Effects of different physical shocks and sampling time on lipid content and fatty acids composition of Nannochloropsis oculata

The microalga Nannochloropsis oculata is marine widely used in aquaculture systems as an essential source of protein, lipid, and polyunsaturated fatty acids. Day/night pH fluctuations driven by photosynthesis and respiration create an environment that exhibits changing pH ranges. The aim of this study was to find whether physical shocks could change the complete pro?le of nutrients (lipid, fatty acid, carbohydrate, chlorophylls, and proteins) in N. oculata. The algae were cultivated in 32 flasks of ten-liter for biomass production for 12 days using Guillard medium (f/2). The cells were reared at 0.5 molar salinity (29 ppt), under 3500 lux light intensity with a 12L:12D photoperiod and 21ºC temperature. After 12 days, when the cell density reached its stationary phase, they were centrifuged. The pellets were then re-suspended in fresh seawater thoroughly and transferred into thirty-two containers with 10-liter volumes, including eight treatments with four replicates. The algae in treatments 3, 4, and 8 were subjected to salinity (88 ppt), starvation, and pH (11) shocks, respectively and treatments 2, 5, 6, and 7 were subjected to salinity + pH + starvation, pH + starvation, salinity + pH and salinity + starvation shocks, respectively. The biochemical composition of N. oculata demonstrated that T3 at the end of the dark period, and T1 at the end of the light period, possessed significantly higher (51.51%), and lower (24.9%) lipid content, respectively. According to the results, EPA under pH shock, linoleic acid under pH + salinity + starvation shock, and DHA and omega-3 under pH + salinity shock at the end of the dark period revealed significant differences with the control group. The saturated fatty acids showed significantly higher value in the control group during the dark period. The monounsaturated fatty acids increased significantly under pH shock at the end of the light period on day 18. Based on the results, the best treatment to obtain more lipid production in N. oculata was using six-day salinity shock and harvesting algae at the end of the dark period, and for more EPA synthesis in N. oculata, pH shock for six days and harvesting the algae at the end of dark period is recommended

Optimizing the co-feeding strategy of Persian sturgeon (Acipenser persicus) larvae using Artemia nauplii and formulated diet

High mortality and labor costs are associated with first-feeding sturgeon culture, particularly during the period of dietary transition from live to formulated feed. Therefore we investigated the effects of various feeding treatments on the survival and growth of the Persian sturgeon (Acipenser persicus) larvae during a 20-day culture period. Three replicate groups (250 fish/replicate) of first-feeding larvae were fed according to four main feeding regimes: (1) live food (live nauplii of brine shrimp Artemia urmiana); (2) indirect transition (5 days live food followed by gradual transition to formulated diet); (3) direct transition (using different combinations of live and formulated diet from the start feeding onwards); (4) formulated feed (FD) from the start feeding. Results indicated that growth and survival were higher in the indirect transition feeding regime than in other regimes. Based on our study, co-feeding of A. persicus should start five days after prior feeding with live food

Improving co‐feeding strategies for Neotropical green terror cichlid (Aequidens rivulatus) larvae with lecithin‐enriched Artemia franciscana nauplii: Effects on survival, growth performance and body composition

The effects of feeding on a commercial diet and lecithin‐enriched (EN) Artemia franciscana nauplii for improving co‐feeding strategies of Neotropical green terror cichlid (Aequidens rivulatus) larvae were conducted. For this purpose, eight groups of fish in triplicates were assigned with two different diets (unenriched Artemia [UN] and EN Artemia) and four feeding regimes (1, 5, 10 and 25 days feeding with UN and EN diets and then a 10% daily replacement Artemia nauplii with commercial diet). The crude lipid (21.4%) and total polar lipid (12.96% of total crud lipid) levels significantly increased in enriched Artemia nauplii (p < 0.05). The highest amount of saturated fatty acids (SFA) were in enriched and UN Artemia nauplii (41.74% and 49.64% respectively) but the highest level of monounsaturated fatty acids (MUFA) (25.69%) and polyunsaturated fatty acids (PUFA) (49.11%) were obtained in commercial diet. Growth performance of fish fed 10 EN and 5 EN had significantly higher values of total weight (120.67, 120.31 mg), %WG (584.48, 580.50%) and SGR (7.69, 7.67%) respectively (p < 0.05). Nevertheless, fish fed 25 EN had significantly higher FCE (190.4%), PER (3.95) and NPU (202.5), in comparison with other groups. In terms of body composition, the EN Artemia nauplii led to increased lipid contents in 25 EN, 10 EN and 5 EN treatments. In conclusion, the results of this study revealed that feeding regimes of 10 EN and 5 EN could improves survival and growth performance of Neotropical green terror cichlid, A. rivulatus larvae.info:eu-repo/semantics/acceptedVersio

