The intensification of aquaculture has emerged as a viable alternative for increasing aquaculture production due to competition that arose from the use of natural resources,such as land and water,by other production a...The intensification of aquaculture has emerged as a viable alternative for increasing aquaculture production due to competition that arose from the use of natural resources,such as land and water,by other production and developmental sectors.However,intensification demands increased inputs,such as fish and feed per unit culture area and,therefore,increased waste generation from the aquaculture production systems.The impact of waste products from aquaculture has increased public concern and threatens the sustainability of aquaculture practices.The need for increasing the production of aquaculture products cannot be overemphasized and,therefore,there is a need to develop culture systems that will increase fish production with efficient waste management in order to limit environmental degradation resulting from aquaculture wastes and ensure its sustainability.This paper reviewed various aspects of waste production from aquaculture,their sources,components,and methods of management,in different culture systems,primarily discussing waste production from feed,chemicals,and pathogens.We aimed to establish the sources of wastes,their contents,and potential harms to both the fish culture and the environment.Suggestions for managing wastes in different culture systems were made to ensure an improved and sustainable aquaculture production.展开更多
The aquafeed industry continues to expand in response to the rapidly growing aquaculture sector.However,the identification of alternative protein sources in aquatic animal diets to replace conventional sources due to ...The aquafeed industry continues to expand in response to the rapidly growing aquaculture sector.However,the identification of alternative protein sources in aquatic animal diets to replace conventional sources due to cost and sustainability issues remains a major challenge.Recently,insects have shown tremendous results as potential replacers of fishmeal in aquafeed.The present study aimed to review the utilization of insects in aquafeeds and their effects on aquatic animals’growth and feed utilization,immune response and disease resistance,and fish flesh quality and safety.While many insect species have been investigated in aquaculture,the black soldier fly(Hermetia illucens),and the mealworm(Tenebrio molitor)are the most studied and most promising insects to replace fishmeal in aquafeed.Generally,insect rearing conditions and biomass processing methods may affect the product’s nutritional composition,digestibility,shelf life and required insect inclusion level by aquatic animals.Also,insect-recommended inclusion levels for aquatic animals vary depending on the insect species used,biomass processing method,and test organism.Overall,while an appropriate inclusion level of insects in aquafeed provides several nutritional and health benefits to aquatic animals,more studies are needed to establish optimum requirements levels for different aquaculture species at different stages of development and under different culture systems.展开更多
Copper （Cu） contamination in the environment has been increased during the years with agricultural and industrial activities. Biotechnological approaches are needed for bioremediation in these areas. The aims of thi...Copper （Cu） contamination in the environment has been increased during the years with agricultural and industrial activities. Biotechnological approaches are needed for bioremediation in these areas. The aims of this study were i） to evaluate the phytoreme- diation capacity of the high-yielding bioenergy plant castor bean （Ricinus communis L.） in vineyard soils （Inceptisol and Mollisol） contaminated with Cu and a Cu mining waste; ii） to characterize the castor bean as a Cu phytoremediation plant; and iii） to evaluate the nutrient uptake by castor bean. Castor bean plants cultivated in soil with toxic levels of Cu for 57 d exhibited high phytomass production, a high tolerance index of roots＇ fresh mass and shoots＇ dry mass, a high level of Cu phytoaccumulation in the roots and also, a robust capacity for Cu phytostabilization. Furthermore, castor bean plants did not significantly deplete soil nutrients （such as N, P, and Mg） during cultivation. Plants cultivated in Inceptisol, Mollisol and Cu mining waste exhibited a strong potential for Cu phytoaccumulation, with values of 5900, 3 052 and 2805 g ha-1, respectively. In addition, the castor bean＇s elevated phytomass production and strong growth in Cu-contaminated soils indicated a high level of Cu phytoaccumulation and a potential application in biofuels. These findings indicate that the castor bean is a efficient hyperaccumulator of Cu and a potential candidate plant for the phytoremediation of Cu-contaminated soil.展开更多
Background:Hepatitis C,caused by the Hepatitis C Virus(HCV),is the second most common form of viral hepatitis.The geographical distribution of HCV genotypes can be quite complex,making it challenging to ascertain the ...Background:Hepatitis C,caused by the Hepatitis C Virus(HCV),is the second most common form of viral hepatitis.The geographical distribution of HCV genotypes can be quite complex,making it challenging to ascertain the most prevalent genotype in a specific area.Methods:To address this,a review was conducted to determine the prevalence of HCV genotypes across various provinces and as a whole in Pakistan.The scientific literature regarding the prevalence,distribution,genotyping,and epidemiology of HCV was gathered from published articles spanning the years 1996-2020.Results:Genotype 1 accounted for 5.1%of the patients,with its predominant subtype being 1a at 4.38%.The frequencies of its other subtypes,1b and 1c,were observed to be 1.0%and 0.31%respectively.Genotype 2 had a frequency of 2.66%,with the most widely distributed subtype being 2a at 2.11%of the patients.Its other subtypes,2b and 2c,had frequencies of 0.17%and 0.36%respectively.The most prevalent genotype among all isolates was 3(65.35%),with the most frequent subtype being 3a(55.15%),followed by 3b(7.18%).The prevalence of genotypes 4,5,and 6 were scarce in Pakistan,with frequencies of 0.97%,0.08%,and 0.32%respectively.The prevalence of untypeable and mixed genotypes was 21.34%and 3.53%respectively.Estimating genotypes proves to be a productive method in assisting with the duration and selection of antiviral treatment.Different HCV genotypes can exhibit variations in their response to specific antiviral treatments.Different genotypes may have distinct natural histories,including variations in disease progression and severity.Some genotypes may lead to more rapid liver damage,while others progress more slowly.Conclusions:This information can guide screening and testing strategies,helping to identify individuals at higher risk of developing severe complications.Studying the distribution of HCV genotypes in a population can provide valuable insights into the transmission dynamics of the virus.展开更多
