Haematological and blood biochemical characteristics of <Emphasis Type="Italic">Glyptosternum maculatum</Emphasis> (Siluriformes: Sisoridae) in Xizang (Tibet)

This study investigated the haematological and blood biochemical characteristics of Glyptosternum maculatum. The haematological and biochemical parameters were measured in 30 adult fish collected from Nyingchi Reach of Yarlung Zangbo River in Tibet. The red blood cell count (RBC), haemoglobin concentration (Hb), haematocrit (Hct), erythrocyte osmotic fragility (maxEof and minEof), the erythrocyte sedimentation rate, mean cell volume (MCV), mean cellular haemoglobin content (MCH), and mean cell haemoglobin concentration (MCHC) were determined. Compared with other Siluriformes fishes, G. maculatum showed similar mean values for Hct, Hb, MCH, and MCHC and had slightly lower RBC and higher MCV. The biochemical parameters were assayed including alanine aminotransferase, aspartate aminotransferase (AST), alkaline phosphatase, total protein, albumin, globulin, albumin/globulin ratio, total bilirubin, direct bilirubin, urea, creatinine, glucose, total cholesterol, and triglyceride. The result showed that the value of AST in G. maculatum was obviously higher than that in Rhamdia quelen as well as in Silurus merdionalis.     

Anaesthetic efficacy and biochemical effects of 1,8‐cineole in rainbow trout (Oncorhynchus mykiss,Walbaum, 1792)

The aim of the present study was to investigate the anaesthetic efficacy and biochemical effects of 1,8‐cineole (cineole) in rainbow trout (Oncorhynchus mykiss). The fish were exposed to 200, 300, 400, 500, 600 and 800 μl/L cineole and time of induction of anaesthesia and recovery from anaesthesia were recorded. Thereafter, the fish haematological and biochemical responses to anaesthesia with different concentrations of cineole were studies. Moreover, the haematological and biochemical response of fish anaesthetized for 300 s with either cineole (283 μl/L) or eugenol (25 μl/L) were compared. Cineole at the concentrations of 200–800 μl/L induced stages 2, 3 and 4 anaesthesia within 109‐29.3, 226‐59 and 418‐117 s respectively. Increase in anaesthesia induction time led to higher stress responses and enzymes’ activity characterized by elevation in red blood cell (RBC), white blood cell (WBC), blood haematocrit and haemoglobin, and plasma cortisol, glucose and lactate levels, and aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase and creatine phosphokinase (CPK) activities. However, cineole concentrations had no significant effects on plasma alanine aminotransferase (ALT) activity and ions levels. Comparison of cineole with eugenol showed that cineole showed less change in blood RBC and plasma AST, ALP, CPK, cortisol and glucose levels compared to eugenol. In conclusion, cineole is efficient to anaesthetize trout at concentrations of 200–800 μl/L. Increase in cineole concentration shortens anaesthesia induction time, stress response and probably tissue damage. The concentrations of 600–800 μl/L cineol is recommended for rapid sampling as it causes the least stress and enzymatic responses. The present results suggest that cineole causes slightly lower side effects in trout compared to eugenol.     

Physiological Responses of Nile Tilapia,Oreochromis niloticus,Fed Vitamin C‐ and Lipid‐Supplemented Diets and Submitted to Low‐Temperature Stress*

Abstract.— Water temperature alterations can determine harmful physiological modifications in fish, which should be prepared to cope with this, and nutrition strategies seem to be essential. This study evaluated the effects of different levels of vitamin C and lipids on physiological responses of Nile tilapia, Oreochromis niloticus, submitted to temperature stress. There were two phases: Phase I – preparing fish to store vitamin C and lipid at appropriate temperature, and Phase II – evaluating the contributions these reserves make to fish physiology under low‐temperature stress. The experiment used a 3 × 2 factorial design with three vitamin C levels (300, 600, and 1200 mg/kg diet) and two lipid levels (8.0 and 12.0%), plus absence of nutrient test and a diet of 6.0% lipids and 125.0 mg/kg vitamin C. In Phase I, 192 fish were kept at 26.0 ± 1.0 C for 112 d, and in Phase II, 48 fish were kept at 18.0 ± 0.5 C for 32 d and at 15.0 ± 0.5 C for 11 d. Fish fed C₀L₀ diet showed lower erythrocytes values in both phases; higher vitamin C supplement determined higher red blood cell (RBC) number and higher hematocrit (Htc) (Phase II); Htc was significantly lower in Phase II; after temperature stress, fish fed C₀L₀ diet had higher mean corpuscular volume, lower hemoglobin corpuscular concentration, and significantly lower vitamin C concentration in the liver; and higher supplementation determined a higher concentration in the liver (Phases I and II). Higher plasmatic cortisol concentration was seen in fish fed C₀L₀ diet. In conclusion, our results show that the absence of vitamin C in diets impairs RBC formation and does not enable fish to cope with stress; excess vitamin C is efficient in mitigating stress and 600 mg/kg diet is economic and physiologically sufficient to prepare fish for coping with low‐temperature stress. Lipid supplementation does not determine alterations in stress biochemical parameters.     