Lecithin-enriched Artemia combined with inert diet and its effects on reproduction and digestive enzymes of Aequidens rivulatus

The present study investigated the effects of soybean lecithin bioencapsulated in adult Artemia franciscana and unenriched Artemia in combination with an inert diet on digestive enzymes activity and reproductive performance in Aequidens rivulatus (green terror cichlid). Eight hundred and ten fish (3.1 ± 0.2 g) were randomly allotted into glass tank (80 L) and assigned to ten dietary treatments with 5 different levels (0, 25, 50, 75, and 100%) of either lecithin-enriched Artemia (EA) or unenriched Artemia (UA) over a period of 90 days. The amount of total polar lipid increased from 39.2% in the unenriched Artemia to 43.7% in the lecithin-enriched Artemia (P < .05). The fish fed with 50% EA had higher total weight, and total length compared with other groups (P < .05). The peculiar functions of total alkaline proteases, α-amylase, and lipase in green terror increased in the groups fed with lecithin-enriched Artemia, compared to the un-enriched groups (P < .05). The highest total alkaline proteases activity was observed in the fish fed with 75% EA treatment. In comparison to the other groups, fish fed 100 and 0% levels of Artemia replacement had significantly highest and lowest α-amylase activity values, respectively. Concerning reproductive performance, the highest average fecundity, egg diameter, egg weight, fertilization, hatching, and larval survival rates, as well as the lowest time between two spawning episodes, were obtained in fish fed 50% EA. In conclusion, this feeding strategy is advisable for a proper nutritional management of broodfish of green terror cichlid.info:eu-repo/semantics/acceptedVersio

Dietary fatty acid profiling in plant protein‐rich diets affects the reproductive performance, egg fatty acid profile and haematological parameters in female rainbow trout (Oncorhynchus mykiss)

The influence of dietary fish oil (FO) substitution with blends of vegetal oils (VO: canola, linseed, olive, sunflower, corn and coconut oils) in plant protein‐rich diets on reproductive performance and fatty acid dynamics of embryos was evaluated in female rainbow trout (Oncorhynchus mykiss) brooders (1.8 ± 0.1 kg). Four diets were formulated in which 20% (FO80/VO20), 50% (FO50/VO50), 75% (FO25/VO75) and 100% (VO100) of FO were replaced by mixture of VO. The above‐mentioned diets were administered for a short period prior to spawning (3 months). Fish fed the VO100 had the lowest fertilization rate (81.3 ± 2.3), whereas brooders fed the FO80/VO20 diet had the lowest survival rates at eyed embryo stage (83.7 ± 1.6%) and hatching rate (79.9 ± 3.1%). The fatty acid dynamics of embryos were not only affected by embryonic developmental stages, but also they were influenced by the dietary fatty acid profile. Our study confirmed that using blends of different VO sources and FM residual fat in the FO25/VO75 for the short‐term period prior to spawning seemed to be a good strategy in terms of successful reproduction for sparing high levels of FM and FO in diet of O. mykiss brooders.info:eu-repo/semantics/acceptedVersio

Dietary conjugated linoleic acid (CLA) and lecithin affects levels of serum cholesterol, triglyceride, lipoprotein and hypoxic stress resistance in rainbow trout (Oncorhynchus mykiss)

Considering the role of conjugated linoleic acid (CLA) and soybean lecithin (SBL) in fat digestion, absorption and metabolism as well as stress resistance in aquatic organisms, the current study was a 74-day attempt to investigate the synergistic effects of these two compounds on stress resistance and blood lipoprotein levels of rainbow trout (Oncorhynchus mykiss) weighing 120±5 g. Nine isonitrogenous and isocaloric experimental diets containing 1, 2 and 3% CLA and 2, 3 and 4% soybean lecithin on the basis of the basal control diet (free from CLA and lecithin) were formulated. The fish were exposed to three ascending periods of hypoxic stress (7.5, 15 and 30 min) at the end of culture period. The dissolved oxygen was decreased to 1.96 ppm by injecting nitrogen gas. Significantly higher levels of cortisol and glucose were detected in fish fed on diets having higher levels of SBL (2%) and CLA (3%) at higher stress time improving the resistance to hypoxia stress (P≤0.05). Moreover, levels of triglyceride (TRG), cholesterol (COL), low density lipoprotein (LDL), very low-density lipoprotein (VLDL) and high density lipoprotein (HDL) also increased significantly compared to the control group (P≤0.05). This study reveals that using 2% SBL and 3% CLA in rainbow trout feed can promote resistance to hypoxic stress

Investigating the effect of input consumption on land depletion and the potential for damage to environmental pollutants in the climatic conditions of Gorgan and Zahedan

