Lake Kivu is experiencing unprecedented decline in production of Tanganyika Sardine (Limnothrissa miodon). This study sought to characterise the value chain of this fish species so as to chart its sustainable utilisation. The study performed in 2015 found two chains; an informal chain that takes 30% of the production and a formal chain that handles 70%. The average catch of sardine was 30 kg/day in the high production season and <15 kg/day in the low season. Two thirds of the fishers were not aware of the governing law. Fishing malpractices included fishing in prohibited sites, beach seining and fishing during moratorium period. Majority of fishers were not satisfied with the price offered in the market as costs involved in fishing was 701 Rwanda Francs/kg caught. This is despite the shift in time since the study was performed. Therefore, there is need for re-training of value chain actors, increasing lake surveillance, strengthening internal controls of the Fishers’ Cooperatives and improving information sharing and communication among value chain actors. Key words: Chain mapping, fisheries, Lake Kivu, stakeholder analysis, Tanganyika Sardine.
{"title":"Enhancing the fisheries sector of African Great lakes: Value chain analysis of the Tanganyika Sardine (Limnothrissa miodon, Boulenger 1906) from Lake Kivu, Rwanda","authors":"A. Murera, M. Verschuur, Donald Rugira Kugonza","doi":"10.5897/IJFA2019.0753","DOIUrl":"https://doi.org/10.5897/IJFA2019.0753","url":null,"abstract":"Lake Kivu is experiencing unprecedented decline in production of Tanganyika Sardine (Limnothrissa miodon). This study sought to characterise the value chain of this fish species so as to chart its sustainable utilisation. The study performed in 2015 found two chains; an informal chain that takes 30% of the production and a formal chain that handles 70%. The average catch of sardine was 30 kg/day in the high production season and <15 kg/day in the low season. Two thirds of the fishers were not aware of the governing law. Fishing malpractices included fishing in prohibited sites, beach seining and fishing during moratorium period. Majority of fishers were not satisfied with the price offered in the market as costs involved in fishing was 701 Rwanda Francs/kg caught. This is despite the shift in time since the study was performed. Therefore, there is need for re-training of value chain actors, increasing lake surveillance, strengthening internal controls of the Fishers’ Cooperatives and improving information sharing and communication among value chain actors. \u0000 \u0000 Key words: Chain mapping, fisheries, Lake Kivu, stakeholder analysis, Tanganyika Sardine.","PeriodicalId":415026,"journal":{"name":"International Journal of Fisheries and Aquaculture","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129092885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The study was carried out between September 2011 and August 2013, using 328 Clarias gariepinus in Oba reservoir, Oyo State, Nigeria. Standard methods were used to determine gonado-somatic index (GSI), fecundity values, and enteroparasitic infestation of the fish. Sex ratio was 1.3:1, male to female, and females on an average invested 20.54% of its body weight in egg production while male GSI was 6.05 ± 0.19%. Spawning was prominent in rainy season; the fish was highly fecund (31,169 eggs) with relative fecundity of 222 ± 10 eggs per gram weight of fish. Fecundity correlated linearly (positive) with gonad weight, body weight, total length and GSI. Over fishing, led the fish to invest its body weight and growth in egg production, to increase and enhance its chances of survival. Parasites recovered were Procamallanus laevionchus, Paracamallanus cyathopharynx, Anomotaenia species, Monobothrium species, Polyonchobothrium clariae, and Neoechinorhynchus rutili. Prevalence and intensity were higher in female than in male and more in dry than rainy season. Parasitic infestation reduces weight growth in the fish; this influenced the values of reproductive indices in which body weight was a numerator or denominator. Keywords: Clarias gariepinus, enteroparasites, fecundity, gonado-somatic.
