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Light is an essential natural factor of fish growth and development. A light regime in indoor aquaculture is critical for sustainable fish production. This research aimed to investigate the effect of light intensity and photoperiod on the growth performance and stress response of Nile tilapia (Oreochromis niloticus), which is an important commercial species, in a recirculating aquaculture system (RAS). Fingerlings with an average weight of 5 ± 0.9 g were randomly assigned to nine 1.5 m3 tanks with 145 fish in each tank, cultured under different light intensities (1000, 2000, and 3000 lx) and photoperiods (12L:12D, 18L:6D, 24L:0D), and fed to apparent satiation twice a day for 160 days. The growth of tilapia subjected to 2000 lx was significantly better than that exposed to 1000 and 3000 lx (P 0.05). Light intensity and photoperiod manipulation did not cause a significant chronic stress response in tilapia. This study demonstrated that light intensity, especially at 2000 lx, and photoperiod manipulation could stimulate the growth of tilapia in the RAS and significantly affect economic profitability. This study also served as an important reference for tilapia indoor aquaculture.

Grass carp has the highest production yield among all the farmed fish species around the world. But the molecular and genetic basis of growth traits is inadequately understood in this fish. In the present study, we apply whole-transcriptome sequencing to identify genes whose expression is different between fast and slow growing grass carp. We identified 1178 differentially expressed genes (DEGs), among which 270 were upregulated in the fast growing group and 908 upregulated in the slow growing group. The GO enrichment analysis revealed that DEGs was significantly enriched in protein synthesis and export machinery, cell division and development and metabolism, suggesting that cell division and metabolism may play key roles in development processes of fish. KEGG pathway analysis showed that MAPK signaling pathway may play a prominent role in growth difference. In addition, the majority of genes in immune responses related pathway were upregulated in the slow growing individuals. These results provide some valuable resources for understanding the molecular mechanisms of growth traits in fish.

Aquaponics is a fish-plant recirculating system where nutrients received from the fish culture are absorbed by the plants for growth. The technology is relatively new for fish culture in Kenya, and the principles and operations remain largely untested for many fish species. This study determined how stocking density affects the growth performance and water quality in a Nile tilapia-lettuce (Lactuca sativa) aquaponics system. The experimental design included five replicates for each of the aquaponic systems stocked at densities of 150, 300, and 450 fish/m3 for a rearing period of 56 days. Each treatment had a planting density of 16 lettuce/m2. The water quality parameters ranges during the rearing period were 3.83–5.35 mg/L for dissolved oxygen, 7.44 to 7.6 for pH, 0.014 mg/L to 0.032 mg/L for total ammonium nitrate (TAN), 1.11–1.34 mg/L for nitrate, and 0.01–0.08 mg/L for nitrite, and all decreased with increasing stocking density. The final weight of fingerlings was 25.2 ± 4.2 g, 32.0 ± 3.8 g and 42.6 ± 3.1 g for 450, 300, and 150 fish/m3 respectively. Specific growth rate (SGR) was reduced with increasing stocking density whereas food conversion ratio (FCR) increased with stocking density. Aquaponic systems with the lowest stocking densities performed better than 300 and 450 fish/m3 respectively.

Fish culture plays an important role in supplying high-quality proteins and omega-3 (n-3) long-chain polyunsaturated fatty acids. Aquaculture has been the fastest growing sector in agriculture. Fishmeal is an important component of commercial fish feeds, but ensuring a sustainable supply of fishmeal is in question. A good source of proteins in aquafeeds is insects. For the past 20 years, investigations have been carried out on insect meals as alternative sources for fishmeal. Thus far, the results on replacing fishmeal in feeding aquaculture species have been promising. However, some challenging issues including costs and scaling up of insect production remains. In this review, we aim to summarize the status of applying meals of eight insect species in formulated aquafeeds. We also discussed issues in replacing fishmeal in fish feeds with insect meals and listed some future research directions to make insect meals an important source of proteins for green, profitable and sustainable (GPS) aquaculture. It is certain that in the near future, large-scale insect farming and processing to produce insect meals as an ingredient of fish feeds will have positive impact on the sustainability and profitability of aquaculture.

One of the most important issues in improving the competitiveness of the fish production sector is to improve the growth rate of fish. The genetic background to this trait is at present poorly understood. In this study, we compared the relative gene expression levels of the Akt1s1, FGF, GH, IGF1, MSTN, TLR2, TLR4 and TLR5 genes in blood in groups of common carps (Cyprinus carpio), which belonged to different growth types and phenotypes. Fish were divided into groups based on growth rate (normal group: n = 6; slow group: n = 6) and phenotype (scaled group: n = 6; mirror group: n = 6). In the first 18 weeks, we measured significant differences (p

Bacterial diseases are the chief constraint in the aquculture industry. Among them Aeromonads causes majority of production loss in fresh water ornamental fish farming. Trend of application of probiotics in any aquaculture farm is being increasing to reduce the environmental degradation caused by chemical treatment methods. In this study, Aeromonas veronii was isolated from diseased koi carp and its virulency was re-confirmed with mortality rate of 73.33 % in koi carp. Susceptibility of A. veronii to commercial probiotic mixture of Bacillus species was proved by in vitro assay where zone of inhibition of 22.67 ± 0.6 mm diameter was observed at 108 CFU mL−1. Bacillus probiotic mixture at 108 CFU g−1 maintained the gut morphology with good goblet cell count against A. veronii infection in koi carp. Thus, severe production loss due to A. veronii in ornamental fish farms can be controlled by probiotic dietary supplementation.

Made available in DSpace on 2021-07-14T10:37:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-26. Added 1 bitstream(s) on 2021-07-14T11:34:35Z : No. of bitstreams: 1 S0101-20612020005026206.pdf: 770771 bytes, checksum: c5a70a2c4ffd62b0dffcbe593c082d95 (MD5) Feeding accounts for 50%-60% of production costs in fish farming, and alternative raw materials are used to lower production costs. These raw materials can alter nutritional values ​​and sensory aspects of the final product. The present study describes the results for the proximal composition, sensory, and microbiological analyses of red tilapia (Oreochromis sp.) fed with a biofloc meal (fish sediment residue). The results showed that the red tilapia biofloc meal contained protein levels over 30%, with 3% nitrogen and 6% calcium. Fish fed biofloc meal showed productive performances within the ranges established for the species. Sensory analysis revealed that the cooked product’s appearance was very characteristic, presenting a slight metallic flavor and moderate juiciness. The bromatological composition analysis indicated that each 100g of tilapia contained 16 g of protein. Finally, the microbiological study guarantees compliance with the local tandards and confirms that the product does not contain significant levels of microorganisms that could cause foodborne diseases when consumed by humans. In conclusion, the use of biofloc meal at a small red tilapia farm proved to be a sustainable alternative for feeding Oreochromis sp. Universidad Cooperativa de Colombia, Animal Science Research Group Centro de Aquicultura da Unesp Centro de Aquicultura da Unesp

Ginseng (Ge) is one of the most famous and precious consumed herbal medicines around the world. Ge plant roots have many advantages regarded as important in increasing fish production. Thus, the present study was conducted to investigate the possibility of using different levels (0.0, 100, and 200 mg/kg diet) of Ge as a reproductive enhancer agent for African catfish, Clarias gariepinus males. Results revealed that fish fed 200 mg Ge/kg diet significantly (P ˂ 0.05) increased growth performance, feed efficiency, gonado-somatic index, hematological parameters, serum follicle-stimulating hormone, total antioxidant capacity, sperm quality parameters, and ultrastructure of spermatozoa, as well as led to positively improved of the histological structure of the testes tissue compared to other treatments. Based on the obtained findings, it could be concluded that the effective use of dietary Ge at a level of 200 mg/kg as a promising reproductive agent for adult African catfish males consequently led to the sustainability of aquaculture for African catfish.

