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Aim: This study investigated the effect of modern drying methods on the proximate, nutritional, and mineral composition of Clarias gariepinus in Port Harcourt, Nigeria. Methods: Fresh C. gariepinus were purchased from Mile 3 Market in Port Harcourt, Rivers State. Samples were dissected using a sharp knife, intestinal components, and gills were removed and the edible portion was washed properly and rinsed with distilled water. Samples were treated in four groups: fresh, smoking using firewood, electric drying (200oC), and non-electric drying (200oC for 30 minutes) methods. Samples were blended using mortar and pestle into powder and kept in an air-tight container prior to analyses. Results: The proximate composition of C. gariepinus revealed that crude protein concentration was in the following proportions; electric drying method (52.16+0.01%), non-electric drying method (43.40+0.00%), smoking method (32.72+0.00%) and fresh (23.01+0.00%). The lipid content of smoked and electric-dried C. gariepinus was significantly (p<0.05) higher compared to the fresh sample. However, there was no significant difference between the lipid content of fresh C. gariepinus sample and non-electric dried sample. The carbohydrate content increased in the smoking and electric drying methods but decreased in the non-electric drying method. The ash content increased only in the smoking method but decreased in both the electric dryer and non-electric dryer methods. Fresh samples had the highest moisture content (74.03+0.00%) while the least was observed in the electric dried sample (38.84+0.00%). The percent anti-nutrient composition of C. gariepinus showed that smoked samples had the highest flavonoid concentration (3.252±0.00%) which was not significantly higher (p>0.05) than the flavonoid content of electric dried C. gariepinus (2.89±0.33). The levels of selected minerals showed varying concentrations of potassium, sodium and calcium for the various processing methods. Conclusion: Modern drying methods had a significant effect on the proximate component, flavonoids, and oxalate composition of C. gariepinus. Electric drying method showed to be a better method of drying Clarias gariepinus compared to other drying methods.
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This research aimed at evaluating the microbiological quality of fresh catfish (Clarias gariepinus) sold in three different markets and ponds in Minna metropolis. The total plate counts from Bosso pond are 2.7 × 102 cfu/mL and 3.8 × 102 cfu/mL (satisfactory) for skin and gills respectively. Kure pond includes total plate counts of 4.7 × 103 cfu/mL and 3.3 × 102 cfu/mL (satisfactory) for skin and gills respectively while Mobil pond had total plate counts of 2.5 × 103 cfu/mL and 2.5 × 102 cfu/mL on skin and gills respectively. The total coliforms counts from Bosso pond are 3.8 × 102 cfu/mL and 3.0 × 101 cfu/mL (satisfactory) for skin and gills respectively. Kure pond includes total coliforms counts of 2.4 × 102 cfu/mL and 2.6 × 102 cfu/mL (satisfactory) for skin and gills respectively while Mobil pond had total coliforms counts of 4.6 × 103 cfu/mL and 3.2 × 104 cfu/mL on skin and gills respectively. The coliforms count of fresh catfish (Clarias gariepinus) obtained from three markets locations are total coliforms counts from Bosso market are 5.6 × 104 cfu/mL and 4.0 × 105 cfu/mL (Unsatisfactory) for skin and gills respectively. Kure market includes total coliforms counts of 1.6 × 103 cfu/mL and 7.2 × 103 cfu/mL (satisfactory) for skin and gills respectively while Mobil market had total coliforms counts of 6.0 × 104 cfu/mL and 4.8 × 104 cfu/mL (Marginal) on skin and gills respectively. The fungal count of fresh catfish (Clarias gariepinus) obtained from three markets locations are Bosso market 1.3 × 102 cfu/mL and 1.5 × 101 cfu/mL (satisfactory) for skin and gills respectively. Kure market 2.0 × 103 cfu/mL and 1.0 × 102 cfu/mL (satisfactory) for skin and gills respectively while Mobil market had total fungal counts of 1.7 × 104 cfu/mL and 1.7 × 102 cfu/mL on skin and gills respectively. The following bacteria were isolated Escherichia coli, Bacillus substilis, Staphylococcus aureus, Pseudomonas species, Streptococcus species, Shigella species and Enterobacter species. The fungi isolated were Rhizopus spp and Aspergillus niger.