{"title":"Aspects of reproductive indices and enteroparasitic infestation of Clarias gariepinus (Burchell, 1822) in a tropical reservoir","authors":"O. O. Ajala, O. O. Fawole","doi":"10.5897/IJFA2019.0731","DOIUrl":"https://doi.org/10.5897/IJFA2019.0731","url":null,"abstract":"The study was carried out between September 2011 and August 2013, using 328 Clarias gariepinus in Oba reservoir, Oyo State, Nigeria. Standard methods were used to determine gonado-somatic index (GSI), fecundity values, and enteroparasitic infestation of the fish. Sex ratio was 1.3:1, male to female, and females on an average invested 20.54% of its body weight in egg production while male GSI was 6.05 ± 0.19%. Spawning was prominent in rainy season; the fish was highly fecund (31,169 eggs) with relative fecundity of 222 ± 10 eggs per gram weight of fish. Fecundity correlated linearly (positive) with gonad weight, body weight, total length and GSI. Over fishing, led the fish to invest its body weight and growth in egg production, to increase and enhance its chances of survival. Parasites recovered were Procamallanus laevionchus, Paracamallanus cyathopharynx, Anomotaenia species, Monobothrium species, Polyonchobothrium clariae, and Neoechinorhynchus rutili. Prevalence and intensity were higher in female than in male and more in dry than rainy season. Parasitic infestation reduces weight growth in the fish; this influenced the values of reproductive indices in which body weight was a numerator or denominator. \u0000 \u0000 Keywords: Clarias gariepinus, enteroparasites, fecundity, gonado-somatic.","PeriodicalId":415026,"journal":{"name":"International Journal of Fisheries and Aquaculture","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125080952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effect of smoking kilns on water activity, microbial load and sensory attributes was evaluated to adopt suitable technology that maintains the quality of fish in South Sudan. A total of 300 fresh Mormyrus caschive and Oreochromis niloticus were purchased, 36 fresh samples were iced and the remaining 264 fish samples were divided into two batches for pit and chorkor smoking. The experiment was done twice in a completely randomized design. Fish samples were analyzed for water activity using Lab-Swift Meter, microbial load using standard microbiological methods and sensory characteristics using 9-point hedonic grading scale. Result revealed that, water activity in pit smoked fish increased at a rate of 1.7 times faster than in chorkor smoked samples during storage. Corresponding to water activity, plate count equally increased at a rate of 1.7 times faster for pit smoked M. caschive and 1.1 times for O. niloticus than samples smoked using chorkor. Similarly, mould load increased at a rate of 1.5 times faster for pit smoked M. caschive and 2.2 times for O. niloticus than samples smoked using chorkor oven. Overall, chorkor smoked fish had significantly better sensory parameters than pit smoked samples after one month’s storage. Therefore, chorkor kiln produced quality smoked fish in terms of microbial load and organoleptic parameters, and the study recommends its adoption for artisan fisheries in South Sudan. However, microbial characteristics of smoked fish need to be further examined for a period exceeding a month to determine microbiological quality and establish fish self-life in order to maintain the quality and safety of fish and fisheries products. Key words: Water activity, microbial load, sensory attributes, smoking technologies, shelf life.
{"title":"Water activity, microbial and sensory evaluation of smoked fish (Mormyrus caschive and Oreochromis niloticus) stored at Ambient Temperature, Terekeka-South Sudan","authors":"Borodi Charles Mondo, P. Akoll, M. Masette","doi":"10.5897/IJFA2020.0783","DOIUrl":"https://doi.org/10.5897/IJFA2020.0783","url":null,"abstract":"The effect of smoking kilns on water activity, microbial load and sensory attributes was evaluated to adopt suitable technology that maintains the quality of fish in South Sudan. A total of 300 fresh Mormyrus caschive and Oreochromis niloticus were purchased, 36 fresh samples were iced and the remaining 264 fish samples were divided into two batches for pit and chorkor smoking. The experiment was done twice in a completely randomized design. Fish samples were analyzed for water activity using Lab-Swift Meter, microbial load using standard microbiological methods and sensory characteristics using 9-point hedonic grading scale. Result revealed that, water activity in pit smoked fish increased at a rate of 1.7 times faster than in chorkor smoked samples during storage. Corresponding to water activity, plate count equally increased at a rate of 1.7 times faster for pit smoked