Dietary cinnamon supplementation has several bioactive compounds with growth-promoting and immunomodulation potential, which is suggested for finfish species. This study evaluated the inclusion of cinnamon at 0, 1, 3, 6, and 12 g/kg diet in Oncorhynchus mykiss fingerlings. After eight weeks, the best growth performance, and feed utilization parameters were calculated in fish treated with 12 g/kg (P < 0.05). Further, the white blood cells and lymphocyte levels were significantly increased and Neutrophil was significantly decreased in fish fed cinnamon at 12 g/kg compared to those fed 0-6 g/kg (P < 0.05). After the feeding trial, in the studied immune and biochemical indices, immunoglobulin ROS, Lysozyme was significantly increased (P<0.05), and Glucose decreased significantly (P < 0.05) in fish treated with cinnamon at 12 g/kg compared to fish fed 0-6 g/kg. Moreover, treated fish with cinnamon had higher levels of C3, C4, total protein and Albumin than the control with the highest value in fish treated with 12 g/kg. The results showed the positive influence of the inclusion of cinnamon in the diets for rainbow trout fingerlings on the growth performance, feed utilization, blood analysis, and immune functions. According to the results, it can be concluded that 12 g cinnamon powder per kg diet is suggested with no adverse effects to improve growth performance, feed utilization and health status in rainbow trout fingerlings.
The present study evaluated the influence of acidic polysaccharide extracted from Sargassum polycystum (SAPE) on growth, immunological responses and resistance to Vibrio harveyi infection of juvenile Penaeus monodon. Five experimental diets supplemented with 100, 500, 1000 and 1500 mg/kg SAPE including a control (0 mg/kg) were formulated and fed to juvenile P. monodon for 50 days. Following the feeding trial growth indices including weight gain and specific growth rate were significantly enhanced, (P < 0.05), in treatment groups fed with diets containing 2000 mg/kg SAPE. Highest survival (46.67 +/- 11.54%, P < 0.05) following the infection challenge test with the pathogenic V. harveyi was observed in the treatment group receiving the 2000 mg/kg SAPE supplementation while all shrimp died in the group receiving the control diet. The enhanced resistance to bacterial infection of SAPE treatment groups was further supported by improved immune responses (P < 0.05) including total hemocyte counts and serum antibacterial activities. The present study indicates that dietary supplementation of acidic polysaccharide extracted from Sargassum polycystum at a dose of 2000 mg/kg could enhance growth performance, elevate immune responses and significantly improve resistance of juvenile P. monodon against V. harveyi infection.
Tilapia is one of the most cultured fish species globally and over the last two decades, its culture has been intensified. However, water quality management in tilapia pond culture is a major barrier for higher productivity. This study assessed the water quality dynamics in 150 m(3) earthen ponds with or without fish over a period of 12 weeks. The two treatments were ponds stocked with fish (fed ponds) and ponds with water but no fish (control pond). The fed ponds comprised two ponds stocked with all-male Nile tilapia (Oreochromis niloticus) sub-adults (Mean mass similar to 40g) fed twice daily with a commercial feed (30% crude protein) while two other ponds were assigned as control. Physicochemical, biological water quality variables as well as nutrients were monitored in all ponds every four days over the 12 weeks. Dissolved oxygen (DO), pH, temperature and conductivity levels were measured in-situ between 7.00 and 8.00 a.m., while water samples were analysed in the laboratory for turbidity, total suspended solids (TSS), total dissolved solids (TDS), alkalinity, ammonia (NH3), nitrite (NO2), nitrate (NO3), ortho-phosphate, biological and chemical oxygen demand (BOD & COD), organic matter (OM) and organic carbon (OC). Additionally, a 24h DO monitoring as well as sludge accumulation and sludge characteristics were determined every three weeks in the experimental ponds. Mean DO levels over the trial duration was 42% lower in the fed ponds. The increased nutrient loadings from the fish and the supplementary feed presumably increased all biological WQ parameters measured which resulted in a higher sludge accumulated in the fed ponds. The fed ponds consistently recorded pre-sunrise DO levels of <1 mgL(-1) while the control ponds recorded DO levels >2 mgL(-1) during the same period. Generally, the results of the study showed deterioration of water quality was more evident in the fed ponds.