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@#Introduction: Catfish oil contains saturated and unsaturated fatty acids. Polyunsaturated fatty acid contributes to maintain the lipid profile. Enterococcus faecium IS-27526 is a novel indigenous probiotic of dadih origin. The aim of this study was to find out the effect of probiotic and catfish (Clarias gariepinus) based functional feed on lipid profile of aged female Cynomolgus monkey/CM (Macaca fascicularis) fed with atherogenic diet. Methods: Nine CMs were randomly devided into 3 groups, in single blind intervention study for 90 days , namely: A1= atherogenic diet as control positive, A2= probiotic, A3= probiotic + catfish oil after 45 days adaptation period. The average of CM’s bodyweight was in a range of 3 to 4 kg. The main ingredients of atherogenic diet were catfish flour, egg, sugar, egg yolk flour, and condiments. Serum lipid profile was assessed monthly by Cholesterol Oxidase-Peroxidase Aminoantipyrine (CHOP-POD) methods for cholesterol, LDL and HDL, while Glycerol-3-Phosphate Oxidase Peroxidase-Antiperoxidase (GPO-PAP) method for Triglyceride. Results: Atherogenic diet did not significantly affect appetite and bodyweight of the animals (p=0,12). The atherogenic diet significantly increased cholesterol and LDL level of animals (p=0.03 and p = 0.04) after 90 days administration . The CMs fed with probiotic E. faecium IS-27526 and catfish oil showed significant higher serum cholesterol (p=0,03) and LDL levels (p=0,04) compared to atherogenic diet alone and atherogic diet with probiotic E. faecium IS-27526. Probiotic E. faecium IS-27526 at 108 cfu/day stabilized the cholesterol and LDL level after 90 days administration compared with other groups of intervention. The TG and HDL of each group showed within normal range during the whole intervention study. Conclusion: Atherogenic feed significantly increased cholesterol and LDL level of CMs. Probiotic E. faecium IS-27526 showed a potential beneficial effect in maintaining lipid profile and could prevent dyslipidemia.
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Abstract The organoleptic evaluation and proximate analysis of Clarias gariepinus and Cyprinus carpio were determined in fresh fish and when refrigerated at two different temperatures (-21 °C and 4 °C) for a period of six weeks. A panel of twelve trained judges evaluated the color (live), texture, softness and flavor of fish meat after two minutes' steam cooking. Average score revealed a general decline in organoleptic properties such as color, texture, freshness, and taste of C. gariepinus and C. carpio stored at two temperatures compared to the fresh fish. Proximate analysis revealed a more decrease in crude protein and lipid contents and increase in ash content in C. gariepinus and C. carpio at the two storage temperatures compared to the fresh fish muscle. Moisture content decreased in the fish muscle samples of both the fish species stored at -21 °C but increased in the 4 °C stored samples. pH of fish was found to increase in the two stored temperatures. There were significant differences (P<0.05) in the organoleptic and proximate composition of the ice stored and fresh C. gariepinus and C. carpio, the same temperature and between the two different temperatures. The quality of fish muscle stored at 4 °C deteriorated faster than that of the -21 °C. Thus, storage temperature and duration have adverse effects on the nutritional quality of fish meat.
Resumo A avaliação organoléptica e a análise aproximada de Clarias gariepinus e Cyprinus carpio foram determinadas em peixe fresco e refrigerado a duas temperaturas diferentes (-21 °C e 4 °C) por um período de seis semanas. Um painel de doze juízes treinados avaliou a cor (ao vivo), textura, maciez e sabor da carne de peixe após dois minutos de cozimento a vapor. O escore médio revelou um declínio geral nas propriedades organolépticas, como cor, textura, frescor e sabor de C. gariepinus e C. carpio armazenados a duas temperaturas em comparação com o peixe fresco. A análise imediata revelou uma maior diminuição nos teores de proteína bruta e lipídios e aumento no teor de cinzas em C. gariepinus e C. carpio nas duas temperaturas de armazenamento em comparação com o músculo do peixe fresco. O teor de umidade diminuiu nas amostras de músculo de peixe de ambas as espécies de peixes armazenadas a -21 °C, mas aumentou nas amostras armazenadas a 4 °C. O pH dos peixes aumentou nas duas temperaturas armazenadas. Houve diferenças significativas (P <0,05) na composição organoléptica e próxima do gelo armazenado e fresco C. gariepinus e C. carpio, a mesma temperatura e entre as duas temperaturas diferentes. A qualidade do músculo do peixe armazenado a 4 °C deteriorou-se mais rapidamente do que a temperatura de -21 °C. Assim, a temperatura e duração do armazenamento têm efeitos adversos na qualidade nutricional da carne de peixe.
