Effect of mercury and methyl parathion on the ovaries of Labeo rohita (Ham)

Adult pre-spawning fish Labeo rohita were sublethally (1/5th 96h LC50) exposed to mercuric chloride and metacid-50 (methyl parathion). Accumulation of mercury and methyl parathion was studied and it was found that pre-spawning ovary appears as a potent organ for deposition of both the pollutants. RNA/DNA ratio of the control and treated fish were studied. It was found that the signifcant decrease in RNA/DNA ratio occurs after 9 and 30 days of exposure for mercury and 30 days for methyl parathion. Fluorescence microscopic studies by acridine orange staining method were also performed to show how much it is related to biochemical alterations. In some cases loss of metachromasia is correlated with the fall in RNA/DNA ratio. Some other abnormalities like fall in stage II: stage I oocyte ratio and necrosis was also observed.     

Zinc induced histological changes in brain and liver of Labeo rohita (Ham.)

Labeo rohita fingerlings were exposed to zinc metal toxicity (5 and 10 ppm) for duration of 5 and 15 days. The histological changes were studied in brain and liver of the treated fish. The brain tissues showed enlarged pyramidal cells with extensive vacoulation while severe necrosis, haemorrhage and degeneration of hepatocytes were witnessed in the liver tissues.     

Feed utilisation and growth in juveniles of Labeo rohita under the stress of endosulfan

The objective of the present study is to evaluate the nutrition and growth of Labeo rohita under the sublethal stress of endosulfan. It has been observed that the feed utilisation and growth were inferior in the fish under the stress of the toxicant. It was more so in the test fish under the influence of higher sublethal concentration. The food conversion ratio was higher suggesting that the nutrients are wasted.     

Influence of sublethal ammonia toxicity on some physiological parameters of Labeo rohita (Hamilton-Buchanan) fingerlings

Fingerlings of Labeo rohita subjected to sublethal unionized ammonia (0.132mg/l) for 30 days exhibited significant changes. Increase in haemoglobin, haematocrit, plasma cortisol, plasma glucose, plasma cholesterol and plasma lactic acid levels whereas, decrease in plasma chloride, liver and muscle glycogen, hepatosomatic index and DNA/RNA ratio of muscles with stable plasma protein was observed. Metabolic recovery was not observed within 30 days of exposure.     

Seasonal ovarian cycle in freshwater teleost, Labeo rohita (Ham.) in Tarai region of Uttaranchal

Seasonal ovarian cycle, based on histophysiological changes, and correlative variations in liver were studied in an Indian major carp, Labeo rohita reared in captivity under ambient environmental conditions in Tarai region of Uttaranchal. The oocyte features used for marking ovarian cycle included nuclear-ooplasmic ratio, yolk vesicle incorporation into ooplasm, number and size of nucleolus and differentiation of follicular layer. Based on these features the ovarian cycle in L. rohita was divided into five phases i.e. resting, preparatory, pre-spawning, spawning and post-spawning/regression. The resting and preparatory phases were characterized by the dominating presence of chromatin-nucleolar and yolk-vesicle stage oocytes. The pre-spawning phase ovary was marked by the prevalence of yolk globule stage oocytes having cortical alveoli and differentiating follicular wall. The oocytes containing densely packed yolk-granules and large masses of yolk vesicles and also exhibiting germinal vesicle movement (GVM) signified the ovary of spawning phase. The ovary in regression phase contained pre-ovulatory atretic oocytes and significant number of oogonia. The histophysiological changes in liver showing augmented biosynthetic activity during preparatory and pre-spawning phases seemed well correlated with the gonadal development. The increasing water temperature and day-length apparently was favourable for the gonadal development in L. rohita.     

Impact of water quality on the stress physiology of cultured Labeo rohita (Hamilton-Buchanan)

Investigation was conducted for 12 months in two water bodies, S1 with optimum water quality and S2 receiving sewage water. The water quality parameters were assessed in relation to the impact on the stress sensitive physiological parameters of fish Labeo rohita. While optimum levels of transparency, dissolved oxygen, unionised ammonia, alkalinity and hardness in S1 reflected in minimum variation of the physiological parameters of L. rohita but suboptimal levels of DO (nil-18.0 mg/l) and CO2 (nil-16.0 mg/l) observed diurnally and unionised ammonia (0.11-0.42 mg/l) found throughout the experimental period, resulted in significant variation in plasma cortisol (90.0-377.0 ng/ml), cholesterol (89.6-285.0 mg/dl) and condition factor (0.7-1.3) in L. rohita. The results are of significance for fish aquatic habitat management.     

