Haematological and haematopoietic response to sodium chloride stress in a freshwater air-breathing fish Channapunctatus Bloch

Results of experiments to determine the sensitivity of Channa punciatus to different levels of sodium chloride (NaCl) (1.2, 3.2 and 6.2g 1⁻¹) are reported. It was found that C. punctatus which is otherwise considered a hardy fish is more sensitive to higher levels of sodium chloride stress. Thus 10% of the LC50 96 h value (1.2 g 1⁻¹ NaCl) was found stressful as evidenced by loss in body weight, while 25 and 50% of the LC50 96 h value (3.2 and 6.2 g 1⁻¹ NaCl) even resulted in mortality. Haematological and associated haematopoietic investigation confirmed stress symptoms in all the parameters tested. Thus microcytic hypochromic anemia together with leucopenia was indicated at the two higher sublethal levels, i.e., 25% and 50% of LC50 96 h value. Differential leucocyte count showed that leucopenia is mainly contributed by thrombocytic and neutrophilic decrease. Other cell types, viz., eosinophils, basophils, large and small lymphocytes, showed a relatively significant (P < 0.01) increase in number.
Haematopoietic studies revealed that the two penultimate stages in both RBC and neutrophil development closely follow the trend of their counterparts in the peripheral blood. However, the stem cells of both these cell types recorded significant increase under sodium chloride stress, which indicated homeostatic response. Biochemical studies revealed a depletion in blood glucose level as well as in liver and muscle glycogen reserves.
Restoration to normal control conditions after 6 weeks of exposure to different levels of sodium chloride stress resulted in a cessation of mortality (if any), gain in body weight and more or less normality in all the haematological parameters within a period of 2 weeks.     

酸性水对几种主要淡水鱼类的影响

在实验室条件下,研究了酸性水对几种主要淡水鱼类的毒性影响,结果表明,这几种淡水鱼的胚胎和鱼苗的死亡率与Ｈ的浓度呈现相关性,在低ｐＨ水平下,胚胎的发育进程明显地迟缓,要使鱼类受精卵正常孵化不受影响,水中的ｐＨ值应保持在６．５以上,在受试的几种鱼类中,没有发现对低ｐＨ敏感性有显著性差异,但在各自的发育过程中,其敏感性呈出现较大的差异,当ｐＨ〈６．０时,鱼的鳃组织就会受到损害,低ｐＨ加上铝,则对鱼类呈现     

Haematological, haematopoietic and biochemical responses to thermal stress in an air-breathing freshwater fish, Channa punctatus Bloch

Results of experiments on fishes maintained at three different temperatures (25, 30 and 35° C), compared with a control group maintained at 14° C, are presented. Fishes showed obvious signs of stress at 30 and 35° C, as indicated by loss of weight and increase in mortality rate. On the other hand, those at 14 and 25° C gained weight steadily and showed normal growth.
Biochemical studies confirm the stress symptoms, as there was a steady, statistically significant fall in blood glucose level and depletion of glycogen reserves in liver and muscle within the first week at 35° C and by the fourth week at 30° C.
These results were further confirmed by haematological investigations. All the parameters tested indicated deviation from the normal healthy conditions seen at 14 and 25° C. The deviations in most of the parameters at 35° C were statistically significant from about the second week, and at 30° C by the fourth week. Erythrocytic polycythemia accompanied by an increase in haemoglobin content and haematocrit values were indicative of thermal stress. Leucopenia was mainly contributed by neutrophil decrease, but a relative increase in thrombocytes was recorded.
Correlated erythropoietic studies indicated an increase both in the initial (small lymphoid haemoblast) and penultimate (mature reticulocyte) stages in red cell development, although the intermediate stages decreased in number. Similar trends in the different stages of neutrophil development were observed. The significance of these changes in the context of homeostatic phenomena is discussed.     