Water reuse in fish farming is a practice that has been spreading significantly, therefore requiring more efficient and vigorous treatment systems. The objective of this study was to evaluate the potential reuse of aquaculture wastewater after being treated in horizontal subsurface flow constructed wetlands (HSSF-CW). Three HSSF-CWs with dimensions of 1.0 m in width, 3.0 m in length, and 0.30 m in depth were evaluated. One HSSF-CW had stargrass (Cynodon nlemfuensis) cultivated; the other had cattail (Typha latifolia), and the third was used as a control, where there was no cultivation. The wastewater was provided from three Nile tilapia breeding tanks, which recirculated the entire system after going through the HSSF-CW. The following variables were determined every five days at the HSSF-CW influent and effluent: temperature, pH, turbidity, electrical conductivity, redox potential, dissolved oxygen, ammonium, and nitrate. The treatment in the HSSF-CW allowed the reuse of aquaculture wastewater as it provides water quality levels according to the recommendation for Nile tilapia breeding. Furthermore, the water quality parameters monitored in HSSF-CW effluent remained within limits established by CONAMA Resolution No. 357/2005 for aquaculture and fishing activity. Water reuse in fish farming is a practice that has been spreading significantly, therefore requiring more efficient and vigorous treatment systems. The objective of this study was to evaluate the potential reuse of aquaculture wastewater after being treated in horizontal subsurface flow constructed wetlands (HSSF-CW). Three HSSF-CWs with dimensions of 1.0 m in width, 3.0 m in length, and 0.30 m in depth were evaluated. One HSSF-CW had stargrass (Cynodon nlemfuensis) cultivated; the other had cattail (Typha latifolia), and the third was used as a control, where there was no cultivation. The wastewater was provided from three Nile tilapia breeding tanks, which recirculated the entire system after going through the HSSF-CW. The following variables were determined every five days at the HSSF-CW influent and effluent: temperature, pH, turbidity, electrical conductivity, redox potential, dissolved oxygen, ammonium, and nitrate. The treatment in the HSSF-CW allowed the reuse of aquaculture wastewater as it provides water quality levels according to the recommendation for Nile tilapia breeding. Furthermore, the water quality parameters monitored in HSSF-CW effluent remained within limits established by CONAMA Resolution No. 357/2005 for aquaculture and fishing activity.

Cardiac abnormalities may pose a threat to salmonid aquaculture due to their potential detrimental effect on fish health and welfare. The teleost heart is an extremely plastic organ with important morphological differences between wild and farmed fish that include ventricular shape, alignment of the bulbus arteriosus and epicardial fat deposition. However, little is known about how different factors and interactions among them may affect cardiac morphology of Atlantic salmon. To determine whether rearing temperature could induce cardiac malformations in large Tasmanian Atlantic salmon, we examined a range of cardiac morphology indicators and growth parameters in a population of 1-2 kg seawater salmon (n = 60 temperature-1 diet-1 ) exposed to control and elevated temperatures of 15 and 19°C, respectively, while fed one of two commercial feeds with different dietary energy levels. Most fish possessed conspicuous fat around the heart with a tendency towards a rounded ventricle and a more obtuse angle of the bulbus arteriosus. However, fish showed no significant differences in heart shape and bulbus alignment in relation to water temperature and dietary energy. These results suggest that cardiac morphology of large Atlantic salmon is unlikely to be affected by rearing temperature and dietary energy during the grow-out phase.

The Amazon is very important regarding the continental extractive fishing as it has the greatest diversity of freshwater fish in the world. Some factors can contribute to identify significant changes in fish production, such as characterization based on common names, and synonyms or classifications only at the genus level. This creates noise in different types of analyzes and mistakes in determining effective productions, as well as levels of exploitation for management. Thus, this study aims to demonstrate the variation in fish production over the years 2001 and 2013, using control data from the fishing colony "Dr. Renato Pereira Gonçalves Z-31" in the municipality of Humaitá, southern Amazonas. These data were analyzed by collaborators from the Laboratory of Ichthyology and Fisheries Management of the Madeira River Valley, at the Federal University of Amazonas. The fish landing monitoring allowed the determination of the species caught in the regional fishery and evaluated the effect of the hydrological level and the pre- and post-installation periods of the Santo Antônio and Jirau HPPs in Rondônia, on the total production. The data set showed the significant decrease in fish production between 2008 and 2013. Among the factors that explain the observed changes are the mistakes in determining the effective production due to the lack of criteria in the grouping of many species, the absence of regulations, such as the "Portaria IBAMA Nº 48" which was created only in 2007, in addition to the installation period of the HPPs on the Madeira River. It was also possible to verify the effect of seasonality through hydrological quotas on fish production, with the highest values observed in July, August and September of the years analyzed.

Aeromonas spp are the most common devastating fish bacterial pathogens associated with a wide range of cultured freshwater fish resulting in mass mortality. The present study plots the Aeromonas research output in fish during 1998–2020 by means of the Web of Science (WoS) database. A total of 1944 publications were used for this investigation to evaluate the scientific productivity in this selected subject area. Global publication share, rank, and its development in terms of research and bibliometric indices such as overall citations, h-index, and average citation per paper were also analysed. China ranked first in terms of total publications among the most productive countries and accounted for 26.18% of the total publications. The network visualisation map revealed that the lead collaborating country was China; however, the collaboration between countries was found to be very less. Lokta’s law was noticed not to be valid for Aeromonas research. The study showed that the funding granted to the research investigations and their research productivity in terms of total publications were correlated positively. The results of the current study displayed the trend of “Aeromonas infection in fish” related research investigations published during 1998–2020. This study also highlighted the focused research areas on this topic on which the future areas of research can be determined by fellow researchers in this specific field. This study also suggests enhancing the research efforts on this bacterial pathogen which has the potential to implicate huge economic loss to the fish farming population in the world.

Catfish have become an important contributor to fish production in Indonesia. Catfish consumption in Indonesia always increases every year. To meet the demand for catfish consumption, it was carried out with an intensive aquaculture system. However, the high cost of feed has been identified as a significant constraint in catfish farming. Efforts to increase catfish growth are needed to reduce feed costs, one of the efforts is by probiotic supplementation through the feed. This study was carried out to determine the best dose of probiotic rabal dried addition to increasing catfish growth. The experiment used four treatments and three replications. Probiotic rabal dried doses: 0% of feed (A)/feed (control), 5% of feed (B), 10% of feed (C), and (D) 15% of were used as treatment. The feed was given ad-satiation with a frequency of feeding three times a day. Observations were made for 45 days. The results indicated that the B treatment of 5% of feed gave the best absolute weight growth and feed conversion ratio. While catfish fish survival rate was not significantly different on all treatments.