Subject(s)
Animals , Catfishes , Carps , Food Quality , Food Preservation/methods , Refrigeration/standards , Cold Temperature , Fish Products/analysis , Fish Products/standards , Meat/analysis , Meat/standardsABSTRACT
Aim: The cholinesterase (ChE) based inhibition and histopathological studies from fish were investigated and represented in this study to develop as one of the great potential biomarkers for heavy metals monitoring. Methodology: In this study, the histopathological study of gills were observed a under microscope. The capability of ChE extracted from the gills of Clarias gariepinus was assessed for declining Cd. ChE was purified through affinity chromatography and continued with the optimisation and inhibition study (IC50) of cholinesterase. Results: Histopathological study of gills was carried out and several changes such as aneurysm, necrosis and lamella fusion were noted. Purification fold obtained from purified enzyme was 1.15 with 30% a yield specific activity 20.726. The optimum temperature for purified AChE was 35°C along with acetylthiocholine iodide (ATC) as a preferable substrate that had the highest Vmax value of 0.5452 U mg-1 and the lowest Km value of 0.0311 mM. The optimum pH was observed to be 10 of Tris-HCl as a medium. Meanwhile, the IC50 of cadmium was 6.808 mg l-1 with R2 value of 0.9532. Interpretation: The result of the study can be used as a tool for further developing a biomarker for the detection of heavy metals in aquatic ecosystems. In addition, the baseline data provided can also be used for designing a kit, which would give rapid and accurate result.
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Aims: Improper utilization and disposal of pig faeces in pig farms have been a great concern due to their hazards and risks they constitute to the environment. This situation calls for effective utilization of pig Feces for fish feed. This project was designed to provide information on safe level of Dried Pig Feces (DPF) on growth, histology and haematology of Clarias gariepinus. Study Design: A twelve week feeding trial experiment was conducted using one hundred and fifty samples of C. gariepinus juveniles. The fish meal was replaced at different graded levels of DPF (0%, 25%, 50%, 75% and 100%) and was coded T1, T2, T3, T4 and T5 respectively. Materials and Methods: Growth parameters, histology of vital organs and haematology of the fish samples were determined according to standard methods. Data obtained were analysed using ANOVA and Duncan multiple range test was used to separate the means. Results: The Mean Weight Gain (MWG) revealed a significant (P<0.05) value in T3 (69.40 g), while 100% inclusion exhibited lowest MWG (21.07%). The Packed Cell Volume, Haemoglobin and Red Blood Cell values obtained decreased with increase in DPF inclusions, while an increase was observed in T4 (26.50%). White Blood Cell count was significant (P<0.05) in T3 (16,150±2.07 g/l) and decreased in T4(15,800±1.01 g/l) and T5(12,650±0.85 g/l) respectively. Histological results confirmed the absence of lesions in the heart, gills and the intestine of fish samples. Lesions in the liver were severed in T4 and T5. Conclusions: The findings of this study revealed that 50% inclusion of DPF is the safe level for growth of C. gariepinus. Since the histological results revealed no lesions in all the vital organs, except the liver that had severe lesions, DPF can be recommended as an alternative feed ingredient.
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Several studies have shown the positive effect of phytase on phosphorus utilization by fish and animals, with the use of phytase sources determined for different fish species. Few studies have tested phytase response to different diets, which may affect nutrient availability for optimum growth due to differences in phytate location. The research, therefore, studied the effect of phytase to diets based on soya bean and groundnut meal for Clarias gariepinus on nutrient availability and growth. In trial 1, four groups of soya bean S1, S2, S3 and S4 replaced fish meal at 25%, 50%, 75% and 100% and supplemented with 250, 500, 750 and 1000 FTU/g phytase, respectively. In trial 2, four groups of groundnut meal diet G1, G2, G3, G4, G5 and G6, were similarly supplemented with the same phytase levels used in experiment 1. Fish meal control (S0=G0) was not supplemented with phytase. Result showed that 250 FTU/g phytase showed the highest mean weight gain for both plants. In conclusion, the research has shown that the chemical nature of phytate, rather than its concentration and location, may influence the utilization of phosphorus for optimum growth in the fish by supplementing 250 FTU/g, with a range of available phosphorus requirement of between 0.75% (Y = 0.363 + 4.155X - 2.772X2, R2 = 0.759) and 0.80% (Y = 0.307 + 3.303X - 2.059X2, R2= 0.210)
ABSTRACT
Abstract The catfish, Clarias gariepinus, was exposed to different acute concentrations (5-10 mg/l) of diazinon and the Lc50 value was recorded as high as 7.3 mg/l for 96 hours. The fishes exposed to three sub-lethal levels of diazinon (0.73, 1.095 and 1.46 mg/l) for 30 days showed that the pesticide induces changes in different blood parameters. Number of red blood cells (RBC), haemoglobin level and haematocrit values were elevated whereas white blood cells (WBC) count was reduced. Various blood indices like mean corpuscular volume (MCV), mean corpuscular haemoglobine (MCH) and mean corpuscular haemoglobine concentration (MCHC) vary insignificantly in the fish treated with diazinon. Glucose level and activity level of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was increased in Clarias gariepinus exposed to diazinon. Protein level in plasma of fish treated with pesticide was changed but the change was insignificant. Histological changes in the liver, gills and kidney of fishes exposed to diazinon were apparent when compared to control. Hepatocytes necrosis and bleeding were more distinct in the fishes exposed to pesticide. Glomerulus hypertrophy and bleeding in kidneys; and fusion and degeneration of secondary lamellae and epithelial hyperplasia in gills were also observed in the exposed fish.