Responses of succinate dehydrogenase and non-specific alkaline phosphatases and mortality of tilapia to ambient pH stress in a sewage-fed aquaculture pond

The fish, tilapia (Oreochromis mossambicus) of 50-60 g body weight was experimentally exposed to effluent gradients of highly alkaline pH in a sewage-fed aquaculture farm for examining the pH stress-induced responses of mortality and the stress marker enzyme succinate dehydrogenase and the non-specific alkaline phosphatases of fish prior to death at different hours of intoxication. A second trial was performed after two months when water quality changed along the sewage effluent gradient. An in situ experiment was also performed for better understanding of the responses of enzymatic activities attributable to different levels of pH conditions. Time required for 100% mortality of fish tended to increase from 30 min in pH 11.6 to 22 hr in pH 10.2. There was no mortality of fish when water quality improved significantly (with pH ranging between 9.6 to 8.0) after two months. The activities of succinate dehydrogenase and intracellular alkaline phosphatases assayed in gills and liver prior to death of fish tended to reduce with increase in survival hour, following a pattern of decay curve. On the other hand, percent of enzymatic inhibition of the exposed fish over the control increased as the survival hour increased following a pattern of exponential curve. It appears that the highest water pH of 11.6. maximum ratio for ammonium to ammonium hydroxide (1: 21) and reduced level of dissolved oxygen (2.62 mg/l) were perhaps responsible for the 100% mortality of fish within 30 min of their exposure and the enzymatic activities in the gills and liver assayed prior to death of fish tended to reduce as the acclimatization period of fish increased and vice-versa.     

Effect of fasting on body composition and responses to stress in sunshine bass

The integrated responses of the hormonal regulation of growth and stress in sunshine bass (Morone chrysops X Morone saxatilis) as regulated by feed deprivation were investigated. Groups of fish were fed 1.5% of the body weight per day or offered no feed for 4 weeks. Another group of fish was not fed for 3 weeks and feed was offered during the fourth week. Fish in each group were sampled immediately before or after a 15-min low water confinement stressor after each week of the experiment. Liver mass and liver glycogen content were decreased after one week of fasting and remained low until the end of the study. However, both recovered after a week of refeeding. Intraperitoneal fat was significantly lower after two weeks of fasting and did not recover after a week of refeeding. None of these components were affected by confinement stress. Plasma glucose in unstressed fish was generally unaffected by fasting or refeeding; however, plasma glucose increased after confinement stress in fed but not in fasted fish. The cortisol stress response was unaltered by fasting and remained robust. Plasma IGF-I generally decreased in fasted fish but was not significantly lower than fed fish until the fourth week. A week of refeeding did not restore plasma IGF-I concentrations. Plasma IGF-I concentrations were higher in confinement stressed fed fish after two and four weeks but were unchanged in the fourth week. There was no change in the plasma IGF-I concentrations in fasted or refed fish due to the stress. Liver weight and liver glycogen were essentially depleted after 2 weeks of fasting. The reduction of liver glycogen greatly reduced the glucose response to stress; however, the cortisol stress response was maintained for at least four weeks of fasting. Intraperitoneal fat was decreased very little after 4 weeks of fasting. Plasma IGF-I concentrations were reduced only after 3 weeks of fasting.     

Effects of acidic pH on predation rates and survivorship of damselfly nymphs

Environmental variables such as pH critically affect the physiology and ecology of aquatic organisms. Our lack of information regarding indirect effects of acid precipitation requires investigation of acid stress and response to acid stress by species of freshwater communities. Damselfly nymphs Enallagma civile (Odonata: Coenagrionidae) are abundant aquatic predators and food items for other secondary consumers.We investigated the effects of low pH on mortality, survivorship, predation rate, respiration rate, and caloric content of nymphs of E. civile. We hypothesized that acid stress would increase mortality and decrease predation rate among surviving individuals. We hypothesized that respiration rate and caloric content as measures of physiological condition would decrease in acid-stress conditions.We cultured individual early-instar nymphs in the laboratory with a controlled diet of mosquito larvae. The nymphs were reared to final instar in pond water and artificially reconstituted soft water (RSW) adjusted to pH 3.5, 4.5, 5.5, and ambient conditions of the collection site.Predation rate was significantly lower in RSW than in pond water in treatments of equivalent H⁺ concentrations. This indicated stress from differences in dissolved solids in RSW compared with pond water. Acid conditions significantly affected predation rates in pond water, but only at pH 3.5 and only for the largest instar. Mortality increased and survivorship decreased at low pH. Early-instar mortality and survivorship were particularly susceptible to acid stress. Treatments of pH 4.5, 5.5 and ambient did not significantly alter respiration rate or caloric content. However, respiration rate and caloric content increased at pH 3.5.Damselfly nymphs tolerated pHs as low as 4.5 without significant changes (including predation rate). However, the effects of pH 3.5 were significant and greatly lowered the predation and fitness of the nymphs.author for correspondence     

Passive transfer of maternal antibodies and their existence in eggs, larvae and fry of Indian major carp, Labeo rohita (Ham.)