Recently, in India, the marine finfish culture is expanding rapidly without adequate knowledge and research information on the coastal and marine finfish disease epidemics. Therefore, for the benefit of farmers, this study was designed to find the prevalence of Vibriosis outbreaks in marine finfish farms. In this study, 167 moribund fishes that show outward symptoms of lethargy, popeye, pale gills, skin erosions, abdominal edema, and hemorrhagic spots on different parts of the body were collected from 26 marine finfish farms (Lates calcarifer, Rachycentron canadum, and Trachinotus blochii) located in the states of Tamil Nadu, Andhra Pradesh, and Kerala, India. A total of 173 bacterial isolates were retrieved from all the fish samples, of which 144 isolates demonstrated a Vibrio-like character during biochemical and Vibriostatic 0/129 examinations. The phenotypic, 16s RNA gene sequencing and histopathological analysis confirm that the isolated bacterial strains were Vibriospecies. In the collected fish samples, the total prevalence of Vibrio species was 83.2% and the remaining 16.8% were other bacterial species. Among these bacteria, V. harveyi was the most predominant bacterium (34.1%) that cause infection in all the three fish species whereas Photobacterium damselae was found to be the least (2.9%) one. In the pathogenicity study, the highest mortality of 83% was observed after 168 h, when the seabass fingerling exposure to V. harveyi at 106 CFU/ml, and established similar clinical signs to the disease specimens of farmed fish. The in vitro antibacterial study confirms that the tested probiotic effectively inhibits the V. harveyi at 125 µl (108 CFU/ml). The above results inspire further in-depth studies on the probiotic efficacy to control the V. harveyi in finfish farms.

Background Helminth infection and infestation in fishes are detrimental and have a major effect on fish health and fish production. Among various factors, parasitic infections are known to modulate antioxidant defences in fish. Similar to other aerobic animals, fish are also susceptible to the effect of reactive oxygen species and thus have well established intrinsic and efficient antioxidant defences. ‘Oxidative stress markers are an important indicator of the physiological state of the parasite and its host’. Indian catfish, Wallago attu is a freshwater fish that serves as the definitive host of the adult piscine trematode Isoparorchis hypselobagri. Our two years prevalence data signifies the intensity of the problem revealing a minimum of 5.5% and a maximum of 54% I. hypselobagri infection in Indian catfish W. attu (unpublished data). The present study aimed to achieve baseline data attributed to changes in some oxidative markers due to parasitic infection. Results During the present study, the level of enzyme activities of Catalase (CAT), Glutathione reductase (GR), Glutathione-S-transferase (GST), Glutathione peroxidase (GPx), Superoxide dismutase (SOD) and lipid peroxidation was investigated to explore the pathogenic impact on the fish host. The level of these oxidative stress markers was monitored in the swim bladder, liver, intestine and muscle of the host. We also recorded the enzyme activities in the parasite I. hypselobagri. Analysis of data revealed an elevation in GST, SOD, GR, GPx and CAT activity in the infected host tissue as compared to the non-infected fish. Further, we observed presence of GST, SOD, GR and GPx enzymes in the parasite I. hypselobagri while CAT did not show any enzyme activity. Conclusions Increased level of enzyme activity in liver, muscle and intestine of infected host has been recorded which indicates increased oxidative stress in the host due to parasitic invasion. The presence of antioxidant enzymes in the parasites suggests an active antioxidant defence system to avoid immune responses to long term survival and establishment in their host.

Misgurnus anguillicaudatus (M. anguillicaudatus) is a widely cultivated fish. However, in M. anguillicaudatus breeding, the frequent cold stress during daily breeding could induce immune suppression and increase the risk of infection, causing serious economic loss. Based on existing findings, CpG Oligonucleotides (CpG-ODNs) may be an ideal protective agent for low temperature fish breeding, performing anti-infective when faced with cold stress with cold shock proteins Y box binding proteins (YBX). Although YBX has pleiotropic functions, its roles in CpG-ODNs-mediated immunity (especially under cold situations) remain largely unexplored. To clarify the relationship among them, we identified the YBX1/YBX2 in M. anguillicaudatus and analyzed using a series of bioinformatics methods. After that, we immunized the fish with 3 types of CpG-ODNs and challenged with Aeromonas hydrophila (A. hydrophila). Here we showed that the best anti-bacterial effect of CpG-B was accompanied by the significant upregulation of YBX1. And the detection of the YBX1 downstream effectors confirmed that CpG-B induced the YBX1-mediated Th1 oriented responses to A. hydrophila by regulation of the NLRP3 (Caspase-A/-B), IL-1β, IL-12 and IFN-γ. Afterwards, we found that under cold stress, CpG-B can activate the NLRP3 and NF-κB pathways through YBX1, a key mediator of anti-A. hydrophila in CpG-B immunization. In this study, we demonstrated CpG-B protection against infection in low temperature, and its interaction with YBX1, expanded the research of CpG-ODN under cold stress, and provided a new CpG-ODN application for low temperature fish farming.

The problem of sewage disposal has received great attention worldwide. The raw sewage contains a variety of high inorganic and organic matters that affect natural water environment. To mitigate such problem, sewage may be recycled through aquaculture practice. Sewage recycling in aquaculture enhances water productivity through nutrients input. Proper loading of sewage ensures viable aquaculture; otherwise, fish mortality occurs due to poor water quality. To optimize sewage application, two different experiments were conducted, each with four treatments. In both experiments, three fish species namely rohu (Labeo rohita Hamilton, 1822), mrigal (Cirrhinus mrigala Hamilton, 1822), and bata (Labeo bata Hamilton, 1822) were tested in triplicate in FRP (Fibre-Reinforced Plastic) tanks. Different sewage concentrations (0, 25%, 50% and 75%) used in first experiment were prepared by mixing freshwater, showing Biochemical Oxygen Demand (BOD) 2.0 ± 0.4 mg/L, 10.8 ± 1.4 mg/L, 19.6 ± 1.5 mg/L and 41.6 ± 2.58 mg/L, respectively. After 30 days rearing, results showed ≥75% fish survival in sewage concentrations up to 50% with BOD level 19.6 ± 1.5 mg/L. Less than 50% fish survived in 75% sewage concentration, with BOD level as 41.6 ± 2.58 mg/L. The second experiment was conducted for 90 days considering 50% sewage concentration as basal dose with BOD level as 19.6 mg/L as an acceptable limit for fish survival. Split doses of sewage were applied in T1, T2 and T3 treatments fortnightly, weekly and semi-weekly intervals, while single dose was used in C (control) treatment. Application of split doses resulted better hydro-biological changes, including nutrients recovery, in T1, T2 and T3 than that of single dose in control. Fish growth plotted with net primary productivity (NPP), phytoplankton and zooplankton densities exhibited positive correlations in T2 (12 doses) and T3 (24 doses), considered as optimal doses to ensure better water productivity for desirable fish production than sewage with single dose or limited doses (6 doses).

