Aspects of the pathology of Lamproglena clariae (Copepoda: Lernaeidae) on gills of Clarias gariepinus from the Vaal River system,South Africa     

《African Zoology》2013,48(2):169-178

Lamproglena clariae attaches to gill filaments of Clarias gariepinus, penetrates the gill tissue and consumes blood. Hence, the purpose of this study was to investigate the mechanical damage caused by this parasite on gill filaments of the host. Infestation intensity and haematocrit values of fish blood were determined and correlated. Fish were killed, gills dissected out and observed with a dissection microscope. Gill filaments with adult females in situ were fixed in a solution of alcohol, formaldehyde and acetic acid and preserved in 70% ethanol. Fixed specimens were studied by histological examination following staining with Heidenhein’s azan solution. Gross morphology revealed varying degrees of swelling of gill filaments near the attached specimens of L. clariae. Epithelial hyperplasia, resulting in fusion of gill lamellae and necrosis of the host tissue in the vicinity of the parasite were revealed through histological examination. No correlation was evident between the infestation intensity and fish haematocrit values. Although results showed that L. clariae causes localized infestation, high intensity of infestation may be detrimental to the fish. Hyperplasia of epithelial tissue resulting in fusion of lamellae would result in restriction of air passages and thus hinder the process of respiration of the host.  相似文献   

Balance trials with African catfish Clarias gariepinus fed phytase-treated soybean meal-based diets     

J.H. VAN WEERD  KHALAF  AARTSEN  & TIJSSEN 《Aquaculture Nutrition》1999,5(2):135-142

Balance trials were conducted with African catfish Clarias gariepinus to assess the effect of phytase treatment of soybean meal-based diets on growth, feed utilization and nutrient budgets. Isocaloric (20–22 kJ g⁻¹) and isonitrogenous (47–50% protein) diets were tested. In a first experiment the control diet (58% fish meal and 18% soybean meal) was compared with two diets containing 6% fish meal and 69% soybean meal, and two diets containing 29% fish meal and 41% soybean meal. One of each of these two diets had been pretreated with phytase (1000 units per kg dry diet). In the second experiment, the control diet (6% fish meal and 69% soybean meal, pretreated with 1000 units phytase kg⁻¹ dry diet) was compared with four diets that were similar in composition but supplemented with increasing amounts of phytase (15, 380, 750, 1000 units kg⁻¹ dry diet). Replacement of fish meal by soybean meal in the first experiment led to a depression in growth rate and feed utilization parameters. Results of both experiments clearly indicated a positive effect of phytase treatment, particularly on phosphorus digestibility and retention, and consequently the phosphorus conversion efficiency and the phosphorus budget. No differences in these parameters were found between addition of equal amounts of phytase by pretreatment or supplementation.  相似文献   

An evaluation of radiography in studies of gastric evacuation in African catfish fingerlings     

Mostafa A.R. Hossain  Graham S. Haylor  Malcolm C.M. Beveridge 《Aquaculture International》1998,6(5):379-385

Groups of 3–4 g African catfish (Clarias gariepinus Burchell, 1822; Family: Clariidae) were offered feeds of two types in three combinations: feed with a radio-opaque marker (Ballotini, 0.16–0.25 mm), feed without marker and a 50:50 mixture of marked and unmarked feeds. Stomach contents were estimated by X-radiography and gastrectomy just after meal termination and at different time intervals (4, 8, 12, 16, 20, 24, 32, 40 and 48 h). There were no significant differences among treatment groups confirming that there was no effect of the marker on feed preference and evacuation rate. Estimations of gastric evacuation rate calculated from gastrectomy and by X-ray sampling were not significantly different. Therefore, gastric evacuation rate of African catfish can be accurately estimated by feeding marked feed and then using X-radiography to monitor feed passage through the gut. © Rapid Science Ltd. 1998  相似文献   

Quantitative estimation of maximum daily feed intake of African catfish, Clarias gariepinus Burchell, fingerlings using radiography     

M.A.R. Hossain  G.S. Haylor  & M.C.M. Beveridge 《Aquaculture Nutrition》1998,4(3):175-182

Gastric evacuation rate, return of appetite and satiation time of African catfish, Clarias gariepinus Burchell 1822, fingerlings, fed with a commercial pelleted feed, were determined under experimental conditions. The gastric evacuation rate was described by an exponential function, which was found to be inversely related to the rate of ingestion (return of appetite). Satiation time remained constant over the experimental period. Based on these data the authors estimated maximum daily ration in relation to feeding schedule and feeding frequency for C. gariepinus fingerlings.  相似文献   

Phosphorus utilization in juvenile Clarias gariepinus fed phytase-supplemented diets based on soya bean (oil-extracted) and full-fat (roasted): A comparison     

