Water hardness does not influence iodine-induced mortality of rainbow trout eyed eggs
June 2021
To evaluate the effects of water hardness on survival to hatch of eyed rainbow trout Oncorhynchus mykiss eggs during iodophor disinfection, hard (300 mg/L CaCl2) and soft water (20 mg/L CaCl2) solutions were used in combination with iodophor treatments of 0, 100, 200, 400, 800, and 1600 mg/L. Water hardness did not significantly influence egg survival-to-hatch. In addition, there was no significant interaction between...
Occupational hazards, risk and injuries of fish processors in Tombo a coastal fish landing site, Sierra Leone, West Africa
June 2021
Fish and fish products bear potential hazards and risks of public health concern. A preliminary study of hazards, injuries and risks among fisherfolk in Tombo, Sierra Leone, West Africa was carried out on November 2018. Sixty subjects from among the organized fish processor groups were interviewed with semi-structured questionnaire. Results obtained from the study were analyzed with Microsoft Excel and presented in...
Enhancing the fisheries sector of African Great lakes: Value chain analysis of the Tanganyika Sardine (Limnothrissa miodon, Boulenger 1906) from Lake Kivu, Rwanda
March 2021
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...
Aspects of reproductive indices and enteroparasitic infestation of Clarias gariepinus (Burchell, 1822) in a tropical reservoir
January 2021
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%....
Water activity, microbial and sensory evaluation of smoked fish (Mormyrus caschive and Oreochromis niloticus) stored at Ambient Temperature, Terekeka-South Sudan
December 2020
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...
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
November 2020
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)...
Effect of stocking density on growth and survival of Nile tilapia (Oreochromis niloticus, Linnaeus 1758) under cage culture in Lake Albert, Uganda
August 2020
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...
Use of different colours of vertically-suspended structure during the hatchery rearing of juvenile landlocked fall Chinook salmon (Oncorhynchus tshawytscha, Walbaum)
July 2020
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...
Is aquaculture production by small-scale farmers profitable in Zambia?
February 2020
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...
Active surveillance of infection caused by Aphanomyces invadans in Malawi
January 2020
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...
Microbiota of catfish (Clarias gariepinus) tissues harvested from vials polluted with soil from e-wastes dumpsite
June 2019
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...
Stress evaluation in dourado females (Salminus brasiliensis) submitted to two different methods of induced spawning
June 2019
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...
Bioeconomic analysis of Engraulicypris sardella (USIPA) in South east arm of Lake Malawi
May 2019
Usipa Engraulicypris sardella is the most abundant small pelagic species in Lake Malawi. It plays an important part in the lake communities’ economy and food security. However, much remains unknown on their stock status and bioeconomic importance. This study is carried out to estimate the maximum economic yield and maximum sustainable yield for Usipa fishery in the South-east arm of Lake Malawi. Structured...
The spatio-temporal dynamics of the fish assemblage of the man-made Lake Buyo (Cote d'Ivoire, West Africa)
March 2019
This study aims to characterize the spatio-temporal variation of the fish assemblages in relation to the environmental variables of Buyo Dam Lake. Sampling was performed from July 2017 to June 2018 using experimental fishing and commercial fishing. Spatio-temporal analysis indicated a significant variation (p <0.05) in pH, electrical conductivity, total dissolved solids, and water transparency. A total of 45 species...
Socio-economic characteristics of small-scale catfish farming enterprise in Obio/Akpor Local Government Area, Rivers State, Nigeria
March 2019
The study of the socio-economic characteristics of any group is a requirement to a successful implementation of effective government assisted programme. The study examined the socio-economic characteristics, production processes and production constraints of small-scale catfish fishing enterprises in Obio/Akpor Local Government Area in Rivers State, Nigeria. Simple randomized sampling technique was used to select 60...
Growth and feed utilization in Clarias gariepinus fingerlings fed on Acacia auriculiformis leaf supplemented diets
March 2019
Effect of ‘Earleaf’ plant (Acacia auriculiformis) as feed additive was examined on Clarias gariepinus fingerlings (4.2±0.5 g) over a period 56 days against farm-made feed which served as the control. A. auriculiformis leaves were collected, air-dried (under shade), powdered and added at varying inclusion levels (0, 0.5, 1.0, 1.5 and 2.0%) to basal diets containing 40% crude protein. Fish were randomly...