Aquatic environment gets highly polluted due to the presence of heavy metals,which are usually discharged into water bodies because of rapid industrialization.The main purpose of this study is to evaluate the effects ...Aquatic environment gets highly polluted due to the presence of heavy metals,which are usually discharged into water bodies because of rapid industrialization.The main purpose of this study is to evaluate the effects of chromium toxicity on histo-biochemical biomarkers of Labeo rohita.A total of 240 randomly selected fish were distributed into four aquaria(n=20).Three groups designated as T_(1),T_(2) and T_(3) were exposed with 1/3rd,1/5th and 1/10th of LC_(50) of chromium chloride,and the fourth group was chromium-free control(T0).Results showed a significant(p<0.05)decrease in blood parameters such as hematocrit,red blood cells,hemoglobin,mean cell hemoglobin and platelets.In contrast,mean cell volume and white blood cell values increased significantly.The results obtained by comet assay showed that DNA damage was increased significantly(p<0.05)in chromium-exposed groups compared to the control.At the histopathological level,observed alterations in the gill tissues are degeneration of epithelium,fusion of secondary lamellae,lamellar curling,hypertrophy,telangiectasis and oedema,while in the liver is necrosis,dilation of the vein,congestion of blood vessels,hepatocytes degeneration,melano-macrophage centers,pigmentation and hemorrhage.In the kidney,histological alterations such as glomerular destruction,necrosis,damaged blood vessels,oedema and pigmentation were seen.Those results suggest that chromium has the ability to bring variations DNA integrity,histopathology and blood of Labeo rohita.展开更多
Objective:To assess the effects of a widely used antibiotic,oxytetracycline(OTC)on the bacterial microflora in two catfish species under artificial culture conditions in the laboratory.Methods:The experiment was condu...Objective:To assess the effects of a widely used antibiotic,oxytetracycline(OTC)on the bacterial microflora in two catfish species under artificial culture conditions in the laboratory.Methods:The experiment was conducted in the Faculty of Fisheries,Bangladesh Agricultural University,Mymensingh-2202.The fish were reared in six aquaria(size 37 cm×30 cm×60 cm)where three aquaria served as replicates of the antibiotic treatment groups and the remaining three aquaria served as an untreated control group.Each aquarium was stocked with 25 fish on an average body weight 15 g.OTC was administered to the fish in the treatment groups at the rate of 2 g/kg in-feed twice daily upto ad libitum,whereas fish in the untreated control groups were given the same feed without antibiotics for 20 d.During the experiment,bacterial loads were estimated as colony forming unit(CFU/g)by every alternate day in the aquarium water,gills,skin and intestine of fish.Results:The administration of OTC in feed resulted in gradual decrease of bacterial loads in the gills,intestine and skin of the two catfish species tested.In contrast,the bacterial loads remain unchanged or slightly increased in the control groups not fed with OTC.Water quality parameters such as dissolved oxygen,pH and total hardness were found to be within suitable range in the test aquaria but not in control aquarium throughout the experimental period.Conclusions:The results of this experiment showed that in-feed antibiotic OTC for a period of 20d reduced the bacterial loads in the gills,intestines and skin of treated fish.展开更多
The response of catfish fed differently timed wet-heat-treated sesame seedmeal was evaluated in the diet of Clarias gariepinus using growth performance, nutrient utilisation and apparent digesti-bility coefficient as ...The response of catfish fed differently timed wet-heat-treated sesame seedmeal was evaluated in the diet of Clarias gariepinus using growth performance, nutrient utilisation and apparent digesti-bility coefficient as indices. Three batches of sesame seed, which were cooked for 10, 20 and 30 minutes, dried, milled, and mechanically defatted using locally made screw press. Each of these differently processed seedmeals was included in the diet of African catfish at varying replacement levels, 15, 30 and 45% with soybean meal. There was good growth performance and nutrient uti-lization by Clarias gariepinus fed with differently timed wet-heat-treated sesame seed that was not significantly different (p > 0.05) from fish fed control diet. More so, the apparent digestibility coef-ficient for organic matter, protein, energy, lipid, fibre, carbohydrate in Clarias gariepinus fed with differently timed wet-heat-treated sesame seedmeal based diets in this study were comparable with the results obtained for fish fed control diets.展开更多
The need for replacement of highly priced soybean meal(SM)in fish diets with unconventional plant materials has become imperative for the sustainability of aquaculture production.This study addressed the effect of rep...The need for replacement of highly priced soybean meal(SM)in fish diets with unconventional plant materials has become imperative for the sustainability of aquaculture production.This study addressed the effect of replacing SM with discarded cashew nut meal(DCNM)on the liver and stomach histology in African catfish(Clarias gariepinus).Total 90 juveniles(24.83±1.52 g)were fed DCNM based diets,inclusion level of 0,50%and 100%.Fish were fed twice daily(8:00 a.m.–4:00 p.m.)at 5%body weight for 56 days.The histology of liver and the stomach were assessed.Histo-morphological changes of the liver tissue were moderate at 100%DCNM fed fish compared to 50%DCNM and control(0 DCNM).Photomicrograph of stomach of 50%DCNM fed fish showed normal histo-morphological features,while moderate to severe histological distortions were observed in the stomach of 100%DCNM fed fish.The findings of the present study showed that partial(50%)replacement of SM with DCNM had no adverse nutritional consequence while total(100%)replacement of SM with DCNM in the diet of C.gariepinus resulted to moderate histological distortions of the liver and stomach.展开更多