Pre‐challenge and post‐challenge haemato‐immunological changes in Oreochromis niloticus (Linnaeus, 1758) fed argan oil against Lactococcus garvieae

The present study investigated the effects of argan oil, obtained from Argania spinosa, on pre‐ and post‐challenge immuno‐haematological and biochemical responses of Nile tilapia, Oreochromis niloticus. For this purpose, the fish were fed diets containing 0, 0.5%, 1% or 2% argan oil for 45 days. Following 45 days of feeding, fish were challenged with Lactococcus garvieae and mortality was recorded for 15 days. During the pre‐challenge period, significantly higher respiratory burst activity, total white blood cell (WBC), serum lysozyme activity and myeloperoxidase activity were determined in the argan oil‐fed groups. The serum glucose and cholesterol levels decreased whilst total protein and albumin did not change in the groups fed with argan oil‐supplemented diets. After challenge with Lactococcus garvieae, the percentage survival (%) was found to be the highest in the 1% and 2% argan oil‐supplemented feeding groups. Also, there was a significant increase in weight gain, specific growth rate and feed conversion ratio in those fish fed argan oil. The results of this study indicated that after the supplementation of fish diets with argan oil, especially at 1% and 2% concentrations, the immunological, haematological and biochemical values remained similar in both the pre‐ and post‐challenge periods and the immune response against L. garvieae in Nile tilapia was modulated.     

Effects of dietary levels of essential oil (EO) extract from bitter lemon (Citrus limon) fruit peels on growth,biochemical, haemato‐immunological parameters and disease resistance in Juvenile Labeo victorianus fingerlings challenged with Aeromonas hydrophila

Essential oils (EOs) are used in the food industry because of their biological activity. We evaluated the effects of administration of essential oil (EO) extracted from bitter lemon (Citrus limon) fruit peels on the growth performance, biochemical, haemato‐immunological parameters and possible disease resistance in fingerlings (4 weeks old) Labeo victorianus challenged with Aeromonas hydrophila. Fish were divided into five groups and fed diets supplemented with C. limon fruit peels EO extract at 1%, 2%, 5% and 8% [as fed basis] and treatment compared with control group fed diet without C. limon fruit peels EO extract. The experiment was executed in triplicate. Concentration of plasma cortisol, glucose, triglyceride and cholesterol decreased while that of total protein and albumin increased as dietary inclusion of the EO extract of C. limon fruit peels was increased from 2% to 5%. Meanwhile haemato‐immunological parameters including red blood cell (RBC), white blood cell (WBC) counts, haematocrit (Htc), mean cell haemoglobin (MCH), mean cell haemoglobin concentration (MCHC) and neutrophiles increased with increasing dietary inclusion from 1% to 5% inclusion of C. limon fruit peels EO extract. Serum immunoglobulins, lysozyme activity and respiratory burst increased with increasing dietary levels up to 5% inclusion of EO extract of C. limon fruit peels. We demonstrate that formulation of feeds by incorporating upto 5% the EO extract from C. limon fruit peels significantly improved biochemical, haematological and immunological response in juvenile fish resulting to lower mortality than the untreated groups and appear to be effective antibacterial against A. hydrophila.     

Haematological, biochemical and immunological parameters as stress indicators in Dicentrarchus labrax and Sparus aurata farmed in off-shore cages

In 2000–2001, an investigation was performed in two Sicilian mariculture sites (Pachino and Castellammare) to monitor physiological and biochemical parameters in sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) specimens farmed in off-shore sea cages. Plasma cortisol and glucose levels, tissue lactate concentration, haematocrit and haemoglobin content, lysozyme, haemolytic and haemagglutinating activities were determined. During the experiment, an increase in tissue lactate and plasma cortisol levels and a reduction in haemolytic and haemagglutinating titers, were recorded. Changes occurring in these haematological, immunological and biochemical values suggest that these parameters can be useful indicators in assessing the condition of chronic stress induced by mariculture operations.     