Value chain analysis of small-scale fisheries in the High Dam Lake in Egypt
February 2019
Although, High Dam Lake small-scale fisheries is an important source of fish for residents of Aswan in Upper Egypt, there is limited information available about the performance of small-scale fisheries value chain. Structured questionnaires with fishers, traders, and processors were used to collect input and output data at each node of the chain. Focus group discussions meeting with stakeholder collected qualitative...
Age, growth and mortality rates of round sardinella, Sardinella aurita (Valenciennes, 1810) from the Senegalese coasts (West Africa)
February 2019
Sardinella aurita is the main species exploited by small-scale fisheries in Senegal and represents an important source of low cost protein in the Senegalese market. The objective of this study was to determine the age, growth and mortality parameters of S. aurita obtained from the Senegalese coastal waters. Age, growth parameters and mortality rates of this species were estimated using FiSAT II (FAO–ICLARM Stock...
Identification of possible causes of fish death in Lake ‘’Lake Kabo’’
February 2019
Any adverse change in the environmental conditions affects the life of aquatic organisms in water. Fish death was suddenly observed in Lake Kabo. To investigate its cause and look for solution, a research team started to consider the Lake. The present study was conducted to identify the reason for the fish deaths that accidentally occur in the lake. To achieve the objective samples were collected from four different...
Effects of feeding rates and feeding frequencies on growth performance, uniformity of the batch and survival rate of Amazon ornamental fish larvae
February 2019
The aim of this study is to evaluate the effect of different feeding rates and frequencies on angelfish (Pterophyllum scalare) and severum (Heros severus) larvae. For this purpose, two similar experiments were conducted in parallel. For each experiment, a total of 360 larvae were distributed in 36-1 L aquariums. The experiments were done using a factorial 3x3 completely randomized design, with four replicates. The...
The abundance, distribution and diversity of benthic invertebrates of Lake Malombe
February 2019
The benthic zone of Lake Malombe was sampled for invertebrates, fungi and bacteria using an Ekman Grab measuring 15.2 cm by 15.2 cm. Thirty-six stations were surveyed for macro-invertebrates which were identified to the lowest taxa and enumerated to estimate abundance for the lake. Snails were the most dominant macro fauna, belonging to four genera Melanoides, Bellamya, Bulinus and Lanistes with the mean densities of...
Assessment of the fishery, challenges and opportunities of Denbi reservoir in Bench Maji Zone, South Western part of Ethiopia
January 2019
The study was conducted to assess the fishery, challenges and opportunities in Denbi reservoir, Ethiopia. Interview, focus group discussion and personal observations were used to generate data. Response was solicited from households within the catchment area of the reservoir, key informants, elders, workers of the reservoir and fishery cooperative members. The data was analyzed by combining quantitative, qualitative...
Assessment of stomach contents of Oreochromis niloticus from the Lagos Lagoon, Nigeria
January 2019
Fish sustainability in an aquatic environment involves continuous and judicious management towards optimum production of resources, for rational utilization and availability for future generation. Stomach composition of Oreochromis niloticus collected from a tropical brackish water environment was investigated to assess food availability towards optimum fish productivity for rational public utilization. Oreochromis...
Is the culture of exotic fish species the answer to low fish productivity? A case study on the use of Oreochromis niloticus in Zambia
November 2018
The study was conducted in the Copperbelt and North-Western Provinces of Zambia which represented the urban and rural strata respectively. A total of two hundred and forty farmers were randomly sampled from the farmer registers kept by the Department of Fisheries (DOF) in the Ministry of Fisheries and Livestock (MFL), Zambia. The main objective of the survey was to determine the productivity of the exotic fish species...
Otolith morphometry and fish length relation of Amblypharyngodon mola (Ham.) from Middle Ganga region (India)
October 2018
The aim of this study was to determine a correlation between the length, width and weight of otoliths and the length and weight of fish samples of Amblypharyngodon mola (Hamilton,1822), a Rasborine fish caught from Middle Ganga region. Total length (TL) measurements were made with a 1mm precision fish length measuring scale. Image J software was used for measuring otolith length and width. This study shows strong...