Microalgae are a sustainable food source for humans and aquatic organisms, and this study explores their nutritional and physiological importance. Marine and freshwater microalgae exist as microscopic photosynthetic organisms. In aquaculture, microalgae are used as food and as live feed for bivalve mollusks, juvenile stages of abalone, crustaceans and some fish species and as zooplankton in food chains. Using microalgae for food and aquatic feed is a sustainable and economically beneficial process. As a source of protein, omega-3, fatty acids and carotenoids, microalgae are more nutrient-dense than traditional forms of animal and aquatic feed, such as millet, grams and other small fish. In addition to being nutritious, they contain antioxidants, antimicrobials and disease-preventative molecules, extending the lifespan of humans and fish.
In the present study, we aimed to identify Saprolegnia spp. from infected rainbow trout eggs in a hatchery in the north (Mazandaran province) of Iran. Morphological identification was conducted by light microscopic observation of various life stages of Saprolegnia. For the molecular characterization, the internal transcribed spacer (ITS) region was amplified by using universal primers ITS 1 and ITS 4. Based on morphological and molecular findings, two Saprolegnia spp. have been identified. i.e., Saprolegnia parasitica (Isolate KMG3, MW819780) and S. salmonis (Isolates KMG1, MW819740 and KMG2, MW819707). It is worth mentioning that the latter - S. salmonis - is the first report in Iran. The phylogenetic tree inferred by a Neighbor-Joining model revealed that three representative isolates with a well-supported value together with the known isolates of S. parasitica and S. salmonis formed a well-defined clade. An in vitro experiment was conducted to study the growth of S. salmonis (KMG2) and S. parasitica (KMG3) at various incubation temperatures. Both species showed similar hyphal growth rates at 10 and 18 degrees C after 3 days of incubation (P > 0.05).
In an aquatic habitat, zooplankton organisms are an extremely valuable resource for aquaculture purposes. Potential zooplankton species (Ceriodaphnia cornuta) have been further explored to evaluate their applicability to fed fish larvae in freshwater aquaculture. There is a need to find more options other than Artemia as live food options in freshwater hatcheries. Thus, this study was conducted by enriching and unenriched C. cornuta (control). The result showed that the best growth performance of C. cornuta occurred when enriched with an F1 and F2 compared to F3 and F4. Meanwhile, the best initial age of reproduction occurred when enriched with F1+F3 and F3+F4 (3.67 ?? 0.57 days and 3.66 ?? 1.15 days). Besides, the gross and net reproduction rate of C. cornuta differed with other enrichments where F1+F3 has the highest rates (67.66 ?? 1.52 offspring/female and 56.32 ?? 0.90 offspring/female) compared to other treatments. The generation time for C. cornuta was shorter when enriched with F2 (7.11 ?? 0.88 days) and longer when enriched with F1+F3 (11.23 ?? 0.66 days). Other than that, the best growth performance of P. nasutus larvae occurs when fed with F1+F3. This study indicates that F1+F3 constitutes better sources of enrichment to improve the growth performance and life history of zooplankton.
The seaweed industry is a rapidly growing global industry. The present study aimed at empirically ascertaining the effect of different colours of visible light spectrum on morphology and growth rate of red algae (Gracilaria edulis), and agar yield and quality of the G. edulis to elucidate the most suitable depth range for culturing G. edulis commercially. Changes in colour and biomass of fresh G. edulis were recorded fortnightly, and the characteristics of agar extracted from G. edulis exposed to different colours of light (natural, red, green, and violet) were evaluated. G. edulis exposed to green light showed the highest growth rate, while the highest agar yield could be obtained from G. edulis exposed to red light. Comparatively higher gel strength, viscosity, and water holding capacity of extracted agar were reported in G. edulis exposed to red light. The growth rate & agar quality of G. edulis cultured under natural light were comparatively lower. The study confirms that G. edulis should be cultured under green light to obtain a significant growth rate and, G. edulis should be cultured under red light to obtain agar of better quality and quantity. Penetration depths of red and green light in the water column are up to 5m and 30m, respectively. Present findings unfold that culture facilities for G. edulis should be established at 1-5m water depths for obtaining a comparatively higher growth rate and high-quality agar. The study warrants empirical studies in-situ to make a robust conclusion.
