Establishing intraspecific breeding and hybridization programs and determining genetic variability are two important issues for aquaculture. However, interspecific hybridization to improve growth and feeding efficienc...Establishing intraspecific breeding and hybridization programs and determining genetic variability are two important issues for aquaculture. However, interspecific hybridization to improve growth and feeding efficiency is limited. For this purpose, the embryonic and larval development of reciprocal crosses of Clarias gariepinus (Burchell, 1822) and Clarias jaensis (Boulenger, 1909) were studied under laboratory conditions. The fertilization rate varied from 63.33% to 92%, while the hatching rate ranged from 55.68% to 76% with the highest value in hybrids ♀Cg × ♂Cj. Crosses between ♀Cj × ♂Cj, ♀Cg × ♂Cj and ♀Cj × ♂Cg had embryonic stages similar to those of the pure sib ♀Cg x ♂Cg. All crosses, however, had different timing for the various embryological stages. Hatching occurred at 32 h 15 min and 38 h for ♀Cj × ♂Cj and ♀Cj × ♂Cg, and 23 h and 23 h 30 min, respectively, for ♀Cg × ♂Cg and ♀Cg × ♂Cj. However, both crosses produced viable larvae until the first external feeding. The external morphological features of the larvae were completely formed by the 10th day after hatching. The body forms of the crosses at this time were indistinguishable from the pure sib. This study thus laid the groundwork for further comparative studies on hybrid performance and characterization.展开更多
Fishmeal is the most preferred source of protein in aquafeeds, but it is expensive and scarce. Hence, Achatina fulica meat meal (AFM), which is much less preferred for human consumption out of three species of African...Fishmeal is the most preferred source of protein in aquafeeds, but it is expensive and scarce. Hence, Achatina fulica meat meal (AFM), which is much less preferred for human consumption out of three species of African giant land snails, was tested as a fishmeal substitute for Clarias gariepinus growth. Five iso-nitrogenous and iso-calorific diets were formulated, in which AFM substituted fish meal at 0% (control or Diet A), 25% (Diet B), 50% (Diet C), 75% (Diet D) and 100% (Diet E). These dietary treatments were each replicated thrice in a completely randomized design experiment, using 36-L plastic tanks in which the fish were fed daily rations corresponding to 5% of their body weight, for 8 weeks. Water quality parameters in the tanks were monitored. Proximate analyses were conducted on the fish meal, snail meal and experimental diets before the feeding trials. Cost-benefit analysis of the different diets was performed. The crude protein content of AFM (69.18%) was significantly higher than that of fish meal (55.81%). There was no significant difference (P > 0.05) in the mean weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio and survival rate in fish fed Diet A and Diet B. The best protein efficiency ratio (0.77) was recorded in fish fed Diet B. Furthermore, the survival rate of fish increased with increased levels of AFM substitution. Water quality parameters were within a suitable range for tropical fish culture, indicating that the AFM did not pollute the water. The fish fed 25% AFM diet significantly (P Clarias gariepinus diets at a 25% substitution level. The aquaculture industry can thus exploit the availability of this feed resource.展开更多
This study focused on the supplementation of four-sided spice fruit powder (Tetrapleura tetraptera) on some zootechnical performances of juveniles of Clarias gariepinus and was carried out from February 14 to July 20 ...This study focused on the supplementation of four-sided spice fruit powder (Tetrapleura tetraptera) on some zootechnical performances of juveniles of Clarias gariepinus and was carried out from February 14 to July 20 at the Massoma Fish Farm of Bojongo Mbeidi located in the Littoral Region, Department of Wouri, Douala IV district. The farm benefits from a climate favorable to aquaculture activity. For this purpose, five (5) treatments were tested including T<sub>0+</sub> (imported feed), T<sub>0-</sub>, T<sub>0.3</sub>, T<sub>0.4</sub>, and T<sub>0.5</sub> respectively for the treatments with 0% supplemented food;0.3%;0.4% and 0.5% of Tetrapleura tetraptera powder. A total of 450 Clarias gariepinus fry with an initial average weight of 7 ± 1.5 g, were distributed in happas of 0.49 m<sup>2</sup> each placed in Triplicate in a completely randomized device. Four isoprotein foods with 38% crude protein were formulated to feed these fry at 7% of their biomass per day for 15 days then to their fullness until the end of the experiment. Intermediate fishing was carried out every fortnight. 75 days later, the results recorded show that the highest average survival rate (96.44% ± 3.5%) was recorded with the subjects fed feed supplemented with 0.4% T. tetraptera powder. The average weight (120.93 ± 67.20), weight gain (113.93 ± 67.20), specific growth rate (3.64 ± 0.79% g/d) and total lengths and standard (26.43 ± 1.9 and 23.66 ± 1.76) the highest were recorded with the T<sub>0+</sub> treatment (imported feed). The highest conditioning factor K (2.14 ± 0.15) was recorded with the treatment supplemented with 0.4% T. tetraptera. The lowest conversion ratio (1.28) was recorded with the treatment fed with imported blue crown food (T<sub>0+</sub>). Furthermore, the lowest production cost was recorded with the treatment supplemented with 0.4% T. tetraptera. It appears from this study that the juveniles of C. gariepinus better value the feed substituted with 0.4% of the powder of four sides (Tetrapleura tetraptera).展开更多
Fishes are excellent markers of the extent of pollution from heavy metals in aquatic environments given that they are found at various levels of the food chain.This study aimed to investigate the bioaccumulation of he...Fishes are excellent markers of the extent of pollution from heavy metals in aquatic environments given that they are found at various levels of the food chain.This study aimed to investigate the bioaccumulation of heavy metals(Zn,Pb,Cd,As,and Hg)as well as the activity of delta-aminolevulinic acid dehydratase(δ-ALA-D)in the livers of cat fishes(Clarias gariepinus)collected from three rivers(Donga,Ibi and Gindin-Dorowa)in Taraba State,Nigeria.The concentrations of heavy metals in the liver tissues were determined using an atomic absorption spectrophotometer in accordance with the method of AOAC(2019),while theδ-ALA-D activity was assayed using the method of Sassa(1982).Results revealed that only Zn and As were present in the liver samples from the three rivers.Pb was found only in the liver from Gindin-Dorowa at the concentration of 0.0012mg/kg which is not significant(P<0.05)when compared with other locations,while Hg and Cd were absent in all the liver samples.The liver sample from Gindin-Dorowa had the highest concentration of Zn(4.2500 mg/kg),followed by Ibi(3.2067 mg/kg),and Donga having the least(2.5500 mg/kg),which were all substantially(P<0.05)different from one another.However,there was no significant(P<0.05)difference in the As composition of liver from Donga(0.0013 mg/kg),Ibi(0.0012 mg/kg)and Gindin-Dorowa(0.0010 mg/kg).The result ofδ-ALA-D activity showed that the highest enzymatic activity was found in the liver sample from Donga which has the least Zn and no Pb content,followed by Ibi sample.This validates the report that heavy metals impairδ-ALA-D activity.Nonetheless,the concentrations of all metals in fish livers from all regions do not exceed the acceptable limits set by international law,making them safe for human consumption and possibly not having a negative impact on public health.Since there is little or no industrial activity in the studied locations,these levels may be consequent to low anthropogenic inputs.The current situation should be safeguarded to prevent pollution of the river’s aquatic biota in the near future,and more appropriate steps should be made to guarantee higher fish quality and life in the rivers.展开更多