Aquaculture industry in Malaysia involves culture of many fish species of either fresh or brackish water origin and among the important fish species are Snakehead, Tilapia and Catfish. There is a substantial culture of these fish in Malaysia nowadays, though there are not one hundred percent native fish species but their presence in Malaysia is getting closer to over several decades and for almost a decade now, these species had been among the highest finfish produced in either fresh or brackish waters. As the global aquaculture production continue growing in order to meet up with ever increasing fish demand, especially as fish from capture has levelled off and makes an increase in aquaculture production as the only hope to meet the demand for fish, one of suggested ways in culturing them is by venturing into integrated fish farming. Integrated fish farming of different species is a practice which links together two or more normally separate farming systems, whereby the fish from different species become subsystems of a whole farming system. Although integrated fish farming may not be huge globally based on the available official statistical data but it is becoming important industry in Malaysia and neighboring countries. This review discussed briefly about the integrated fish farming of three commercially popular species (Snakehead, Tilapia and Catfish) in Malaysia and neighboring countries.

Fishmeal (FM) is the main protein source in fish feed. However, it is quite expensive due to its limited resources. Therefore, finding a dietary alternative to the FM to sustain fish production is crucial, and the current study was performed to assess the impact of poultry offal silage (POS) with or without betaine supplementation; as an effective and cheaper alternative to FM; on feed efficiency, growth performance, spleen morphology and intestinal morphometry of Nile tilapia (Oreochromis niloticus) fingerlings. Four dietary treatments were formulated: (1) FM based diet, (2) FM-B; FM diet +0.7% betaine, (3) POS diet and (4) POS-B; POS diet +0.7% betaine. Each dietary treatment consisted of three replicates (n = 10/replicate), and the experiment was continued for 16 weeks. By the end of the experiment, spleen and intestine specimens were collected from 15 fish (n = 5/replicate) for histopathological assessment. The results were statistically analysed using GLM procedures of SAS 9.4. Feed efficiency increased in both POS-B and FM-B groups (p = 0.01), while body weight and body weight gain showed only weak tendencies towards an increase (p = 0.10 and 0.12, respectively). The villi length was the highest in POS-B fed group (p

The aim of this study was to assess the levels of heavy metals in both wild and farmed tilapia on Lake Kariba in Zambia and to evaluate the impact of intensive fish farming on wild tilapia. Three sites for wild fish (2 distant and 1 proximal to fish farms) and two fish farms were selected. One hundred fish (52 from distant sites; 20 near fish farms; 28 farmed fish) were sampled and muscle tissues excised for analysis of heavy metals (Mg, Fe, Zn, Al, Cu, Se, Co, Mo, As, Cr, V, Ni, Hg, Pb, Li, Cd, and Ag) by acid (HNO3) digestion and ICP-MS. All metals were found to be below the maximum limits (MLs) set by WHO/EU. Essential metals were higher in farmed tilapia, whereas non-essential metals were higher in wild tilapia. Significantly higher levels of essential metals were found in wild fish near the fish farms than those distant from the farms. Estimated weekly intake (EWI) for all metals were less than the provisional tolerable weekly intakes (PTWI). Target hazard quotients (THQ) and Hazard Indices (HI) were

This study aimed to determine artifcial semi-dry wetlands' performance to wastewater treatment from fish farming and Lactuca sativa production in an aquaponics system. This trial model observed the effects of different stocking biomass on the growth rate of Colossoma macropomum and yield of two L. sativa varieties. A factorial design consisting of three fish density treatments in quadruplicate and two Lettuces variety was used. Nine hundred and sixty fingerlings with 8.35±0.91 g were stocked at three stocking biomass treatments in quadruplicate: 40 fingerlings or 334 g m-3; 80 fingerlings 668 g m-3; 120 fingerlings or 1002 g m-3. Delice American Lettuce and Purple Crested Lettuce were cultured in the semi-dry wetlands. The fnal mass (g), consumed food, feed conversion ratio, and yield of fngerling were statistically diferent between the tested densities, but survival did not. The artificial semi-dry wetlands were efcient on water treatment and the recovery of nutrients in all fsh densities trials, and it has potential as support for lettuce production. The recovery of nutrients was shown on the increment of the number of leaves, total fresh mass (g), and lettuces yield by area (kg m-2) in both varieties of plants tested. Precocious fowering in 30% of lettuce varieties, incidence of mealybug and whitefly, temperature and defciency of calcium and magnesium were factors that may have compromised the full lettuce development. The aquaponics system eficiently treated the fsh efuent at the densities tested, being appropriate for fish farming and lettuces production. Made available in DSpace on 2021-11-17T02:10:25Z (GMT). No. of bitstreams: 1 CPAF-AP-2021-Are-artificial-semi-dry.pdf: 1696307 bytes, checksum: 2b1402e1ed6adcf4dc8bc4f45ec130e5 (MD5) Previous issue date: 2021

Aquaculture production has seen much increase in Nigeria in recent times due to the rise in fish farming occasioned by the availability of water and materials for setting up, the profit turn-over, increase in demand for fish, and the effort to curb the rising youth unemployment rate. However, this massive surge of interest in aquaculture and fish farming is accompanied by the challenge of pollution as the effluent from aquacultural settings gets discharged into nearby water bodies hence the need for remediation. Aquatic plants have been used to remediate polluted water bodies and possess many advantages over other methods. Therefore, this study aimed to investigate the effectiveness of Eichhornia crassipes in the clean-up of aquaculture effluent. Wastewater collected from a commercial fish pond in Benin City, Nigeria, were divided into two treatment groups. One group was diluted with an equal volume of distilled water (50%), and the other group consisted of 100% wastewater. Distilled water was used as a control (0%). The samples were treated with Eichhornia crassipes for 14 days, following which samples were collected for physicochemical analysis. The result showed that E. crassipes reduced significantly the pH from 7.44 to 5.98 and 7.28 to 6.10 in the 50% and 100% effluent samples, respectively. The removal efficiency of E. crassipes in the 100% effluent sample was 69% for phosphate, and 94% for nitrate. The study suggests that E. crassipes may be effective in improving the quality of aquaculture wastewater.

African catfish (Clarias gariepinus) is a popular fish in the community because it provides a high level of protein at a low cost. The motile aeromonas septicemia (MAS) disease produced by Aeromonas hydrophila (A. hydrophila) infection is one of the things that create difficulties in the cultivation of this fish. Synthetic antibiotics are commonly used in MAS disease control management efforts in fish farming, which have have an influence not only on fish but also on consumers. The application of probiotic Bacillus sp isolated from the digestive tract of catfish as a means of preventing the sickness is one option. Enzymatic tests (lipolytic, amylolytic, cellulolytic, proteolytic activity) and antagonist testing were used to assess the probiotic activity of the Bacillus sp isolates.