Haemato‐immunological and serum biochemical parameters,intestinal histomorphology and growth performance of rainbow trout (Oncorhynchus mykiss) fed dietary fermentable fibre (Vitacel®)

The aim of this study was to investigate the effects of dietary fermentable fibre (Vitacel^®) on haemato‐immunological and serum biochemical parameters, intestinal histomorphology, growth performance and proximate body composition of rainbow trout (Oncorhynchus mykiss). One hundred and twenty fish (81.65 ± 1.49 g) were fed diets containing 0 and 10 g kg^?1 fermentable fibre (Vitacel^®) for 50 days. At the end of feeding trial, growth performance parameters were significantly improved in fermentable fibre (Vitacel^®)‐fed fish. Although feeding on fermentable fibre (Vitacel^®)‐supplemented diet had no remarkable effect on haematological parameters (RBC, Htc and Hb) (P > 0.05), white blood cell (WBC) count and monocyte level were significantly affected (P = 0.040 and P = 0.020, respectively). In case of serum biochemical parameters, a significant increase and decrease were observed in serum total protein (P = 0.040) and cholesterol level (P = 0.000), respectively. Also, lysozyme level was significantly increased following administration of Vitacel^® in diet (P = 0.006). Histomorphological evaluations revealed that villus length (P = 0.004) and tunica muscularis thickness (P = 0.000) were significantly higher in fermentable fibre (Vitacel^®)‐fed fish. These results indicate that fermentable fibre can be considered as a dietary supplement for improving the health status and performance of rainbow trout.     

Effects of long-term silymarin oral supplementation on the blood biochemical profile of rainbow trout (<Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>)

Silymarin, an extract from “milk thistle” (Silybum marianum) plant is traditionally used as herbal medicine. The present study was conducted to investigate the clinical effects and possible side effects of silymarin on biochemical blood parameters of rainbow trout (Oncorhynchus mykiss). Fishes were treated with 0 (control), 100, 400, and 800 mg of silymarin per kg of food during 4 weeks. Plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), creatine kinase (CK), glucose, total protein, creatinine, triglyceride, cholesterol, urea, uric acid and liver cellular total antioxidant, and protein content were measured after 7, 14, and 28 days of silymarin treatment. The results showed that oral administration of silymarin in fish significantly reduced plasma glucose and cholesterol levels and relatively increased plasma total protein and globulin concentrations (P < 0.05). Increasing plasma albumin levels indicate the important role of albumin in drug transportation in circulatory system of fish. Silymarin also stabilized cellular membrane structure and regulated the levels of AST, ALT, ALP, CK, and LDH activity. In conclusion, on the basis of these results, oral administration of silymarin up to 400 mg per 1 kg of food has no side effect on blood biochemical and clinical parameters of fishes. However, oral administration of 800 mg/kg- of silymarin caused cytotoxicity and modifications in blood biochemical parameters of fish.     

Effect of dietary eucalyptol on stress markers,enzyme activities and immune indicators in serum and haematological characteristics of common carp (Cyprinus carpio) exposed to toxic concentration of ambient copper

In the present study, protective effects of dietary eucalyptol were investigated against copper toxicity in common carp (Cyprinus carpio). The fish were fed with diets supplemented with 0 (control), 0.5% and 1% eucalyptol for 14 days before exposure to 0.25 mg/L ambient copper for 7 days. Blood samples were taken from the fish before and 1, 3 and 7 days after copper challenge. Before copper challenge, eucalyptol significantly decrease serum aspartate aminotransferase (AST) activity, but increase blood WBC, RBC, hematocrit and haemoglobin, serum lysozyme, total immunoglobulin (Ig) compared with the control. Copper exposure led to stress, tissue damage and immunosuppression. After the copper challenge, significant elevation in serum cortisol, glucose, alanine aminotransferase (ALT) and AST, but decrease in blood RBC and WBC, and serum lysozyme, complement (ACH50) and total immunoglobulin (Ig) was observed. Eucalyptol administration significantly mitigated the increase in serum cortisol, glucose, ALT and AST, and decrease in WBC, ACH50, lysozyme and total Ig. Dietary 1% eucalyptol had significantly higher protective effects than 0.5% in the case of serum AST, lysozyme, total Ig and ACH50. In conclusion, eucalyptol has beneficial health effects on common carp and enables to mitigate copper‐induced stress, tissue damage, and immunosuppression. Eucalyptol at the dietary 1% level is recommended to protect common carp against adverse effects of copper toxicity.     