Performance of Nile tilapia (Oreochromis niloticus) fed with diets containing caffeine
September 2018
The objective of this study was to investigate the possible effects of caffeine on the performance of juveniles of Nile tilapia. One hundred and forty four (144) juveniles of Nile Tilapia with mass, total length and initial mean height of 2.94 ± 0.16 g, 5.19 ± 0.14 cm and 1.49 ± 0.04 cm, respectively, were used. The fishes were housed in 24 plastic boxes in a closed water recirculation system, where...
Anaesthetic effects and haematological responses of heterobranchus bidorsalis juveniles exposed to clove oil
September 2018
This study aims to investigate the use of clove oil as an anaesthetic agent for Heterobranchus bidorsalis juveniles and assess the effects on the test fish, using some hematological parameters. Different concentrations of clove oil (0.8 to 1.2 ppm) were used in static water to determine the induction time and recovery time of the test organisms. Behavioral changes of the test fish were observed, the time the fish became...
Seasonality in the photosynthetic productivity and biomass of phytoplankton in Lake Tinishu Abaya (Rift Valley, Ethiopia): The basis for fish production
August 2018
The present study was undertaken to investigate the photosynthetic productivity and biomass of phytoplankton for Lake Tinishu Abaya to observe the potentiality of the lake water for fish production. The study was carried out from January to December 2016. For the analysis of various physicochemical parameters, water samples collection was taken from two predefined sampling stations (open-water and nearshore). Biomass of...
Observations on the biology of Nile tilapia, Oreochromis niloticus L., in Tekeze Reservoir, Northern Ethiopia
July 2018
The study was done to examine some aspects of the reproductive biology of Nile tilapia (Oreochromis niloticus) in Tekeze Reservoir a newly man made hydropower reservoir. A total number of 1826 specimens of Nile Tilapia (O. niloticus) were collected from the reservoir from July 2015 to June 2016. Size at first maturity, sex ratio, gonado-somatic index (GSI), breeding season and fecundity were studied. The overall...
Substitution of the fish meal by the earthworm and maggot meal in the feed of Nile tilapia Oreochromis niloticus reared in freshwater
June 2018
The present experiment was conducted to evaluate the efficacy of dietary protein from maggot meal and earthworm meal to replace fish meal protein in Oreochromis niloticus juvenile feed. The fish used for this experiment come from the experience of the larval phase during which fish were fed with the formulated diets [fish diet (FD), maggot diet (MD) and earthworm diet (ED)] content 40% crude protein and the commercial...
Physical, chemical parameters and plankton in a tropical earthen pond catfish farm in Badagry, Nigeria
June 2018
The physico-chemical parameters and plankton abundance of four artificial fish ponds in Omageyu Farms, Ijotun, Badagry, Nigeria was studied and analysed using standard methods monthly from June to December 2015. Water temperature, pH and dissolved oxygen ranged from 27.80 to 32.00°C, 6.90 to 7.40 and 6.80 to 10.00 mg/l, respectively in the four ponds. Water temperature, pH, and dissolved oxygen in Pond A were...
Zooplankton communities as an indicator of ecosystem productivity in Lake Tinishu Abaya, Rift Valley, Ethiopia
May 2018
The ultimate objective of this study was, to explore community structure and biomass of zooplankton in relation to key environmental drivers to bear out the productivity of Lake Tinishu Abaya. Zooplankton samples collection was carried out for a year from January to December 2016 from two sampling sites (open and shore) using 30 µm mesh size net within the euphotic depth. Biomass of zooplankton was anticipated...
Mortality, recruitment pattern and exploitation rates of two Schilbe Oken, 1817 populations: Schilbe mandibularis and Schilbe intermedius from the Aghien Lagoon; estuarine system of West Africa
April 2018
In Côte d’Ivoire, the Aghien Lagoon is under heavy fishing pressure. Mortality, recruitment pattern and exploitation rate of Schilbe mandibularis and Schilbe intermedius were investigated in this lagoon. Fish samples of both sexes (N = 575) were collected monthly between June 2014 and May 2015 from artisanal and experimental captures. Natural mortality was higher in S. intermedius (M = 0.89 years-1) than in...