Heavy metals have harmful effects on human health,and exposure to these metals has been increased by industrial and anthropogenic activities and modern industrialization.Heavy metals content of the liver tissues was d...Heavy metals have harmful effects on human health,and exposure to these metals has been increased by industrial and anthropogenic activities and modern industrialization.Heavy metals content of the liver tissues was determine d using Atomic Absorption Spectrophotometer method,while lipid peroxidation was carried out.Heavy metals analyzed include;lead(Pb),cadmium(Cd),zinc(Zn),Arsenic(As),and Mercury(Hg).The findings revealed that the heavy metal Zinc(Zn)has high concentrations in the muscles of the fish species,the concentration of this heavy metal Zinc is high in River Gindin Dorowa th a n in River Ibi and River Donga shows less concentration of this heavy metal though it’s above WHO permissible limits.Results revealed that only Zn and Cd were present in the muscle from the three rivers.Pb was found only in the liver from Gindin-Dorowa at the concentration of 0.017 mg/kg,which is not significant(P<0.05)when compared with other locations,while Hg and As were absent in all the muscle samples.The highest concentration of Zn was found in the muscle sample from Gindin-Dorowa(7.450 mg/kg)followed by Ibi(6.16 mg/kg)and the least being Donga(4.365 mg/kg)which are significantly(P<0.05)different from one another.However,there was no significant(P<0.05)difference among the Cd composition of muscle from Gindin-Dorowa(0.025 mg/kg),Donga(0.024 mg/kg)and Ibi(0.015 mg/kg),respectively.The TBA was found in the hepatic tissue sample from Gidin-Dorowa,which has the highest Zn,Cd and no Pb content,followed by Ibi and then the Donga sample.This suggests that there is a positive relationship between heavy metals and the effect of TBA on the hepatic tissues,justifying the fact that heavy metals affect the hepatic tissues of fish,while on the cerebral tissue.In conclusion,it revealed that there is a negative relation between heavy metals and the effect of TBA on the cerebral tissues to protect or save aquatic habitat s of fish quality and aquatic life.展开更多
A twelve week experiment was conducted to compare the effects of diets with plant-based and animal-based ingredients on growth and gonad development of Clarias gariepinus. One hundred and 12 sub-adult C. gariepinus wi...A twelve week experiment was conducted to compare the effects of diets with plant-based and animal-based ingredients on growth and gonad development of Clarias gariepinus. One hundred and 12 sub-adult C. gariepinus with an average weight of 205 ×5.09 g, were stocked in six concrete tanks (9 × 4 × 2 m3) containing 20 fish each. Experiment had 3 replicates and animals fed daily at 5% body weights. There was no significant difference (P 〈 0.05) in proximate compositions of the two experimental feeds and controls. Fecundity, gonad weight and gonasomatic index were higher in fish fed diet 13 than A and C. Similarly, growth indices were higher in fish fed diet B than in A and C. Histology of gonads showed a faster development of oocytes of eggs in fish fed animal-based ingredients than plant-based and combined plant and animal diets. Although there were slight differences in growth parameters and gonad development in favor of feed with animal-based ingredients, plant-based feed compared favorably in the growth and gonad development of C. gariepinus. Plant-based ingredients are recommended on the basis of affordability and availability as substitute for animal-based ingredients in C. gariepinus feed.展开更多
Specimens of Clarias gariepinus were treated with lethal(70,75,80,85,90,and 95 mg/L) and sub-lethal concentrations(8,12 and 16 mg/L) of uranyl acetate,a low-radiotoxicity uranium salt. The LC 50 value was registered a...Specimens of Clarias gariepinus were treated with lethal(70,75,80,85,90,and 95 mg/L) and sub-lethal concentrations(8,12 and 16 mg/L) of uranyl acetate,a low-radiotoxicity uranium salt. The LC 50 value was registered as 81.45 mg/L. The protein and glycogen concentrations in liver and muscles were decreased in the fish exposed to sub-lethal concentrations. The red blood cell(RBC) and white blood cell(WBC) counts,haemoglobin(Hb) concentration and haematocrit(Hct) values were decreased. Different blood indices like mean corpuscular volume(MCV),mean corpuscular haemoglobin(MCH) and mean corpuscular haemoglobin concentration(MCHC) were negatively affected. Level of plasma glucose was elevated whereas protein was decreased. The level of calcium concentration(Ca) was declined in the blood of exposed fish whereas magnesium(Mg) remains unchanged. The activity level of glutamic-oxaloacetic transaminase(GOT) and glutamic-pyruvic transaminase(GPT) was elevated in exposed fish. These effects were more pronounced in the last period of exposure and in higher concentrations. Results of the present study indicate that uranyl acetate has adverse effects on C larias gariepinus and causes changes in the biochemical and hematological parameters of the fish.展开更多
Seasonal variations in serological profiles and growth status of farmed and wild Clarias gariepinus were investigated. Serological profiles of Clarias gariepinus can be an effective tool for proper monitoring of stres...Seasonal variations in serological profiles and growth status of farmed and wild Clarias gariepinus were investigated. Serological profiles of Clarias gariepinus can be an effective tool for proper monitoring of stress induced by management practices in intensive fish culture, which may elicit devastating effect on fish. Spectrophotometry procedures were used to analyze serum parameters of Clarias gariepinus. No different seasonal patterns were observed for mean values of albumin, total protein, urea, cholesterol, glucose and alanine amino-transferase. However, aspartate amino-transferase showed different seasonal pattern. Levels of cholesterol and alanine amino-transferase were highly significant in farmed and wild fish, separately. Juvenile fish had high level of urea irrespective of season. Seasonal variations in water quality parameters were observed except for pH which had no seasonal pattern. The growth exponential shows b-values between -0.048 and 7.434 for Clarias gariepinus. Adult female and juvenile fish from the wild had the highest b-value and the least b-value, separately. In this study, b-values were higher in the wild fish than the farmed fish. The condition factor for Clarias gariepinus ranged from 0.422 to 0.698, and was observed to be high in juvenile fish. With a condition factor less than 1, fish may not be doing well, probably due to environmental stress. Some serological parameters varied according to season and environment of fish. Thus, serological profile of fish is an effective and sensitive tool to monitor fish response to stress factors in the environment.展开更多
A research was conducted to assess the effects of three different drying techniques, namely open sun drying (OSD), solar dryers (SD) and solar tent dryers (STD). Data on physical characteristics such as weight, ...A research was conducted to assess the effects of three different drying techniques, namely open sun drying (OSD), solar dryers (SD) and solar tent dryers (STD). Data on physical characteristics such as weight, total length and standard length were recorded and proximate composition of the fish sample Clarias gariepinus (Burchell, 1822) was carried out before, during and after drying to assess changes on physical characteristics and nutrient composition at different level. After drying, the samples were subjected to storage for eight weeks. The result obtained shows that there was no significant (P 〉 0.01) difference in the drying weight of the fish samples between the direct SD and the STD. However, for the total and standard length there was significant (P 〈 0.01) difference in the drying techniques, but no significant difference (P 〉 0.05) in the drying period. There was no significant (P 〉 0.05) difference on the physical parameters, storage period, proximate composition of both direct SD and STD and the drying period, respectively. Therefore, direct SD can be substituted with the STD without altering the quality of the product.展开更多