Lack of immune competence in the early stages of life leads to severe mortality in larval stages of different fish species including Indian major carp (IMC). Investigation through indirect enzyme linked immunosorbent assay (ELISA) and agglutination test revealed a significant increase in specific serum antibody response in the brood fish of Indian major carp, Labeo rohita (Ham.) following immunisation with a virulent Aeromonas hydrophila bacterin 1 month prior to breeding, which was transferred to larvae through the egg. No significant differences (P > 0.05) in mean antibody levels in larvae at the 1st and 2nd weeks post-hatch was recorded while a slight rise in antibody level was observed in 3-week-old fry, perhaps due to exposure to A. hydrophila present in the aquatic environment. Immunised brood fish serum, egg and larval extracts in non-reducing sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and subsequent western blot analysis revealed an antibody molecule of approximate molecular weight 210 kDa. On challenge with virulent A. hydrophila, a significant reduction in mortality was recorded in immunised larvae and fry (58.0, 43.75 and 37.14% in the 1st, 2nd and 3rd week, respectively) relative to control fish (87.0, 79.0 and 76.4% in 1st, 2nd and 3rd week, respectively). The present study indicated the role of maternally derived antibody in protection of hatchlings of Indian major carp against specific pathogens.     

Ion and acid-base balance in three species of Amazonian fish during gradual acidification of extremely soft water

Sensitivity to acid water was assessed in three species of Amazonian fish that encounter naturally acidic blackwaters to differing degrees in the wild: tambaqui (Colossoma macropomum), matrincha (Brycon erythropterum), and tamoatá (Hoplosternum littorale), in decreasing order of occurrence in blackwater. Fish were exposed to a graded reduction in water pH, from pH 6 to 5 to 4 to 3.5, followed by return to pH 6. Fish were exposed to each new pH for 24 h. During these exposures, net transfers of ions (Na+, K+, Cl-, and Ca2+) and acid-base equivalents to and from the external water were used as physiological indicators of acid tolerance. Exposure to pH 5 had a minimal effect on net ion fluxes. Significant net losses of all ions (except Ca2+) were recorded in all three species during the first few hours of exposure to pH 4. However, ion balance was usually restored within 18 h at pH 4. Exposure to pH 3.5 caused even greater ion losses in all three species and proved to be acutely lethal to tamoatá. Matrincha sustained irreversible physiological damage at pH 3.5, as ion fluxes did not recover following return to pH 6 and there was some mortality. Tambaqui suffered the least ionoregulatory disturbances at pH 3.5 and was the only species to make a full recovery on return to pH 6. In all species, there was a tendency for ammonia excretion to increase at low water pH, but even at pH 3.5, there was no significant net uptake of acid from the water. Overall, there was a strong relationship between the magnitude of ionic disturbances and the lethality of exposure to low pH. The relative insensitivity of the ionoregulatory system of tambaqui to low pH indicates that this is a feature of fish native to blackwater systems rather than one that is common to all Amazon fish.     

Laboratory studies on food intake, growth and food conversion of young herring, Clupea harengus (L.)

Food intake, growth and food conversion of young, O-group herring were studied at two temperatures and feeding regimes over a period of 19 weeks. The food intake of fish fed to satiation twice daily showed considerable variation. Food intake per fish at 14.5° C was about three times that at 6.5° C, and was generally much higher than in most other species of fish studied. The mean increase in wet weight over the 19-week period was 0.581 g/week at 14.5° C and 0.236 g/week at 6.5° C in fish fed to satiation and 0.094 g/week at 6.2° C and a ration of 1.3% of the body weight. Growth depensation was found to occur even in fish fed to satiation. The changes in specific growth rate, that is the percentage increase in weight/day, showed similar trends at different temperatures and food regimes. The mean conversion efficiency of fish on a ration of 1.3% at 6.2° C was higher than that of fish fed until satiation, at 14.5 and 6.5° C. The conversion efficiency of fish fed to satiation at 14.5° C showed a distinct decrease with increasing weight while at 6.5° C such a clear trend was not observed. In general, the conversion efficiency of young herring were found to be much lower than that of most other species studied. The weight exponent of the quantitative relationship between food intake and body weight at 14.5° C was 0.744. The total metabolic expenditure at 14.5° C, calculated using Winberg's (1956) 'utilization coefficient, gave a weight exponent of 0.773.     