Resumo O peixe-gato, Clarias gariepinus, foi exposto a diferentes concentrações agudas (5-10 mg / l) de diazinon e o valor de Lc50 foi registrado tão alto quanto 7,3 mg / l por 96 horas. Os peixes expostos a três níveis sub-letais de diazinon (0,73, 1,095 e 1,46 mg / l) por 30 dias mostraram que o pesticida induz mudanças nos diferentes parâmetros sanguíneos. O número de glóbulos vermelhos, o nível de hemoglobina e os valores do hematócrito foram elevados, enquanto a contagem de leucócitos foi reduzida. Vários índices sanguíneos, como volume corpuscular médio (VCM), hemoglobina corpuscular média (HCM) e concentração de hemoglobina corpuscular média (CHCM) variam insignificantemente nos peixes tratados com diazinon. Nível de glicose e nível de atividade de AST e ALT foi aumentado em Clarias gariepinus expostos a diazinon. O nível de proteína no plasma de peixes tratados com pesticidas foi alterado, mas a mudança foi insignificante. Alterações histológicas no fígado, brânquias e rins de peixes expostos ao diazinon foram aparentes quando comparados ao controle. A necrose e o sangramento de hepatócitos foram mais distintos nos peixes expostos ao agrotóxico. Hipertrofia do glomérulo e sangramento nos rins; e fusão e degeneração de lamelas secundárias e hiperplasia epitelial em brânquias também foram observadas nos peixes expostos.
Subject(s)
Animals , Catfishes/metabolism , Catfishes/blood , Diazinon/toxicity , Gills/drug effects , Gills/pathology , Kidney/drug effects , Toxicity Tests , Kidney/pathology , Liver/drug effects , Liver/pathologyABSTRACT
Aim: Cholinesterase (ChE) inhibition and histopathological features of brain tissues of Clarias gariepinus were investigated with a purpose to develop biomarkers for monitoring heavy metals. Methodology: The effects of cadmium toxicity on C. gariepinus were assessed by ChE inhibition and characterisation of ChE by affinity chromatography and histological variations in brain tissues were studied by H&E staining under light microscope. Results: The purified enzyme gave 10.58 fold purification with the recovery of 12% with specific activity of 159.729 U mg-1. The Michaelis-Menten constant (Km) and Vmax value obtained was 1.985 mM and 0.4479 µmol min-1 mg-1, respectively. The enzyme showed the ability to hydrolyse acetylthiocholine iodide (ATC) at a faster rate compared to other two synthetic substrates, propionylcholine iodide (PTC) and butyrylthiocholine iodide (BTC). ChE showed highest activity at 35°C in Tris-HCl pH 7.5. The metal inhibition study also found the maximal inhibitory concentration (IC50) value for cadmium to be 0.6517 mg l-1. Histological study revealed decrease in the number of cells, degeneration of Purkinje cells, increased aggregation area and cells necrosis. Interpretation: Inhibition of cholinesterase activity and degeneration of Purkinje cells observed in the present study can be used as a tool for further developing a biomarker for detecting heavy metals in the aquatic ecosystems.