Rapid population growth globally and urbanization have caused a significant drop in fossil fuel feedstocks, pushing countries to seek alternative sources. Microalgae are a feasible biofuel feedstock due to their high photosynthetic efficiency, which gives various potential benefits for the environmentally friendly biofuel production process, besides the high biomass productivity strains required for a longterm integrated platform. Consequently, modifying lipid metabolic pathways to increase lipid production in microalgae cells consider a viable strategy. Overexpression and transformation of key genes involved in lipid biosynthesis are regarded to be crucial methods for increasing lipid production. Whereas transformation and gene editing are two approaches affecting these alterations, that have been sufficiently established in microalgae, transforming these strains into a very adaptive stage for successfully designing ways to produce biofuel. The current mini-review focuses on potential strategies for improving microalgae metabolic engineering, specifically lipogenesis, by regulated overexpression of native genes or transgenes such as acetyl coenzyme-A carboxylase, diacylglycerol acyltransferase, and malic enzyme genes, as well as current limitations and gaps and future directions.
The bacterial genus Pseudoalteromonas is commonly found in the ocean and frequently associated with marine invertebrates. This bacterial group produces metabolites with antibacterial, algicidal, antifouling, and biofilm promoting activities that have interested the scientific community for years. Unlike corals, reports on diseased symbiotic, soft-body cnidarians are scarce, suggesting their surface mucus layer may be efficient in fighting potential bacterial pathogens. With the aim to study attributes of cnidaria-associated bacteria, we isolated a Pseudoalteromonas pigmented strain from the surface mucus layer of a bleached jellyfish Cassiopea xamachana with a 99,66% similarity to P. piscicida, as identified through 16S rRNA sequencing. This Pseudoalteromonas sp. yellow isolate specifically inhibited the growth of the potential bacterial pathogen Serratia marcescens, and an Aurantimonas sp. strain. This isolated Pseudoalteromonas strain also showed activity against epibionts, reducing the settlement of medusa larvae by 50% compared to controls. A 40% inhibition in the settlement of medusa larvae was scored for an organic extract prepared from a filtrate of the cultured isolate as well as positive protease activity. Overall, our results suggest Pseudoalteromonas sp. yellow isolate can fight potential pathogens and produce extracellular vesicles with metabolites that can influence the settlement and survival of larvae, presenting positive attributes for this animal host.
The present study aimed to evaluate the influence of different salinities on water quality, growth performance, and hematology of the Nile tilapia Oreochromis niloticus cultured in a biofloc system. Four different salinities with four replicates were evaluated: 2, 8, 15, and 22 PSU. The fish (200 ?? 10 g) were stocked at a density of 15 fish m-3 in tanks with 800 L of useful volume for 56 days. Fish were fed with a 32 % crude protein commercial feed. Water quality remained stable throughout the study. The growth parameters differed, with the salinities of 2 and 8 PSU presenting higher growth and survival. The treatment of 15 PSU showed high survival, however, with reduced growth. The salinity of 22 PSU had lower results than the others for all parameters analyzed. The hematological evaluation showed differences in RBC, hematocrit, and glucose counts, indicating that salinity may have caused stress to animals cultured at higher salinities, thus, causing low growth and survival. These results indicate that Nile tilapia can tolerate high salinities when cultured in a biofloc system. However, salinities above 15 PSU may compromise its growth and weight gain.