Objective:To assess the catch composition and seasonal variation in catch of set bagnet fishery from the coastal Payra river,to understand the importance and impact of set bagnet fishery on biodiversity and fisheries,...Objective:To assess the catch composition and seasonal variation in catch of set bagnet fishery from the coastal Payra river,to understand the importance and impact of set bagnet fishery on biodiversity and fisheries,and to find out feasible strategies to reduce the negative impact of set bagnet fishery.Methods:The research was conducted with selection of research area,preparation of gear survey and catch assessment form,sample collection,laboratory analysis and selection of analytical methods to achieve the objectives of the study.Results:A total of 52 species belonging to 23 families were recorded from set bagnet in the Payra river.Most important commercial fishes and their annual catch by set bagnet in the study area were 51.03 MT Ilish(Tenualosa ilisha),8.83 MT Rita(Rita rita),6.92 MT Air(Sperata aor),4.72 MT Chital(Chitala chitala),2.03 MT Boal(Wallago attu),1.84 MT Baghair(Bagarius bagarius),3.35 MT Foli(Notopterus notopterus)and 13.46 MT Golda chingri(Macrobrachium rosenbergii).All these species were mostly caught at initial stages of their life cycle,which usually move with the tidal current.Conclusions:Study suggested that set bagnet should be restricted to allowable limit with strong monitoring system for the protection and conservation of valuable fish species in the coastal areas of Bangladesh.展开更多
Different kinds of human chronic diseases may develop the mechanism of autoimmune diseases.As a group of disorders,in the Western world autoimmunity possess as the third most prevalent morbidity and mortality.However,...Different kinds of human chronic diseases may develop the mechanism of autoimmune diseases.As a group of disorders,in the Western world autoimmunity possess as the third most prevalent morbidity and mortality.However,the mechanism of most autoimmune diseases is still under investigation.Viral infection is the principal factor involved in the induction of autoimmune diseases other than genetic factors and cytokine activity.Different mechanisms have been proposed by which viral infection might interrupt tolerance to self and induce autoimmune cascade which eventually leads to the destruction of a specific type of cell or a whole-body organ.The autoimmune attack can be understood through the different immune systems and other possible mechanisms such as molecular mimicry,bystander activation and epitope spreading.In addition to genetic and viral factors,other environmental factors are also involved including bacterial,parasitic and fungal infections.However,different animal models have been studied which provide strong evidence that viruses induced AIDs as well as accelerated and increased lesions in conditions where self-tolerance is interrupted.In the current review,we discussed the virus-induced autoimmunity and the molecular mechanism which is associated with this phenomenon.Here we also discussed the different viruses such as rubella virus,enteroviruses,measles virus,human T-lymphotropic virus type1,human cytomegalovirus,human herpes virus-6,Epstein-Barr virus,rotavirus and some other viruses which modulate the development of AIDs.展开更多
Objective: To evaluate the effect of Zingiber officinale (ginger) and Hibiscus sabdariffa (roselle) as dietary supplements on serum biochemistry and some metabolites (urea and creatinine) in Clarias gariepinus (C. gar...Objective: To evaluate the effect of Zingiber officinale (ginger) and Hibiscus sabdariffa (roselle) as dietary supplements on serum biochemistry and some metabolites (urea and creatinine) in Clarias gariepinus (C. gariepinus). Methods: A total of 150 C. gariepinus juveniles [initial weight (35.41 ± 1.53) g] were randomly assigned to five test diets. Ginger and roselle were added to diets as additives at 2 g and 4 g respectively while control diet contained none of the substances. Blood samples were collected from treatment groups for biochemical analysis after 70 days feeding trial. Results: Significant changes (P < 0.05) were observed in serum enzymes (alkaline phosphatase, alanine amino transferase and aspartate amino transferase) activities. Significant increase (P < 0.05) in serum total protein was noticed in treated fish when compared to control. Relative changes in urea and creatinine levels were observed in fish fed with roselle based diets while insignificant changes (P > 0.05) were seen in ginger treated fish. Conclusions: The present study revealed that ginger and roselle added to the diets as additives had no adverse effect on the examined serum biochemistry in C. gariepinus.展开更多
Nigeria waters are rich with a variety of fish species but only very few are cultured and available for consumption.This study was conducted to know the fillet quality,gut content and condition of Parachanna obscura a...Nigeria waters are rich with a variety of fish species but only very few are cultured and available for consumption.This study was conducted to know the fillet quality,gut content and condition of Parachanna obscura and Clarias agboyiensis in Nigeria using Igbokoda river as a reference because it is a the major fishing site in the nation.Studies were conducted on the viscera somatic index based on the organ weight and the body weight of the fish and the food item consumed by Parachanna obscura and Clarias agboyiensis between May to October,2019 to infer on the fillet quality and gut content of P.obscura and C.agboyiensis in the water body respectively.A summary of food items that constituted the diet of Clarias agboyiensis are Baccillariophyta,fish,fat droplets,dinoflagellate,insect and Chlorophyta which constituted the most important food items both occurring in all stomachs containing food.The fishes has more muscle than the viscera organs which indicate that the weight of the fish before dressing out is higher than the weight of the fish after dressing out.This is suggestive of a good quality of food fish.There was a significant correlation between body weight and total length of specimens found in this study.Increases in total length resulted in corresponding increases in body weight.The result for the condition factor showed was below the expected or standard value(K=1)which shows this species was not in favorable environmental condition.It is therefore necessary to allow phytoplanktons grow well in water body to increase availability of food items to Parachanna obscura and Clarias agboyiensis.P.obscura and C.agboyiensis are also good food fishes of a high fillet quality.They are omnivorous feeders therefore having potentials for aquaculture.展开更多