M. caschive and 1.1 times for O. niloticus than samples smoked using chorkor. Similarly, mould load increased at a rate of 1.5 times faster for pit smoked M. caschive and 2.2 times for O. niloticus than samples smoked using chorkor oven. Overall, chorkor smoked fish had significantly better sensory parameters than pit smoked samples after one month’s storage. Therefore, chorkor kiln produced quality smoked fish in terms of microbial load and organoleptic parameters, and the study recommends its adoption for artisan fisheries in South Sudan. However, microbial characteristics of smoked fish need to be further examined for a period exceeding a month to determine microbiological quality and establish fish self-life in order to maintain the quality and safety of fish and fisheries products. \u0000 \u0000 Key words: Water activity, microbial load, sensory attributes, smoking technologies, shelf life.","PeriodicalId":415026,"journal":{"name":"International Journal of Fisheries and Aquaculture","volume":"289 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132361548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Toussaint Mikpon, D. Dah-Nouvlessounon, N. Agbodjato, Halfane Lehmane, O. Amogou, C. N’tcha, W. Moussé, H. Sina, H. Ahissou, A. Adjanohoun, L. Baba-Moussa
Crabs play an important economic and bio-ecological role in most aquatic ecosystems and occupy an important place in the variety of trophic niches. Callinectes amnicola Rochebrune and Cardisoma armatum Herklots are two edible species widely exploited in Benin. The present work aims to i) evaluate the socio-economic and cultural importance of those two crab species, ii) analyze the dynamics of the value chain, and iii) monitor the flow of their resources. Surveys were carried out during February 2018 to September 2019 among target groups in Oueme, Atlantic and Littoral administrative Departments of Benin through structured and semi-structured interview methods as well as free interview. Results indicate that fishermen/catchers (12.76%), wholesalers/collectors (25.53%) and retailers (61.70%) are the actors involved in the crab value chain. Between 40 and 50% of fishery products are exported to markets in Togo and Ghana. Not all of the exoskeletons resulting from post-capture losses and those resulting from treatments for consumption, in particular C. amnicola (74.46%) and C. armatum (76.59%) are used, which poses an environmental management problem. The gains made in the sector vary from 8.000±2.828 Financial Community African Franc (FCAF) (C. amnicola) to 20.000±21.213 FCAF (C. armatum). The study found that crabs (C. armatum and C. amnicola) have remarkable socio-economic importance in Southern Benin, Africa. Key words: Crab, economic analysis, monitoring, Benin.
{"title":"Socio-economic and cultural values of two species of crabs (Cardisoma armatum Herklots and Callinectes amnicola Rochebrune) in Southern Benin, Africa: Management of post-harvest losses and exoskeletons","authors":"Toussaint Mikpon, D. Dah-Nouvlessounon, N. Agbodjato, Halfane Lehmane, O. Amogou, C. N’tcha, W. Moussé, H. Sina, H. Ahissou, A. Adjanohoun, L. Baba-Moussa","doi":"10.5897/ijfa2020.0779","DOIUrl":"https://doi.org/10.5897/ijfa2020.0779","url":null,"abstract":"Crabs play an important economic and bio-ecological role in most aquatic ecosystems and occupy an important place in the variety of trophic niches. Callinectes amnicola Rochebrune and Cardisoma armatum Herklots are two edible species widely exploited in Benin. The present work aims to i) evaluate the socio-economic and cultural importance of those two crab species, ii) analyze the dynamics of the value chain, and iii) monitor the flow of their resources. Surveys were carried out during February 2018 to September 2019 among target groups in Oueme, Atlantic and Littoral administrative Departments of Benin through structured and semi-structured interview methods as well as free interview. Results indicate that fishermen/catchers (12.76%), wholesalers/collectors (25.53%) and retailers (61.70%) are the actors involved in the crab value chain. Between 40 and 50% of fishery products are exported to markets in Togo and Ghana. Not all of the exoskeletons resulting from post-capture losses and those resulting from treatments for consumption, in particular C. amnicola (74.46%) and C. armatum (76.59%) are used, which poses an environmental management problem. The gains made in the sector vary from 8.000±2.828 Financial Community African Franc (FCAF) (C. amnicola) to 20.000±21.213 FCAF (C. armatum). The study found that crabs (C. armatum and C. amnicola) have remarkable socio-economic importance in Southern Benin, Africa. \u0000 \u0000 Key words: Crab, economic analysis, monitoring, Benin.","PeriodicalId":415026,"journal":{"name":"International Journal of Fisheries and Aquaculture","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116799610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Abaho, T. Zaabwe, A. Izaara, H. Kasigwa, N. Mushabe, S. Byenkya, M. Nkambo, S. Baguma, D. Hafashimana, J. Efitre
