Catfish Clarias Lazera Research Articles

Heavy metals contamination in the catfish Clarias lazera inhabiting Alkhalil lakes, Almadinah Almonawara, Saudi Arabia.

Monitoring heavy metals contamination in aquatic organisms especially fishes is of paramount consideration as the fishes accumulate metals in their tissues and pose a risk to human health as a result of their daily consumption. The catfish Clarias lazera was collected from Alkhalil sewage lakes (north of Almadina Almonwarrah) and the gills, muscles, liver and kidneys were removed, dried and acid digested for the determination of 8 different heavy metals using ICP-MS. Results showed that Cu was the highest accumulated element in all analyzed fish organs. The study revealed that gills, kidneys, and liver accumulate greater amounts of heavy metals fishes than the muscle tissues. The current study concluded that edible portion (muscles) of C. lazera is currently safe for human consumption but monitoring studies should be continued to record any changes in the accumulation rate.

The Determination of Shelf Life and Some Nutritional Components of Catfish (Clarias lazera) After Hot Smoking

Changes in the quality of hot smoked catfish Clarias lazera were determined just after smoking and during refrigerated storage (4°C±1). Chemical, sensory, and microbiological analyses of the samples were carried out during the storage to test their shelf life and quality. Significant (p<0.05) differences were found in the chemical composition of fresh and smoked Clarias lazera. The process reduced moisture content and pH and increased crude protein, crude fat, and ash. During storage at 4°C±1 the percentage of total protein, the ash contents, and the pH increased significantly (p<0.05), whereas the moisture contents and the crude fat significantly (p<0.05) decreased. Microbiological analysis results demonstrated that the smoking techniques reduced the microbial content of the fish; total viable counts (TVC) of bacteria in fresh fish used as raw material had a total microbial load reaching 19.6×106 cfu/g. After smoking, TVC recorded 3.2×106 cfu/g and pathogenic micro-organisms Escherichia coli were counted at about 3.8×106 cfu/g, therefore Salmonella spp and Staphylococcus aureus were not detected in the fish samples. No yeast or mould was detected in the fresh and smoked samples. During storage at 4°C the weekly change in microbial loads of smoked C. lazera was increased, micro-organisms E. coli and Salmonella spp were observed, while Staphylococcus aureus was not detected. Sensory evaluation of smoked fish samples showed that the quality of the smoked fish might still be acceptable 28 days after smoking under refrigerator conditions.

Effects of probiotic as food additives on Nile catfish Clarias lazera.

Effects of probiotic as food additives on Nile catfish Clarias lazera.

Changes in the Intestinal Bacterial Profile and Serum Biochemical Parameters of Nile Catfish Clarias Lazera after Feeding with Probiotic

Changes in the Intestinal Bacterial Profile and Serum Biochemical Parameters of Nile Catfish Clarias Lazera after Feeding with Probiotic

Changes in the intestinal bacterial profile and serum biochemical parameters of Nile Catfish Clarias lazera after feeding with probiotic.

In this study, the experimental set-up was based on fed Clarias lazera commercial diet with probiotic for 45 days either 1 time/week (W1) all over the experiment or 3 times/week for the 1 st two weeks then 1 time/week till the end of the experiment (W3). Bacteriological and biochemical examinations were done on intestinal tract and serum respectively. Bacteriological investigation revealed the presence of Escherichia coli and Klebsiella spp. in all groups and Pseudomonas aeruginosa failed to be isolated from W1 and W3. Bacterial isolates proved to be pathogenic for mice, positive for Congo red binding activity and toxigenic in infant mice. The intestinal total aerobic bacterial count; Enterobactereacae count and coliform count in males and females of both W1 and W3 fish groups were significantly lower than the respective values in control group. Significant low values were detected in W3 group compared to W1 group. Significant sex differences in the three counts were detected in the three groups of fish except the Enterobactereacae count in W3 group. Concentrations of serum ammonia and urea were significantly decreased in both treated groups compared to the control group. Both serum items were significantly lower in W3 group than that in W1 group. Significant sex difference was recorded in serum creatinine of the three groups (females lower than males). The activities of serum alkaline phosphatase; alanine aminotransferase and aspartate aminotransferase enzymes significantly differed according to sex with a general trend that these enzymes were significantly higher in W3 group than that of W1 group. Serum total protein, albumin, globulin and A/G ratio in fish of W1 group were more affected by probiotic administration than that in W3 group. These serum protein items in all groups were significantly affected by sex. Serum IgM level in both sexes of W1 group was significantly higher than that in both control and W3 groups. A correlation analysis was conducted to determine the strength of the association between serum biochemical parameters and viable total bacterial count; Enterobactereacae and coliform counts in the guts of fish. Male fish showed similarity of the correlations analysis between the three bacterial counts and the different serum biochemical parameters, while female fish detected some variations according to the type of bacterial count.