Benjamin U. Akpoilih  Bamidele O. Omitoyin  Emmanuel K. Ajani 《Journal Of Applied Aquaculture》2017,29(2):126-151

The effect of microbial phytase on phosphorus utilization in juvenile Clarias gariepinus (initial fish body weight 11.55 ± 0.2 g) was tested on two different diets based on oil-extracted soya bean (Experiment 1) and roasted soya bean meal (Experiment 2) using a 5 × 5 experimental design for 84 days. The basal isonitrogenous and isocaloric diets for oil-extracted and roasted soya bean were formulated to replace fish meal at 25% (S1E), 50% (S2E), 75% (S3E), 100% (S4E); and 25% (S1), 50% (S2), 75% (S3), 100% (S4), respectively. Each treatment was replicated four times. Microbial phytase was supplemented in each replicate at 250 FTU/g (P1), 500 FTU/g (P2), 750 FTU/g (P3), and 1,000 FTU/g (P4). Basal controls, which included a fish meal-based diet (S0), were not supplemented with phytase (P0). The result in Experiment 1 showed that there was a significant increase in whole-body protein and reduction in fat with phytase compared to a diet without phytase (P < 0.05). Serum total protein declined significantly with phytase supplementation (P < 0.05). Serum phosphorus and glucose were higher with phytase supplementation compared to control (P < 0.05). Bone minerals declined significantly with increasing level of soya bean compared to fish meal diet (P < 0.05). In Experiment 2, serum phosphorus was improved with phytase compared to control with no phytase (P > 0.05). A significant reduction in whole-body protein and increase in fat was observed for fish fed phytase diets compared to diets with no phytase, regardless of soya bean level (P < 0.05); however, ash content was improved with phytase (250 FTU/g) compared to control (P < 0.05). Phytase supplementation improved bone phosphorus (250 FTU/g), calcium (250 FTU/g), magnesium (250–500 FTU/g), and zinc (250–1,000 FTU/g) compared to control (P < 0.05). In conclusion, the research has demonstrated that improved bone phosphorus (P) and growth could be achieved with the supplementation of dietary phytase.  相似文献   

Effects of the probiotic, Lactobacillus acidophilus, on the growth performance, haematology parameters and immunoglobulin concentration in African Catfish (Clarias gariepinus, Burchell 1822) fingerling     

Mohammed Abdullah Al-Dohail  Roshada Hashim  & Mohammed Aliyu-Paiko 《Aquaculture Research》2009,40(14):1642-1652

This experiment was carried out to evaluate the effects of the probiotic, Lactobacillus acidophilus , on the growth performance, haematology parameters and immunoglobulin concentration in African catfish Clarias gariepinus fingerling. Two experimental diets were formulated to contain 35 g kg⁻¹ crude protein and 10 g kg⁻¹ lipids accordingly and fed three times daily for 12 weeks to 25 C. gariepinus fingerlings per fibreglass tank in 12 replicates each. The control diet was prepared with no probiotic supplementation whereas the second diet was prepared supplemented with a probiotic, L. acidophilus , containing about 3.01 × 10⁷ colonies/g of diet. The results show that growth performance [specific growth rate (SGR) and relative growth rate (RGR)], nutrient utilization [protein efficiency ratio (PER) and feed conversion ratio (FCR)] and survival were significantly ( P <0.05) higher in fish maintained on the probiotic-supplemented diet compared with those on the control diet. Haematology parameters (packed cell volume, haemoglobin, erythrocyte sedimentation rate, red blood cell and white blood cell, total serum protein, Ca²⁺, Mg²⁺, Cl⁻, glucose and cholesterol) and total immunoglobulin concentrations were also significantly better in fish fed the probiotic-supplemented diet than in the control. Although the water quality parameters monitored were better in the fish fed the probiotic-supplemented diet than in the control, the parameters were not significantly different ( P >0.05). From the results of this experiment, we conclude that L. acidophilus can be used as a probiotic agent in African catfish culture, to enhance fish health, survival and better feed efficiency and growth performance.  相似文献   

Expression of four muscle proteins at different growth stages of Günther's walking catfish Clarias macrocephalus     

Supawadee Poompuang  Dutrudi Panprommin 《Aquaculture Research》2010,41(9):e144-e154