Effect of cypermethrin on breeding performances of a freshwater fish,Labeo rohita (Hamilton)

Abstract

Concentrations of the related elements calcium, strontium, barium, and lead were determined in soil extract, consumer stomach contents, and consumers in lead polluted and unpolluted areas. Discrimination against the nonessential metals relative to the nutritious metal calcium, as the metals were transferred through a trophic pathway was determined. Discrimination of metals varied systematically as a function of degree of nonessential element similarity to calcium. The existence of systematic trends of discrimination may facilitate the assessment of natural levels of some toxic elements (e.g. lead) in organisms.     

A preliminary report on effect of pulsed magnetic fields on fresh water fish (Labeo rohita) chromosomes

Marine-life scientists around the world are already carrying out investigative trials to obtain higher yields under in-captive breeding conditions, on both edible varieties and ornamental fishes with optimal inputs. However, for such trials to succeed there is a need for genetic improvement. The idea that fish production can be enhanced by genetic manipulation is gaining acceptance, as there is a strong possibility that qualitative improvement of economically important traits can be achieved by identifying and utilizing more effective genotypes. In the present communication a tentative plan for genetic manipulation of fresh water fish using controlled, pulsed magnetic fields, is being discussed. Chromosome preparations of Labeo rohita were made using Colchicine-Methanol-Acetic acid air drying technique, using tissue from gills. The fish were exposed to Pulsed Magnetic Field (PMF)with intensity 0.2 Gauss, pulsing at 50 Hz frequency (sine wave) for 6 hours / day for a total period of 30 days inside specially designed magnetic field enclosures. The karyological investigations revealed no distinct difference between "test" and "control" groups.     

Carbofuran induced changes in breeding of a freshwater fish,Labeo rohita (Hamilton)

The effect of carbofuran, a carbamate pesticide, on the breeding performance of the freshwater fish Labeo rohita (Hamilton) has been investigated in the present study. Breeding of L. rohita was conducted after treatment with three sublethal concentrations, i.e. 0.06, 0.15 and 0.30 mg L^?1 of carbofuran for 96 h. The present investigation showed that the number of total eggs and total amount of eggs (litre per kg body weight) decreased significantly (p < 0.01) at all concentrations of carbofuran in comparison to controls, while the reduction in fertilization percentage at all concentrations of carbofuran was not significantly different from controls. The reduction in hatching percentage, the expected number of hatchlings, and the expected number of hatched larvae were significantly (p < 0.01) different between treated and control groups at all carbofuran concentrations. No significant differences for the 96 h survivability of hatched larvae were reported at all concentrations of carbofuran.     

Acute toxicity I: effect of profenofos and triazophos (organophosphates) and carbofuran and carbaryl (carbamates) to Labeo rohita

Profenofos and trizaophos (organophosphates) carbofuran and carbaryl (carbamates) are among the major toxicants polluting freshwater bodies, as well as exerting a significant effect on the health of fish. In this study, the 96 h LC₅₀ of the most commonly used organophosphates and carbamates was determined in one of the indigenous fish species, Labeo rohita fingerlings. Pesticides were applied to fingerlings that had been grown under optimized standard conditions under a maintained static bioassay system. Probit analysis was used for the determination of LC₅₀ values, which were ascertained as 6.64, 0.32, 1.4, and 8.24 mg/L for triazophos, profenofos, carbofuran, and carbaryl, respectively. Acute toxic stress was noted with fish exhibiting behavioral toxicity including suffocation, lying on the bottom, erratic swimming, lethargy and downward movements, and gulping prior to mortality.     

Impact of industrial effluents on the biochemical composition of fresh water fish Labeo rohita

In acute toxicity (96 hr) experiment the fingerlings of freshwater fish Labeo rohita was exposed to tannery, electroplating and textile mill effluents. The LC0 and LC50 concentrations were 15% and 20% for tannery effluents, 3% and 6% for electroplating effluents and 18% and 22% for textile mill effluents respectively. It was found that, electroplating effluent was more toxic than tannery and textile mill wastes. After acute toxicity experiments for different industrial effluents, various tissues viz. gill, liver, muscle and kidney were obtained separately from control, LC0 and LC50 groups. These tissues were used for biochemical estimations. The glycogen content in all the tissues decreased considerably upon acute toxicity of three industrial effluents except muscle in LC50 group of tannery effluent and kidney in LC50 group of textile mill effluent, when compared to control group. The total protein content decreased in all tissues in three effluents except gills in LC50 group of tannery effluent, kidney in LC50 group of electroplating effluent and kidney in LC0 group of textile mill effluent. In general total lipid content decreased in all tissues after acute exposure when compared to control group. The results obtained in the present study showed that, the industrial effluents from tannery, electroplating and textile mills caused marked depletion in biochemical composition in various tissues of the fish Labeo rohita after acute exposure.     