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A comparative study on the growth performance of African catfish (Clarias gariepinus) fed shrimp based diet (SBD), chicken offal based diet (COBD) and coppens feed was carried-out for 22 weeks in concrete tanks measuring 3.5 x 1.7 x 1.5 m3. Triplicate groups of 40 juveniles with average length of 9.15 ± 0.17cm and weight of 20.00 ± 2.58g were stored in each tank. A total of 360 juveniles were used throughout the study. Fish were fed daily at 3% of their body weight through-out the duration of the experiment. The nutrient composition of the 3 nutrients differed significantly at p<0.05. Weight gain (WG) (g) was highest (17189.33 ± 506.61g) in fish fed diet A (Coppens feed), followed by 15045.33±202.42 g (diet B) (SBD) and least (14357.33 ± 108.25 g) (diet C) (COBD). The Growth rate (GR) was highest in fish fed with diet A (111.62 ± 3.29 g/day), followed by 97.69±1.31 g/day (diet B), and least (93.23±0.70 g/day) in diet C. Specific growth rate (SGR) was highest in juveniles fed diet A (2.02 ± 0.02 %/day), followed by 1.94±0.01 %/day for diet B, and least (1.91±0.01 %/day) for diet C. Mean growth rate (MGR) was highest in juveniles fed diet A (11.88 ± 0.29 mg/day), followed by 11.74±0.15 mg/day for diet B, and least (11.69±0.09 mg/day) in fish fed diet C. The WG, GR and SGR varied significantly between the juvenile fish group fed the 3 diets at p<0.05, while MGR did not vary significantly between fish group fed the 3 diets at p>0.05. Fish fed diet A had a higher feed consumption (FC) (41650.00 ± 315.34 g/kg), than that fed diet B (39034.24 ± 86.34 g/kg) and then diet C (38276.00 ± 342.97 g/kg). Juveniles fed Coppens feed did better, with a feed conversion ratio (FCR) of 2.42 ± 0.06, followed by 2.59±0.04 for diet B and 2.67 ± 0.03 for fish fed diet C. Feed conversion efficiency (FCE) was higher in fish fed diet A (41.26±0.94 %), followed by 38.54 ± 0.54 % (diet B) and least (37.52 ± 0.51 %) (diet C). The FC and FCR varied significantly between the fish fed the 3 diets at p<0.05, while FCE was not significantly different between the 3 treatment groups at p>0.05. The water parameters of the culture water varied significantly between each treatment groups (p<0.05), and were within the rage suitable for normal growth of fish. Though coppens feed yielded better growth performance and feed utilisation, the use of COBD and SBD is recommended for fish farmers in Nigeria. More researches should be carried out on using chicken offals and shrimps in fish feed formulation.
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This study investigated the reproductive performance of pawpaw (Carica papaya) seeds, hibiscus plant (Hibiscus rosa-sinensis) leaves and sweet potato (Ipomoea batatas) leaves on some reproductive parameters (ovary weight, mean egg diameter and egg fecundity) in female African catfish (Clarias gariepinus). One hundred and twenty (120) juveniles of C. gariepinus were collected from the University of Calabar fish farm. The 120 fish were randomly divided into 12 experimental tanks measuring 80x80x80 cm (L x W x H) using a completely randomized design (CRD). Three grams (3 g) of each test plant were incorporated into 1 kg of Coppens feed (3 g/kg) and reformulated into four experimental diets; Treatment A- Control, B- pawpaw seed meal, C- Hibiscus leaf meal and D- sweet potato leaf meal. The experiment was done in three replications. The fish were fed twice daily for 6 months. Data obtained were analyzed using a one way analysis of variance (ANOVA). Results obtained revealed that the different test substances significantly (p<0.05) negatively affected the different reproductive parameters studied. The ovary weight, gonadosomatic index (GSI), egg diameter, fecundity as well as total weight significantly (p<0.05) decreased in all the treated fish when compared with that of the control. Pawpaw seed meal (PSM) had the highest effect on the reproductive parameters of the fish studied (ovary weight, GSI, fecundity and egg diameter values of 14.89±5.51, 0.82±0.30, 19371±51.84 and 0.63±0.07, respectively) when compared to the other test plants. The findings of this study suggest that C. papaya seeds, hibiscus leaves and sweet potato leaves have the potential to impair reproductive performance in female African catfish. Therefore, holistic measures should always be taken when using these plants considering the effect it could exert on other aquatic inhabitants and systems.