Intestinal pH profile in rainbow trout Oncorhynchus mykiss and microhabitat preference of the flagellate Spironucleus salmonis (Diplomonadida)

In farmed rainbow trout Oncorhynchus mykiss, the flagellate Spironucleus salmonis (Diplomonadida) is often found in the pyloric region of the intestine. While previous in vitro studies report a pH of 7.5 to 8.0 as optimal for presumed S. salmonis, no previous in vivo studies have investigated the relationship between pH and microhabitat preference. Therefore, in 698 rainbow trout (75% were 5 to 6 mo old juveniles, 10 to 20 cm total length), we recorded occurrence and density of S. salmonis, and pH, in the pyloric, anterior, middle, and posterior intestine. There were no significant differences in total length or weight between infected and uninfected fish. S. salmonis preferred the pyloric region, with occurrence and density decreasing significantly from pyloric to posterior regions. In infected fish, pH in pyloric (6.8 to 7.9, mean 7.3) and posterior regions (6.5 to 8.0, mean 7.1) was significantly lower than in anterior (6.5 to 8.5, mean 7.7) and middle (6.8 to 8.2, mean 7.7) regions; in uninfected fish, the pH profile was similar. At the individual level, 90 % of infected fish and 79% of uninfected fish showed this pH profile. In the pyloric region, pH was not significantly different among uninfected fish, and fish with light, moderate, or heavy infections. Our in vivo study suggests the optimal pH for S. salmonis is between 7.1 and 7.5, possibly close to 7.3 (the mean in pyloric region of infected fish). We conclude that while the presence of S. salmonis reflected tolerable pH, density of infection was not correlated with pH, and thus a causal relationship between microhabitat preference and pH is unlikely.     

Copper and the herbicide atrazine impair the stress response of the freshwater fish Prochilodus lineatus

In order to evaluate the effects of copper and atrazine on the stress response of the freshwater fish Prochilodus lineatus, juvenile fish were pre-exposed to copper (20 μg L(-1)) or atrazine (10 μg L(-1)) for 24 h and then submitted to air exposure for 3 min. Simultaneously fish kept in dechlorinated water for 24 h were subjected to air exposure and a non-stress group was not subjected to air stress or any contaminants. Animals were sampled immediately (t0) and after 1, 3 and 6 h of air exposure (t1, t3 and t6 respectively) for the analysis of plasma cortisol, glucose and Na(+), hepatic glycogen, branchial Na(+)/K(+)-ATPase (NKA), number of red blood cells per cubic millimeter of blood (RBC), hematocrit (Hct) and hemoglobin content (Hb). In fish pre-exposed to copper the stress response was inhibited, and at t1 and t3 both cortisol and glucose remained significantly lower compared to fish subjected to air stress only. In fish pre-exposed to atrazine there was no rise in cortisol, but there was an increase in plasma glucose, RBC, Hct and Hb at t0 and a return of these parameters to basal levels at t1, as they did not differ significantly in relation to non-stressed fish. Animals pre-exposed to either Cu or atrazine showed a significant reduction in NKA activity at t1 and t3, in relation to air stressed fish. These results clearly indicate that copper and atrazine impair cortisol stress response of P. lineatus and that fish subjected to a contaminant-induced stress, either by copper or atrazine, may not be able to respond to any additional stressors.     