Microalgae are unicellular organisms with different shapes and sizes. Wide range of biomolecules (protein, fatty acids, carotenoids, phycobiliproteins, etc.) could be produced and accumulated by these organisms. P. cruentum is known as a source of high-value biomolecules named phycobiliproteins. These pigments used in various areas such as food, cosmetics, nutraceutical and pharmaceutical industries. In this study, the effect of ferric chloride (FeCl3) concentration (0.234 x 10(-5) - 1.17 x 10(-5)M) in F/2 medium on growth and pigment composition of P. cruentum was investigated. Using the 0.585 x 10(-5) M of FeCl3 (group C) provides higher cell number than other concentrations on P. cruentum culture (P<0.05). The 0.234 X 10(-5) FeCl3 was provided the highest phycoerythrin production while the highest cellular phycoerythrin accumulation was obtained with 5.85 x 10(-5) FeCl3 concentration. It was found that pigment accumulation was induced by low and high concentrations of ferric chloride. As a result of this study, it was concluded that the ferric chloride could be used as a promoter for pigment accumulation in P. cruentum biomass.
Members of Vibrio spp. are important risk factors in aquaculture, acting as opportunistic pathogens in marine fish. Therefore, we investigated, using quantitative polymerase chain reaction (qPCR) with Vibrio- specific primers, the behavior of Vibrio spp. during short-term rearing of tiger puffer (Takifugu rubripes). The results showed that the abundance of Vibrio spp. and total bacterial counts increased markedly from the first week after the fish were placed in the tank, and that these values decreased when the fish were removed. The abundance (copies/mL) of Vibrio spp. increased linearly with total bacterial counts, but their density (cells/mL) was estimated to be about two orders of magnitude lower than total bacterial counts. Vibrio spp. in the rearing water were less abundant than other bacterial groups, indicating that many other non-Vibrio microbial communities exhibit similar dynamics. The increase in total bacterial counts, including Vibrio spp., during the rearing period may reflect the spread of pufferfish gut bacteria in the rearing water via the fish feces, along with growth of the bacteria on organic matters derived from mucus, feces, and uneaten food. These results strongly suggest that effective control of vibriosis in fish farms requires surveillance of Vibrio spp., not only in rearing water but also in the fish gut and live diet. The qPCR method used in this study is suitable for surveillance of Vibrio spp. in aquaculture because it is highly accurate and results can be obtained in 5 ??? 6 h.
Algae biomass could be one of the most important economic values in near future. For this reason, we determined the biochemical compositions and molecular weight profiles (MWPs) of eight macroalgae; Green Algae (Codium fragile, Ulva intestinalis, Chaetomorpha linum, and Codium bursa), Red Algae ( Ellisolandia elongata, Jania rubens, and Amphiroa rigida), Brown Algae (Padina pavonica) collected from different regions in Turkey. The differences measured between biochemical compositions such as ash, lipid, and protein of macroalgae species were statistically significant (P<0.05). The lowest and highest ash, lipid, and protein values of eight macroalgae tested were 30.599 +/- 2.739 % (Ulva intestinalis)-81.231 +/- 0.527 % (Amphiroa rigida), 0.190 +/- 0.063 % (Ellisolandia elongata)-1.764 +/- 0.090 % (Chaetomorpha linum), and 2.057 +/- 0.093 (Amphiroa rigida)-15.280 +/- 0.621 (Chaetomorpha linum). The highest levels of MWP of macroalgae tested were determined in 2532 Da >. The lowest levels of MWP belonging to the macroalgae was observed in 2532-13000 Da except for Ulva intestinalis and Padina pavonica belonging to 67000 Da <=. The values observed 2532 Da > were similar to each other except for Ulva intestinalis. The 13700 - 67000 Da and 2532-13000 Da levels belonging to Ulva intestinalis were higher than those of other tested macroalgae. However, level of Ulva intestinalis (67000 Da <=) was lower than those of tested macroalgae species, followed by Padina pavonica. In conclusion, biochemical compositions of tested macroalgae can make important contributions to feed formulations and functional foods. In addition, based on our biochemical composition analysis the specific macroalgae species are the most promising algal content for use in different industrial areas such as cosmetics, drugs, and functional foods.