Alteration of certain blood parameters of freshwater teleost <Emphasis Type="Italic">Mystus vittatus</Emphasis> after chronic exposure to Metasystox and Sevin

Indiscriminate use of pesticides has elevated the risk of contamination of environment and aquatic habitat. Considering the above fact, the present study has been under taken to investigate the alteration of some blood parameters of freshwater teleost Mystus vittatus after chronic exposure to sublethal concentrations of Metasystox (4 ppm.) and Sevin (7 ppm.) individually. The main alterations observed in certain haematological parameters were clotting time (CT), erythrocyte sedimentation rate (ESR), haemoglobin percentage (Hb%), red blood corpuscles (RBCs), white blood corpuscles (WBCs), pack cell volume (PCV), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC). Alterations in organic constituents of blood, such as glucose, blood urea, total plasma protein and cholesterol, and in inorganic constituents, such as calcium, iron, magnesium, and phosphorus, were also studied. Alteration of enzymes such as glucose-6-phosphatase (G-6-pase), fructose-1-6-diphosphatase (F-1-6-dipase), serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) were also studied, so that the changes in the blood biochemistry due to the pesticidal stress could be understood. Results indicated that CT, WBCs, MCH, MCHC, glucose, blood urea, cholesterol, magnesium and SGOT were increased, whereas other parameters were found to be decreased in both cases. Possible reasons for the above elevation are discussed in the light of available literature.     

The study of some haematological and serum biochemical parameters of juvenile beluga (<Emphasis Type="Italic">Huso huso</Emphasis>) fed oligofructose

A study was conducted to investigate the effects of dietary oligofructose (1, 2 and 3%) on the blood profiles of beluga (Huso huso) juveniles (18.77 ± 0.76 g) compared to fish fed an un-supplemented diet. After 7 weeks of feeding on the experimental diets, haematological parameters, metabolic products (cholesterol, glucose and total protein) and serum enzymes (lactate dehydrogenase, alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase) were measured. Compared to the control group (0% oligofructose), dietary oligofructose had no effect on red blood cell counts (RBC), mean corpuscular volume (MCV), mean cellular haemoglobin (MCH) or mean cell haemoglobin concentration (MCHC) (P > 0.05). However, haemoglobin (Hb) concentration, leucocyte (WBC) levels and the proportion of lymphocytes were significantly higher (P > 0.05) in the 2% oligofructose fed fish than in the 3% oligofructose fed fish. Additionally, haematocrit (Hct) values (P = 0.049) and the proportion of lymphocytes (P ≤ 0.01) were significantly higher in the 2% oligofructose group than in the control group. Although serum glucose and total protein remained unaffected, serum cholesterol was significantly lower in the 2% oligofructose group than in the control and 3% oligofructose group (P < 0.05). The results of the present study showed that oligofructose had no significant effects on serum lactate dehydrogenase, alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase. These results indicate that fish blood profiles could be affected by prebiotics, which should be taken into account in future studies.     

Effects of sulfamerazine on selected haematological and immunological parameters in rainbow trout (Onchorhynchus mykiss, Walbaum, 1792)

In the present study, effects of sulfamerazine on some haematological and immunological parameters of rainbow trout ( Oncorhynchus mykiss ) were examined. Four groups of rainbow trout were fed experimental diets containing either no sulfamerazine (control) or supplemented with sulfamerazine at 100 mg kg⁻¹ (Exp-A), 200 mg kg⁻¹ (Exp-B) or 400 mg kg⁻¹ (Exp-C) for 21 days. Blood samples were taken for the haematological and immunological parameters from fish on the third, seventh, 14th and 21st days of feeding. Haematological parameters [haematocrit, leucocrit, numbers of erythrocytes (RBC) and leucocytes (WBC), haemoglobin (Hb), mean corpuscular volume (MCV), mean haemoglobin concentration (MHC) and mean corpuscular haemoglobin concentration (MCHC)] and immunological parameters [phagocytic ratio (PR) and index (PI), glass-adherent NBT-positive cell activation, total plasma protein and total immunoglobulin (Ig)] were evaluated during the experimental trial. It has been observed that MCV ( P <0.05), PR and PI ( P >0.05) were increased and haematocrit and leucocrit value, numbers of erythrocytes and leucocyte, haemoglobin, MHC and MCHC values and total plasma protein and total Ig levels were decreased in rainbow trout after application of three different doses of sulfamerazine.     