Haematological and haematopoietic responses to starvation in an air-breathing fish Channapunctatus Bloch

Changes in haematological values (RBC numbers, haemoglobin content, haematocrit value, MCV, MCH, MCHC, TLC and DLC) based on weekly samples from a group of starved fish were investigated. After 8 weeks of starvation, the effects of restoration to a normal diet was evaluated. Parallel studies on haematopoietic tissues were also made. Changes in some biochemical values such as blood glucose, liver and muscle glycogen were also examined to correlate biochemical effects with those of haematological changes. Erythrocytes, thrombocytes and neutrophils were found to be most sensitive to starvation. The initial response to deprivation of food was an increase in RBCs and related values and in total leukocyte population. However, from week 5 onwards a sharp decline in these cell populations was noted. The leukocytes and thrombocytes showed a change parallel to RBC and the total leukocyte counts. However, neutrophils were observed to show a consistent increase throughout the starvation period. A blood glucose level below SOmglOOmh¹ appeared critical in relation to blood cell population. Haematopoietic studies revealed that reticulocytes and mesomyelocytes were unable to keep pace with the changing peripheral blood picture. Other stages in development responded to the changes in the peripheral blood.     

Conformational Changes of Myoglobin Upon Interaction with Negatively-Charged Phospholipid Vesicles

Abstract

The interaction between myoglobin and negatively-charged liposomes composed of phosphatidylcholine/phosphatidylglycerol (1:1) was studied at low ionic strength under acidic conditions. Changes in the absorbance and the fluorescence spectra of myoglobin were recorded upon addition of liposomes to partially unfolded (pH 3.5) and native (pH 4.5 and pH 6.5) myoglobin. Association of myoglobin with liposomes was a relatively fast process at pH 3.5 and pH 4.5. Although at pH 3.5 myoglobin was unfolded partially before the addition of the liposomes while at pH 4.5 before the addition of liposomes myoglobin retained its native form, similar interaction patterns of myoglobin with liposomes were observed. The fluorescence and absorption spectra in the Soret region of myoglobin clearly indicated that at these pH values myoglobin was associated with the liposomes in a (partially) unfolded state. At pH 6.5 the kinetics of myoglobin association with liposomes was much slower than at pH 3.5 and 4.5. The spectroscopic measurements also indicated that the interaction of myoglobin with liposomes at pH 6.5 followed a different pattern and resulted in different protein structures in comparison with pH 3.5/4.5.     

Bioremediation of textile azo dyes by an aerobic bacterial consortium using a rotating biological contactor

The degradation of an azo dye mixture by an aerobic bacterial consortium was studied in a rotating biological reactor. Laterite pebbles of particle size 850 microm to 1.44 mm were fixed on gramophone records using an epoxy resin on which the developed consortium was immobilized. Rate of degradation, BOD, biomass determination, enzymes involved, and fish bioassay were studied. The RBC has a high efficiency for dye degradation even at high dye concentrations (100 microg/mL) and high flow rate (36 L/h) at alkaline pH and salinity conditions normally encountered in the textile effluents. Bioassays (LD-50) using Thilapia fish in treated effluent showed that the percentage mortality was zero over a period of 96 h, whereas the mortality was 100% in untreated dye water within 26 h. Fish bioassay confirms that the effluent from RBC can be discharged safely to the environment.     

Ionoregulatory specializations for exceptional tolerance of ion-poor, acidic waters in the neon tetra (Paracheirodon innesi)

To better understand how fish are able to inhabit dilute waters of low pH, we examined ionoregulation in exceptionally acid-tolerant neon tetras (Paracheirodon innesi), which are native to the ion-poor, acidic Rio Negro, Amazon. Overall ion balance was unaffected by 2-wk exposure to pH 4.0 and 3.5. Measurements of unidirectional Na+ fluxes during exposure to pH 3.5 showed that tetras experienced only a mild, ionic disturbance of short duration (相似文献   

Vanadium induced changes in glycogen content of Clarias batrachus (Linn) and Channa punctatus (Bloch)

Clarias batrachus (Linn) and Channa punctatus (Bloch) were exposed to 5, 10 and 15 ppm of vanadium and investigated the effects on tissue glycogen at 3, 6 and 9 hrs. Results indicated the variations in the level of glycogen were highest at 15 ppm after 9 hr exposure in liver than muscle, brain, kidney and heart of Clarias batrachus as compared to Channa punctatus. The variation recorded in tissue glycogen content was discussed in relation to respiratory distress, formation of mucus on the whole fish and disturbed behaviour of the fish.     