This study aimed to investigate the effects of stocking density on Litopenaeus vannamei at the nursery phase in low-salinity biofloc system. Post-larvae of L. vannmei were cultured for 28 days at 2000, 4000 and 6000 shrimp m(-3), and the water quality, plankton composition and growth performance were evaluated. The water quality variables remained within the ideal range for the shrimp culture, and only total suspended solids showed a significant difference between treatments - the highest stocking density has increased the levels of total suspended solids. In regarding to zooplankton structure, the Protozoa group had the greatest diversity regardless of treatment, and also the greatest abundance (> 66%). For phytoplankton structure, Bacillariophyta (Navicula sp. and Cyclotella sp.) was the dominant class in phytoplankton structure throughout the culture, although a Cyanobacteria bloom has reported at the end of the cultivation at 2000 shrimp m(-3). At the end of cultivation, the shrimp yield (0.133 +/- 0.028 kg m(-3)) was significantly higher in the 6,000 shrimp m(-3). In contrast, the shrimp survival was significantly higher in the lowest stocking density (71.66 +/- 10.36%). Our findings suggest that a density of 6,000 shrimp m(-3) should be used under these conditions, but an economic feasibility study should be considered in the future.
Plastic pellets are granules of different polymers used in the manufacture of various plastic products. Plastic pellets can reach the environment due to losses after their manufacturing process, especially the transportation. Loading in harbour areas and transport by ships are the main sources of plastic pellets to the ocean and coastal areas. After pellets reach the environment, they may adsorb and concentrate chemicals contaminants from different sources. Moreover, the weathering of plastic pellets may result in color changes, from white to brownish. This study aimed to analyse the color pattern of pellets collected on beaches of the central coast of Sao Paulo, Brazil, as an indicator of weathering and ageing processes. Plastic pellets were collected in four sampling surveys conducted between April 2012 and September 2015, and then separated in five color groups: white, yellowish, orange, brown, and pigmented. All sampled beaches had a consistent pattern of light-toned pellets (white and yellowish). This pattern was also found over time, suggesting a constant supply of plastic pellets to the beaches, coming from the harbour area. We also recommend the use of the color pattern of plastic pellets in citizen science monitoring programs.
Helminth parasites cause severe physiological disturbances and pathological conditions in fish due to generation of different free radicals or reactive oxygen species. These reactive oxygen species cause extensive damage to antioxidant status of fish which is an important and sophisticated defense in fish against the reactive oxygen species. Present study was conducted to analyze the effect of some helminth parasites on antioxidant markers, some biochemical parameters and DNA in the tissues of Cyprinus carpio communis collected from Sukhnag stream. Fish specimens only with Bothriocephalus acheilognathi (n=10), with Pomphorhynchus kashmirensis infection (n=10) and uninfected (n=10) were selected for carrying out the present work. Estimation of antioxidant markers (GSH, glutathione peroxidase, glutathione reductase, glutathione-s-transferase, superoxide dismutase and catalase), lipid peroxidation (LPO), protein content and DNA damage in muscle, intestine, liver and gill tissues was carried out. Serum biochemical constituents like alanine aminotransferase (ALT), aspartate aminotransaminase (AST), cholesterol and triglycerides were also monitored in parasitized and non-parasitized fishes. Analysis of data revealed the decline in GSH content in muscle, intestine and liver whereas increase in enzymatic antioxidants and lipid peroxidation (LPO) in muscle, intestine and liver was noticed in parasitized fishes in comparison to non-parasitized fishes. Significant elevation also observed in ALT, AST, cholesterol and triglycerides in parasitized fishes. DNA degradation was observed in intestinal tissues in parasitized fishes with respect to intestinal DNA of uninfected ones. This study concluded that helminth parasites have a significant impact in fish tissues by inducing oxidative stress which modifies the antioxidant activities, biochemical constituents and damages DNA. The parameters outlined in the present study may be employed as tools in monitoring the health status of fish in culture practices.
The knowledge of feeding and reproduction ecology of Coptodon zillii, as an aggressive species for endemic fisheries stocks and aquaculture activity, is very important. Sampling was performed monthly for one year in the northern area of Shadegan Wetland. The relationship between length and weight showed negative allometric growth. According to the gut contents; macrophytes, fish scale, fish eggs, cladocerans, copepods, and periphyton were preferred food. The feeding type of this species was identified as vegetarian with low animal source origin. The condition index showed that the species condition was good in terms of being fat. The highest hepatosomatic (HSI) and gonadosomatic indices (GSI) indices were recorded in February and May, respectively. The highest relative fecundity index was 1315.26 +/- 379-July, and the lowest was 78.86 +/- 28 eggs per gram of female somatic weight. Therefore, based on food and reproduction conditions, it can be said that C. zillii had successfully resided in Shadegan Wetland and had relatively good ecological conditions. It could be harmful risk for practical aquaculturists because of the aggressive potential of this species in interaction with endemic and farmed fishes, and should be managed with fisheries decision-makers.