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This study evaluates the growth, body composition, and resistance to Aeromonas hydrophila challenge in juvenile African catfish (Clarias gariepinus) fed diets supplemented with spirulina (Arthrospira platensis). Five experimental diets containing different percentages of locally grown dried spirulina (0, 1, 3, 5 and 7%) were fed daily to catfish juveniles at 5% of their body weight. The growth and body composition of the catfish were determined up to 90 days of the study period. At day 91, the catfish were intraperitoneally injected with 107 CFU/ml of virulent A. hydrophila. Generally, the growth and body composition of the catfish in spirulina inclusion groups showed no significant difference with the control group. The survival rate following A. hydrophila challenge was significantly low in the control group compared to all of the other treatment groups. After the challenge trial, only the white blood cell count value was significantly higher in all of the groups supplemented with spirulina compared to the control group. We concluded that the locally grown spirulina do not improve growth and body composition, but it increased the catfish resistance towards A. hydrophila infection.
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ABSTRACT The purpose of the current study was to examine the effects of different feeds/nutrients and temperature on the gonadal development of Clarias gariepinus. The gonadosomatic index (GSI) and blood parameters including red blood cell count (RBCs), white blood cell count (WBCs), hemoglobin (Hgb) level, hematocrit (HCT), platelets (PLT) and mean corpuscular volume (MCV) were investigated. Four types of fish feed of 36% protein content [D1(fish meal), D2 (soybean meal), D3 (peameal) and D4 (commercial tilapia feed)] and 3 different levels of temperature (T1(24℃), T2(28℃) and T3(32℃) were tried in this study for a duration of 4 months. The mean values were as follows: female GSI (14.68 ± 4.86), male GSI (0.70 ± 0.32), RBCs x 106(2.45± 0.64), WBCs x 103(9.28 ± 2.34), Hgb (12.42± 2.21g/dl), HCT (29.06 ± 3.54%), PLT (90.75 ± 9.18/mm3), and MCV (118.08 ± 10.3 g/l). Fish meal diet revealed the most significant (p<0.05) increase in weight gain, female GSI, and also exerted significant increases on most of the blood parameters. This study revealed that animal-based protein diet and temperature around 28℃ were the critical requirements for the physiological performance and relative gonadal weight of C. gariepinus. GSI and blood parameters were useful indicators of stress exerted by nutrition and temperature on fish, and their study is critical for fish health and mass production of viable seeds for aquaculture enterprise.
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Abstract The organoleptic evaluation and proximate analysis of Clarias gariepinus and Cyprinus carpio were determined in fresh fish and when refrigerated at two different temperatures (-21 °C and 4 °C) for a period of six weeks. A panel of twelve trained judges evaluated the color (live), texture, softness and flavor of fish meat after two minutes steam cooking. Average score revealed a general decline in organoleptic properties such as color, texture, freshness, and taste of C. gariepinus and C. carpio stored at two temperatures compared to the fresh fish. Proximate analysis revealed a more decrease in crude protein and lipid contents and increase in ash content in C. gariepinus and C. carpio at the two storage temperatures compared to the fresh fish muscle. Moisture content decreased in the fish muscle samples of both the fish species stored at -21 °C but increased in the 4 °C stored samples. pH of fish was found to increase in the two stored temperatures. There were significant differences (P 0.05) in the organoleptic and proximate composition of the ice stored and fresh C. gariepinus and C. carpio, the same temperature and between the two different temperatures. The quality of fish muscle stored at 4 °C deteriorated faster than that of the -21 °C. Thus, storage temperature and duration have adverse effects on the nutritional quality of fish meat.
Resumo A avaliação organoléptica e a análise aproximada de Clarias gariepinus e Cyprinus carpio foram determinadas em peixe fresco e refrigerado a duas temperaturas diferentes (-21 °C e 4 °C) por um período de seis semanas. Um painel de doze juízes treinados avaliou a cor (ao vivo), textura, maciez e sabor da carne de peixe após dois minutos de cozimento a vapor. O escore médio revelou um declínio geral nas propriedades organolépticas, como cor, textura, frescor e sabor de C. gariepinus e C. carpio armazenados a duas temperaturas em comparação com o peixe fresco. A análise imediata revelou uma maior diminuição nos teores de proteína bruta e lipídios e aumento no teor de cinzas em C. gariepinus e C. carpio nas duas temperaturas de armazenamento em comparação com o músculo do peixe fresco. O teor de umidade diminuiu nas amostras de músculo de peixe de ambas as espécies de peixes armazenadas a -21 °C, mas aumentou nas amostras armazenadas a 4 °C. O pH dos peixes aumentou nas duas temperaturas armazenadas. Houve diferenças significativas (P 0,05) na composição organoléptica e próxima do gelo armazenado e fresco C. gariepinus e C. carpio, a mesma temperatura e entre as duas temperaturas diferentes. A qualidade do músculo do peixe armazenado a 4 °C deteriorou-se mais rapidamente do que a temperatura de -21 °C. Assim, a temperatura e duração do armazenamento têm efeitos adversos na qualidade nutricional da carne de peixe.