Heavy Metal Concentrations in some Biotic and Abiotic Components of the Olezoa Wetland Complex (Yaoundé-Cameroon, West Africa)

Abstract Concentrations of cadmium (Cd), copper (Cu), zinc (Zn) and lead (Pb) in water, sediments, fish organs and plants from two ponds of the Olezoa wetland complex were analyzed. Plants investigated were Cyperus papyrus, Enydra fluctuans, Ipomoea aquatica and Echinocloa pyramidalis. The fish species studied was the walking catfish Clarias lazera and the heavy metal concentrations were measured in the digestive tract, gills, flesh and liver. Average concentrations in water were 6 x 10-2 ppm for Cd, 14.53 ppm for Cu, 2.88 ppm for Zn and 17.69 ppm for Pb. These values were low compared to those recorded in the sediments, plants and fish organs. Results revealed an increase of heavy metal concentrations from water to plants and fish organs, with magnification factors ranging from 580 to 5700 and from 577 to 8173, respectively. In the sediments and the floating mat of the eutrophic fish ponds, these factors ranged from 491 to 1065 and 624 to 758, respectively. In the fish organs, particularly, the following accumulation gradients were foreseen: gills Ŵ flesh Ŵ digestive tract Ŵ liver for Cd and Pb; and flesh Ŵ gills Ŵ digestive tract Ŵ liver for Cu and Zn. The four plants studied appeared to be good candidates for phytoremediation of water metal pollution. The quantity of heavy metals in this wetland complex is considerable and will constitute a potential hazard for biota.

Physiological and Histological Studies on the Effect of Lupine Seeds on the Fish, Clarias lazera Treated with Glucose and Alloxan

Catfish Clarias lazera (C. gariepinus) was used to study the effect of aqueous lupine seed suspension (ALSS) (Lupinus termis) on normal or treated fish with alloxan or glucose after 5, 24 and 4 days. Injection of alloxan was followed by hyperglycemia, hyperlipidemia, hypercholesterolemia, and rise in serum levels of total free amino acids (TFAA), AST and ALT compared with control. In liver, alloxan significantly reduced glycogen and total lipid/triglyceride ratio, while it accumulated lipids and elevated AST and ALT compared with control values. Also, alloxan induced lipid and glycogen depletion in red and white muscles. However, all disturbances in these parameters were restored to normal after ALSS administration. In glucose-treated fish, ALSS significantly increased glycogen content in white and red muscles. Also, glucose plus ALSS treatment increased red muscle contents of TFAA, total lipids and triglycerides. ALSS treatment did not induce any histological changes in liver. Both glucose and alloxan treatments induced damage effect on liver besides, ultrastructural alterations in the liver were observed. Furthermore, histochemical observation revealed a high liver glycogen following repeated glucose doses, while liver glycogen was depleted in response to alloxan injection. Alloxan induced necrosis, mitochondrial damage, few ribosomes on the surface of rough endoplasmic reticulum (rER) with disrupted cisternae in liver cells. Repeated doses of glucose injection for 4 days led to necrosis, clumps of rarefied cytoplasm as well as some cisternae of rER appeared to be devoid of ribosomes. However, most histological and ultrastructural changes in the liver were restored to normal after ALSS administration. In conclusion, it could be suggested that the lupine seeds have a protecting effect against both metabolic disturbances and damaging effect on liver cells in response to repeated doses of glucose or to alloxan treatments.

THE PROTECTIVE EFFECT OF ASCORBIC ACID ON THE HISTOLOGICAL CHANGES CAUSED BY THE HERBICIDE (RONSTAR) IN NILOTIC CATFISH : CLARIAS LAZERA ( C GARIEPINUS)

Ronstar was applied at concentration s of 2.0,5.75 and 9.5 mg/L. Histological alterations were determined in liver and kidney of the catfish Clarias lazera. The histological changes in liver of catfish C lazera intoxicated with different doses of Ronstar, included dilation of the blood veins and sinusoids, vacuolation in the cytoplasm and pyknosis in the nuclei of the hepatocytes, haemorrhage is also noticed in the veins and sinusoids. The phagocytic Kupffer and endothelial cells are also abundant as an immunoresponse reaction. The vacuolation is the most frequent histological alteration observed at all tested doses of Ronstar. Ascorbic acid (lOmg/lkg of body *weight)was reported to reduce some of the histological damage occurred in the liver tissue. It alleviated the rate ofpyknosisand vacuolationThe rate of ascorbic acid healing effect depends on the Ronstar tested dose. Ronstar induced different histological alterations in the kidney of the catfish C lazera The glomeruli became expanded and their capillaries were extended, the subcapsular space enlarged or disappeared. The haemopoietic tissue exhibited some vaculation and the renal tubules were swollen or degenerated. Some of them took an irregular shape .The expanded glomeruli with extended capillaries