Nowadays, following the development of agriculture, there are concerns about adverse environmental consequences such as water, soil, air pollution, reduced fertility, soil erosion, and depletion of resources based on the use of non-renewable inputs that need to be addressed. It's about. This study was conducted to investigate the effect of input consumption on land depletion and the potential for damage to environmental pollutants in the climatic conditions of Gorgan and Zahedan during the 2019-2020 crop year. In this study, the fuel consumption of diesel, water, vermicompost fertilizer, use of nitrogen fertilizer nano-chelate, phosphorus nano-chelate and potassium nano-chelate, and complete use of chemical fertilizer (from urea, triple superphosphate, and potassium sulfate) as inputs were considered prone to environmental damage. In general, for the production of one ton of portulaca oleracea, Gorgan city creates less environmental burdens than Zahedan city due to less consumption of inputs in all sectors. Based on the results of the final index, it can be concluded that among the impact groups, the impact group of global warming with a value of 5.819 kg (kg CO2 eq.) in Zahedan city and 5.814 kg (kg CO2 eq.) in Gorgan city in the production of one ton of portulaca oleracea has more potential for environmental damage than other impacts, then the impact group of fossil resources depletion at the rate of 4.489 MJ / kg (kg equivalent to crude oil) in both Zahedan and Gorgan has the potential Environmental damage. Based on the evaluation results of the environmental index (Eco-X) and resource depletion index (RDI) for the production of one ton of portulaca oleracea, Zahedan city has a higher environmental index (Eco-X = 5.819) than Gorgan city (Eco-X = 814.5) showed and created more environmental burdens. However, the resource depletion index (RDI), considering the 100-year target time interval, which means the time when the resource is expected to be available, is for Zahedan city (RDI = 7.677) and Gorgan city was calculated at the rate of (RDI = 5.945)

Effects of dietary soybean lecithin on growth performance, blood chemistry and immunity in juvenile stellate sturgeon (Acipenser stellatus)

An eleven weeks feeding trial was conducted to determine the effects of different levels of dietary soybean lecithin (SBL) on growth performance, blood chemistry and immunity in juvenile stellate sturgeon (Acipenser stellatus). Fish were fed seven isoproteic (44% crude protein) and isolipidic (17% crude fat) diets containing graded levels of SBL: 0 (control), 1, 2, 4, 6, 8 and 10%. Results showed that dietary SBL supplementation significantly improved the final body weight (BW) and weight gain (WG). Fish fed 6% SBL showed the highest BW and WG values in comparison to fish fed the control diet (P 6%, >4%, >2% and 2% SBL, respectively (P < 0.05). Based on somatic growth parameters, blood chemistry and systemic immunity parameters, diets containing ca. 6% SBL are recommended for juvenile stellate sturgeon.info:eu-repo/semantics/acceptedVersio

Effects of zinc oxide nanoparticles on renal function in mice

Background: Considering the medical applications of zinc oxide nanoparticles, evaluating their adverse effects on the organisms is important. Materials and Methods: In this study, the effect of a single injection (ip) of zinc oxide nanoparticles (50, 100, 200, 300mg/kg) on changes in the renal parameters (uric acid, creatinin, urea) was studied after 8 and 30 days of the treatment. Results: Results showed that the urea and creatinine levels in the 300 mg/kg group were significantly increased 8 days after the injection (P<0.001). The amount of uric acid reduced significantly in all the groups compared to the control group (P<0.001), while no significant difference was found between the groups 30 days after the injection. Conclusion: It seems that a single injection of zinc oxide nanoparticles, especially at high doses (300 mg/kg), has a short-term effect (8 days) on the renal function, but after a month, possibly with the gradual elimination of nanoparticles uptake into the kidney, these effects disappear. However, further studies with more injections are essential

Optimizing the co-feeding strategy of Persian sturgeon (Acipenser persicus) larvae using Artemia nauplii and formulated diet

High mortality and labor costs are associated with first-feeding sturgeon culture, particularly during the period of dietary transition from live to formulated feed. Therefore we investigated the effects of various feeding treatments on the survival and growth of the Persian sturgeon (Acipenser persicus) larvae during a 20-day culture period. Three replicate groups (250 fish/replicate) of first-feeding larvae were fed according to four main feeding regimes: (1) live food (live nauplii of brine shrimp Artemia urmiana); (2) indirect transition (5 days live food followed by gradual transition to formulated diet); (3) direct transition (using different combinations of live and formulated diet from the start feeding onwards); (4) formulated feed (FD) from the start feeding. Results indicated that growth and survival were higher in the indirect transition feeding regime than in other regimes. Based on our study, co-feeding of A. persicus should start five days after prior feeding with live food