In Uganda fish is a great source of animal dietary protein, however, natural stocks continue to decline. Therefore, aquaculture provides a viable option to bridge the increasing fish supply-demand gap. Accordingly, a study was conducted from March to August 2016 to investigate the effect of stocking density on the growth performance, and survival of Nile tilapia (Oreochromis niloticus) in floating net-cages to contribute to aquaculture production in Uganda. Nile tilapia fingerlings, with an average weight of 4.07 g were stocked in 8 m3 cages at three different stocking densities; 200, 250, and 300 fish/m3, and fed on a locally formulated commercial feed for 180 days. At the end of the experimental period, results showed that fish stocked at lower densities were heavier than those stocked at higher densities. The mean final weights of fish were; 150.79±85.71, 127.82±68.43 and 118.73±49.29 g in cages stocked with 200, 250 and 300 fish/m3, respectively. The mean final weight in lower density (200 fish /m3) treatments was significantly higher (P 0.05) among the stocking densities. Survival rate and stocking density were negatively correlated. The best survival rate (94.19%) was obtained in low stocked cages (200 fish/m3) compared to 92.98% in highly stocked cages (300 fish/m3). The results of this study suggest that 200 fish/m3 of a cage, is the best stocking density in terms of fish growth parameters. Key words: Aquaculture, animal protein, per capita, livelihood, yield.
{"title":"Effect of stocking density on growth and survival of Nile tilapia (Oreochromis niloticus, Linnaeus 1758) under cage culture in Lake Albert, Uganda","authors":"I. Abaho, T. Zaabwe, A. Izaara, H. Kasigwa, N. Mushabe, S. Byenkya, M. Nkambo, S. Baguma, D. Hafashimana, J. Efitre","doi":"10.5897/ijfa2018.0671","DOIUrl":"https://doi.org/10.5897/ijfa2018.0671","url":null,"abstract":"In Uganda fish is a great source of animal dietary protein, however, natural stocks continue to decline. Therefore, aquaculture provides a viable option to bridge the increasing fish supply-demand gap. Accordingly, a study was conducted from March to August 2016 to investigate the effect of stocking density on the growth performance, and survival of Nile tilapia (Oreochromis niloticus) in floating net-cages to contribute to aquaculture production in Uganda. Nile tilapia fingerlings, with an average weight of 4.07 g were stocked in 8 m3 cages at three different stocking densities; 200, 250, and 300 fish/m3, and fed on a locally formulated commercial feed for 180 days. At the end of the experimental period, results showed that fish stocked at lower densities were heavier than those stocked at higher densities. The mean final weights of fish were; 150.79±85.71, 127.82±68.43 and 118.73±49.29 g in cages stocked with 200, 250 and 300 fish/m3, respectively. The mean final weight in lower density (200 fish /m3) treatments was significantly higher (P 0.05) among the stocking densities. Survival rate and stocking density were negatively correlated. The best survival rate (94.19%) was obtained in low stocked cages (200 fish/m3) compared to 92.98% in highly stocked cages (300 fish/m3). The results of this study suggest that 200 fish/m3 of a cage, is the best stocking density in terms of fish growth parameters. \u0000 \u0000 Key words: Aquaculture, animal protein, per capita, livelihood, yield.","PeriodicalId":415026,"journal":{"name":"International Journal of Fisheries and Aquaculture","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125623976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Misty D. Jones, J. Voorhees, Nathan Huysman, E. Krebs, M. E. Barnes
This study investigated the effects of coloured structures on the growth of juvenile landlocked fall Chinook salmon (Oncorhynchus tshawytscha, Walbaum) during hatchery rearing. Structures consisted of an array of four aluminum angles painted one of four colours: Silver, red, black and green, which were vertically suspended in circular tanks. After 25 days, mean total lengths and weights of individual salmon reared in tanks with the green arrays were significantly (P 0.05) among the colour treatments. Final total tank biomass and gain were also not significantly different (P > 0.05) among the colour treatments. The results of this study indicate that structural colours could be considered to maximize juvenile Chinook salmon growth during hatchery rearing. Key words: Chinook salmon, colour, Oncorhynchus tshawytscha, hatchery rearing.