The present study is on the haematological and hepatic responses of the African catfish fingerlings Clarias gariepinus to sublethal toxicity of industrial effluents(IE)from the environment of Ologe Lagoon,Lagos,Nigeri...The present study is on the haematological and hepatic responses of the African catfish fingerlings Clarias gariepinus to sublethal toxicity of industrial effluents(IE)from the environment of Ologe Lagoon,Lagos,Nigeria.The fish were cultured in five concentrations of industrial effluents:0%(control),5%,15%,25%,and 35%.Trials were carried out in triplicates for twelve(12)weeks.The culture system was a static renewable bioassay and was carried out in the fisheries laboratory of the Lagos State University,Ojo-Lagos.Weekly physico-chemical parameters:Temperature(°C),pH,conductivity(ppm)and dissolved oxygen(DO in mg/L)were measured in each treatment tank.Haematological parameters:packed cell volume(PCV),red blood cells(RBC),white blood cell(WBC),neutrophil and lymphocytes etc.,and hepatological alterations were measured after 12 weeks.The physico-chemical parameters showed that the pH ranged from 7.82±0.25~8.07±0.02.DO ranged from 1.92±0.66~4.43±1.24 mg/L.The conductivity values increased with increase in concentration of I.E.While the temperature difference remained insignificant with mean value range between 26.08±2.14~26.38±2.28.The DO showed significant differences at p<0.05.Though survival was 100%during the sublethal study,haematological results showed that C.gariepinus had PCV ranging from 13.0±1.7~27.7±0.6,RBC ranged from 4.7±0.6~9.1±0.1,and neutrophil ranged from 26.7±4.6~61.0±1.0 amongst others.The highest values of these parameters were obtained in the control and lowest at 35%.While the reverse effects were observed for WBC and lymphocytes,the liver shows normal liver cells in the control(0%),but at higher toxic levels,there were:vacoulation,destruction of the hepatic parenchyma,tissue becoming eosinophilic(i.e.tending towards Carcinogenicity)and severe disruption of the hepatic cord architecture.This study therefore shows that disposal of effluents into the aquatic environment affects the health of fishes by impairing normal hepatic functions and hindering vital physiological processes if exposure continues for a long period of time(sublethal effect).展开更多
A total of 190 bacterial isolates have been successfully isolated from 50 diseased African Catfish (C/arias gariepinus) namely; 70 isolates of Flavobacterium sp., 50 isolates of Aeromonas hydrophila, 30 isolates of ...A total of 190 bacterial isolates have been successfully isolated from 50 diseased African Catfish (C/arias gariepinus) namely; 70 isolates of Flavobacterium sp., 50 isolates of Aeromonas hydrophila, 30 isolates of Edwardsiella tarda and 20 isolate of each Hafnia alvei and Pseudomonas aeruginosa. This study was conducted to investigate bacteria that infected the broodstocks of African catfish cultured at Manir River, Terengganu as well as their antibiogram and Multiple Antibiotic Resistance (MAR) index. In the present study, antibiotic sensitivity and intermediary case were reported as 52.7% and 7.8%, respectively. Meanwhile, antibiotic case was recorded as 34.5%. The MAR index values obtained by each bacterial species was ranging from 0.24 to 0.52 whereas the average MAR index value was 0.39 which indicated that the cultured fish has been highly exposed to tested antibiotics.展开更多
Fumonisin B<sub>1</sub> (FB<sub>1</sub>) is produced by fungus of the genus Fusarium (Fusarium verticiloides and F. proliferatum), and occurs predominantly in maize. The consumption of feed con...Fumonisin B<sub>1</sub> (FB<sub>1</sub>) is produced by fungus of the genus Fusarium (Fusarium verticiloides and F. proliferatum), and occurs predominantly in maize. The consumption of feed contaminated with FB<sub>1</sub> has been reported to cause deleterious effects in some fish species. This study was designed to determine the effects of dietary FB<sub>1</sub> on growth and lipids profile of Clarias gariepinus. 450 juvenile catfish were stocked into 5 groups of tanks consisting of 3 tanks per group and fed one of five diets amended with FB<sub>1</sub> (0.0 mg;10.0 mg;20.0 mg;40.0 mg and 80.0 mg FB<sub>1</sub>/kg) for 56 days. At time point’s day 7, 14, 28 and 56, five fish were sampled from each tank weighted, length measured and bled for of lipids profile determinations. Results show that there was a significant reduction (P < 0.05), in the mean body length of the fish fed diets amended with various amounts of FB<sub>1</sub> compared with those fed control diet;also, there was a significant reduction (P < 0.05) in the weight gain of fishes fed diets amended with FB<sub>1</sub> compared with the control. The specific growth rate and the feed conversion ratio at 56 days shows fish fed 0.0 mg FB<sub>1</sub>/kg had the highest specific growth rate (0.39 ± 0.14%/day) and the lowest feed conversion ratio (0.59 ± 0.01) whereas, fish fed 80.0 mg FB<sub>1</sub>/kg had the least specific growth rate (0.07% ± 0.01%/day) and the highest feed conversion ratio (1.95 ± 0.11). Dietary FB<sub>1</sub> caused significant increases (P < 0.05) in serum cholesterol, HDL-C;LDL-C;triglycerides and the sphinganine-sphingosine ratio. Dietary FB<sub>1</sub> at an inclusion rate ≥ 20 mg FB<sub>1</sub>/kg of diet produced significant reduction in weight gain and hyperlipidemia marked by hypercholesterolemia, increased blood high-density lipid cholesterol, increased blood low-density lipid cholesterol, elevated blood triglycerides and elevated sphinganine-sphingosine ratio.展开更多
The present study was carried out to determine LC<sub>50</sub> of deltamethrin (DM) in the African catfish;Clarias gariepinus, investigate its effects on the biochemical parameters and the antioxidant stat...The present study was carried out to determine LC<sub>50</sub> of deltamethrin (DM) in the African catfish;Clarias gariepinus, investigate its effects on the biochemical parameters and the antioxidant status of various tissues, and assess the protective role of Spirulina platensis (SP) against DM induced toxicity in C. gariepinus. The fish were distributed into seven groups of 10 fish/each for 30 days as follows: Group 1, control;Group 2, orally administered saline;Group 3, oral SP (150 mg/kg b.w.);Group 4, exposed to 5.19 μg/l DM;Group 5, exposed to 5.19 μg/l DM and orally administered SP (150 mg/kg b.w.);Group 6, exposed to 12.97 μg/l DM;and Group 7, exposed to 12.97 μg/l DM and orally administered SP (150 mg/kg b.w.). Results revealed marked elevation in serum AST, ALT, ALP, creatinine, urea and uric acid. Significant decrease in serum total protein and albumin was recorded. At the same time, the level of malondialdehyde (MDA) was significantly increased in liver, kidney and gills. While, tissue level ofGSHand, SOD,CATandGSH-Px activities were reduced. Treatment with SP improved the biochemical parameters and attenuated the DM induced oxidative damage. Therefore, this study confirmed the protective role of SP as an antioxidant against the toxicity of DM in catfish.展开更多
Interspecific crossing was carried out among and between two strains of Clarias gariepinus with mouth malformation and crooked-back traits to determine the source(s) of their deformities and the effects of these mor...Interspecific crossing was carried out among and between two strains of Clarias gariepinus with mouth malformation and crooked-back traits to determine the source(s) of their deformities and the effects of these morphological deformities on their growth and survival. Synthetic ovaprim hormone was used for their inducement at 0.5 mL/kg of the brood stock body weight at FEDAK integrated farm, Ado-Ekiti, Nigeria. Under indoor management, highest mean survival rate was 73% recorded in the hybrid of female mouth malformed C. gariepinus x male crooked back C. gariepinus and the least mean survival rate was 70% recorded in the mouth malformed C. gariepinus parental. Under outdoor rearing crooked back C. gariepinus parental had the highest mean growth rate (11.20 grammes) while the hybrid of the cross between female crooked back C. gariepinus and male with mouth malformed C. gariepinus had the least mean growth rate (8.63 grammes). High frequency of occurrence of various morphological aberrations (0.92%) was recorded in the mouth malformed C. gariepinus parental and low frequency of occurrence (0.57%) of morphological aberrations recorded in hybrid of female crooked back C. gariepinus x male mouth malformed C. gariepinus. The reoccurrence of some of these morphological deformities in Clarias is a mystery based on their consistent occurrence even under a very good hatchery management. More research works still need to be done in this area of study of Clarias to unravel the mystery behind this morphological imbalance, because the deformities play special roles in discouraging both the farmers and the consumers of this fish.展开更多