The complete cDNA sequences of four contractile muscle genes of walking catfish Clarias macrocephalus were characterized by assembling partial EST sequences from a skeletal muscle cDNA library. The four genes were parvalbumin 4 (PV4) (670 bp), troponin C (TnC) (1065 bp), troponin I (TnI) (843 bp) and myosin light chain 3 (MLC3) (953 bp), leading to deduced amino acid sequences of 109, 160, 176 and 150 residues respectively. During the larval stage, TnC mRNA showed the highest levels of expression with a 1.4‐fold increase from day 1 to day 30 post hatch. At 90 days, the relative expression levels of PV4, TnC and MLC3 were the highest, with similar proportions in the skeletal muscle, corresponding to the highest relative growth rate of walking catfish. Expression of the three calcium‐binding proteins remained high in 6‐month‐old fish, with higher levels of PV4. The different proportions of muscle proteins expressed suggested the significance of their contributions to fish growth and appeared to be correlated with the functional properties of muscle cells, which were observed from changes in the swimming activity of the fish.  相似文献   

Fish proteins not lipids are the major nutrients limiting the use of vegetable ingredients in catfish nutrition          下载免费PDF全文

A. Sourabié  S.N.M. Mandiki  F. Geay  T. Sene  A. Toguyeni  P. Kestemont 《Aquaculture Nutrition》2018,24(5):1393-1405

The objective of this study was to determine the major nutrient limiting growth and lipid metabolism in African catfish fed diets composed of vegetable ingredients. Four diets were formulated from contrasted meal (fish meal: FM; vegetable meal: VM) and oil (fish oil: FO; vegetable oil: VO) sources. Replacement of FO by VO did not affect specific growth rate (SGR) and feed efficiency, whereas lower values were recorded in the case of FM replacement. LC‐PUFAs muscle contents were higher in fish fed control FMFO diet than in fish fed vegetable ingredients. However, the decrease in docosahexaenoic acid (DHA) concentration in FMVO group was limited compared to VM groups despite the same low DHA level in those three diets. These results may suggest an activation of LC‐PUFA biosynthesis from PUFA precursors brought with vegetable oils in FMVO group. This hypothesize is reinforced by the significant stimulation of elovl5 gene expression in liver and intestine from fish fed FMVO. Therefore, this study demonstrated that African catfish is able to bioconvert LC‐PUFAs at a significant biological level when FO is replaced by VO whereas the use of plant proteins has strong detrimental effects on growth performances.  相似文献   

Effects of Pawpaw Seed Powder as an Additive on Growth of Catfish Fingerlings Reared in an Indoor Tanks     

《东北农业大学学报(英文版)》2016,(4):55-60

Since the demand of African Catfish (Clarias gariepinus) is on increase there is need to increase its production so as to meet the protein requirement of the populace. An investigation was conducted for six weeks feeding trial to determine the performance of African catfish (Clarias gariepinus) fingerlings feed diets containing varying replacement level of fish meal with pawpaw seed powder meal (Carica papaya). Fingerlings of Clarias gariepinus were subjected to five different dietary treatments with varying levels of pawpaw seed powder meal. The diets I-V contained 0, 20%, 40%, 60% and 80% replacement levels, respectively. The experiment was carried out in an 80 litres circular plastic bowls, the treatments were in triplicate. Each bowl contained 12 fingerlings. Feeding was done at 3% body weight per day and fishes were weighed every week. Growth parameters such as specific growth rate (SGR), weight gained (WG), food conversion ratio (FCR), protein efficiency ratio (PER) and mortality were determined. Therefore, it could be concluded that fish meal could be replaced up to 80% with pawpaw seed powder meal in the diet of Clarias gariepinus fingerlings to encourage growth, while at 40% pawpaw seed powder meal inclusion mortality was reduced.  相似文献   

Food consumption and digestive enzyme activity of Clarias batrachus exposed to various temperatures     

T. Ahmad  S.P. Singh  B.K. Khangembam  J.G. Sharma  R. Chakrabarti 《Aquaculture Nutrition》2014,20(3):265-272

The effect of temperature on the food consumption rate and the digestive enzyme activities of Clarias batrachus (80.60 ± 5.34 g) were evaluated. Fish were exposed to six different temperatures of 10, 15, 20, 25, 30 and 35 °C following an acclimation temperature of 25 °C. The rate of temperature change was 2 °C day^?1. Highest food consumption was recorded at 25 °C. It gradually reduced with decreasing water temperature. Food consumption rate was significantly (P < 0.05) lower at 10 °C compared with other treatments. Hence, 46.67, 8.20–23.58 and 1.02–6.15% reduced food consumptions were recorded in groups exposed at 10, 15 and 20 °C temperatures, respectively, compared with the 25 °C. The consumption rate was not affected in fish exposed at 30 and 35 °C. Total protease, trypsin and chymotrypsin activities were significantly (P < 0.05) higher in fish exposed at 25 °C compared with others. Lipase activity was significantly (P < 0.05) higher in fish exposed at 30 °C compared with others. Lowest enzyme activities were recorded at 10 °C. Water temperature below 25 °C affected the food consumption and digestive enzyme activities in fish that served as indicators of stress in fish.  相似文献