The experiment compared the physical characteristics of aqua feed with crude or gelatinized tapioca starch as sources of energy.The bulk density(BD),water absorption index(WAI),water solubility index(WSI),pellet durab...The experiment compared the physical characteristics of aqua feed with crude or gelatinized tapioca starch as sources of energy.The bulk density(BD),water absorption index(WAI),water solubility index(WSI),pellet durability index(PDI)and water stability(WS)were measured in both experimental diets.The results showed significant variations(p<0.05)in BD and WAI in diet with crude tapioca starch while non-significant variations(p>0.05)were recorded for WSI and WS in both diets.The higher BD of a diet,the better its ability in resisting external forces that can cause disintegration.A high BD also reduces ability to the feed material shrinking,thereby preventing loss to feed dust and fines.The results of WSI,WS and PDI of diets denotes that both pellets were water stable and could spend about same time in water but diet with gelatinized starch had a better water absorption index and pellet durability index.Furthermore,proximate composition of diets showed that diets with gelatinized starch had low moisture(9.04%),low fibre(5.24%),and higher ash(13.61%)and lipid(9.64%)contents.It can be concluded from this experiment that diets with gelatinized starch stands the chance of being a better functional feed for small-scale fish farmers in Sub-Saharan Africa.展开更多
A 70-day feeding trial was conducted to evaluate the efficacy of Chlorella vulgaris supplementation in diets of giant freshwater prawn(Macrobrachium rosenbergii)post larvae.Resistance of the prawns against Aeromonas h...A 70-day feeding trial was conducted to evaluate the efficacy of Chlorella vulgaris supplementation in diets of giant freshwater prawn(Macrobrachium rosenbergii)post larvae.Resistance of the prawns against Aeromonas hydrophila and several immune parameters(total hemocyte count and prophenoloxidase activity)were also assessed in the study.Iso-nitrogenous,iso-lipidic,and iso-caloric prawn feeds were prepared utilizing a fishmeal based positive control diet(F0)and four dietary treatments with C.vulgaris inclusion levels of 2(F2),4(F4),6(F6),and 8(F8)%.Post larvae of M.rosenbergii were stocked randomly(mean initial body weight of 0.39�0.38 g)in fifteen net cages(8.1 m�8.9 m with an average depth of 1 m)in an earthen pond for the assessment of growth parameters.Overall growth indices for prawn fed Chlorella containing diets were enhanced in comparison to the control treatment.Prawn fed diets with Chlorella showed significantly higher(P<0.05)prophenol oxidase activity,total hemocyte counts,and survival rates post bacterial infection.These findings demonstrated that inclusion of 4%,6%,and 8%C.vulgaris in prawn diets provided optimal growth rates and improved immunity of the post larvae.展开更多
Culture trial of 7,488 juveniles of the giant freshwater prawn, Macrobrachium vollenhovenii (Herklots, 1857) was carried out for 180 d in concrete tanks to determine their adaptability, survival, feed utilization and ...Culture trial of 7,488 juveniles of the giant freshwater prawn, Macrobrachium vollenhovenii (Herklots, 1857) was carried out for 180 d in concrete tanks to determine their adaptability, survival, feed utilization and growth performance under culture condition. Twelve experimental concrete tanks each measuring 10 m × 5 m × 1.0 m were used for the experiment from March to August 2016. The prawns were stocked two weeks after treatment of tanks with agricultural lime at the rate of 2,279 kg/ha and poultry manure at the rate of 114 kg/ha. Four experimental diets tested were designated as T1: powdered broiler starter, T2: commercial brine shrimp, T3: combination of broiler starter and brine shrimp and T4: Mississippi Agricultural and Forestry Experimental Station (MAFES) diet formula. Diets were randomly assigned to the four treatment tanks and replicated three times in a 4 × 3 = 12 experimental units as a completely randomized design experiment (CRD). Each tank was stocked with 624 juvenile prawns with mean total length of 1.5 cm and body weight of 10.0 g. Prawns were fed at 5% body weight and twice at 0600 h and 1800 h. Sampling for growth was carried out bi-weekly while water quality was tested weekly. Results were statistically evaluated with one way analysis of variance (ANOVA). Water quality of the four tanks was not significantly different (p > 0.05) from one another throughout the culture period and conformed to recommended tolerable limits in prawn culture ponds. Growth performance was best in diet T4 (the MAFES formula), with a survival rate of 75%, mean weight gain (MWG) of 65 g, relative growth rate (RGR) of 650%, specific growth rate (SGR) of 1.12%, average daily growth (ADG) of 0.3 g/day and food conversion ratio (FCR) of 1.44. The above values differed quite significantly (p < 0.05) from growth responses of other diets. The computed gross ratio (GR) of 0.62 suggests that prawn culture is a highly lucrative business.展开更多
The present study deals with the monitoring for a real implementation of management policies in marine environments and the potential conflicts between professional and recreational fishery in the coastal areas of the...The present study deals with the monitoring for a real implementation of management policies in marine environments and the potential conflicts between professional and recreational fishery in the coastal areas of the Mediterranean Sea.A comprehensive database of fishing effort and fisheries infringements from professional small-scale and recreational fisheries was screened to identify hotspots areas of fishing pressure in the coastal zones of Ionian Sea.Mapping points showed that the number of the recorded infringements conducted both by professional and recreational fishers are too low(1 and 6 recorded infringements per 104 km2 of vessel days per year)and that fishing effort,and subsequently the recorded infringements,are not evenly distributed but concentrated on specific fishing grounds.These revealed high-risk areas prone to illegal fishing activities and are implying problems in the implementation of the fisheries regulations rather than a low delinquency of the fishers to comply with the rules.Findings represents a step forward in applying tracking technology to the surveillance of small-scale fishery and are crucial towards the specification of the critical zones for setting an efficient control system.展开更多