ABSTRACT
Abstract The catfish, Clarias gariepinus, was exposed to different acute concentrations (5-10 mg/l) of diazinon and the Lc50 value was recorded as high as 7.3 mg/l for 96 hours. The fishes exposed to three sub-lethal levels of diazinon (0.73, 1.095 and 1.46 mg/l) for 30 days showed that the pesticide induces changes in different blood parameters. Number of red blood cells (RBC), haemoglobin level and haematocrit values were elevated whereas white blood cells (WBC) count was reduced. Various blood indices like mean corpuscular volume (MCV), mean corpuscular haemoglobine (MCH) and mean corpuscular haemoglobine concentration (MCHC) vary insignificantly in the fish treated with diazinon. Glucose level and activity level of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was increased in Clarias gariepinus exposed to diazinon. Protein level in plasma of fish treated with pesticide was changed but the change was insignificant. Histological changes in the liver, gills and kidney of fishes exposed to diazinon were apparent when compared to control. Hepatocytes necrosis and bleeding were more distinct in the fishes exposed to pesticide. Glomerulus hypertrophy and bleeding in kidneys; and fusion and degeneration of secondary lamellae and epithelial hyperplasia in gills were also observed in the exposed fish.
Resumo O peixe-gato, Clarias gariepinus, foi exposto a diferentes concentrações agudas (5-10 mg / l) de diazinon e o valor de Lc50 foi registrado tão alto quanto 7,3 mg / l por 96 horas. Os peixes expostos a três níveis sub-letais de diazinon (0,73, 1,095 e 1,46 mg / l) por 30 dias mostraram que o pesticida induz mudanças nos diferentes parâmetros sanguíneos. O número de glóbulos vermelhos, o nível de hemoglobina e os valores do hematócrito foram elevados, enquanto a contagem de leucócitos foi reduzida. Vários índices sanguíneos, como volume corpuscular médio (VCM), hemoglobina corpuscular média (HCM) e concentração de hemoglobina corpuscular média (CHCM) variam insignificantemente nos peixes tratados com diazinon. Nível de glicose e nível de atividade de AST e ALT foi aumentado em Clarias gariepinus expostos a diazinon. O nível de proteína no plasma de peixes tratados com pesticidas foi alterado, mas a mudança foi insignificante. Alterações histológicas no fígado, brânquias e rins de peixes expostos ao diazinon foram aparentes quando comparados ao controle. A necrose e o sangramento de hepatócitos foram mais distintos nos peixes expostos ao agrotóxico. Hipertrofia do glomérulo e sangramento nos rins; e fusão e degeneração de lamelas secundárias e hiperplasia epitelial em brânquias também foram observadas nos peixes expostos.