The growth and survival are considered as the crucial factors that should be taken into consideration in any aquaculture system. The experiment was aimed to evaluate the growth performance and subsequent survival rate of the rohu (Labeo rohita) and tilapia (Oreochromis niloticus). It is important to evaluate the growth responses in relation to Feed Conversion Ratio (FCR) and assessment of the total production of the culture unit. As per the recommended stocking density of 320 fishes/decimal in intensive aquaculture system 8 fry per tank was released to assess the growth performance, survival and production of both rohu (T1) and tilapia (T2). During experimental period, there were three replications for each treatment and feed was supplied at the rate of 12%, 8%, and 4% of the body weight of rohu and 20%, 15%, and 10% of the body weight of tilapia in 1st, 2nd and 3rd month for T1 and T2, respectively. The initial weight of individual tilapia was 7.52±1.81 gm and 14.75±0.19 gm for T1 and T2, respectively. The mean final weight was 44.01±4.03 g for T1 and 139.94±1.29 for T2. The weight gains of fish were 36.49±4.09 gm and 125.19±1.29 gm for T1 and T2, respectively. The mean percent weight gain of tilapia was higher in T2 (1715.05±0.00) than T1 (485.23±0.00). The Specific Growth Rates (SGR) of T1 and T2 were found 4.98±2.28 and 6.26 ±3.83, respectively. There was significant difference (p>0.05) in term of SGR between the treatments. Feed Conversion Ratio (FCR) in T1 and T2 were 2.86±0.14 and 2.23±0.18, respectively. Higher total production was obtained in T2 (1119.52 gm) than T1 (278.19 gm) with 100% survival in both the treatments. The water quality parameters for both of the species were within the suitable range. This study reveals a promising arena for fish culture in tank-based intensive aquaculture system as an efficient way of overcoming the scarcity of water and land. This culture system may be an excellent way of producing fish in a small parcel of land with securing the propitious production and expected outcomes within a limited period of time.

Nile tilapia feed on plankton in natural environments. This food source can be increased in ponds through fertilization and can reduce feed expenses or improve fish performance when used as supplementary food. Organic fertilization is an alternative to commercial fertilization; however, its use increases concerns regarding water quality and sanitary aspects. This study aimed to evaluate the effects of the use of poultry litter as organic fertilizer on the physical and chemical parameters of water, gill ectoparasite metazoan abundance, and growth of Nile tilapia (Oreochromis niloticus) during the culture cycle lasting 240 days. Four earthen ponds, two fertilized with poultry litter and two non-fertilized ponds, as fertilized and non-fertilized treatments, respectively, were used. Stocking density was 3 fish per m2 with an average initial weight of 0.64 ± 0.15 g. The mean water quality values and the growth performance parameters of Nile tilapia did not show significant differences between the two treatments. The gill parasites found in the fish belonged to the class Monogenea, comprising two genera, Cichlidogyrus and Scutogyrus, with significant differences between treatments. The non-fertilized treatment showed a high abundance of parasites throughout the culture cycle months, with peak abundance in the months with low concentrations of dissolved oxygen in the water.

Skeletal deformities in cultured fish are known worldwide and it had affected the survival, growth and appearance of the fish which contribute to production loss. Clarias gariepinus is known as number one farmed fish in Malaysia. C. gariepinus also effected in these deformities especially in cultured species. The objectives of this study are to identify the skeletal deformities that occur in juvenile stages and to compare the bone structure between the normal and deformed fish. A total of 50 juveniles’ fish were collected from Aquaculture Extension and Community Centre Machang, Kelantan. The juvenile was measured before undergo staining process. The fish were starved for one day then fixed in 70% ethanol for two weeks. The fish were then stained with alizarin red S for cartilage and Alcian blue for bone. The specimens were photographed in order to observe the deformities. The data showed only 13.0% juveniles have skeletal deformities, 10.9% with lordosis and 2.2% scoliosis. The cause of the deformities may be due to the heterogenous growth but other factors might also contribute to the problem. As the conclusion, the skeletal deformities observed in juvenile C. gariepinus were detected with the whole-mount staining method ranged from size 7.3 and 26.0 cm in total length. This study shows there is heterogenous growth rearing at low percentage even from skilled farm. Further study should concentrate on hidden factors that affected the deformity rate and mineralization of the juvenile fish.

Highlight Research: It has been found that many fish died with wounds from farmers in Blitar, Indonesia. The mucosal smear test from mucosal gills of C. carpio infected with Myxobolus . In the blood smear test of C. carpio , there was no myxobolus found in the blood. In gill organ testing using SEM that Myxobolus is found in gills ( C. carpio ). The shape of Myxobolus resembles an imperfect ball with a hollow in the middle. Abstract The biggest problem that is often considered to be an obstacle to Common carp culture is the emergence of disease attacks. One type of disease that often attacks the seeds of Cyprinus carpio is Myxobolus (a systemic parasite that can cause harm to fish farming). The aim of this study was to determine the molecular expression through the smear test on C. carpio gills, to determine the image of the gill organs of C. carpio using the SEM test, and to determine the description of the spores of Myxobolus sp. Data were analyzed using descriptive methods. Descriptive method used was comparative descriptive comparing molecular expression in the test of gill mucosal smear of fish using a light microscope and gill organ testing using Scanning Electron Microscope (SEM) on C. carpio infected by Myxobolus sp. In this study, the results showed that in C. carpio infected with true Myxobolus found the presence of Myxobolus in the mucosal smear test and SEM test on gill tissue, but not found in the blood smear test.

Fish production and fish processing waste have straight connection. In India, the waste produced during the processing of fish is predicted to be approximate 3.6 million metric tonnes, 48 per cent of the total body weight of Indian and exotic major carps is thrown away as waste (non-edible ). The present research, it was conducted to compare the total lipid content (TLC) and fatty acid composition from the liver of captured and cultured fish, Labeo rohita (Hamilton) having weight more than 500 gram during different months as well as to evaluate its nutritional quality. Maximum total lipid content (33.33±0.14%) was found in the liver of cultured fish in May month, while the minimum (15.26±0.24%) was in the liver of captured fish in the month of January. During the study, total lipid content was found to be considerably elevated in cultured than captured Fish, Labeo rohita (Hamilton). The amount of three major groups of fatty acids namely polyunsaturated fatty acids, monounsaturated fatty acids and saturated fatty acids was found to be maximum in captured fish during the month of March 97.19±0.96%, 61.30±0.56% and 95.39±0.31% month of April respectively. Total n-6 polyunsaturated fatty acids were observed to be highest (21.95±8.05%) in the waste of liver in cultured fish during the month of March. Hence, it is concluded that the processing waste (liver) of the captured and cultured, Labeo rohita (Hamilton) is a prosperous resource of the essential fatty acids i.e. PUFAs and total lipids. Further, it is observed that captured species are rich in fatty acid composition as compared to cultured species. Food industries can manufacture by-products from these high nutritional value contents of waste for human utilization. EPA and DHA also reduce the risk of various life threatening diseases.