Objective:To investigate the effect of Tetracarpidium conophorum(T.conophorum)seed powder as dietary supplementation on the reproductive indices in male Clarias gariepinus(C.gariepinus)broodstocks.Methods:Fifteen outd...Objective:To investigate the effect of Tetracarpidium conophorum(T.conophorum)seed powder as dietary supplementation on the reproductive indices in male Clarias gariepinus(C.gariepinus)broodstocks.Methods:Fifteen outdoor concrete tanks consisting of triplicates for each treatment group were used.Triplicate groups of male C.gariepinus[(303.22±1.89)g body weight]were fed with four diets supplemented T.conophorum seed powder respectively,a control diet without T.conophorum seed powder 2 times a day at 3%of body weight for 70 days.Male C.gariepinus broodstocks[average individual weight,(303.22±1.89)g]were randomly distributed with density of 10 fish into 15 outdoor concrete tanks.At the end of the 70-day experiment,gonado-somatic index and reproductive indices were determined.Results:Fish fed experimental diets showed significantly improved gonado-somatic index and reproductive indices over the control treatment.Higher gonado-somatic index and reproductive indices were recorded for the fish fed diet of 200 mg/kg T.conophorum seed powder compared to other experimental diets.The results indicated that supplement diets with medicinal plant(T.conophorum)enhanced growth and improved gonado-somatic index,and reproductive indices of male C.gariepinus broodstocks.Conclusions:T.conophorum have a potential pro-fertility property which can be exploited in fish seed production by hatchery operators.展开更多
文摘The intensification of aquaculture has emerged as a viable alternative for increasing aquaculture production due to competition that arose from the use of natural resources,such as land and water,by other production and developmental sectors.However,intensification demands increased inputs,such as fish and feed per unit culture area and,therefore,increased waste generation from the aquaculture production systems.The impact of waste products from aquaculture has increased public concern and threatens the sustainability of aquaculture practices.The need for increasing the production of aquaculture products cannot be overemphasized and,therefore,there is a need to develop culture systems that will increase fish production with efficient waste management in order to limit environmental degradation resulting from aquaculture wastes and ensure its sustainability.This paper reviewed various aspects of waste production from aquaculture,their sources,components,and methods of management,in different culture systems,primarily discussing waste production from feed,chemicals,and pathogens.We aimed to establish the sources of wastes,their contents,and potential harms to both the fish culture and the environment.Suggestions for managing wastes in different culture systems were made to ensure an improved and sustainable aquaculture production.
基金funded by the Ministry of Education of Malaysia under the Fundamental Research Grant Scheme(FRGS)(R/FRGS/A07.00/00387A/005/2013/00107)Niche Research Grant Scheme(NRGS)(R/NRGS/A0.700/00387A/006/2014/00152)partially supported by Chiang Mai University。
文摘The aquafeed industry continues to expand in response to the rapidly growing aquaculture sector.However,the identification of alternative protein sources in aquatic animal diets to replace conventional sources due to cost and sustainability issues remains a major challenge.Recently,insects have shown tremendous results as potential replacers of fishmeal in aquafeed.The present study aimed to review the utilization of insects in aquafeeds and their effects on aquatic animals’growth and feed utilization,immune response and disease resistance,and fish flesh quality and safety.While many insect species have been investigated in aquaculture,the black soldier fly(Hermetia illucens),and the mealworm(Tenebrio molitor)are the most studied and most promising insects to replace fishmeal in aquafeed.Generally,insect rearing conditions and biomass processing methods may affect the product’s nutritional composition,digestibility,shelf life and required insect inclusion level by aquatic animals.Also,insect-recommended inclusion levels for aquatic animals vary depending on the insect species used,biomass processing method,and test organism.Overall,while an appropriate inclusion level of insects in aquafeed provides several nutritional and health benefits to aquatic animals,more studies are needed to establish optimum requirements levels for different aquaculture species at different stages of development and under different culture systems.
基金Supported by the Coordenao de Aperfeic oamento de Pessoal de N'vel Superior (CAPES) of Brazil and the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) of Brazil
文摘Copper （Cu） contamination in the environment has been increased during the years with agricultural and industrial activities. Biotechnological approaches are needed for bioremediation in these areas. The aims of this study were i） to evaluate the phytoreme- diation capacity of the high-yielding bioenergy plant castor bean （Ricinus communis L.） in vineyard soils （Inceptisol and Mollisol） contaminated with Cu and a Cu mining waste; ii） to characterize the castor bean as a Cu phytoremediation plant; and iii） to evaluate the nutrient uptake by castor bean. Castor bean plants cultivated in soil with toxic levels of Cu for 57 d exhibited high phytomass production, a high tolerance index of roots＇ fresh mass and shoots＇ dry mass, a high level of Cu phytoaccumulation in the roots and also, a robust capacity for Cu phytostabilization. Furthermore, castor bean plants did not significantly deplete soil nutrients （such as N, P, and Mg） during cultivation. Plants cultivated in Inceptisol, Mollisol and Cu mining waste exhibited a strong potential for Cu phytoaccumulation, with values of 5900, 3 052 and 2805 g ha-1, respectively. In addition, the castor bean＇s elevated phytomass production and strong growth in Cu-contaminated soils indicated a high level of Cu phytoaccumulation and a potential application in biofuels. These findings indicate that the castor bean is a efficient hyperaccumulator of Cu and a potential candidate plant for the phytoremediation of Cu-contaminated soil.