Ultrastructural responses and oxidative stress induced by cypermethrin in the liver of Labeo rohita

The present study was conducted to establish the relationship between selected oxidative stress parameters and ultrastructural responses in liver tissue of Labeo rohita fingerlings exposed to cypermethrin. Fish were exposed to lethal (4.0 μg L^?1) and sublethal (0.4 μg L^?1) concentrations of cypermethrin for a period of 24, 48, 72 and 96 h for acute studies and 1, 5, 10 and 15 days for subacute studies, respectively. Results showed increased catalase (CAT) and protease activity, hydrogen peroxide (H₂O₂), malondialdehyde (MDA), protein carbonyls and free amino acid (FAA) levels at both concentrations. This suggests participation of free-radical-induced oxidative cell injury in mediating the hepatotoxicity of cypermethrin. In corroboration of this, ultrastructural lesions witnessed a reduction in the number of cell organelles, swollen, vacuolated and condensed mitochondria, dilated rough endoplasmic reticulum, and reduced numbers of smooth enodplasmic reticulum, peroxisomes and lysosomes at the lethal (4.0 μg L^?1) concentration. At the sublethal (0.4 μg L^?1) concentration, cytoplasmic vacuolation, condensed, vacuolated and swollen mitochondria, dilated rough endoplasmic reticulum and an absence of hepatocyte microvilli were prominent. Ultrastructural changes were exhibited as subcellular responses due to the imbalance in cellular oxidative status by means of oxidative damage.     

Responses of the Indian major carp Labeo rohita to deltamethrin at acute and sublethal concentrations

The effects of deltamethrin at acute and sublethal concentrations on some hematological and biochemical profiles in the Indian major carp Labeo rohita have been examined. The lethal concentrations (LC₅₀) of deltamethrin for 24 and 96 h were found to be 0.44 and 0.38 mg L^?1, respectively. During acute treatment (24 h), hemoglobin (Hb), hematocrit (Hct), red blood cell (RBC), white blood cell (WBC), mean cellular volume (MCV), mean cellular hemoglobin (MCH), and mean cellular hemoglobin concentration (MCHC) values were significantly increased compared to control group. Plasma glucose, protein, cholesterol, albumin, globulin, triglyceride, and glycogen in gill and muscle were significantly decreased. Upon sublethal treatment (0.044 mg L^?1, 10th of 24 h LC₅₀), RBC and the biochemical parameters, except glucose and cholesterol, decreased significantly, while MCV, MCH, and MCHC values increased up to the 28th day and then declined. Cholesterol level was significantly increased throughout the study period. A biphasic response in the levels of Hb, Hct, WBC, and glucose were observed during sublethal treatment.     

Effect of phenol on haematological components of Indian major carps Catla catla, Labeo rohita and Cirrhinus mrigala

The effect of phenol on haematological components of Indian major carps, Catla catla, Labeo rohita and Cirrhinus mrigala were observed. After exposure to sublethal concentrations of 5.17 mg l(-1), 6.06 mg l(-1) and 6.99 mg l(-1), the number of red blood cells, haemoglobin content and packed cell volume all decreased but the glucose level increased. The order of decrease in the haematological components of the three fish is in the order of Catla catla > Labeo rohita > Cirrhinus mrigala.     

Effect of acute concentration of zinc on the biochemical contents of brain of Labeo rohita: an FT-IR study

Heavy metal discharges to aquatic environment are of great concern due to their toxicity and accumulative behavior. Zinc is an essential trace element required for different physiological functions and plays important role in cellular metabolism. However, it becomes toxic when elevated concentrations are introduced into the environment. The aim of this work is to analyze zinc induced biochemical changes in the brain tissues of Labeo rohita fingerlings using Fourier Transformation Infrared Spectroscopy. Several important features have been observed in the zinc intoxicated brain tissues, namely, altered membrane lipid, altered protein profile and decreased glycogen content, indicating an alteration in the lipid and protein profiles leading to modification in membrane composition. Further, it is observed that the acute exposure to zinc causes some alteration in protein profile with a decrease in α-helix and an increase in random coil structures.     