As it is common in tropical and temperate zones, mullet species constitute the most important fish species caught along the coast and estuaries of Turkey. In terms of ecology, tourism and and fish productivity (52 kg/ha), Koycegiz-Dalyan Lagoon Ecosystem (KDLES) is the most important lagoon, with a 5500 ha surface area, is the Mediterranean Coast of Turkey. In the dalyan (barrier fish trap) systems; approximately 225 tons (80-405 tons) of mullets are caught to obtain 5 tons of dried fish eggs per year. Seventy percent of fish production in the lagoon is composed of mullets. The mullet samples were collected monthly between October 1992 and September 1994 from eight stations (one of them is a marine station) by trammel nets. The ages were determined using by scales anda ge composition varied form 0 to 6 ages. Species composition of 1159 sampled individuals were proportionally determined as Mugil cephalus 45%, Liza aurata 35%, Liza saliens 14%, Liza ramada 12%, Chelon labrasus 6%. The growth performance indices calculated from von Bertalanffy growth parameters using by all individuals for the M. cephalus, L. aurata, L. saliens, L. ramada and C. labrasus were determined as 2.957, 2.866, 2.692 and 2.719, respectively. The highest growth performance index was calculated for M. cephalus. The growth performance indeces of mullet species in Köyceğiz-Dalyan Lagoon Ecosystem were found around the world averages.

The article provides data on the place and role of some common bird species in the Fergana Valley in biological damage. The reasons for the occurrence of biological damage in birds are discussed, the nature and degree of biological damage caused by white storks, green bee-eaters, myna, Indian and field sparrows on fish farms, power grid enterprises, viticulture and grain crops (wheat and rice) are discussed. Building their huge nests on the poles of high-voltage power lines during the year, white storks make short circuits, which lead to an interruption in the power supply. In the post-nesting period, large flocks of white storks arrive at fish farms. One bird eats an average of 600–800 g of fish per day. During spring and autumn migrations, green bee-eaters gathering at beekeeping farms, one pair per day destroys about 350–400 worker bees. Mynas, after the chicks leave the nests, together with fledglings, flies into the vineyards and, on average, damage 18.5% of the grape harvest. Field and Indian sparrows consume an average of 16.95% of the crop during the milky-wax ripeness of wheat. In rice fields during autumn migrations, the harm from sparrows is 2.1–13.4%. The article also provides data on some of the repellents used in preventing and reducing bio-damage caused by birds, discusses their effectiveness.

The objective of this study was to evaluate biochemical parameters and histopathology of liver in Matrinxã (Brycon cephalus) and Pacu (Piaractus mesopotamicus) fish chronically exposed to dietary aflatoxins. Fish feed was artificially contaminated with aflatoxins and the treatments were: Control – feed without toxin; Treatment A – feed + 10 μg aflatoxin B1 (AFB1)/kg; Treatment B – feed + 20 μg AFB1/kg; and Treatment C – feed + 50 μg AFB1/kg. Matrinxã and Pacu juvenile fish were placed in tanks for 180 days. Five experimental units per treatment were monthly sampled and submitted to blood collection and removal of hepatic tissue. Thus, twenty blood and liver samples for each species were collected monthly, adding up to 240 samples analysed. To verify biochemical changes, analyses included total proteins, albumin, globulins, aspartate aminotransferase (AST) and alkaline phosphatase (ALP). The hepatic tissue was examined microscopically and the slides presenting histopathological changes were photo-documented. There was effect of treatment (P0.05) was observed in Pacu. A reduction (P1.

The traditional strategy for national surveillance of salmonid alphavirus (SAV) infection in Norwegian fish farms relies on a costly, time-consuming, and resource-demanding approach based on the monthly sampling of fish from all marine farms with salmonids. In order to develop an alternative surveillance method, a water filtration method was tested in parallel with the ongoing surveillance program at 7 Norwegian marine farm sites of Atlantic salmon Salmo salar L. with no current suspicion of SAV infection. During the period from May 2019 to January 2020, seawater samples were collected from the top layer water inside all net-pens at these 7 sites. The samples were concentrated for SAV by filtration through an MF-Millipore™ electronegative membrane filter, followed by rinsing with NucliSENS® Lysis Buffer, before RNA extraction and analysis by RT-qPCR. SAV was detected from seawater at an earlier stage compared to traditional sampling methods, at all sites where the fish tested positive for SAV. A significant negative relationship was observed at all sites between the SAV concentration found in seawater samples and the number of days until SAV was detected in the fish. This means that the fewer the SAV particles in the seawater, the more days it took until SAV was detected in the fish samples. Based on this, sampling of seawater every month for the surveillance of SAV has a great potential as an alternative method for early detection of SAV in Atlantic salmon farms.

The annual increase in Egyptian & Global fish production is mainly due to annual increase in fish production from aquaculture compared to natural fisheries during the study period (2000-2018), and also increasing the relative importance of fish production from aquaculture compared to natural fisheries since 2003 and 2013 in the world and Egypt, respectively. Fish Aquaculture patterns vary according to water types used in Aquaculture (freshwater, brackish water, salt water). in World, The freshwater aquaculture production is higher (60.1%) than the salt water aquaculture production (31.5%) and the brackish water (8.4%) respectively, but in Egypt, Fish that are cultured in fresh water (Tilapia, Catfishes, Carps, Bagrus spp, and Nile perch) contribute about 77.72% of the average fish production from aquaculture during the study period (2000-2018), which is estimated at about 648.8 thousand tons, while fish are farmed in brackish water, which are represented by the mullets family contributed about 18.77%, while the fish that are cultured in salt water (Seabream, Seabass, Meager, Shrimp, Eels, and Gropers) contribute very little due to the novelty of this type of aquaculture in Egypt, estimated about 3.51% Average fish production from aquaculture during the study period. Aquaculture in Egypt contributes about 80.7% of the total Egyptian fish production in 2018, which reflects its important role in filling the fish gap in Egypt. The most important determinants affecting aquaculture fish production in Egypt during the study period (2000-2018) are: (1) The average price per ton of cultured fish: increase in the average price per ton of farmed fish by 1% leads to an increase in the amount of annual aquaculture fish production about 1.3%, (2) the number of freshwater frys and fingerlings produced in private hatcheries: by increasing the number of freshwater frys and fingerlings produced in private hatcheries by 10%, leads to an increase in the amount of annual aquaculture fish production about 3.0%.

Sustainable development of fresh water (FW) aquaculture requires minimal environmental impact, by reducing the waste discharged into the surrounding waters. To assess the water quality status and impact of flow-through trout farming in the Louros river (NW Greece), a seasonal evaluation of the trout production in the river was performed. Seasonal samples of river water entering and discharged were obtained to monitor some water quality parameters. The parameters were temperature, pH, ammonium, phosphate, dissolved oxygen (DO), biochemical oxygen demand (BOD5), electrical conductivity (EC), total dissolved solids (TDS), total nitrogen (TN), and total phosphorus (TP) of flow-through trout farms alongside the river. All monitored parameters indicated minimal environmental impact of the fish farms; pH ranged from 7.57 to 8.03, TDS ranged from 151.43 to 242.56 mg/L, DO ranged from 6.28 to 9.16 mg O2/L, BOD ranged from 0 to 2 mg O2/L. As for the nutrients, mean values were below each limit set for freshwater systems. NH4-N ranged from 0 to 0.28 mg/L, and PO4-P ranged from 0.15 to 0.42 mg/L. Based on the comparison of water quality parameters in the outlets and on the Environmental Impacts and Environmental Quality Standards (EQS), it can be concluded that trout fish farms had no significant environmental impact on the river water quality during any of the tested seasons. All parameters presented strong increasing trends during spring and summer and low decreasing trends in autumn and winter. In conclusion, the results indicated minimal aquaculture impact on river Louros water quality.