文摘Background:Hepatitis C,caused by the Hepatitis C Virus(HCV),is the second most common form of viral hepatitis.The geographical distribution of HCV genotypes can be quite complex,making it challenging to ascertain the most prevalent genotype in a specific area.Methods:To address this,a review was conducted to determine the prevalence of HCV genotypes across various provinces and as a whole in Pakistan.The scientific literature regarding the prevalence,distribution,genotyping,and epidemiology of HCV was gathered from published articles spanning the years 1996-2020.Results:Genotype 1 accounted for 5.1%of the patients,with its predominant subtype being 1a at 4.38%.The frequencies of its other subtypes,1b and 1c,were observed to be 1.0%and 0.31%respectively.Genotype 2 had a frequency of 2.66%,with the most widely distributed subtype being 2a at 2.11%of the patients.Its other subtypes,2b and 2c,had frequencies of 0.17%and 0.36%respectively.The most prevalent genotype among all isolates was 3(65.35%),with the most frequent subtype being 3a(55.15%),followed by 3b(7.18%).The prevalence of genotypes 4,5,and 6 were scarce in Pakistan,with frequencies of 0.97%,0.08%,and 0.32%respectively.The prevalence of untypeable and mixed genotypes was 21.34%and 3.53%respectively.Estimating genotypes proves to be a productive method in assisting with the duration and selection of antiviral treatment.Different HCV genotypes can exhibit variations in their response to specific antiviral treatments.Different genotypes may have distinct natural histories,including variations in disease progression and severity.Some genotypes may lead to more rapid liver damage,while others progress more slowly.Conclusions:This information can guide screening and testing strategies,helping to identify individuals at higher risk of developing severe complications.Studying the distribution of HCV genotypes in a population can provide valuable insights into the transmission dynamics of the virus.
文摘Aquatic environment gets highly polluted due to the presence of heavy metals,which are usually discharged into water bodies because of rapid industrialization.The main purpose of this study is to evaluate the effects of chromium toxicity on histo-biochemical biomarkers of Labeo rohita.A total of 240 randomly selected fish were distributed into four aquaria(n=20).Three groups designated as T_(1),T_(2) and T_(3) were exposed with 1/3rd,1/5th and 1/10th of LC_(50) of chromium chloride,and the fourth group was chromium-free control(T0).Results showed a significant(p<0.05)decrease in blood parameters such as hematocrit,red blood cells,hemoglobin,mean cell hemoglobin and platelets.In contrast,mean cell volume and white blood cell values increased significantly.The results obtained by comet assay showed that DNA damage was increased significantly(p<0.05)in chromium-exposed groups compared to the control.At the histopathological level,observed alterations in the gill tissues are degeneration of epithelium,fusion of secondary lamellae,lamellar curling,hypertrophy,telangiectasis and oedema,while in the liver is necrosis,dilation of the vein,congestion of blood vessels,hepatocytes degeneration,melano-macrophage centers,pigmentation and hemorrhage.In the kidney,histological alterations such as glomerular destruction,necrosis,damaged blood vessels,oedema and pigmentation were seen.Those results suggest that chromium has the ability to bring variations DNA integrity,histopathology and blood of Labeo rohita.
基金Supported by Bangladesh Fisheries Research Institute(BFRI)under the core research project Impact of Aquaculture Drugs and Chemicals on Aquatic Ecology and Productivity[Grant No:BFRI/ARP/10/3161(4)].
文摘Objective:To assess the effects of a widely used antibiotic,oxytetracycline(OTC)on the bacterial microflora in two catfish species under artificial culture conditions in the laboratory.Methods:The experiment was conducted in the Faculty of Fisheries,Bangladesh Agricultural University,Mymensingh-2202.The fish were reared in six aquaria(size 37 cm×30 cm×60 cm)where three aquaria served as replicates of the antibiotic treatment groups and the remaining three aquaria served as an untreated control group.Each aquarium was stocked with 25 fish on an average body weight 15 g.OTC was administered to the fish in the treatment groups at the rate of 2 g/kg in-feed twice daily upto ad libitum,whereas fish in the untreated control groups were given the same feed without antibiotics for 20 d.During the experiment,bacterial loads were estimated as colony forming unit(CFU/g)by every alternate day in the aquarium water,gills,skin and intestine of fish.Results:The administration of OTC in feed resulted in gradual decrease of bacterial loads in the gills,intestine and skin of the two catfish species tested.In contrast,the bacterial loads remain unchanged or slightly increased in the control groups not fed with OTC.Water quality parameters such as dissolved oxygen,pH and total hardness were found to be within suitable range in the test aquaria but not in control aquarium throughout the experimental period.Conclusions:The results of this experiment showed that in-feed antibiotic OTC for a period of 20d reduced the bacterial loads in the gills,intestines and skin of treated fish.
文摘The response of catfish fed differently timed wet-heat-treated sesame seedmeal was evaluated in the diet of Clarias gariepinus using growth performance, nutrient utilisation and apparent digesti-bility coefficient as indices. Three batches of sesame seed, which were cooked for 10, 20 and 30 minutes, dried, milled, and mechanically defatted using locally made screw press. Each of these differently processed seedmeals was included in the diet of African catfish at varying replacement levels, 15, 30 and 45% with soybean meal. There was good growth performance and nutrient uti-lization by Clarias gariepinus fed with differently timed wet-heat-treated sesame seed that was not significantly different (p > 0.05) from fish fed control diet. More so, the apparent digestibility coef-ficient for organic matter, protein, energy, lipid, fibre, carbohydrate in Clarias gariepinus fed with differently timed wet-heat-treated sesame seedmeal based diets in this study were comparable with the results obtained for fish fed control diets.
文摘The need for replacement of highly priced soybean meal(SM)in fish diets with unconventional plant materials has become imperative for the sustainability of aquaculture production.This study addressed the effect of replacing SM with discarded cashew nut meal(DCNM)on the liver and stomach histology in African catfish(Clarias gariepinus).Total 90 juveniles(24.83±1.52 g)were fed DCNM based diets,inclusion level of 0,50%and 100%.Fish were fed twice daily(8:00 a.m.–4:00 p.m.)at 5%body weight for 56 days.The histology of liver and the stomach were assessed.Histo-morphological changes of the liver tissue were moderate at 100%DCNM fed fish compared to 50%DCNM and control(0 DCNM).Photomicrograph of stomach of 50%DCNM fed fish showed normal histo-morphological features,while moderate to severe histological distortions were observed in the stomach of 100%DCNM fed fish.The findings of the present study showed that partial(50%)replacement of SM with DCNM had no adverse nutritional consequence while total(100%)replacement of SM with DCNM in the diet of C.gariepinus resulted to moderate histological distortions of the liver and stomach.
