, globulin, and albumin/globulin ratio) was significantly decreased by 15% NP supplemented group. Meanwhile, liver enzymes (alanine transaminase, and aspartate transaminase) activities were not significantly affected by NP dietary supplementation (P < 0.05). Serum lysozyme activity, nitric oxide (NO), and nitroblue tetrazolium (NBT) levels were significantly enhanced only in 5% NP supplemented group (P < 0.05). Interestingly, the hepatopancreatic and intestinal tissues had apparently normal histomorphology of Nile tilapia fed at 5% NP-supplemented diets. Significant upregulation of cytokines [interleukin 1beta (IL-1β), interleukin 8 (IL-8), interferon-gamma (IFN-γ), transforming growth factor-beta (TGF- β), and tumor necrosis factor-alpha (TNF-α)], with significant downregulation of the antioxidant gene [superoxide dismutase (SOD)] in 10% and 15% NP supplemented groups. Attractively, the relative level of protection (RLP) against challenge with pathogenic A. veronii was significantly elevated in 10% and 15% NP supplemented groups. Conclusively, the obtained results reflect the beneficial roles of dietary NP to improve growth and boost the immune responses of Nile tilapia. • Different levels of Nannochloropsis oculata (NP) were included in the diets of Nile tilapia. • Fish fed 5% NP-supplemented diets had better growth performance indices. • 5% NP-enriched diets improved the non-specific immunity of Nile tilapia. • 5% NP diets maintained normal histomorphometric characters of fish intestine and liver. • Upregulation of the immune-related genes were observed in fish groups fed 10 and 15% NP-supplemented diets. [ABSTRACT FROM AUTHOR]

Ozone (O 3 ) is an important ground-level pollutant. O 3 levels and emissions of O 3 precursors have increased significantly over recent decades in East Asia and export of this O 3 eastward across the Pacific Ocean is well documented. Here we show that East Asian O 3 is also transported southward to tropical Southeast (SE) Asia during the Northeast Monsoon (NEM) season (defined as November to February), and that this transport pathway is especially strong during ‘cold surges’. Our analysis employs reanalysis data and measurements from surface sites in Peninsular Malaysia, both covering 2003–2012, along with trajectory calculations. Using a cold surge index (northerly winds at 925 hPa averaged over 105–110°E, 5°N) to define sub-seasonal strengthening of the NEM winds, we find the largest changes in a region covering much of the Indochinese Peninsula and surrounding seas. Here, the levels of O 3 and another key pollutant, carbon monoxide, calculated by the Monitoring Atmospheric Composition and Climate (MACC) Reanalysis are on average elevated by, respectively, >40% (∼15 ppb) and >60% (∼80 ppb) during cold surges. Further, in the broader region of SE Asia local afternoon exceedances of the World Health Organization's air quality guideline for O 3 (100 μg m −3 , or ∼50 ppb, averaged over 8 h) largely occur during these cold surges. Day-to-day variations in available O 3 observations at surface sites on the east coast of Peninsular Malaysia and in corresponding parts of the MACC Reanalysis are similar, and are clearly linked to cold surges. However, observed O 3 levels are typically ∼10–20 ppb lower than the MACC Reanalysis. We show that these observations are also subject to influence from local urban pollution. In agreement with past work, we find year-to-year variations in cold surge activity related to the El Nino-Southern Oscillation (ENSO), but this does not appear to be the dominant influence of ENSO on atmospheric composition in this region. Overall, our study indicates that the influence of East Asian pollution on air quality in SE Asia during the NEM could be at least as large as the corresponding, well-studied spring-time influence on North America. Both an enhanced regional observational capability and chemical modelling studies will be required to fully untangle the importance of this long-range influence relative to local processes. [ABSTRACT FROM AUTHOR]

Summary: Using the rain rate from Tropical Rainfall Measuring Mission (TRMM) 3h data, we made an attempt to explore the diurnal variation of rainfall occurrences in the spatial domain of Peninsular Malaysia. This data set is available for 10years period from 1999 to 2008 at a high spatial resolution of 25km latitude–longitude grid. The rainfall characteristics such as the percentage of rain occurrence and the relative contribution to the total seasonal rainfall in different intensity classes have been studied in detail for different seasons namely northeast monsoon (DJF), pre-monsoon (MAM), southwest monsoon (JJA) and early northeast monsoon (SON). We arbitrarily classified the rainfall into four different categories such as small, moderate, high and very high intensity classes. The diurnal variation of frequency of rainfall over the spatial domain of Peninsular Malaysia during different seasons is presented in detail. The diurnal variation is different in the coastal areas and the central parts of the Peninsula in all the seasons. Two peaks are noticed in the coastal areas, however, in the inland regions only a prominent single peak is observed. From the analysis of the very high intensity classes, we observed that the flash flood prone areas are east coastal belt especially the coastal belt from Kuantan to Kota Bharu during the northeast monsoon season. Isolated maxima were also observed in the western region surrounded by Klang Valley during the same season. During the southwest monsoon period, flash floods may be expected over the latitudinal belt between 2°N and 4°N. The number of occurrences of very high rainfall events and their relative contribution to the seasonal rainfall are high over the above region. [ABSTRACT FROM AUTHOR]