Myxosporean parasites of the catfish, Clarias lazera (Valenciennes)

Five new species of myxosporean were found in the catfish Clarias lazera (Val.) in Israel. These species are described as: Henneguya laterocapsulata n. sp. (cyst-like trophozoites in the skin), H. suprabranchiae n. sp. (cyst-like trophozoites in the suprabranchial respiratory organs), Sphaerospora inaequalis n. sp. (spores in the lumen of the kidney tubules), Myxidium clariae n. sp. (spores in the gall bladder) and Myxobolus heterofilamentatus n. sp. (spores in the kidney, spleen, liver, suprabranchial respiratory organ, gills, heart and urinary bladder). Their taxonomic affinities to other species are discussed. ac]19860407

Effect of dietary protein level on caged Catfish Clarias lazera, raised under different stocking rates

Effect of dietary protein level on caged Catfish Clarias lazera, raised under different stocking rates

Aspects of the biology of the catfish Clarias lazera (Cuv. & Val.) related to its economic cultivation

Aspects of the biology of the catfish Clarias lazera (Cuv. & Val.) related to its economic cultivation

Effects of 11-desoxycorticosterone-acetate and carp pituitary suspension on follicle maturation in the ovaries of the African catfish, Clarias lazera (C. & V.)

Administration of 11-desoxycorticosterone-acetate (DOCA) or carp pituitary suspension (CPS) to broodfish of the African catfish Clarias lazera leads to maturation of postvitellogenic oocytes. CPS also causes ovulation, but not oviposition. After DOCA injection, ovulation and oviposition of mature oocytes can be evoked mechanically by stripping. Only postvitellogenic oocytes measuring more than 1 mm in diameter undergo maturation, and only eggs that have passed through all stages of maturation develop into normal fry upon fertilization. The time required for postvitellogenic oocytes to give the highest hatching percentages and the lowest fractions of deformed fry is 11–14 h for CPS and about 14 h for DOCA at 25°C. By producing an eosinophilic material, the granulosa cells of atretic follicles and postovulatory follicles contribute to the disintegration and clearance of degenerating oocytes and over-ripe eggs.

Respiratory behaviour, oxygen consumption and relative dependence on aerial respiration in the African lungfish (Protopterus annectens, owen) and an air-breathing teleost (Clarias lazera, C.).

The relative dependence on branchial and pulmonary organs was studied in the African lungfish P. annectens and in the catfish Clarias lazera. The frequency of pulmonary ventilation varied, in the normal state, with the activity and age of the fish and followed a circadian rhythm. Small specimens of both species exhibited a higher branchial ventilatory rate than older specimens and depended largely on aquatic O2 uptake (over 85% and 90% in Clarias and Protopterus respectively). The dependence on aerial respiration appeared to develop gradually with age in Clarias but occurred over a limited age-range (200–300 g) in Protopterus. In mature fish (over 400 g), pulmonary respiration constituted 50–60% of the total in Clarias and 80–85% in Protopterus. Partitioning of O2 uptake between air and water depended on the O2 content of the water and that of O2 and CO2 in the pulmonary organs. Protopterus and Clarias surfaced for air when the O2 content of the respiratory organs was reduced to 90% and 85% (of that immediately following an air-breath) respectively. An increase in the pulmonary O2 content lengthened the apnoeic period and reduced pulmonary respiration more markedly in Protopterus than in Clarias whereas an increase of that of CO2 produced the reverse effects.

Distribution and tissue retention of cesium-134 and cobalt-6o in the nile catfish clarias lazera (cuv. & val.)

The Nile catfish, Clarias lazera was found to concentrate radioactive cesium-134 and cobalt-6o from the aquatic environment. For cesium-134 the rate of uptake increased by increase of exposure time, while for cobalt-6o maximum uptake occurred after one day of exposure. The corresponding concentration factors at maximum uptake levels were 0.37 and 0.36 for cesium and cobalt respectively. The internal distribution of these radionuclides in the different tissues and organs of the fish due to uptake from the aquatic environment followed the decreasing order: For 134Cs: muscle, bone, gills, stomach, kidneys, intestine and liver. For 60Co: bone, muscle, gills, intestine, kidneys, stomach and liver. The internal distribution due to ingestion of these radionuclides followed nearly the same order as was found in case of uptake from the aquatic environment.