基金Supported by the Ministry of Science and Technology,Government of the People’s Republic of Bangladesh[NST-2013-2014,No.:39.012.002.01.03.019.2013-283(459),Sl.No.:258].
文摘Objective:To assess the catch composition and seasonal variation in catch of set bagnet fishery from the coastal Payra river,to understand the importance and impact of set bagnet fishery on biodiversity and fisheries,and to find out feasible strategies to reduce the negative impact of set bagnet fishery.Methods:The research was conducted with selection of research area,preparation of gear survey and catch assessment form,sample collection,laboratory analysis and selection of analytical methods to achieve the objectives of the study.Results:A total of 52 species belonging to 23 families were recorded from set bagnet in the Payra river.Most important commercial fishes and their annual catch by set bagnet in the study area were 51.03 MT Ilish(Tenualosa ilisha),8.83 MT Rita(Rita rita),6.92 MT Air(Sperata aor),4.72 MT Chital(Chitala chitala),2.03 MT Boal(Wallago attu),1.84 MT Baghair(Bagarius bagarius),3.35 MT Foli(Notopterus notopterus)and 13.46 MT Golda chingri(Macrobrachium rosenbergii).All these species were mostly caught at initial stages of their life cycle,which usually move with the tidal current.Conclusions:Study suggested that set bagnet should be restricted to allowable limit with strong monitoring system for the protection and conservation of valuable fish species in the coastal areas of Bangladesh.
文摘Different kinds of human chronic diseases may develop the mechanism of autoimmune diseases.As a group of disorders,in the Western world autoimmunity possess as the third most prevalent morbidity and mortality.However,the mechanism of most autoimmune diseases is still under investigation.Viral infection is the principal factor involved in the induction of autoimmune diseases other than genetic factors and cytokine activity.Different mechanisms have been proposed by which viral infection might interrupt tolerance to self and induce autoimmune cascade which eventually leads to the destruction of a specific type of cell or a whole-body organ.The autoimmune attack can be understood through the different immune systems and other possible mechanisms such as molecular mimicry,bystander activation and epitope spreading.In addition to genetic and viral factors,other environmental factors are also involved including bacterial,parasitic and fungal infections.However,different animal models have been studied which provide strong evidence that viruses induced AIDs as well as accelerated and increased lesions in conditions where self-tolerance is interrupted.In the current review,we discussed the virus-induced autoimmunity and the molecular mechanism which is associated with this phenomenon.Here we also discussed the different viruses such as rubella virus,enteroviruses,measles virus,human T-lymphotropic virus type1,human cytomegalovirus,human herpes virus-6,Epstein-Barr virus,rotavirus and some other viruses which modulate the development of AIDs.
文摘Objective: To evaluate the effect of Zingiber officinale (ginger) and Hibiscus sabdariffa (roselle) as dietary supplements on serum biochemistry and some metabolites (urea and creatinine) in Clarias gariepinus (C. gariepinus). Methods: A total of 150 C. gariepinus juveniles [initial weight (35.41 ± 1.53) g] were randomly assigned to five test diets. Ginger and roselle were added to diets as additives at 2 g and 4 g respectively while control diet contained none of the substances. Blood samples were collected from treatment groups for biochemical analysis after 70 days feeding trial. Results: Significant changes (P < 0.05) were observed in serum enzymes (alkaline phosphatase, alanine amino transferase and aspartate amino transferase) activities. Significant increase (P < 0.05) in serum total protein was noticed in treated fish when compared to control. Relative changes in urea and creatinine levels were observed in fish fed with roselle based diets while insignificant changes (P > 0.05) were seen in ginger treated fish. Conclusions: The present study revealed that ginger and roselle added to the diets as additives had no adverse effect on the examined serum biochemistry in C. gariepinus.
文摘Nigeria waters are rich with a variety of fish species but only very few are cultured and available for consumption.This study was conducted to know the fillet quality,gut content and condition of Parachanna obscura and Clarias agboyiensis in Nigeria using Igbokoda river as a reference because it is a the major fishing site in the nation.Studies were conducted on the viscera somatic index based on the organ weight and the body weight of the fish and the food item consumed by Parachanna obscura and Clarias agboyiensis between May to October,2019 to infer on the fillet quality and gut content of P.obscura and C.agboyiensis in the water body respectively.A summary of food items that constituted the diet of Clarias agboyiensis are Baccillariophyta,fish,fat droplets,dinoflagellate,insect and Chlorophyta which constituted the most important food items both occurring in all stomachs containing food.The fishes has more muscle than the viscera organs which indicate that the weight of the fish before dressing out is higher than the weight of the fish after dressing out.This is suggestive of a good quality of food fish.There was a significant correlation between body weight and total length of specimens found in this study.Increases in total length resulted in corresponding increases in body weight.The result for the condition factor showed was below the expected or standard value(K=1)which shows this species was not in favorable environmental condition.It is therefore necessary to allow phytoplanktons grow well in water body to increase availability of food items to Parachanna obscura and Clarias agboyiensis.P.obscura and C.agboyiensis are also good food fishes of a high fillet quality.They are omnivorous feeders therefore having potentials for aquaculture.