A 56-day feeding experiment was carried out to investigate the influences of dietary organic selenium (OS) on the growth, body composition, serum biochemistry, stress responses, and immune indices of Nile tilapia reared under sub-optimal temperature. Fish (5.61 ± 0.5 g) were allotted in seven experimental groups (5 replicates per each) and fed on a basal diet supplemented with 0.0 (CTR), 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 mg OS/kg diet and reared under temperature ranged 21.50 ± 0.50 °C. Final body weight, weight gain, and specific growth rate were significantly increased in OS groups compared to the CTR group. Moreover, the feed conversion ratio was significantly decreased in OS groups, especially at fish groups fed 0.3–0.6 mg OS/kg diet compared to the other groups. The lowest survival rate (%) was found in OS groups between 0.0 and 0.2 mg/kg diet. A significant increase in the crude protein (%) and dry matter (%) in OS groups alongside a significant decrease in the ash (%) compared to the CTR group. Blood proteins (total protein, albumin, and globulin), reduced glutathione, immunoglobulin M, and complement C3 values alongside the serum lysozyme and catalase activities were significantly increased compared to the CTR group. Contrarywise, serum transaminases (alanine transaminase and aspartate transaminase), cortisol, urea, and creatinine values were significantly decreased in OS groups than the CTR group. No significant differences were noticed in the mRNA transcripts of the hepatic heat shock protein 70 among all experimental groups. Meanwhile, significant differences were observed in the mRNA transcripts of hepatic heat shock protein 27, superoxide dismutase, and glutathione peroxidase genes among all experimental groups. The second order polynomial regressions illustrated that the optimal inclusion OS level in diets for Nile tilapia reared under sub-optimal temperature is 0.36–0.39 mg/kg diet based on weight gain and cortisol levels, respectively. Conclusively, the present study exemplified that dietary inclusion with 0.36–0.39 mg OS/kg diet improved the growth, immunity and modulate the stress responses in Nile tilapia reared under sub-optimal temperature. • Dietary organic selenium (OS) improved the growth performance of Nile tilapia reared under sub-optimal temperature. • Fish reared under sub-optimal temperature and fed OS-supplemented diets had an increased antioxidative capacity and immune responses than those fed the basal diet. • OS upregulated antioxidative genes of Nile tilapia reared under sub-optimal temperature. • The optimum dietary requirements of OS for Nile tilapia reared under sub-optimal temperature is 0.36–0.39 mg/kg diet. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the antioxidative and immunity roles of diets supplemented with ChNP and vitamin C on Oreochromis niloticus against sublethal Imidacloprid (IMID) toxicity effects. A total of healthy 210 tilapia fish (average initial weight 21.21 ± 0.05 g) were separated into seven groups: The first group reared on clean water and were fed a basal diet (control group which was called group C). The other six fish groups were stocked in water contaminated with sublethal IMID concentration (0.01 μg L−1) and fed supplemented diets as follows: IMID (basal diet), ChNP (5 g ChNP kg−1 diet), VC 1 (250 mg vitamin C kg−1 diet), VC 2 (250 mg vitamin C kg−1 diet), ChNP+ VC 1 (5 g ChNP +250 mg vitamin C kg−1 diet), and ChNP+ VC 2 (5 g ChNP +500 mg vitamin C kg−1 diet). The results indicated significant enhancement in all growth-performance parameters, body indices, and Survival Rates (SR) by the dietary-combined ChNP and vitamin C levels. Additionally, a diet supplemented with a combination of ChNP and vitamin C (ChNP+VC 1 and ChNP+VC 2) significantly decreased imidacloprid residual concentration in fish tissue compared with the IMID group. A marked increment of both hematological and antioxidative enzymes and innate immunity parameters were fortified with dietary ChNP supplementation combined with high vitamin C levels. The liver histopathological examination showed a clear improvement in all treated groups and seemed to be a normal structure in the dietary-combined ChNP and vitamin C groups. In conclusion, the combined dietary supplementation of ChNP and vitamin C exerted a beneficial health effect against imidacloprid toxicity in tilapia. • The dietary combining vitamin C and ChNP showed an immunomodulatory against imidacloprid toxicity of Nile tilapia. • ChNP and vitamin C supplementation improved growth and feed utilization under pesticides polluted water. • Non-specific immunity besides antioxidant status increased in ChNP and vitamin C groups exposed to imidacloprid toxicity. • Dietary vitamin C combined with ChNP enhancing hepatocytes structure, and fish health under sublethal imidacloprid toxicity. [ABSTRACT FROM AUTHOR]