Biochemical responses of matrinxãBrycon cephalus (Günther, 1869) after sustained swimming

Juvenile matrinxã, Brycon cephalus, were submitted to sustained swimming for 72 days at 1.0 body length s^?1. Exercised fish (EF) grew more than non‐EF and their feed conversion ratio (FCR) improved; haematological responses demonstrated a decrease in haemoglobin and mean cell haemoglobin contents and increase in the mean cell volume. In the plasma, sodium, ammonia and amino acid concentrations increased; plasma triglycerides decreased while free fatty acids increased. Liver glucose, free amino acids, ammonia, the rate protein per fish weight and total lipid content increased, while the glycogen per fish ratio declined. Glutamate dehydrogenase (GDH) activity increased while pyruvate kinase (PK) and lactate dehydrogenase (LDH) decreased. White muscle glucose, lactate, the glycogen per fish‐weight ratio and total lipid content exhibited a decrease in their values; ammonia, free amino acids and the protein per fish‐weight ratio increased. GDH and PK decreased their activities. In the red muscle glycogen store, the glycogen per fish‐weight ratio and glucose were reduced. Juvenile matrinxãs, under sustained swimming, were physiologically and biochemically adapted to exercise as indicated by improved blood flow, transport and oxygen uptake, FCR, amino acid and protein incorporation and growth. Continuous exercise is a good practice for B. cephalus cultivation.     

Effects of cadmium on some haematological and biochemical characteristics of <Emphasis Type="Italic">Oreochromis niloticus</Emphasis> (Linnaeus, 1758) dietary supplemented with tomato paste and vitamin E

The present study investigates the potential protective effects of tomato paste (9 mg/kg-lycopene) in comparison with vitamin E (50 mg/kg) against the impacts of cadmium (Cd) toxicity (4.64 mg/l: ¼ of 96 h LC50) on fishes Cd exposed for 15 and 30 days. Cd impacts were evaluated in terms of biological, haematological and biochemical characteristics. Cd significantly induced free radicals in serum and liver. The activities of aspartate aminotransferase and alanine aminotransferase in serum were significantly increased due to Cd. Treatment with Cd caused a significant increase in Lipid peroxidation and DNA fragmentation in liver tissue and serum glucose and total lipid. On the other hand, Cd significantly led to decline in serum total protein, blood haemoglobin, red blood cell count, haematocrit value, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration. Dietary supplementation with vitamin E and/or tomato paste to Cd-exposed fish declined significantly the increased lipid peroxidation and DNA fragmentation in liver tissue and the increased aspartate aminotransferase, alanine aminotransferase, glucose and total lipid in serum to the normal condition. This supplementation also significantly increased the declined serum total protein, blood haemoglobin, red blood cell count, haematocrit value, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration to the normal state. Cd impacts and tomato paste/or vitamin E supplementations did not reflected on the condition factor of the fish. These findings demonstrated the beneficial diet supplementation of tomato paste phytonutrients and vitamin E in counteracting the harmful effects of Cd on the characters investigated.     

Modulatory effect of lycopene against carbofuran toxicity in African catfish, <Emphasis Type="Italic">Clarias gariepinus</Emphasis>