This study investigated bacteria that are associated with milt in cultured samples of African catfish-Clarias gariepinus.Male broodstocks of Clarias gariepinus were collected from private Fish Farm in Ogun State,Niger...This study investigated bacteria that are associated with milt in cultured samples of African catfish-Clarias gariepinus.Male broodstocks of Clarias gariepinus were collected from private Fish Farm in Ogun State,Nigeria,while the fish’s milt was collected and analyzed for microbial load at laboratory of the Department of Microbiology,Federal University of Agriculture,Abeokuta,Ogun State.The molecular characterization of the amplicon was done at International Institute of Tropical Agriculture,Ibadan.Bio-edit was used for importing and mining nucleotide sequences into gene bank.As revealed by the results,bacterial organisms that were present in the milt of Clarias gariepinus are Aeromonas caviae,Proteus mirabilis,Serratia rubidaea,Pseudomonas mosselii,Acinetobacter soli and Klebsiella variicola.The Basic Local Alignment Search Tools revealed the percentage similarity ranging from 86%-97.04%and their accession numbers.These bacteria indicated high levels of faecal contamination in the environment.In conclusion,bacteria were found in the milt of cultured catfish and are capable of being pathogenic to humans and may increase the vertical transfer to fry during breeding and rearing stage.Therefore,fish farmers should maintain a hygiene and serene environment during breeding and culturing of catfish.展开更多
This study was carried out to evaluate the effects of dietary replacement of maize with sweet potato peel in the diet of Clarias gariepinus juveniles.The levels of the SPP inclusion in the experimental diets were 0%,2...This study was carried out to evaluate the effects of dietary replacement of maize with sweet potato peel in the diet of Clarias gariepinus juveniles.The levels of the SPP inclusion in the experimental diets were 0%,25%,50%,75%and 100%.All the diets were iso-nitrogenous.One hundred and fifty(150)C.gariepinus juveniles(33 g~35 g)were randomly distributed to five treatments with three replicates each and 5%of their body weight for 12 weeks.Fish carcass proximate compositions analyzed before and after feeding with the experimental diets shows that CP and EE differed significantly(p<0.05)among the experimental fish and the control,except the percentage CP of the fish fed SPP0%and SPP50%in which there was no significant difference(p>0.05).Highest MWG of 207.70±25.95 g was obtained in the fish fed SPP100%followed by 191.30±16.15 g obtained in the fish fed SPP75%.The least MWG of 149.83±16.01 g was recorded in fish fed SPP25%.The highest FCR of 3.61±0.45 g was recorded in the fish fed SPP100%.A steady decrease in FCR was observed with decreasing inclusion levels of SPP meal.However,higher FW,FL,SGR and PER were observed in the experimental fish as from 50%inclusion levels of the SPP.The cost of feed per kg was reduced and the NP and WG increased with increasing levels of SPP and the profitability was enhanced at 100%SPP inclusion level.The results revealed that C.gariepinus juvenile could tolerate up to 50%,75%and 100%inclusion levels of SPP.The best growth performance was recorded in the fish fed SPP100%,therefore,sweet potato peel can replace maize in the diet of C.gariepinus without any inauspicious effect on the growth performance and nutrient utilization.展开更多
Fingerlings of African catfish,Clarias gariepinus [mean total length,(7.0±1.0) cm SD;mean weight,(3.0±0.7) g SD] were exposed to acute concentrations of amine salt of 2,4-D(0,50,200,250,350,and 400 mg/L) to ...Fingerlings of African catfish,Clarias gariepinus [mean total length,(7.0±1.0) cm SD;mean weight,(3.0±0.7) g SD] were exposed to acute concentrations of amine salt of 2,4-D(0,50,200,250,350,and 400 mg/L) to determine the behavioural responses and mortality.When raised in aquaria the fish became hyperactive.The beat frequencies(opercular and tail beat frequency per minute,OBF and TBF) of the exposed fish declined with increase in the exposure duration and concentration,but the reverse was the case with percent mortality.These variables signifi cantly differed at both the exposure duration and concentration of the toxicant(P<0.05).Anova of the linear regression between variables-OBF,TBF and mortality on exposure duration indicated a strong positive relationship(P<0.001) with the entire variables except mortality and exposure duration.OBF and TBF were inversely correlated with exposure duration(r=-0.99;P<0.05).The 96 h lethal concentration was 165.36(133.29~190.51,C.L.) mg/L and the median lethal time at the highest concentration was 20.41(11.87~27.46) h.The results from this study revealed that 2,4-D was very toxic to C.gariepinus under laboratory conditions and its application should therefore,be restricted in the field.展开更多
The culture of African sharptooth catfish(Clarias gariepinus)in most developing countries lacks suitable diets for semi-intensive production.The present study evaluated the growth performance,survival,nutrient utiliza...The culture of African sharptooth catfish(Clarias gariepinus)in most developing countries lacks suitable diets for semi-intensive production.The present study evaluated the growth performance,survival,nutrient utilization,hepatosomatic index(HSI),body composition,yield and feeding cost of African catfish fed on semi-intensive feeds 1(SMF1)and semi-intensive feed 2(SMF2)produced on-farm and an industrially manufactured(IM)feed as a control.Two hundred fish(14.95±0.24 g)were stocked in triplicate earthen ponds and fed the three diets at 5%of the body weight for eight weeks.The final weight,specific growth rate and yield of fish fed the SMF2 diet was significantly lower than SMF1 and IM diets.However,no significant differences were revelead in final weight,specific growth rate and yield between fish fed SMF1 and IM diets.The survival rate,feed conversion ratio and protein efficiency ratio of fish did not differ among the diets.Apparent net protein utilization was significantly higher on fish fed the SMF2 and SMF1 diets than IM diet.The HSI of fish fed the IM diet was significantly higher and the livers were yellow-coloured compared to smaller and brownish/reddish livers of fish fed the SMF1 and SMF2 diets.The fish fed the IM diet had statistically lower ash content than SMF1 diet.The incidence cost of fish fed the IM diet was 35%higher,while its profit index was 31%lower than fish fed the SMF1 and SMF2 diets.Taken together,African catfish farmers can reduce feed cost up to 30%by using on-farm produced feeds when formulated properly and blended without affecting fish growth performance,survival and yield while obtaining better protein retention and healthier fish.展开更多
Objectives:Three medicinal plants:Zingiber officinale rhizome,Allium sativum bulb,and Moringa oleifera seeds,were evaluated for progeny inhibition in fish beetle,Dermestes maculatus,and incidence of bacteria and fungi...Objectives:Three medicinal plants:Zingiber officinale rhizome,Allium sativum bulb,and Moringa oleifera seeds,were evaluated for progeny inhibition in fish beetle,Dermestes maculatus,and incidence of bacteria and fungi in smoked-dried Clarias gariepinus.Materials and Methods:Cleaned C.gariepinus were separately soaked in extracts of these selected plants(50 g/1000 ml)for 60 min before smoke-drying in a mud kiln at 105℃ and later divided into lots.Sensory evaluation was conducted on uninfested fishes in lot A while fishes in lot B was artificially infested with five pairs of newly emerged adult D.maculatus for 10 days.Number of emerged larva,adult insects,and incidence of microorganisms before and following 90 days in storage after infestation were used as indices of potency of the extracts.Results:Results obtained showed that all the treated uninfested smoked-dried C.gariepinus retained high scores for taste,texture,aroma,and appearance within the first 5 weeks of storage after smoking when compared with the control.This implied that the tested extracts had no negative effect in terms of sensory attributes on the treated fish during storage and can therefore be used for fish preservation.Meanwhile,A.sativum among all the selected extracts had the least number of larvae(17.67±1.45),adult(21.00±1.53),fungi(9.00×10^(2)±0.53 sfu/ml)and bacteria counts(11.33×10^(2)±0.33 cfu/ml)following 90 days in storage after infestation.Conclusion:Allium sativum among the tested extracts proved to be most effective and could be recommended for control of D.maculatus and microorganisms in smoked C.gariepinus.展开更多