There is an interesting in using of medical and aromatic plants or spices as feed additives in fish diets instead of chemical products to avoid side effects and achieve organic aquaculture. Feeding experiment was conducted to evaluate the growth of the Nile tilapia fingerlings fed four isonitrogenous (30% crude protein) experimental diets containing different levels 0.0% (control), 1.0%, 1.5%, or 2% of Moringa lectin (MLM). The diet containing 1.5% MLM resulted in significantly greater (P < 0.05) specific growth rate (SGR), feed conversion ratio (FCR). Moreover, PER and APU values increased significantly at MLM-supplemented diets. While, there was no significant difference among all treatments of MLM in EU%. In regard to body composition, there was no significant difference in dry matter, lipids, and ash (P > 0.05) contents due to lectin supplementation. While, crude protein content increased significantly by increasing the MLM levels (P<0.05). Blood plasma profile showed an improvement in hemoglobin (HB), red blood cell (RBCS), hematocrite (Hct), WBCs, Lymphocytic, Monocytic, Granulocyte, glucose and gloubin, while, there was a decrease in total protein, total lipids, decrease in creatinine, urea, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and cholesterol in fish fed 1.5% MLM. Moringa lectin supplementation enhance non-specific immune response of O. niloticus as lysozyme activity and respiratory burst activity showed significant increase in group fed 1.5 MLM then group fed 2 % followed by 1 % than control group. Moringa lectin was found to have an antibacterial activity antagonistic to Aeromonas hydrophila infection in fish. Improvement in Superoxide dismutase activity (SOD), Catalase activity (CAT), Glutathione S-transferase (GST) and Malondialdehyde (MDA) activities were observed at 1.5% MLM activities which was consistent with the immune response. Performance and FCR improvement translated into a 22.74% decrease in feed costs associated with the 2% MLM diet. [ABSTRACT FROM AUTHOR]

The present study was performed to evaluate the toxic effects of imidacloprid (IMI) insecticide on the growth performance, oxidative status, and immune response of Nile tilapia, Oreochromis niloticus (L.), and the protective role of dietary supplementation of spirulina, Arthrospira platensis, (SP). Fish (20.2 ± 0.5 g) were assigned to bifactorial design (2 IMI levels x 3 SP levels) to represent 6 treatments in triplicates. Spirulina was incorporated in diets at levels of 0.0 (control), 20, and 40 g/kg diet. Under each SP level, fish were exposed to 0.0 or 0.05 μg IMI/L. Fish in each treatment were fed on the corresponding diets up to apparent satiation thrice a day for 8 weeks. Two-way ANOVA revealed a significant decline in growth indices, hepatic superoxide dismutase, catalase, and glutathione peroxidase activities in the IMI-exposed fish. Contrariwise, serum alanine and aspartate aminotransferases, alkaline phosphatase, urea, creatinine, and malondialdehyde levels were markedly higher along with significant reductions of the reduced glutathione, nitric oxide as well as lysozyme values in the IMI-exposed fish group. The dietary supplementation of SP showed stimulating effects on the growth performance, haemato-biochemical, oxidants/antioxidants, and immune biomarkers of Nile tilapia with optimum level of 20 g SP/kg diet. Interestingly, the dietary supplementation of SP to Nile tilapia attenuated the above-mentioned variables with improving the growth performance, haemato-biochemical, oxidative stress, and immunity biomarkers. Therefore, the dietary supplementation of 20 g SP /kg diet could be a valuable candidate as a natural antioxidant for ameliorating the IMI toxicity in Nile tilapia. [Display omitted] • The protective effect of dietary SP on the growth and welfare of IMI-intoxicated Nile tilapia was investigated. • The IMI toxicity significantly retarded the growth, haemato-biochemical, and immunity variables in fish. • The dietary SP improved the growth, oxidative stress, and immunity biomarkers. • The dietary SP has antagonistic function against the IMI toxicity in Nile tilapia. • The dietary SP (20 g/kg diet) is a recommended candidate for ameliorating IMI toxicity in Nile tilapia. [ABSTRACT FROM AUTHOR]