In the current study, African catfish, Clarias gariepinus, was exposed to a sublethal concentration of carbofuran (CF) to investigate its negative effects on biochemical and oxidative stress biomarkers. Also, the putative role of lycopene (LYC) administration in alleviating these negative effects was evaluated. Fish were divided into six groups in triplicates as follows: group I was without treatment, group II was orally administered corn oil, group III was orally administered 18 mg LYC/kg body weight, group IV was exposed to 0.121 mg CF/L, group V was orally administered 9 mg LYC/kg body weight and exposed to 0.121 mg CF/L, and group VI was orally administered 18 mg LYC/kg body weight and exposed to 0.121 mg CF/L for 4 weeks. At the end of this period, blood and tissue (liver and kidney) samples were collected and biochemical and oxidative stress biomarkers were analysed. Also, histopathological changes were determined. Carbofuran caused significant increments of glucose, cortisol, aspartic amino transferase, alanine amino transferase, cholesterol, urea, and creatinine; meanwhile, serum acetylcholinesterase, total protein, albumin, and total lipids were significantly reduced. Significant increments in hepatic and renal malondialdehyde (MDA) and superoxide dismutase (SOD) levels and marked reduction in hepatic and renal catalase (CAT), glutathione (GSH), and total antioxidant capacity (TAC) levels were observed in CF-exposed fish comparing to the control group. Treatment with LYC attenuated the CF-induced oxidative stress, and this improvement was more pronounced in fish received the high LYC dose (18 mg/kg body weight). Further, congestion of the central vein with infiltration of mononuclear inflammatory cells, vacuolar necrosis, and haemorrhage was observed in the livers of CF-exposed fish. Oral administration of LYC reduced behavioural changes and histopathological alterations. All the altered biochemical parameters and antioxidant biomarkers were also restored to be near the normal levels. The obtained results evoked that LYC administration alleviated the destructive effects of carbofuran and reduced its toxicity effect on African catfish.     

Physiological responses to feed restriction and starvation in juvenile Siberian sturgeon Acipenser baerii (Brandt, 1869): Effects on growth,body composition and blood plasma metabolites

An 8‐week study was applied to evaluate the effects of feed restriction and starvation on growth, proximate composition, haematological and biochemical factors in juvenile Siberian sturgeon Acipenser baerii with an average weight of 54 ± 0.6 g. Fish were randomly divided into nine indoor tanks (1,050 L volume) with 30 fish per tank in a flow‐through system at 18 ± 0.4°C. Three feeding strategies were considered: I) fed at satiation (F), II) restricted feeding at the rate of 1% body weight per day (R) and III) starvation (S) each with 3 replicates. Fish were fed with commercial pellets 4 times daily, but no feed was considered for S group throughout the trial. Basal level at the start, 4 and 8 weeks after initiation of the experiment, blood samples were taken from 5 fish/tank to measure the haematological and biochemical parameters. Moreover, growth performance was recorded every 2‐week interval. At the end of the experiment, the growth parameters and proximate composition were significantly different among the treatments. As expected, the highest weight (164.7 ± 2.1 g) was observed in F group compared to R (101 ± 1.7 g), or S (42.4 ± 0.8 g) groups. The highest (12.07 ± 0.14%) and lowest (5.37 ± 0.42%) fat contents were observed in F and S groups, respectively, while the protein was not affected in R group compared with F group. In addition, most haematological and biochemical indices of Siberian sturgeon were affected by starvation at week 4 and 8, while few changes were observed in restricted feeding. The highest mean corpuscular volume, mean corpuscular haemoglobin, plasma total protein, cholesterol and triglyceride was found in S group, while the lowest value of plasma glucose was observed in this group. It can be concluded that Siberian sturgeon adjusts the physiological condition in short‐term (4 weeks) feed restriction using stored metabolites to have basal metabolism and due to this, a short period of feed restriction strategy recommends to the optimum nutritional management of Siberian sturgeon to cost‐saving during unsuitable conditions.     

Effects of triploidy on the Caspian salmon <Emphasis Type="Italic">Salmo trutta caspius</Emphasis> haematology