Skeletal abnormalities in farmed fish are one of the main problems that negatively affect the production enterprises in terms of economic, biological and animal health. Fish with skeletal deformities in hatcheries are considered as non-economic individuals and are therefore detected and removed manually from the production tanks, which is a time consuming and laborious work for the facilities. Since the formation of abnormalities in the skeletal structure of the fish during the early growth period cause reduced swimming ability or speed that prevent fish to compete during feeding. Further, since deformed fish has no market value, even the share of a small amount of feed among deformed fish will reduce the feed conversion for the market targeted individuals within the culture tank that in terms may increase the production cost per fish. Therefore, in culture conditions it is important to remove the deformed fish from the tank environment by quickly determining those fellows at the early stage of growth. The present study evaluates the effects of water velocity on swimming behavior of juvenile seabass (Dicentrarchus labrax) and provides a solution for a rapid identification -and mechanical removal of deformed fish from the culture environment by using swimming speed slowdown -and behavioral differences as an indicator of deformation.

To assess the effects of two rations on growth performance of Clarias gariepinus fry, a study was carried out at the Peyrie fish farm station in Libreville, Gabon. To this effect, 3000 fry aged 14 days with 80 mg live weight were used. The animals were randomly distributed into six plastic tanks of 0.62 m3 each with three replications per treatment. They were fed the ration T, a ration formulated with fishmeal and broiler chick feed, and the commonly used ration (CR), within 4 weeks. Weight growth, mean weight gain (MWG), daily individual growth (DIG), specific growth rate (SGR), survival rate (SR), nutrient quotient (NQ), protein efficiency ratio (PER), quantity of feed distributed and manufacturing cost per kg of feed were evaluated. It appears that there is no significant difference (p> 0.05) between the growth parameters of the fry regardless of the ration (T and CR). Thus, at the end of the study, for the CR and the ration T, a final mean weight of 3.481 ± 1.02 g vs 3.409 ± 0.97 g respectively was obtained; a MWG of 3.401 ± 0.31 g vs 3.330 ± 0.23 g; a DIG of 20.24 ± 7.44 mg/day vs 19.82 ± 5.58 mg/day, a SGR of 1.54 ± 0.22% mg/day vs 1.49 ± 0.27% mg/day and a SR of 26.13 ± 4.44% vs 20.60 ± 1.47%. In addition, a NQ of 1.52 ± 1.08 vs 1.21 ± 0.65 and a PER of 1.41 ± 0.81 vs 1.84 ± 0.39 and the quantity of feed of 1.96 kg vs 1.77 kg were also determined. In view of all these results, the ration T can be recommended for feeding Clarias gariepinus fry at the age of 14 days.

Elopichthys bambusa is an economically important freshwater fish with high nutritional value. In this study, we compared domesticated and wild fish at the physiological, biochemical, histological, and molecular levels to better understand the changes that occur in farmed fish in order to provide ideas about how to optimize the artificial feed formulation used in aquaculture of this species. Water, ash, and crude protein contents did not differ significantly between the two groups. The methionine and glutamic acid contents were 20% and 13.4% higher in the domesticated group than that in the wild group, respectively. Twenty-three types of fatty acids were detected in the wild group compared to 11 in the domesticated group. The iron content in the domesticated group was higher than that in the wild group. The blood index values did not differ significantly between the two groups, except for alanine aminotransferase (ALT), total protein (TP), and globulin (GLO) contents. The ALT content in the wild group was significantly higher and the TP and GLO contents were significantly lower than those in the domesticated group. Histologically, significant differences in the numbers of folds, villi, and goblet cells were detected between the two groups. The expression of t1r1 and t1r3 in the intestines and gills of the domesticated group was significantly lower than that of the wild group. This study provides an important theoretical basis for the reproduction and breeding studies and the quality identification of domesticated Elopichthys bambusa. It will promote the development of large-scale farming of Elopichthys bambusa.

Arsenic-contaminated food including farmed fish is one of the main routes of human exposure. Fish farmed in contaminated environment accumulates arsenic in different tissues with great variability. Thus, it is utmost important to quantify the risk associated with different farmed fish species in arsenic-contaminated aquaculture systems. In the present study, arsenic content was measured in twelve fish species (Labeo rohita, L. catla, Cirrhinus mrigala, Oreochromis niloticus, O. mossambicus, Liza tade, Puntius javanicus, L. calbasu, Glossogobius giuris, Macrobrachium rosenbergii, Ctenopharyngodon idella, and Bellamya bengalensis (gastropod)) collected from arsenic-contaminated aquaculture systems. Among the studied finfishes, C. idella was found to accumulate the lowest amount of arsenic (

Aquatic macrophytes are plants that live in water or wet soil, grow profusely in lakes and waterways, and provide several ecological benefits. Lake Nasser, an artificial reservoir, has been the most critical element in Egypt’s social and economic development. The temperature changes and the Ethiopian Renaissance Dam represent the most prominent challenge that poses the greatest threat to the Lake’s water. Intense disturbance in aquatic macrophytes, caused by the very large fluctuation in water level and temperature was observed. Currently, only three submerged macrophyte species (Myriophyllum spicatum, Potamogeton schweinfurthii and Najas marina) were detected at Lake Nasser. The composition and structure of the submerged macrophytes community had a pronounced impact on fish production and diversity in the Lake. As the Lake is located in the subtropical region, where warm water fosters plant growth, the dangers of some macrophytes may be high. Therefore, additional studies are needed to avoid the negative effects of climate change and the impact of the Renaissance Dam on Lake Nasser and to optimize the most benefit of its aquatic macrophytes.

In marine ecosystems, fluctuations in surface-seawater carbon dioxide (CO2), significantly influence the whole metabolism of marine algae, especially during the early stages of macroalgal development. In this study, the response of the green alga Ulva fasciata for elevating ocean acidification was investigated using four levels of pCO2 ∼280, 550, 750 and 1050 µatm. Maximum growth rate (6.6 % day-1), protein (32.43 %DW) and pigment (2.9 mg/g) accumulation were observed at pCO2-550 with an increase of ∼2-fold compared to control. On the other hand, lipid and carbohydrate contents recorded their maximum production (4.23 and 46.96 %DW, respectively) at pCO2-750 while control showed 3.70 and 42.37 %DW, respectively. SDS-PAGE showed the presence of unique bands in response to pCO2, especially at 550 µatm. Dominant associated bacteria was shifted from Halomonas hydrothermalis of control to Vibrio toranzoniae at pCO2-1050. These findings suggest that ocean acidification at 550 µatm might impose noticeable effects on growth, protein, pigments, and protein profile of U. fasciata, which could be a good source for fish farming. While, pCO2-750 was recommended for energetic purpose, due to its high lipid and carbohydrate contents.