ABSTRACT
The study evaluated the effect of sub-lethal concentration of phostoxin on Clarias gariepinus juveniles. C. gariepinus juveniles belonging to the same cohort (40.1±1.2g; 18.1±1.1cm) from a commercial fish farm were randomly placed ten in each of 15 plastic tanks containing 15 liters of water. They were exposed for 96 hrs to three sub-lethal concentrations (treatments) of phostoxin (0.125, 0.250, 0.5mg L-1) and a phostoxin free control. At the end of 96 hrs exposure, they were dissected and the tissues need for histopathology removed and fixed in Bouin's fluid. The gill filament exhibited fusion at the secondary lamella that was progressive with concentration. At the highest concentration of exposure, the secondary lamellae showed marked pyknotic and necrotic changes characterized by epithelia detachment. The hepatic tissue showed mild inflammatory changes at lower concentrations while at the highest concentration of exposure there was marked inflammation with observed hydropic degeneration. In the kidney, an inflammatory change was only observed in the interstices at the highest dose of exposure with the convoluted tubules showing partial shrinkage. Phostoxin showed to have significantly caused alterations in cyto-architecture of the gills and to a considerable extent liver and kidney of C. gariepinus.(AU)
Subject(s)
Animals , Catfishes/anatomy & histology , Insecticides/adverse effects , Insecticides/analysis , Insecticides/poisoning , Nigeria , Histological Techniques/veterinary , Pest Control , Water Pollution/adverse effectsABSTRACT
Industrialization has led to huge waste generation over the last decades, the absence of adequate facilities for treating such wastes in most developing nations has led to the discharge of effluents into the environment without proper treatment. Toxicological effects of effluents from rubber processing plant (collected during the period of low rivertide i.e. between October 2012 and February 2013) were carried out in this study. Lethal concentration (96-h LC50) was evaluated using 0.25mg/L, 0.30mg/L, 0.35mg/L and 0.40mg/L while sub-lethal effects (42 days) was carried out on haematological parameters like Red Blood Cell (RBC), White Blood Cell (WBC), Haemoglobin (Hb), Packed Cell Volume (PCV), Mean Corpuscular Volume (MCV), Mean Corpuscular Haemoglobin (MCH) and Mean Corpuscular Haemoglobin Concentration (MCHC) using 0.064mg/L, 0.048mg/L, 0.032mg/L and 0.016mg/L which are the 20%, 15%, 10% and 5% of the 96-h LC50 value. Mortality increased as the concentrations of the effluent increases and 0.32mg/L was obtained as LC50. In comparison with the control, the mean value obtained for PCV, HB and RBC showed significant differences (P<0.05) most especially at highest concentration while there was no significant difference in all values obtained for WBC, MCV, MCH and MCHC. It was concluded that the rubber processing effluent had some negative effect on the haematology of Clarias gariepinus. Therefore, it is recommended that the effluent should be properly treated before discharge into the environment.
ABSTRACT
The aim of this work was to study the effects of sub-lethal exposure of lead acetate on the histopathology of the gills, liver, kidney and muscle and its accumulation in these organs of Clarias gariepinus. Results showed that lead accumulation in the tissues of C. gariepinus was dependent on the exposure period and lead concentration. Gills and liver were the predominant storage tissue and the order of accumulation in tissues was gill > liver > kidney > muscle. Some structural changes were observed in different organs, especially in the gills of the fishes exposed to lead acetate. Epithelial hypertrophy and epithelial lifting were apparent in the gills of exposed fishes. The degeneration of cytoplasm and secondary lamellae was also observed. Necrosis of hepatocytes was apparent. Glomerular expansion and gaps between the muscular bundles were found in the fishes exposed to lead acetate.
ABSTRACT
Aim: To study the changes in haematological and plasma biochemical parameters of diuron at different sub-lethal levels on Clarias gariepinus juvenile. Place and Duration of Study: Department of Animal Science and Fisheries Management laboratory, Bowen University, lwo, Osun State, between October 2010 to April 2011. Methodology: The acute and chronic toxicity of various concentrations of Diuron on C. gariepinus juveniles was evaluated. Blood samples were taken after 14 and 28 days for the haematological and plasma biochemical analysis respectively. Results: 96hr LC50 value of a working dilution of Diuron (0.03g/l) was obtained. The highest value of PCV and Hb was obtained in fish exposed to 1/10LC50 Diuron. At higher concentration (1/2LC50), significant decreases were observed in total protein and albumin. Fish exposed to a working dilution of 1/10LC50 (0.003g/l) in this study showed no significant difference to the control. Conclusion: Diuron, a substituted urea, could be toxic at high concentration; therefore, further studies are required to evaluate the potential environmental risk of Diuron.
ABSTRACT
A ten-week nutritional study was carried out to evaluate the practical replacement of fishmeal with toad meal in different protein levels in the diet of Clarias gariepinus fingerlings. One hundred and fifty (150) fingerlings with an average weight of 7.99 – 27.64g were stocked at the rate of ten (10) fish per experimental tank. The fingerlings were subjected to five different dietary feeds with varying levels of toad meal at 0%, 25%, 50%, 75%, and 100% respectively. Each treatment was replicated thrice. Feeding was done at 3% body weight per day and records of weekly weight increase were kept. The feed conversion ratio, weight gain, survival rate revealed that the control (0% toadmeal inclusion) and diet 5 (100% toadmeal inclusion) were best in growth performance, unlike the mixed fishmeal and toadmeal that showed adequate growth performance. Water quality parameters of the experiment measured constantly were within the normal optimum requirements that had no negative effects on the experimental fish. Finally based on biological and financial evaluation of the feeding trials diet 5 (100%) was recommended as the most economical and practically acceptable for large-scale intensive fish culture.