Objective:To determine the occurrence of Cryptosporidium species in catfish(Clarias gariepinus)harvested from two lakes and ponds in Zaria,Kaduna State,Nigeria.Methods:Catfish samples(n=200)from two lakes and(n=200)fr...Objective:To determine the occurrence of Cryptosporidium species in catfish(Clarias gariepinus)harvested from two lakes and ponds in Zaria,Kaduna State,Nigeria.Methods:Catfish samples(n=200)from two lakes and(n=200)from two private fish ponds were collected and their gills and gastrointestinal tract samples were analysed for Cryptosporidium oocysts using modified Ziehl-Neelsen staining technique was used,followed by microscopy.Results:Oocysts of Cryptosporidium species were found in all the sampling sites with an overall positivity rate of 49.75%.A comparison between the lakes and ponds as sampling sites revealed a statistically significant(P<0.05)higher percentage of occurrence of Cryptosporidium oocyst from the lakes(39.25%)than from the ponds(10.50%).Conclusions:These findings document for the first time the natural occurrence ofCryptosporidium sp.in catfish intended for human consumption and therefore,underlines the need for public enlightenment to guard against any possible zoonotic transmission.展开更多
文摘Establishing intraspecific breeding and hybridization programs and determining genetic variability are two important issues for aquaculture. However, interspecific hybridization to improve growth and feeding efficiency is limited. For this purpose, the embryonic and larval development of reciprocal crosses of Clarias gariepinus (Burchell, 1822) and Clarias jaensis (Boulenger, 1909) were studied under laboratory conditions. The fertilization rate varied from 63.33% to 92%, while the hatching rate ranged from 55.68% to 76% with the highest value in hybrids ♀Cg × ♂Cj. Crosses between ♀Cj × ♂Cj, ♀Cg × ♂Cj and ♀Cj × ♂Cg had embryonic stages similar to those of the pure sib ♀Cg x ♂Cg. All crosses, however, had different timing for the various embryological stages. Hatching occurred at 32 h 15 min and 38 h for ♀Cj × ♂Cj and ♀Cj × ♂Cg, and 23 h and 23 h 30 min, respectively, for ♀Cg × ♂Cg and ♀Cg × ♂Cj. However, both crosses produced viable larvae until the first external feeding. The external morphological features of the larvae were completely formed by the 10th day after hatching. The body forms of the crosses at this time were indistinguishable from the pure sib. This study thus laid the groundwork for further comparative studies on hybrid performance and characterization.
文摘Fishmeal is the most preferred source of protein in aquafeeds, but it is expensive and scarce. Hence, Achatina fulica meat meal (AFM), which is much less preferred for human consumption out of three species of African giant land snails, was tested as a fishmeal substitute for Clarias gariepinus growth. Five iso-nitrogenous and iso-calorific diets were formulated, in which AFM substituted fish meal at 0% (control or Diet A), 25% (Diet B), 50% (Diet C), 75% (Diet D) and 100% (Diet E). These dietary treatments were each replicated thrice in a completely randomized design experiment, using 36-L plastic tanks in which the fish were fed daily rations corresponding to 5% of their body weight, for 8 weeks. Water quality parameters in the tanks were monitored. Proximate analyses were conducted on the fish meal, snail meal and experimental diets before the feeding trials. Cost-benefit analysis of the different diets was performed. The crude protein content of AFM (69.18%) was significantly higher than that of fish meal (55.81%). There was no significant difference (P > 0.05) in the mean weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio and survival rate in fish fed Diet A and Diet B. The best protein efficiency ratio (0.77) was recorded in fish fed Diet B. Furthermore, the survival rate of fish increased with increased levels of AFM substitution. Water quality parameters were within a suitable range for tropical fish culture, indicating that the AFM did not pollute the water. The fish fed 25% AFM diet significantly (P Clarias gariepinus diets at a 25% substitution level. The aquaculture industry can thus exploit the availability of this feed resource.
文摘This study focused on the supplementation of four-sided spice fruit powder (Tetrapleura tetraptera) on some zootechnical performances of juveniles of Clarias gariepinus and was carried out from February 14 to July 20 at the Massoma Fish Farm of Bojongo Mbeidi located in the Littoral Region, Department of Wouri, Douala IV district. The farm benefits from a climate favorable to aquaculture activity. For this purpose, five (5) treatments were tested including T<sub>0+</sub> (imported feed), T<sub>0-</sub>, T<sub>0.3</sub>, T<sub>0.4</sub>, and T<sub>0.5</sub> respectively for the treatments with 0% supplemented food;0.3%;0.4% and 0.5% of Tetrapleura tetraptera powder. A total of 450 Clarias gariepinus fry with an initial average weight of 7 ± 1.5 g, were distributed in happas of 0.49 m<sup>2</sup> each placed in Triplicate in a completely randomized device. Four isoprotein foods with 38% crude protein were formulated to feed these fry at 7% of their biomass per day for 15 days then to their fullness until the end of the experiment. Intermediate fishing was carried out every fortnight. 75 days later, the results recorded show that the highest average survival rate (96.44% ± 3.5%) was recorded with the subjects fed feed supplemented with 0.4% T. tetraptera powder. The average weight (120.93 ± 67.20), weight gain (113.93 ± 67.20), specific growth rate (3.64 ± 0.79% g/d) and total lengths and standard (26.43 ± 1.9 and 23.66 ± 1.76) the highest were recorded with the T<sub>0+</sub> treatment (imported feed). The highest conditioning factor K (2.14 ± 0.15) was recorded with the treatment supplemented with 0.4% T. tetraptera. The lowest conversion ratio (1.28) was recorded with the treatment fed with imported blue crown food (T<sub>0+</sub>). Furthermore, the lowest production cost was recorded with the treatment supplemented with 0.4% T. tetraptera. It appears from this study that the juveniles of C. gariepinus better value the feed substituted with 0.4% of the powder of four sides (Tetrapleura tetraptera).
文摘Fishes are excellent markers of the extent of pollution from heavy metals in aquatic environments given that they are found at various levels of the food chain.This study aimed to investigate the bioaccumulation of heavy metals(Zn,Pb,Cd,As,and Hg)as well as the activity of delta-aminolevulinic acid dehydratase(δ-ALA-D)in the livers of cat fishes(Clarias gariepinus)collected from three rivers(Donga,Ibi and Gindin-Dorowa)in Taraba State,Nigeria.The concentrations of heavy metals in the liver tissues were determined using an atomic absorption spectrophotometer in accordance with the method of AOAC(2019),while theδ-ALA-D activity was assayed using the method of Sassa(1982).Results revealed that only Zn and As were present in the liver samples from the three rivers.Pb was found only in the liver from Gindin-Dorowa at the concentration of 0.0012mg/kg which is not significant(P<0.05)when compared with other locations,while Hg and Cd were absent in all the liver samples.The liver sample from Gindin-Dorowa had the highest concentration of Zn(4.2500 mg/kg),followed by Ibi(3.2067 mg/kg),and Donga having the least(2.5500 mg/kg),which were all substantially(P<0.05)different from one another.However,there was no significant(P<0.05)difference in the As composition of liver from Donga(0.0013 mg/kg),Ibi(0.0012 mg/kg)and Gindin-Dorowa(0.0010 mg/kg).The result ofδ-ALA-D activity showed that the highest enzymatic activity was found in the liver sample from Donga which has the least Zn and no Pb content,followed by Ibi sample.This validates the report that heavy metals impairδ-ALA-D activity.Nonetheless,the concentrations of all metals in fish livers from all regions do not exceed the acceptable limits set by international law,making them safe for human consumption and possibly not having a negative impact on public health.Since there is little or no industrial activity in the studied locations,these levels may be consequent to low anthropogenic inputs.The current situation should be safeguarded to prevent pollution of the river’s aquatic biota in the near future,and more appropriate steps should be made to guarantee higher fish quality and life in the rivers.