Members of genus Vibrio, which are known as opportunistic pathogens of fish, often inhabit the gut of marine fishes. Polymerase chain reaction (PCR) primers specific to Vibrio spp. are required for rapid detection and quantification of opportunistic bacteria, which present a risk for infectious diseases. In this study, a primer set (VIB-F and VIB-R) was developed based on known probe sequences. The primer set amplified sequences from all strains of the genus Vibrio and related genera of the family Vibrionaceae, but not from strains of other families. In addition, clones in the library generated from marine fish gut using this primer set all corresponded to Vibrio spp. and other genera of Vibrionaceae, namely Aliivibrio, Enterovibrio, and Photobacterium. These results suggested that this primer set has sufficient specificity to permit estimation of the abundance of Vibrio spp. in the marine fish gut, facilitating the risk management of vibriosis. The quantitative PCR (qPCR) technique showed that the abundance of Vibrio spp. in the gut of coastal fishes was 1.1 x 10(5) - 9.9 x 10(10) copies/g. These results revealed that the total count of bacteria in the gut of coastal fishes is relatively constant (ranging from 1.5 x 10(9) - 2.2 x 10(11) cells/g), while the abundance of Vibrio spp. varies greatly. These results strongly suggest that the combination of Vibrio-specific primer set (VIB-F and VIB-R) and qPCR technique is a powerful tool for risk management against outbreaks of vibriosis in marine farms.
The massive energy required for biomass gathering makes current commercial microalgal biofuel manufacturing economically unsustainable. A present harvesting method is provided as an inexpensive and energy-efficient way; nano-flocculation by employing nanoparticles to concentrate and flocculate microalgae of interest. In this study, we used calcium oxide nanoparticles (CaONPs) derived from waste products of the Fayoum Sugar Factory (FSF) as a low-cost flocculent for a microalgae flocculation process that was tuned using three control parameters: temperature, flocculent dose, and medium pH values. Furthermore, FSF wastewater was employed as a nourishment source for microalgae production. FT-IR, X-RD, Zeta potential, and TEM were used to further identify and characterize CaONPs. According to the current data, using CaONPs under the best conditions for algae harvesting (pH 9.8 and temperature 45 degrees C with 250 mg/L) resulted in 99.3% algal coagulation. The advantages of the current method are that it is safe, rapid, does not require the addition of chemicals, is simple and effective, sustainable, and is cost-efficient because there are no costs associated with pre-treatment of the biomass.
The phytochemical constituents, total phenolic and flavonoid contents, antioxidant and antimicrobial activities of the ethanolic extract of the marine green alga Ulva pertusa collected from floating fish net cages off the coast of Guimaras island, Philippines, were investigated. Qualitative phytochemical analysis revealed the presence of bioactive compounds including alkaloids, flavonoids, phenols, saponins, tannins, and terpenoids. Quantitatively, total phenolic and flavonoid contents of the extract were 20.54 +/- 2.08 mg gallic acid equivalent (GAE) g(-1) and 539.07 +/- 6.36 mg rutin equivalent (RE) g(-1), respectively. The antioxidant activity of the extract using 1,1-diphenyl-1-picrylhydrazyl (DPPH) assay exhibited a concentration-dependent radical scavenging capacity. Additionally, the ethanolic extract inhibited the growth of Staphylococcus aureus ATCC25923, Escherichia coli ATCC25922, Streptococcus agalactiae, Aeromonas hydrophila, A. sobria, and Vibrio harveyi in a concentration-dependent manner with strong inhibitory activity at 100 mg mL(-1) concentration. Taken together, U. pertusa contains bioactive compounds that possess potent antibacterial activity and remarkable antioxidant capacities. These substances are promising candidates that may be utilized in the synthesis of novel drugs.