{"title":"Use of different colours of vertically-suspended structure during the hatchery rearing of juvenile landlocked fall Chinook salmon (Oncorhynchus tshawytscha, Walbaum)","authors":"Misty D. Jones, J. Voorhees, Nathan Huysman, E. Krebs, M. E. Barnes","doi":"10.5897/ijfa2019.0762","DOIUrl":"https://doi.org/10.5897/ijfa2019.0762","url":null,"abstract":"This study investigated the effects of coloured structures on the growth of juvenile landlocked fall Chinook salmon (Oncorhynchus tshawytscha, Walbaum) during hatchery rearing. Structures consisted of an array of four aluminum angles painted one of four colours: Silver, red, black and green, which were vertically suspended in circular tanks. After 25 days, mean total lengths and weights of individual salmon reared in tanks with the green arrays were significantly (P 0.05) among the colour treatments. Final total tank biomass and gain were also not significantly different (P > 0.05) among the colour treatments. The results of this study indicate that structural colours could be considered to maximize juvenile Chinook salmon growth during hatchery rearing. \u0000 \u0000 Key words: Chinook salmon, colour, Oncorhynchus tshawytscha, hatchery rearing.","PeriodicalId":415026,"journal":{"name":"International Journal of Fisheries and Aquaculture","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114103366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The current and anticipated demographic changes worldwide are expected to increase fish and other animal protein consumption. Capture fisheries alone cannot meet these requirements. Aquaculture offers a way out if it can further be developed. However, in most developing countries, aquaculture is still in its infancy and the evidence on the industry is quite thin. We assess the profitability of small-scale aquaculture production in Zambia using primary data collected through a structured questionnaire that was supplemented with focus group discussions with individual fish farmers. The analysis combined descriptive statistics, enterprise budgets, and financial analysis tools. The profitability of the aquaculture venture was determined using the indicators of investment returns including, net present value (NPV), internal rate of return (IRR) and benefit-cost ratio (BCR). The results from the profitability analysis show positive net revenue, NPV and IRR. The Benefit-Cost Ratio is also greater than one, implying that investment in aquaculture production is a profitable and viable business venture for small-scale farmers. The results reveal that over the useful life of the ponds, which is assumed to be 10 years, the estimated NPV is 17,524.13 ZMW and the IRR is 42.38%, measured at the discount rate of 15%. The positive NPV implies that the aquaculture enterprise is feasible and profitable. Key words: Aquaculture, profitability, Zambia
{"title":"Is aquaculture production by small-scale farmers profitable in Zambia?","authors":"Thelma Namonje-Kapembwa, P. Samboko","doi":"10.5897/IJFA2019.0737","DOIUrl":"https://doi.org/10.5897/IJFA2019.0737","url":null,"abstract":"The current and anticipated demographic changes worldwide are expected to increase fish and other animal protein consumption. Capture fisheries alone cannot meet these requirements. Aquaculture offers a way out if it can further be developed. However, in most developing countries, aquaculture is still in its infancy and the evidence on the industry is quite thin. We assess the profitability of small-scale aquaculture production in Zambia using primary data collected through a structured questionnaire that was supplemented with focus group discussions with individual fish farmers. The analysis combined descriptive statistics, enterprise budgets, and financial analysis tools. The profitability of the aquaculture venture was determined using the indicators of investment returns including, net present value (NPV), internal rate of return (IRR) and benefit-cost ratio (BCR). The results from the profitability analysis show positive net revenue, NPV and IRR. The Benefit-Cost Ratio is also greater than one, implying that investment in aquaculture production is a profitable and viable business venture for small-scale farmers. The results reveal that over the useful life of the ponds, which is assumed to be 10 years, the estimated NPV is 17,524.13 ZMW and the IRR is 42.38%, measured at the discount rate of 15%. The positive NPV implies that the aquaculture enterprise is feasible and profitable. \u0000 \u0000 Key words: Aquaculture, profitability, Zambia","PeriodicalId":415026,"journal":{"name":"International Journal of Fisheries and Aquaculture","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124995314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Barnett Kaphuka, Gilson R. Njunga, G. Kamwendo, Brino B. Chirwa
In Malawi, fish is regarded as a cheapest source of animal proteins and other macronutrients. Recent epizootic ulcerative syndrome (EUS) outbreaks reported in countries sharing Chobe-Zambezi river system like Zambia, Democratic Republic of Congo, Botswana, Namibia, Zimbabwe and Republic of South Africa, have posed a major threat to fish production. Malawi’s biggest and important Shire River connects to Zambezi River and there is sharing of waters with Zambia during floods in some areas in north western Malawi. Active surveillance in Malawi was, therefore, conducted in four high risk areas to establish the presence or absence of EUS. Fish were inspected for EUS-like lesions by a trained surveillance team. No fish was found with EUS-like lesions. However, one Barbus paludinosus from Vwaza Marsh had a reddish and swollen caudal peduncle which after doing laboratory tissue squash did not show any evidence of fungal hyphae to suspect EUS but numerous inflammatory cells were seen. Key words: Barbus paludinosus, marsh, EUS, Aphanomyces invadans, sampling sites.