Effect of calcium and magnesium on copper,cadmium, and some essential elements of Indian major carps Labeo rohita (Hamilton) and Catla catla (Hamilton) treated with copper and cadmium

The effect of calcium and magnesium either singly or in combination on accumulation of cadmium and copper in Labeo rohita (rohu) and Catla catla (catla) was investigated in this study under laboratory conditions. The investigation showed that copper accumulation in rohu exposed to 0.25 mg L^?1 of copper for 14 days reduced from 31.0 ± 0.4 mg kg^?1 at no calcium/magnesium treatment to 3.5 ± 0.2 and 2.2 ± 0.1 mg kg^?1, respectively, at 75 mg L^?1 calcium or magnesium treatment. The copper level in catla exposed to 0.20 mg L^?1 of copper for 14 days reduced from 5.7 ± 0.1 mg kg^?1 at no calcium/magnesium treatment to 3.4 ± 0.2 and 3.3 ± 0.1 mg kg^?1, respectively, at 300 mg L^?1 calcium or magnesium treatment. The cadmium accumulation in rohu exposed to 0.20 mg L^?1 of cadmium for 14 days reduced from 1.7 ± 0.1 mg kg^?1 at no magnesium treatment to 1.4 ± 0.1 mg kg^?1 at 120 mg L^?1 magnesium treatment. The cadmium accumulation in catla exposed to 0.20 mg L^?1 of cadmium for 14 days reduced from 0.8 ± 0.2 mg kg^?1 at no magnesium treatment to 0.6 ± 0.2 mg kg^?1 at 80 mg L^?1 magnesium treatment. Copper and cadmium treatments also reduced some essential microelements of rohu and catla. Both the fishes restored these elements at different levels of calcium and magnesium.     

Gill lesions in the major carp, Labeo rohita exposed to lethal and sublethal concentrations of tannery effluent

The major carp, Labeo rohita were exposed to (0.873%) lethal and sublethal (0.073%) concentrations of tannery effluent for 24h and 40 days respectively under static bioassay condition. The surface architecture of gill revealed severe damages such as : fusion and clumping in the middle and distal parts of the primary lamellae, swelling and deterioration of the cells. The interlamellar space was filled either with hyperplastic epithelial or mucous cells. Secondary lamellae lost their identity and appeared finger like in structure in the lethal concentration and necrosis was observed in the primary and secondary epithelium. Swelling of primary and secondary epithelial cells was evident in sublethal concentration.     

Studies of some biochemical changes in the tissues of Catla catla (Hamilton), Labeo rohita (Hamilton) and Cirrhinus mrigala (Hamilton) exposed to NH3-N,NO2-N and NO3-N

Biochemical changes, total proteins, glycogen, aspartate and alanine (AAT and ALAT) amino transferases were studied with exposure of sublethal concentrations of NH3-N, NO2-N and NO3-N to the freshwater fish Catla catla (Hamilton), Labeo rohita (Hamilton) and Cirrhinus mrigala (Hamilton). Depletion in the food reserves and enzyme activity was observed in all the three fish species exposed to these toxicants. Hence, the concentrations of NH3, NO2 and NO3 in water need to be monitored in water quality in aquaculture practices.     

Effect of water extract of the bark of Buchanania lanzan linn. on behaviour and chromatophores of a fresh water fish,Labeo rohita

Fish exposed to 150 ppm and 250 ppm doses saparately, showed eratic swimming with hyper-excitability, spiralling, convulsion and mortality. However at 350 ppm dose fish became lethargic and steady at the bottom of aquarium. This behaviour appears to be due to sedative effects of fish implicating the phychoactive nature of the plant B. Ianzan. At 150 ppm to 350 ppm doses, fish scale changed from reticulate to punctate chromatophores; and treated fish when transferred to fresh water, were slowly regained to normal behaviour after 96 h exposure. Hence doses regaining from 150 ppm to 350 ppm is considered to be psychoative in nature. In higher doses 450 ppm and 550 ppm fish could survive only 76 h and 4.30 h respectively and then died indicating toxicity of plant for the said doses. It is found that scale present on its body is most suitable test system for the study of psychoactivity and toxicity of plant extracts on fish, Labeo rohita.