文摘Heavy metals have harmful effects on human health,and exposure to these metals has been increased by industrial and anthropogenic activities and modern industrialization.Heavy metals content of the liver tissues was determine d using Atomic Absorption Spectrophotometer method,while lipid peroxidation was carried out.Heavy metals analyzed include;lead(Pb),cadmium(Cd),zinc(Zn),Arsenic(As),and Mercury(Hg).The findings revealed that the heavy metal Zinc(Zn)has high concentrations in the muscles of the fish species,the concentration of this heavy metal Zinc is high in River Gindin Dorowa th a n in River Ibi and River Donga shows less concentration of this heavy metal though it’s above WHO permissible limits.Results revealed that only Zn and Cd were present in the muscle from the three rivers.Pb was found only in the liver from Gindin-Dorowa at the concentration of 0.017 mg/kg,which is not significant(P<0.05)when compared with other locations,while Hg and As were absent in all the muscle samples.The highest concentration of Zn was found in the muscle sample from Gindin-Dorowa(7.450 mg/kg)followed by Ibi(6.16 mg/kg)and the least being Donga(4.365 mg/kg)which are significantly(P<0.05)different from one another.However,there was no significant(P<0.05)difference among the Cd composition of muscle from Gindin-Dorowa(0.025 mg/kg),Donga(0.024 mg/kg)and Ibi(0.015 mg/kg),respectively.The TBA was found in the hepatic tissue sample from Gidin-Dorowa,which has the highest Zn,Cd and no Pb content,followed by Ibi and then the Donga sample.This suggests that there is a positive relationship between heavy metals and the effect of TBA on the hepatic tissues,justifying the fact that heavy metals affect the hepatic tissues of fish,while on the cerebral tissue.In conclusion,it revealed that there is a negative relation between heavy metals and the effect of TBA on the cerebral tissues to protect or save aquatic habitat s of fish quality and aquatic life.
文摘A twelve week experiment was conducted to compare the effects of diets with plant-based and animal-based ingredients on growth and gonad development of Clarias gariepinus. One hundred and 12 sub-adult C. gariepinus with an average weight of 205 ×5.09 g, were stocked in six concrete tanks (9 × 4 × 2 m3) containing 20 fish each. Experiment had 3 replicates and animals fed daily at 5% body weights. There was no significant difference (P 〈 0.05) in proximate compositions of the two experimental feeds and controls. Fecundity, gonad weight and gonasomatic index were higher in fish fed diet 13 than A and C. Similarly, growth indices were higher in fish fed diet B than in A and C. Histology of gonads showed a faster development of oocytes of eggs in fish fed animal-based ingredients than plant-based and combined plant and animal diets. Although there were slight differences in growth parameters and gonad development in favor of feed with animal-based ingredients, plant-based feed compared favorably in the growth and gonad development of C. gariepinus. Plant-based ingredients are recommended on the basis of affordability and availability as substitute for animal-based ingredients in C. gariepinus feed.
基金Supported by the Deanship of Scientific Research at King Saud University(No.PRG-1436-011)
文摘Specimens of Clarias gariepinus were treated with lethal(70,75,80,85,90,and 95 mg/L) and sub-lethal concentrations(8,12 and 16 mg/L) of uranyl acetate,a low-radiotoxicity uranium salt. The LC 50 value was registered as 81.45 mg/L. The protein and glycogen concentrations in liver and muscles were decreased in the fish exposed to sub-lethal concentrations. The red blood cell(RBC) and white blood cell(WBC) counts,haemoglobin(Hb) concentration and haematocrit(Hct) values were decreased. Different blood indices like mean corpuscular volume(MCV),mean corpuscular haemoglobin(MCH) and mean corpuscular haemoglobin concentration(MCHC) were negatively affected. Level of plasma glucose was elevated whereas protein was decreased. The level of calcium concentration(Ca) was declined in the blood of exposed fish whereas magnesium(Mg) remains unchanged. The activity level of glutamic-oxaloacetic transaminase(GOT) and glutamic-pyruvic transaminase(GPT) was elevated in exposed fish. These effects were more pronounced in the last period of exposure and in higher concentrations. Results of the present study indicate that uranyl acetate has adverse effects on C larias gariepinus and causes changes in the biochemical and hematological parameters of the fish.
文摘Seasonal variations in serological profiles and growth status of farmed and wild Clarias gariepinus were investigated. Serological profiles of Clarias gariepinus can be an effective tool for proper monitoring of stress induced by management practices in intensive fish culture, which may elicit devastating effect on fish. Spectrophotometry procedures were used to analyze serum parameters of Clarias gariepinus. No different seasonal patterns were observed for mean values of albumin, total protein, urea, cholesterol, glucose and alanine amino-transferase. However, aspartate amino-transferase showed different seasonal pattern. Levels of cholesterol and alanine amino-transferase were highly significant in farmed and wild fish, separately. Juvenile fish had high level of urea irrespective of season. Seasonal variations in water quality parameters were observed except for pH which had no seasonal pattern. The growth exponential shows b-values between -0.048 and 7.434 for Clarias gariepinus. Adult female and juvenile fish from the wild had the highest b-value and the least b-value, separately. In this study, b-values were higher in the wild fish than the farmed fish. The condition factor for Clarias gariepinus ranged from 0.422 to 0.698, and was observed to be high in juvenile fish. With a condition factor less than 1, fish may not be doing well, probably due to environmental stress. Some serological parameters varied according to season and environment of fish. Thus, serological profile of fish is an effective and sensitive tool to monitor fish response to stress factors in the environment.
文摘A research was conducted to assess the effects of three different drying techniques, namely open sun drying (OSD), solar dryers (SD) and solar tent dryers (STD). Data on physical characteristics such as weight, total length and standard length were recorded and proximate composition of the fish sample Clarias gariepinus (Burchell, 1822) was carried out before, during and after drying to assess changes on physical characteristics and nutrient composition at different level. After drying, the samples were subjected to storage for eight weeks. The result obtained shows that there was no significant (P 〉 0.01) difference in the drying weight of the fish samples between the direct SD and the STD. However, for the total and standard length there was significant (P 〈 0.01) difference in the drying techniques, but no significant difference (P 〉 0.05) in the drying period. There was no significant (P 〉 0.05) difference on the physical parameters, storage period, proximate composition of both direct SD and STD and the drying period, respectively. Therefore, direct SD can be substituted with the STD without altering the quality of the product.