The demand for wild tambaqui has led to overfishing of their natural stocks, and has thus increased the demand for farmed fish. This has raised a question regarding the nutritional value of these groups of individuals; to see if they differ when they grow in wild and farmed environments. The meat of 28 tambaqui was evaluated by measuring the moisture, ash and total proteins among the fish from the two different environments in the states of Amazonas and Rondônia, Brazil. The averages of the centesimal composition showed significant differences, between environments and states. The moisture values of wild fish between the states did not differ, but were higher than those farmed in either of the states. The ash value also showed differences between groups by environment and between states. However, it was found that wild tambaqui from both states exhibited the best levels of protein and did not show statistical dissimilarities. The group farmed in Rondônia was also similar to the wild ones caught in that state. As for farmed fish, the averages between states were different, with the lowest value attributed to fish from Amazonas. The data show that wild tambaqui had a higher nutritional value than farmed fish.

Lipid metabolism disorders are found ubiquitously in farmed fish and occur as a result of excessive fat accumulation. Previous studies have found that miR-33 is involved in lipid metabolism; however, its role in fish lipid metabolism is unclear. We sought to clarify this relationship in grass carp in vivo and in vitro. Our findings revealed the length of miR-33 to be 65 bp. Phylogenetic tree analysis showed that grass carp miR-33 was most closely related to fish miR-33 (Siganus canaliculatus). Hepatocytes transfected with miR-33 mimic displayed markedly raised TG content (P

To make crucial prevention, reduce fish losses and minimize the economic damage of diseases on the fish farm owners, a rapid detection of fish pathogens is mandatory. In this study, a loop-mediated isothermal amplification assay combined with hydroxynaphthol blue dye (LAMP-HNB) was developed and used for the rapid detection of Aeromonas salmonicida that caused significant economic losses in fish farming. Firstly, a pair of outer and inner primers specific for conserved fragment of vapA gene in A. salmonicida were designed and synthesized. Secondly, by optimizing the reaction conditions including reaction temperature, time, Mg2+ concentration, dNTP concentration and primer ratio, a LAMP-HNB assay was successfully established for the detection of A. salmoncida. Thirdly, the assay showed good specificity with no false-positive and false-negative results, and good sensitivity with the detection limit of 3.077 × 10-6 ng/μl, which was 102 times more sensitive than the conventional PCR. Finally, the LAMP-HNB assay was validated by the fish samples inoculated with different concentrations of A. salmoncida. This is the first development of rapid visual detection of A. salmonicida based on LAMP-HNB assay, which has great application prospect and market for diagnostic testing, health certification and active surveillance programmers.

The applications of exogenous hormones in different species for the induction of oocyte production, final oocyte maturation (FOM), and spawning for their reproduction is getting more attention day by day. The current preliminary research work was carried out to induce breeding in Clarias gariepinus, commonly known as African catfish, imported from Thailand. Single doses of two hormones as Ovaprim and human menopausal gonadotropin (hMG) were used and the research work was carried out at Muzaffargarh Fish Hatchery Punjab, Pakistan. A total of twenty-four (n = 24) C. gariepinus were selected having body weight approximately 2 kg and divided into two main groups based on gender as male (n = 12) and female (n = 12). For milt collection, all males were treated with Ovaprim 0.5 mg/kg body weight (b.w.) and female fish were divided into three groups as A, B, and C with four (n = 4) fish in each group. Group A was injected with only normal saline (control group) while fish in group B and group C were treated with hMG at 0.5 mg/kg b.w. and Ovaprim 0.5 mg/kg b.w., respectively. Then, after 6 h of hormone injections until 48 h, spawned eggs, eggs’ weight, fertilization rate, hatching rate, survival rate, fecundity, and deformed larvae were investigated. The results revealed that Ovaprim injection significantly (p

The objective of this study was to determine molecular typing and comparison analysis of 24 Aeromonas hydrophila isolated from the diseased fish with hemorrhagic septicemia in freshwater ponds and cage in Mosul and Duhok cities, Iraq. A total of 24 A. hydrophila isolates that were collected from various fish ponds and cage, were used in this study. Identification of isolates was made by the standard microbiological and molecular methods. ERIC-PCR was done with different primers to establish the genetic relationship between strains. ERIC-PCR typing showed that 24 strains of A. hydrophila were classified into 11 ERIC types (genotypes). Genotypes 9 and 7 represented the most prevalent clone. All A. hydrophila strains that were isolated from the same fish were genetically diverse. There was minimal genetic similarity between some strains which were retrieved from the same geographical source area. Also, some isolates from different geographic source area were showed a 100% genetically similar. Aeromonas hydrophila was genotypically heterogeneous and clonally dispersed among different fish ponds and cage in Mosul and Duhok cities, Iraq. Besides, one fish can be infected with more than one strains of A. hydrophila.

Tambaqui, a species native to the Amazon and Orinoco Basins and their tributaries, has a history marked by biological resilience that makes this species a model for studies focused on ecology, physiology, and fish farming. In addition, it is of economic interest, due to its favorable characteristics for production in farms and its unique flavor. As the tambaqui responds in a unique way to several environmental disturbances of natural origin, the species is often used in environmental studies. Some of these studies have been revisited in this review. We revised aspects related to its natural history, habitats and geographic distribution, physiological and biochemical adaptations, and zootechnical performance. The extraordinary adaptation of the tambaqui is the fast expansion of its lower lip when exposed to low oxygen availability that is improved simultaneously with other adjustments. The resilience of this species to significant alterations in water pH is also surprising, and is incomparable with that of other species, as only when it is exposed to pH 3.5, does the tambaqui begin to present physiological-biochemical disturbances. The analysis of the gene expression of tambaqui specimens under different experimental conditions has shed light on the adaptive mechanisms used by this unique Amazonian species. In this sense, this review sought to gather information regarding the tambaqui, and its many biological features employed to survive environmental challenges.

In Nigeria, farming of freshwater fish, mainly that of Clarias gariepinus has gained prominence as means of improved protein supply and livelihood. Many farmers suffer untold losses in their bid to make a living from commercial fish production. Among the major causes of infectious disease outbreaks in fish farms are pathogenic bacteria of the genus Aeromonas. This is a case report of outbreak of Aeromonas caviae infection complicated by nitrite toxicity in Clarias gariepinus. Carcasses of 17 African catfish juveniles and two water samples were presented to the poultry and fish clinic of the Veterinary Teaching Hospital, University of Jos for investigation. The fishes had been on medication (Fish cure antibiotic +®) for over 5 days with cumulative mortality of 230 out of 2,500 fishes (9.2 %). Necropsy was conducted and samples were taken for microbial analysis and histopathology while water samples were subjected to chemical analysis. Gross lesions were broken barbels, cutaneous depigmentation, branchial pallor, ascites, renal and splenic congestion. Histologically, there was dissociation of hepatic cords, necrosis of hepatocytes with vacuolation and mononuclear cellular infiltrations. Also, there was renal tubular epithelial necrosis with mononuclear and heterophilic infiltration while micro abscesses were observed in the brain. Marked Zenker’s necrosis and edema were seen in the skeletal muscles. Organism isolated from livers and kidneys was identified as Aeromonas caviae and was susceptible to enrofloxacin, furaltadone and florfenicol. Nitrite in fish pond water was 1mg/L. Bath medication with enrofloxacin at 33mg/litre of water for 6 hours treatment per day was done to reduce the mortality. The farmer was advised to change the source of water for the fish pond immediately. It is recommended that to avoid losses in fish farming, farmers should check the quality of water intended for use on fish farms and ensure early health check on fingerlings purchased for rearing.