Stochastic modelling of Lake Malawi Engraulicypris sardella (Gunther, 1868) catch fluctuation
April 2018
Lake Malawi continues experiencing serious depletion of most valuable fish species. Presently, commercial and artisanal fishery are forced to target less valuable fish species. Evidently, economic importance of Engraulicypris sardella in Malawi cannot be negated as it currently contributes over 70% of the total annual landings. However, such highest contribution could be a sign of harvesting pressure. Therefore, as the...
Consumers’ preference and perception of smoke-dried white shrimp (Nematopalaemon hastatus) in coastal areas of Ondo State, Nigeria
March 2018
The study assessed consumers’ preference and perception of smoke-dried white shrimps in Igbokoda, a coastal area of Ondo State, Nigeria. The community was purposively chosen because the town is a major cluster for natives from coastal communities in Ilaje and Ese-Odo LGAs of Ondo State, Nigeria. Forty shrimp consumers (20 males and 20 females) were randomly selected for this study. They assessed the sensory...
Effect of gamma irradiation on the microbiological quality and shelf life of Engraulis encrasicolus in Ghana
March 2018
The effect of irradiation on microbial load and shelf-life of anchovies (Engraulis encrasicolus) was assessed in this study. Irradiation doses used in the study were 2.5, 5.0, 7.5 and 10 kGy. The assessment was carried out at 3 weeks intervals for the period of 9 weeks. Samples were analyzed for microbial load (total viable count, total coliform count and Staphylococcus aureus). Smoked samples were more contaminated as...
Morphometric relationships of African big barb, Labeobarbus intermedius (Rüppell, 1836) in Lake Koka, Ethiopia
February 2018
Morphometric relationships of African big barb, Labeobarbus intermedius (Rüppell, 1836) (Pisces: Cyprinidae) in Lake Koka, Ethiopia was studied based on the total number of 266 adult fish samples collected in April-May and July-August 2011. Fish ranging from 23.3 to 49.0 cm in total length (35±4.1 cm) and from 95.4 to 1200 g in total weight (434.4±206.5 g) were randomly sampled. Of these, 55.6%...
Effects of Lead Nitrate on catalase production levels in post juvenile Clarias gariepinus (Burchell, 1822)
January 2018
The effects of Lead Nitrate on catalase (CAT) production levels in post juvenile Clarias gariepinus were investigated. A total of 250 samples of the fish were acclimatized for two week. Six samples of the fish were exposed to the sub-lethal concentrations of 00, 28, 43 and 57 mg/L with replicate in each case for 28 days. Two samples of the fish were randomly selected from the treatments and control for the bioassay of...
Côte d’Ivoire aquaculture systems perception: Characteristics and influence on national fish production
December 2017
This study was undertaken in the main Côte d’Ivoire fish farming production regions. Fish farming were surveyed on the basis of socio-economic characteristics of fish farmers, farming practices and production depending to the systems. Results show that majority of fish farmers used semi intensive (51.8%) and extensive (42.9%) systems. Intensive system represented only 1.3% and rice-fish system 4.0% of fish...
Physical losses of fish along the value chain in Zambia: A case study of Barotse Floodplain
November 2017
The study was conducted in three districts of Western Province of Zambia namely; Mongu, Nalolo and Senanga that lie along the Zambezi River in the Barotse Floodplain. The study employed two main data tools aimed at understanding the extent of post-harvest losses in the fishing, processing and trading nodes in the fish value chain study sites. The tools were the Exploratory Fish Loss Assessment Method (EFLAM) study and a...
Assessment of monthly physico-chemical properties and fish yields of two micro dams of Tigray Region, Northern Ethiopia
October 2017
This study was conducted to assess some physico-chemical properties and yields of two micro dams (Korrir and Laelay Wukro) located in eastern zones of Tigray region (Northern Ethiopia). In each location, water samples and fish yield were examined from October 2013 to March 2014 once per month in each dams. The examined physico-chemical parameters were: Dissolved oxygen (DO), electrical conductivity (EC), total dissolved...
Determination of heavy metal levels in Oreochromis niloticus and Chrysichthys nigrodigitatus from Ogun River, Nigeria
August 2017
Comparison of heavy metal levels in Oreochromis niloticus and Chrysichthys nigrodigitatus caught in Ogun River (Nigeria) was carried out to reveal the potential health risks associated with fish consumption from the river. Concentrations of copper, lead and cadmium were determined in the gills, eyes, bone, flesh, liver and stomach of the fish species. Ten fish of each species were obtained commercially and analyzed for...