文摘The experiment compared the physical characteristics of aqua feed with crude or gelatinized tapioca starch as sources of energy.The bulk density(BD),water absorption index(WAI),water solubility index(WSI),pellet durability index(PDI)and water stability(WS)were measured in both experimental diets.The results showed significant variations(p<0.05)in BD and WAI in diet with crude tapioca starch while non-significant variations(p>0.05)were recorded for WSI and WS in both diets.The higher BD of a diet,the better its ability in resisting external forces that can cause disintegration.A high BD also reduces ability to the feed material shrinking,thereby preventing loss to feed dust and fines.The results of WSI,WS and PDI of diets denotes that both pellets were water stable and could spend about same time in water but diet with gelatinized starch had a better water absorption index and pellet durability index.Furthermore,proximate composition of diets showed that diets with gelatinized starch had low moisture(9.04%),low fibre(5.24%),and higher ash(13.61%)and lipid(9.64%)contents.It can be concluded from this experiment that diets with gelatinized starch stands the chance of being a better functional feed for small-scale fish farmers in Sub-Saharan Africa.
文摘A 70-day feeding trial was conducted to evaluate the efficacy of Chlorella vulgaris supplementation in diets of giant freshwater prawn(Macrobrachium rosenbergii)post larvae.Resistance of the prawns against Aeromonas hydrophila and several immune parameters(total hemocyte count and prophenoloxidase activity)were also assessed in the study.Iso-nitrogenous,iso-lipidic,and iso-caloric prawn feeds were prepared utilizing a fishmeal based positive control diet(F0)and four dietary treatments with C.vulgaris inclusion levels of 2(F2),4(F4),6(F6),and 8(F8)%.Post larvae of M.rosenbergii were stocked randomly(mean initial body weight of 0.39�0.38 g)in fifteen net cages(8.1 m�8.9 m with an average depth of 1 m)in an earthen pond for the assessment of growth parameters.Overall growth indices for prawn fed Chlorella containing diets were enhanced in comparison to the control treatment.Prawn fed diets with Chlorella showed significantly higher(P<0.05)prophenol oxidase activity,total hemocyte counts,and survival rates post bacterial infection.These findings demonstrated that inclusion of 4%,6%,and 8%C.vulgaris in prawn diets provided optimal growth rates and improved immunity of the post larvae.
文摘Culture trial of 7,488 juveniles of the giant freshwater prawn, Macrobrachium vollenhovenii (Herklots, 1857) was carried out for 180 d in concrete tanks to determine their adaptability, survival, feed utilization and growth performance under culture condition. Twelve experimental concrete tanks each measuring 10 m × 5 m × 1.0 m were used for the experiment from March to August 2016. The prawns were stocked two weeks after treatment of tanks with agricultural lime at the rate of 2,279 kg/ha and poultry manure at the rate of 114 kg/ha. Four experimental diets tested were designated as T1: powdered broiler starter, T2: commercial brine shrimp, T3: combination of broiler starter and brine shrimp and T4: Mississippi Agricultural and Forestry Experimental Station (MAFES) diet formula. Diets were randomly assigned to the four treatment tanks and replicated three times in a 4 × 3 = 12 experimental units as a completely randomized design experiment (CRD). Each tank was stocked with 624 juvenile prawns with mean total length of 1.5 cm and body weight of 10.0 g. Prawns were fed at 5% body weight and twice at 0600 h and 1800 h. Sampling for growth was carried out bi-weekly while water quality was tested weekly. Results were statistically evaluated with one way analysis of variance (ANOVA). Water quality of the four tanks was not significantly different (p > 0.05) from one another throughout the culture period and conformed to recommended tolerable limits in prawn culture ponds. Growth performance was best in diet T4 (the MAFES formula), with a survival rate of 75%, mean weight gain (MWG) of 65 g, relative growth rate (RGR) of 650%, specific growth rate (SGR) of 1.12%, average daily growth (ADG) of 0.3 g/day and food conversion ratio (FCR) of 1.44. The above values differed quite significantly (p < 0.05) from growth responses of other diets. The computed gross ratio (GR) of 0.62 suggests that prawn culture is a highly lucrative business.
文摘The present study deals with the monitoring for a real implementation of management policies in marine environments and the potential conflicts between professional and recreational fishery in the coastal areas of the Mediterranean Sea.A comprehensive database of fishing effort and fisheries infringements from professional small-scale and recreational fisheries was screened to identify hotspots areas of fishing pressure in the coastal zones of Ionian Sea.Mapping points showed that the number of the recorded infringements conducted both by professional and recreational fishers are too low(1 and 6 recorded infringements per 104 km2 of vessel days per year)and that fishing effort,and subsequently the recorded infringements,are not evenly distributed but concentrated on specific fishing grounds.These revealed high-risk areas prone to illegal fishing activities and are implying problems in the implementation of the fisheries regulations rather than a low delinquency of the fishers to comply with the rules.Findings represents a step forward in applying tracking technology to the surveillance of small-scale fishery and are crucial towards the specification of the critical zones for setting an efficient control system.
文摘Objective:To investigate the effect of Tetracarpidium conophorum(T.conophorum)seed powder as dietary supplementation on the reproductive indices in male Clarias gariepinus(C.gariepinus)broodstocks.Methods:Fifteen outdoor concrete tanks consisting of triplicates for each treatment group were used.Triplicate groups of male C.gariepinus[(303.22±1.89)g body weight]were fed with four diets supplemented T.conophorum seed powder respectively,a control diet without T.conophorum seed powder 2 times a day at 3%of body weight for 70 days.Male C.gariepinus broodstocks[average individual weight,(303.22±1.89)g]were randomly distributed with density of 10 fish into 15 outdoor concrete tanks.At the end of the 70-day experiment,gonado-somatic index and reproductive indices were determined.Results:Fish fed experimental diets showed significantly improved gonado-somatic index and reproductive indices over the control treatment.Higher gonado-somatic index and reproductive indices were recorded for the fish fed diet of 200 mg/kg T.conophorum seed powder compared to other experimental diets.The results indicated that supplement diets with medicinal plant(T.conophorum)enhanced growth and improved gonado-somatic index,and reproductive indices of male C.gariepinus broodstocks.Conclusions:T.conophorum have a potential pro-fertility property which can be exploited in fish seed production by hatchery operators.