{"title":"Active surveillance of infection caused by Aphanomyces invadans in Malawi","authors":"Barnett Kaphuka, Gilson R. Njunga, G. Kamwendo, Brino B. Chirwa","doi":"10.5897/ijfa2019.0728","DOIUrl":"https://doi.org/10.5897/ijfa2019.0728","url":null,"abstract":"In Malawi, fish is regarded as a cheapest source of animal proteins and other macronutrients. Recent epizootic ulcerative syndrome (EUS) outbreaks reported in countries sharing Chobe-Zambezi river system like Zambia, Democratic Republic of Congo, Botswana, Namibia, Zimbabwe and Republic of South Africa, have posed a major threat to fish production. Malawi’s biggest and important Shire River connects to Zambezi River and there is sharing of waters with Zambia during floods in some areas in north western Malawi. Active surveillance in Malawi was, therefore, conducted in four high risk areas to establish the presence or absence of EUS. Fish were inspected for EUS-like lesions by a trained surveillance team. No fish was found with EUS-like lesions. However, one Barbus paludinosus from Vwaza Marsh had a reddish and swollen caudal peduncle which after doing laboratory tissue squash did not show any evidence of fungal hyphae to suspect EUS but numerous inflammatory cells were seen. \u0000 \u0000 Key words: Barbus paludinosus, marsh, EUS, Aphanomyces invadans, sampling sites.","PeriodicalId":415026,"journal":{"name":"International Journal of Fisheries and Aquaculture","volume":"704 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123834276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study the microbiota of Clarias gariepinus tissues harvested from e-waste-soil polluted vials were assessed. Soil samples contaminated with e-waste were analyzed using standard analytical protocol while the microbial study was obtained using standard conventional microbiological techniques. The results revealed that the soil was sandy-loamy and blackish in colour. High organic matter (17.60%) and organic carbon (10.17%) were obtained. Also, higher calcium (182.00 mg/kg) and phosphorus (146.65 mg/kg) contents compared to other mineral constituents were recorded while, the heavy metals ranged from 0.32- 64.90 mg/kg. Bacterial count ranged from 9.0 × 102 to 4.0 × 103 cfu/L while the fungal count from 4.0 × 102 to 2.3 ×103 sfu/L. The genera of bacteria isolate were identified as Staphylococcus, Proteus, Bacillus, Listeria, Salmonella, Enterobacter, Pseudomonas, Lactobacillus and Corynebacterium and fungal isolates were Penicilliun, Candida, Articulospora, Aspergillus, Rhizopus, Mucor, Zoopage, Varcosporium and Rhodotorula. Microbial species richness of fish tissues from polluted vials indicates a more poly-diverse microbial community compared to those from unpolluted vial. Differences were observed in the occurrence of fungi on the surfaces of catfish tissues in control vial compare to those on fishes from polluted vials. Hence, there is a need for proper water management for fish culturing and caution in the exploration of fishes from polluted natural waters for human consumption. Key words: Clarias gariepinus, e-waste, fish tissues, microbiota, pollution, microbial species richness.