Haematological profile of Heterobranchus bidorsalis fingerlings fed processed Delonix regia seeds at different inclusion levels of diets
July 2017
This study aimed at investigating the haematological profile of Heterobranchus bidorsalis fingerlings fed processed Delonix regia seeds at different inclusion levels of diets. Ten isonitrogenous diets (40% crude protein) were formulated with processed D. regia seed at 0% (Control), 10, 20 and 30% inclusion, respectively. The parameters analysed were pack cell volume (PCV), red blood cell (RBC), white blood cell (WBC),...
Effects of protease enzyme supplementation on protein digestibility of legume and/or fish meal-based fish feeds
July 2017
Improving protein digestibility in nutrient poor fish feeds through incorporation of dietary enzymes is expected to be achieved with protease. Understanding the role of other dietary enzymes was therefore evaluated to guide appropriate use for optimal fish growth. Protein digestibility of 30, 35, 50 and 55% crude protein (CP) diets was determined with catfish gut enzyme extract, sprouted sorghum, protease and phytase...
A prognosis of the causes of vulnerability of Lake Malawi fish resources in Karonga town
June 2017
There is evidence that ammonia, hydrogen sulphide and dissolved oxygen are implicated in fish kills occurring on the Lake Malawi shores of Karonga town. Exposure to fish is influenced by strong winds while water temperature differences cause upwelling and fish mortalities in surface waters. The vulnerability of fish in Karonga town to physico-chemical factors was computed from secondary sources data obtained in 2000 to...
Morphological and genetic variability among Mpasa (Opsaridium microlepis Günther, 1864) populations from the inflow rivers of Lake Malawi
May 2017
Fisheries management continues to be a nightmare due to over exploitation of fish stocks and various anthropogenic activities resulting in a reduction of genetic resources. Opsaridium microlepis, a commercially exploited fish species from Lake Malawi, is no exception, hence it is listed among as endangered species. Opsaridium microlepis stocks from four different rivers, were analyzed using 13 geometric morphometric...
A review of the farming of common carp (Cyprinus carpio L.) in Malawi: Policy research directions for aquaculture development in Malawi
May 2017
The lack of better performing native fish species for aquaculture led the government of Malawi to import the exotic common carp (Cyprinus carpio L.) from Israel in 1976. Growth trials at Domasi and Kasinthula Experimental Stations had shown that common carp grew faster and to a larger size than the indigenous fish species. The government decided to distribute the fish to farmers for grow-out. Barely five years into...
Dietary effect of varying linseed oil compositions on growth response, survival and polyunsaturated fatty acid levels in Tilapia (Oreochromis niloticus)
April 2017
The present study evaluated the impact of varying dietary linseed oil composition on growth, survival and tissue polyunsaturated fatty acids (PUFA) profiles in Nile tilapia (Oreochromis niloticus). Five iso-nitrogenious diets with varying linseed and sunflower oil concentrations were formulated and fish fed twice daily to for 3 months. Commercial diet was used as a control in triplicate tanks set for each diet...
Revisiting the ‘three-pillared design’ of a management system for the Elephant Marsh Wetland Fishery in Malawi
March 2017
This paper revisits and builds on the work of Ishmael Kosamu, Wouter de Groot and Patrick Kambewa who, in 2016, proposed a management system for the Elephant Marsh Wetland Fishery in Malawi, and identified key issues that would help the fishery to be sustainable in the short to medium term. They postulated that a sustainable three-pillared (locally based, weak, and amorphous) institution for the Elephant Marsh Wetland...
Growth performance of Oreochromis variabilis larvae: A case study of effect of live and formulated diets on growth and survival rates
February 2017
Oreochromis variabilis Boulenger (1906) is an indigenous and critically endangered fish species of Lake Victoria. It is among the species targeted for stock enhancement and restoration in Kenya. Such mass stock enhancement requires simple and easily applicable techniques to maximize its larviculture. This study investigated the growth potential of O. variabilis from fry to fingerling stages using diets formulated from...
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