文摘The present study is on the haematological and hepatic responses of the African catfish fingerlings Clarias gariepinus to sublethal toxicity of industrial effluents(IE)from the environment of Ologe Lagoon,Lagos,Nigeria.The fish were cultured in five concentrations of industrial effluents:0%(control),5%,15%,25%,and 35%.Trials were carried out in triplicates for twelve(12)weeks.The culture system was a static renewable bioassay and was carried out in the fisheries laboratory of the Lagos State University,Ojo-Lagos.Weekly physico-chemical parameters:Temperature(°C),pH,conductivity(ppm)and dissolved oxygen(DO in mg/L)were measured in each treatment tank.Haematological parameters:packed cell volume(PCV),red blood cells(RBC),white blood cell(WBC),neutrophil and lymphocytes etc.,and hepatological alterations were measured after 12 weeks.The physico-chemical parameters showed that the pH ranged from 7.82±0.25~8.07±0.02.DO ranged from 1.92±0.66~4.43±1.24 mg/L.The conductivity values increased with increase in concentration of I.E.While the temperature difference remained insignificant with mean value range between 26.08±2.14~26.38±2.28.The DO showed significant differences at p<0.05.Though survival was 100%during the sublethal study,haematological results showed that C.gariepinus had PCV ranging from 13.0±1.7~27.7±0.6,RBC ranged from 4.7±0.6~9.1±0.1,and neutrophil ranged from 26.7±4.6~61.0±1.0 amongst others.The highest values of these parameters were obtained in the control and lowest at 35%.While the reverse effects were observed for WBC and lymphocytes,the liver shows normal liver cells in the control(0%),but at higher toxic levels,there were:vacoulation,destruction of the hepatic parenchyma,tissue becoming eosinophilic(i.e.tending towards Carcinogenicity)and severe disruption of the hepatic cord architecture.This study therefore shows that disposal of effluents into the aquatic environment affects the health of fishes by impairing normal hepatic functions and hindering vital physiological processes if exposure continues for a long period of time(sublethal effect).
文摘A total of 190 bacterial isolates have been successfully isolated from 50 diseased African Catfish (C/arias gariepinus) namely; 70 isolates of Flavobacterium sp., 50 isolates of Aeromonas hydrophila, 30 isolates of Edwardsiella tarda and 20 isolate of each Hafnia alvei and Pseudomonas aeruginosa. This study was conducted to investigate bacteria that infected the broodstocks of African catfish cultured at Manir River, Terengganu as well as their antibiogram and Multiple Antibiotic Resistance (MAR) index. In the present study, antibiotic sensitivity and intermediary case were reported as 52.7% and 7.8%, respectively. Meanwhile, antibiotic case was recorded as 34.5%. The MAR index values obtained by each bacterial species was ranging from 0.24 to 0.52 whereas the average MAR index value was 0.39 which indicated that the cultured fish has been highly exposed to tested antibiotics.
文摘Fumonisin B<sub>1</sub> (FB<sub>1</sub>) is produced by fungus of the genus Fusarium (Fusarium verticiloides and F. proliferatum), and occurs predominantly in maize. The consumption of feed contaminated with FB<sub>1</sub> has been reported to cause deleterious effects in some fish species. This study was designed to determine the effects of dietary FB<sub>1</sub> on growth and lipids profile of Clarias gariepinus. 450 juvenile catfish were stocked into 5 groups of tanks consisting of 3 tanks per group and fed one of five diets amended with FB<sub>1</sub> (0.0 mg;10.0 mg;20.0 mg;40.0 mg and 80.0 mg FB<sub>1</sub>/kg) for 56 days. At time point’s day 7, 14, 28 and 56, five fish were sampled from each tank weighted, length measured and bled for of lipids profile determinations. Results show that there was a significant reduction (P < 0.05), in the mean body length of the fish fed diets amended with various amounts of FB<sub>1</sub> compared with those fed control diet;also, there was a significant reduction (P < 0.05) in the weight gain of fishes fed diets amended with FB<sub>1</sub> compared with the control. The specific growth rate and the feed conversion ratio at 56 days shows fish fed 0.0 mg FB<sub>1</sub>/kg had the highest specific growth rate (0.39 ± 0.14%/day) and the lowest feed conversion ratio (0.59 ± 0.01) whereas, fish fed 80.0 mg FB<sub>1</sub>/kg had the least specific growth rate (0.07% ± 0.01%/day) and the highest feed conversion ratio (1.95 ± 0.11). Dietary FB<sub>1</sub> caused significant increases (P < 0.05) in serum cholesterol, HDL-C;LDL-C;triglycerides and the sphinganine-sphingosine ratio. Dietary FB<sub>1</sub> at an inclusion rate ≥ 20 mg FB<sub>1</sub>/kg of diet produced significant reduction in weight gain and hyperlipidemia marked by hypercholesterolemia, increased blood high-density lipid cholesterol, increased blood low-density lipid cholesterol, elevated blood triglycerides and elevated sphinganine-sphingosine ratio.
文摘The present study was carried out to determine LC<sub>50</sub> of deltamethrin (DM) in the African catfish;Clarias gariepinus, investigate its effects on the biochemical parameters and the antioxidant status of various tissues, and assess the protective role of Spirulina platensis (SP) against DM induced toxicity in C. gariepinus. The fish were distributed into seven groups of 10 fish/each for 30 days as follows: Group 1, control;Group 2, orally administered saline;Group 3, oral SP (150 mg/kg b.w.);Group 4, exposed to 5.19 μg/l DM;Group 5, exposed to 5.19 μg/l DM and orally administered SP (150 mg/kg b.w.);Group 6, exposed to 12.97 μg/l DM;and Group 7, exposed to 12.97 μg/l DM and orally administered SP (150 mg/kg b.w.). Results revealed marked elevation in serum AST, ALT, ALP, creatinine, urea and uric acid. Significant decrease in serum total protein and albumin was recorded. At the same time, the level of malondialdehyde (MDA) was significantly increased in liver, kidney and gills. While, tissue level ofGSHand, SOD,CATandGSH-Px activities were reduced. Treatment with SP improved the biochemical parameters and attenuated the DM induced oxidative damage. Therefore, this study confirmed the protective role of SP as an antioxidant against the toxicity of DM in catfish.
文摘Interspecific crossing was carried out among and between two strains of Clarias gariepinus with mouth malformation and crooked-back traits to determine the source(s) of their deformities and the effects of these morphological deformities on their growth and survival. Synthetic ovaprim hormone was used for their inducement at 0.5 mL/kg of the brood stock body weight at FEDAK integrated farm, Ado-Ekiti, Nigeria. Under indoor management, highest mean survival rate was 73% recorded in the hybrid of female mouth malformed C. gariepinus x male crooked back C. gariepinus and the least mean survival rate was 70% recorded in the mouth malformed C. gariepinus parental. Under outdoor rearing crooked back C. gariepinus parental had the highest mean growth rate (11.20 grammes) while the hybrid of the cross between female crooked back C. gariepinus and male with mouth malformed C. gariepinus had the least mean growth rate (8.63 grammes). High frequency of occurrence of various morphological aberrations (0.92%) was recorded in the mouth malformed C. gariepinus parental and low frequency of occurrence (0.57%) of morphological aberrations recorded in hybrid of female crooked back C. gariepinus x male mouth malformed C. gariepinus. The reoccurrence of some of these morphological deformities in Clarias is a mystery based on their consistent occurrence even under a very good hatchery management. More research works still need to be done in this area of study of Clarias to unravel the mystery behind this morphological imbalance, because the deformities play special roles in discouraging both the farmers and the consumers of this fish.