Effect of prenatal exposure to diagnostic ultrasound on the development of mice.

Pregnant Swiss albino mice were exposed to diagnostic ultrasound (3.5 MHz, approximately 65 mW) for 10 min on Day 3.5 (preimplantation period), 6.5 (early organogenesis period), or 11.5 (late organogenesis period) of gestation. Sham-exposed controls were maintained for comparison. Exposed as well as control fetuses were dissected out on the 18th day of gestation, and changes in total mortality, body weight, body length, head length, brain weight, sex ratio, and microphthalmia were recorded. Exposure on Day 3.5 of gestation resulted in a small increase in the resorption rate and a significant reduction in fetal body weight. A low fetal weight and an increase in the number of growth-retarded fetuses were produced by exposure on Day 6.5 postcoitus. A statistically nonsignificant increase in the incidence of microphthalmia was induced in fetuses exposed on Day 6.5 or Day 11.5 of gestation. These results indicate that ultrasound may have some adverse effects on the mouse embryos depending on the developmental stage at which the exposure occurred.     

Effect of environmental acidity and alkalinity on the physiology of Tilapia mossambica during acclimation

The pattern of carbohydrate metabolism in the muscle of the freshwater fish, Tilapia mossambica (Peters) varied according to the pH of the environmental medium. On acclimation to a more acidic water, the white muscle showed an elevated glycogen content with suppressed glycolysis. In contrast, the muscle tissue showed an accelerated glycolytic pathway with the accumulation of metabotic acids on acclimation to a basic water. In an acidic medium phosphorylase activity was inhibited with an elevated LDH activity, while the reverse pattern was observed in an alkaline medium. The oxidative pathway was elevated in both. Acclimation to acidic and basic environmental waters leads to an adaptive compensatory mechanisms providing increased resistance capacity to the fish under pH stress.     

Effects of pH on the gill ATPase activity and blood composition of whitefish (Coregonus peled) and trout (Salmo trutta fario)

1. The effects of pH on blood composition and gill (Na+ + Mg2+) ATPase activity were studied in 142 whitefish and trout kept for 3 to 17 hr in tanks at pH 3.0-9.5 in Northern Finland. 2. pH clearly influenced all blood values, except plasma alanine and aspartate aminotransferases. Blood haemoglobin and packed cell volume of whitefish and trout were lower at pH 9.5 but higher at pH 3.0 than those of controls at pH 6.5. 3. Both fishes had lowest plasma sodium and chloride values in groups kept for 9 to 17 hr in tanks with water acidified to pH 3.0 to 3.5. Changes in the plasma chloride concentration were associated with plasma sodium (r = 0.92, n = 102, P less than 0.001). 4. The gill (Na+ + K+ + Mg2+) ATPase of trout showed high activity over wide ranges of pH (6.0-7.5) at 13 degrees C having a distinct optimum at pH 7.0. 5. Blood glucose and lactate concentrations of whitefish and trout increased after exposure to acid and base. High values at pH 3.0 to 3.5 suggested hypoxic stress due to acidaemia.     

Anomalous tolerance to low pH in the estuarine killifish Fundulus heteroclitus

1. The euryhaline fish Fundulus heteroclitus has an incipient lethal pH between 3.75 and 4.0 in fresh water.2. Fish exposed to pH 3.5 in sea water or fresh water died in about 3 hr, and had greatly elevated or depressed body sodium concentrations, respectively. The direction and degree of change in body sodium level depended on the sodium diffusion gradient between the environment and the fish. This is the first time that the death of fish in sea water at low pH has been shown to be associated with hypernatremia.3. Yet, sodium fluxes during the first hour of exposure to pH 3.5 in water of 3.5 or 35 ppt salinity were not different from controls, and body and plasma sodium concentration did not change during 2hr exposure to pH 3.5. This initial insensitivity of gill sodium regulation to blockage by low pH is quite different from the response of previously studied freshwater fish.4. The degree of acid tolerance displayed by F. heteroclitus is surprising considering its estuarine habits. This paradoxical tolerance appears to be a secondary consequence of its ability to adjust sodium balance in relation to rapid changes in salinity.