{"title":"Microbiota of catfish (Clarias gariepinus) tissues harvested from vials polluted with soil from \u0000e-wastes dumpsite","authors":"D. Adegunloye, A. I. Sanusi","doi":"10.5897/IJFA2018.0718","DOIUrl":"https://doi.org/10.5897/IJFA2018.0718","url":null,"abstract":"In this study the microbiota of Clarias gariepinus tissues harvested from e-waste-soil polluted vials were assessed. Soil samples contaminated with e-waste were analyzed using standard analytical protocol while the microbial study was obtained using standard conventional microbiological techniques. The results revealed that the soil was sandy-loamy and blackish in colour. High organic matter (17.60%) and organic carbon (10.17%) were obtained. Also, higher calcium (182.00 mg/kg) and phosphorus (146.65 mg/kg) contents compared to other mineral constituents were recorded while, the heavy metals ranged from 0.32- 64.90 mg/kg. Bacterial count ranged from 9.0 × 102 to 4.0 × 103 cfu/L while the fungal count from 4.0 × 102 to 2.3 ×103 sfu/L. The genera of bacteria isolate were identified as Staphylococcus, Proteus, Bacillus, Listeria, Salmonella, Enterobacter, Pseudomonas, Lactobacillus and Corynebacterium and fungal isolates were Penicilliun, Candida, Articulospora, Aspergillus, Rhizopus, Mucor, Zoopage, Varcosporium and Rhodotorula. Microbial species richness of fish tissues from polluted vials indicates a more poly-diverse microbial community compared to those from unpolluted vial. Differences were observed in the occurrence of fungi on the surfaces of catfish tissues in control vial compare to those on fishes from polluted vials. Hence, there is a need for proper water management for fish culturing and caution in the exploration of fishes from polluted natural waters for human consumption. \u0000 \u0000 Key words: Clarias gariepinus, e-waste, fish tissues, microbiota, pollution, microbial species richness.","PeriodicalId":415026,"journal":{"name":"International Journal of Fisheries and Aquaculture","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114823125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The goals of this study were to evaluate dourado female egg viability submitted to stress condition caused by two different reproductive induction methods, extruded and semi-natural. Sixteen females randomly chosen were induced with pituitary extract and allocated in two groups; the first, in which oocytes were manually extruded and the second group, females were allowed to naturally spaw. Blood samples were collected for glucose, cortisol and hematocrit determinations as well as for red blood cells and white blood cells smears evaluations. A control group had its blood collected before hormonal induction. Fertilization rate was 40.6 and 91.7% for extruded and semi-natural methods, respectively, and the survival rate was higher in semi-natural groups. Both experimental groups showed higher glucose and cortisol levels compared to control group. The results for hematocrit, hemoglobin concentration and erythrocytes numbers did not differ among groups. Extruded and semi-natural procedures elevated monocytes percentage. In conclusion, the semi-natural procedures are more efficient than extruded method and should be taken into account for Salminus brasiliensis handling of breeders. Key words: Fish breeders, reproductive methodology, hematological parameters.
{"title":"Stress evaluation in dourado females (Salminus brasiliensis) submitted to two different methods of induced spawning","authors":"M. A. Zanoni, S. Carvalho, F. G. Costa, F. Seiva","doi":"10.5897/IJFA2019.0726","DOIUrl":"https://doi.org/10.5897/IJFA2019.0726","url":null,"abstract":"The goals of this study were to evaluate dourado female egg viability submitted to stress condition caused by two different reproductive induction methods, extruded and semi-natural. Sixteen females randomly chosen were induced with pituitary extract and allocated in two groups; the first, in which oocytes were manually extruded and the second group, females were allowed to naturally spaw. Blood samples were collected for glucose, cortisol and hematocrit determinations as well as for red blood cells and white blood cells smears evaluations. A control group had its blood collected before hormonal induction. Fertilization rate was 40.6 and 91.7% for extruded and semi-natural methods, respectively, and the survival rate was higher in semi-natural groups. Both experimental groups showed higher glucose and cortisol levels compared to control group. The results for hematocrit, hemoglobin concentration and erythrocytes numbers did not differ among groups. Extruded and semi-natural procedures elevated monocytes percentage. In conclusion, the semi-natural procedures are more efficient than extruded method and should be taken into account for Salminus brasiliensis handling of breeders. \u0000 \u0000 Key words: Fish breeders, reproductive methodology, hematological parameters.","PeriodicalId":415026,"journal":{"name":"International Journal of Fisheries and Aquaculture","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125914384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：