文摘This study investigated bacteria that are associated with milt in cultured samples of African catfish-Clarias gariepinus.Male broodstocks of Clarias gariepinus were collected from private Fish Farm in Ogun State,Nigeria,while the fish’s milt was collected and analyzed for microbial load at laboratory of the Department of Microbiology,Federal University of Agriculture,Abeokuta,Ogun State.The molecular characterization of the amplicon was done at International Institute of Tropical Agriculture,Ibadan.Bio-edit was used for importing and mining nucleotide sequences into gene bank.As revealed by the results,bacterial organisms that were present in the milt of Clarias gariepinus are Aeromonas caviae,Proteus mirabilis,Serratia rubidaea,Pseudomonas mosselii,Acinetobacter soli and Klebsiella variicola.The Basic Local Alignment Search Tools revealed the percentage similarity ranging from 86%-97.04%and their accession numbers.These bacteria indicated high levels of faecal contamination in the environment.In conclusion,bacteria were found in the milt of cultured catfish and are capable of being pathogenic to humans and may increase the vertical transfer to fry during breeding and rearing stage.Therefore,fish farmers should maintain a hygiene and serene environment during breeding and culturing of catfish.
文摘This study was carried out to evaluate the effects of dietary replacement of maize with sweet potato peel in the diet of Clarias gariepinus juveniles.The levels of the SPP inclusion in the experimental diets were 0%,25%,50%,75%and 100%.All the diets were iso-nitrogenous.One hundred and fifty(150)C.gariepinus juveniles(33 g~35 g)were randomly distributed to five treatments with three replicates each and 5%of their body weight for 12 weeks.Fish carcass proximate compositions analyzed before and after feeding with the experimental diets shows that CP and EE differed significantly(p<0.05)among the experimental fish and the control,except the percentage CP of the fish fed SPP0%and SPP50%in which there was no significant difference(p>0.05).Highest MWG of 207.70±25.95 g was obtained in the fish fed SPP100%followed by 191.30±16.15 g obtained in the fish fed SPP75%.The least MWG of 149.83±16.01 g was recorded in fish fed SPP25%.The highest FCR of 3.61±0.45 g was recorded in the fish fed SPP100%.A steady decrease in FCR was observed with decreasing inclusion levels of SPP meal.However,higher FW,FL,SGR and PER were observed in the experimental fish as from 50%inclusion levels of the SPP.The cost of feed per kg was reduced and the NP and WG increased with increasing levels of SPP and the profitability was enhanced at 100%SPP inclusion level.The results revealed that C.gariepinus juvenile could tolerate up to 50%,75%and 100%inclusion levels of SPP.The best growth performance was recorded in the fish fed SPP100%,therefore,sweet potato peel can replace maize in the diet of C.gariepinus without any inauspicious effect on the growth performance and nutrient utilization.
文摘Fingerlings of African catfish,Clarias gariepinus [mean total length,(7.0±1.0) cm SD;mean weight,(3.0±0.7) g SD] were exposed to acute concentrations of amine salt of 2,4-D(0,50,200,250,350,and 400 mg/L) to determine the behavioural responses and mortality.When raised in aquaria the fish became hyperactive.The beat frequencies(opercular and tail beat frequency per minute,OBF and TBF) of the exposed fish declined with increase in the exposure duration and concentration,but the reverse was the case with percent mortality.These variables signifi cantly differed at both the exposure duration and concentration of the toxicant(P<0.05).Anova of the linear regression between variables-OBF,TBF and mortality on exposure duration indicated a strong positive relationship(P<0.001) with the entire variables except mortality and exposure duration.OBF and TBF were inversely correlated with exposure duration(r=-0.99;P<0.05).The 96 h lethal concentration was 165.36(133.29~190.51,C.L.) mg/L and the median lethal time at the highest concentration was 20.41(11.87~27.46) h.The results from this study revealed that 2,4-D was very toxic to C.gariepinus under laboratory conditions and its application should therefore,be restricted in the field.
基金funded by the World Bank through the University of Dar es Salaam,under the project“Higher Education Science and Technology(HEST)”component CIA:5.1.
文摘The culture of African sharptooth catfish(Clarias gariepinus)in most developing countries lacks suitable diets for semi-intensive production.The present study evaluated the growth performance,survival,nutrient utilization,hepatosomatic index(HSI),body composition,yield and feeding cost of African catfish fed on semi-intensive feeds 1(SMF1)and semi-intensive feed 2(SMF2)produced on-farm and an industrially manufactured(IM)feed as a control.Two hundred fish(14.95±0.24 g)were stocked in triplicate earthen ponds and fed the three diets at 5%of the body weight for eight weeks.The final weight,specific growth rate and yield of fish fed the SMF2 diet was significantly lower than SMF1 and IM diets.However,no significant differences were revelead in final weight,specific growth rate and yield between fish fed SMF1 and IM diets.The survival rate,feed conversion ratio and protein efficiency ratio of fish did not differ among the diets.Apparent net protein utilization was significantly higher on fish fed the SMF2 and SMF1 diets than IM diet.The HSI of fish fed the IM diet was significantly higher and the livers were yellow-coloured compared to smaller and brownish/reddish livers of fish fed the SMF1 and SMF2 diets.The fish fed the IM diet had statistically lower ash content than SMF1 diet.The incidence cost of fish fed the IM diet was 35%higher,while its profit index was 31%lower than fish fed the SMF1 and SMF2 diets.Taken together,African catfish farmers can reduce feed cost up to 30%by using on-farm produced feeds when formulated properly and blended without affecting fish growth performance,survival and yield while obtaining better protein retention and healthier fish.
文摘Objectives:Three medicinal plants:Zingiber officinale rhizome,Allium sativum bulb,and Moringa oleifera seeds,were evaluated for progeny inhibition in fish beetle,Dermestes maculatus,and incidence of bacteria and fungi in smoked-dried Clarias gariepinus.Materials and Methods:Cleaned C.gariepinus were separately soaked in extracts of these selected plants(50 g/1000 ml)for 60 min before smoke-drying in a mud kiln at 105℃ and later divided into lots.Sensory evaluation was conducted on uninfested fishes in lot A while fishes in lot B was artificially infested with five pairs of newly emerged adult D.maculatus for 10 days.Number of emerged larva,adult insects,and incidence of microorganisms before and following 90 days in storage after infestation were used as indices of potency of the extracts.Results:Results obtained showed that all the treated uninfested smoked-dried C.gariepinus retained high scores for taste,texture,aroma,and appearance within the first 5 weeks of storage after smoking when compared with the control.This implied that the tested extracts had no negative effect in terms of sensory attributes on the treated fish during storage and can therefore be used for fish preservation.Meanwhile,A.sativum among all the selected extracts had the least number of larvae(17.67±1.45),adult(21.00±1.53),fungi(9.00×10^(2)±0.53 sfu/ml)and bacteria counts(11.33×10^(2)±0.33 cfu/ml)following 90 days in storage after infestation.Conclusion:Allium sativum among the tested extracts proved to be most effective and could be recommended for control of D.maculatus and microorganisms in smoked C.gariepinus.
基金Supported by Ahmadu Bello University,Zaria,Nigeria with Grant No.ABU/P16945.
文摘Objective:To determine the occurrence of Cryptosporidium species in catfish(Clarias gariepinus)harvested from two lakes and ponds in Zaria,Kaduna State,Nigeria.Methods:Catfish samples(n=200)from two lakes and(n=200)from two private fish ponds were collected and their gills and gastrointestinal tract samples were analysed for Cryptosporidium oocysts using modified Ziehl-Neelsen staining technique was used,followed by microscopy.Results:Oocysts of Cryptosporidium species were found in all the sampling sites with an overall positivity rate of 49.75%.A comparison between the lakes and ponds as sampling sites revealed a statistically significant(P<0.05)higher percentage of occurrence of Cryptosporidium oocyst from the lakes(39.25%)than from the ponds(10.50%).Conclusions:These findings document for the first time the natural occurrence ofCryptosporidium sp.in catfish intended for human consumption and therefore,underlines the need for public enlightenment to guard against any possible zoonotic transmission.