The aim of this study was a comparison of key haematological features of diploid (2n) and triploid (3n) Caspian salmon (Salmo trutta caspius). Morphometric indices of erythrocytes were determined on blood smears by light microscopy. Triploidy significantly (P < 0.001) increased all morphometric indices measured in the erythrocytes including cell size, cell surface area, and cell volume. The increase in cell size was larger for the major (27%) axis than for the minor (22%) axis, thus making erythrocytes of 3n Caspian salmon more ellipsoidal. The estimated increase in erythrocyte nuclear volume (87%) was bigger than the theoretical expected 50% increase. Haematological indices were measured manually by hemocytometry. Triploids had lower numbers of red blood cells (RBC: 1,120,000 cells/mL in 2n vs. 700,000 cells/mL in 3n; P < 0.001) but they were larger in size (mean erythrocytic volume [MEV]: 363.1 nm³ in 2n vs. 483.3 nm³ in 3n; P < 0.001). The decrease in RBC number was not compensated by the increase in MEV and, thus, triploidy affected the haematocrit (Hct: 38.8% in 2n vs. 33.06% in 3n; P < 0.05). Total blood hemoglobin concentration was lower in triploid fish (Hb: 9.9 g/dL in 2n vs. 8.9 g/dL in 3n; P < 0.05). In contrast, mean erythrocytic hemoglobin (MEH: 95 μg in 2n vs. 133.2 μg in 3n; P < 0.001) was higher for 3n Caspian salmon as a result of their larger erythrocytes, although MEH concentration (MEHC: 0.26 g/dL in 2n vs. 0.27 g/dL in 3n) did not significantly differ (P > 0.05). White blood cell (WBC) counts (lymphocytes and neutrophiles) were measured and WBC/RBC ratios were calculated. There were no significant differences in WBC (15,710 cells/mL in 2n vs. 12,683 cells/mL in 3n; P > 0.05), lymphocytes, and neutrophils as %WBC as well as WBC/RBC ratios between two ploidy levels (P > 0.05). Triploid Caspian salmon showed higher erythrocyte abnormalities such as ‘twisted’, ‘tailed’, and ‘anucleated’ cells as well as high portions of immature RBC in blood smears in comparison with diploids (P < 0.001).     

Hematologic and serum biochemical values for jundiá (<Emphasis Type="Italic">Rhamdia quelen</Emphasis>)

The determination of hematologic parameters for jundiá Rhamdia quelencultivated in ponds is an easy and useful tool for the control of their sanitary and nutritional conditions. In the present work hematologic indices (RBC, WBC, Ht, Hb, MCV, MCH, MCHC), electrolytes (Cl, Na, K, Ca, Mg, P), metabolic products (creatinine, urea, ammonia, glucose, total protein, triglycerides, cholesterol, bilirubin) and enzymes (alanine and aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase) were measured in a population of jundiá. The mean ± SEM and range were established.     

Respiratory and hematological response of tench, Tinca tinca (L.) to a short-term cadmium exposure

The effects of 3 h exposure to 96hLC50 of cadmium (4.5 mg dm⁻³) on oxygen consumption rate, and hematological parameters (RBC, WBC, erythrocyte and leukocyte pattern) of juvenile tench were evaluated. Oxygen consumption significantly decreased beginning from 24 h postexposure, and remained reduced until the end of the experiment (96 h postexposure). RBC gradually increased, together with the percentage of juvenile cells in circulation. On the other hand, cadmium induced damage to the red cells – the share of cellular anomalies significantly increased with time postexposure. They included abnormal cell shape, vacuolization, swelling, chromatin disintegration in the nucleus, and nucleus indentation. The exposed fish showed a gradual and significant decrease in WBC without a shift of lymphocyte/neutrophil proportion. No significant changes in thrombocyte count occurred. The results show that short-term exposure to cadmium reduced fish energetic metabolism, and suppressed immune abilities. The symptoms gradually developed after the end of exposure, and no recovery took place until␣96 h.     

Effect of starving and feeding on some haematological and physiological responses of the Nile catfish, <Emphasis Type="Italic">Clarias gariepinus</Emphasis> exposed to copper at extreme seasons

The lethal concentration for 50% of fish for 96h (96h LC₅₀) of copper (Cu²⁺) was estimated for the Nile catfish (Clarias gariepinus) in extreme seasons, winter and summer, 4.31 and 4.79 mg/l, respectively. The Nile catfish was exposed to 96h LC₅₀ of copper for 7 days in extreme winter and summer. The body indices, haematological parameters as well as some plasma and liver enzyme activities and metabolite level were significantly differed in fish exposed to copper over than those of the control fish. Most of the tested parameters were not significantly different between the control fish of winter and summer (winter, water temperature 18 ± 2°C and summer, 27 ± 2°C). The effect of two ration sizes on copper toxicity in two different seasons on C. gariepinus was justified. It was found that the haematological parameters and the tested plasma activities of enzymes were significantly valid due to season differences. The blood parameters as well as plasma activities of enzymes were significantly differed in fishes fed elevated ration (3%) and exposed to copper challenge. On the other hand, the exploit of low feeding ration (0.5%) along with copper exposure during the examined seasons induced non-significant differences of the tested parameters, from those of the corresponding control. Therefore, the low feeding ration provides some tolerance against the possible water-borne copper exposure.