Fisheries

ABSTRACT Cyprinus carpio is a stenohaline species but can tolerate some ranges of changes in environmental salinities, so histomorphological methods and Na + -K + ATPase and Aquaporin 3 immunohistochemistry were performed on common carp kidney as an osmoregulatory organ in experimental groups and control in order to investigate their possible roles during salinity challenge. Five groups of fish (n=25) with salinities ranging from 3, 6, 9 and 12 g/l marine salt and a control group (tap water) were used. The experiment was continued for two weeks. Kidney samples from control and experimental groups were fixed in 4% paraformaldehyde and were embedded in paraffin. The Na + -K + ATPase and Aquaporin 3 intensity of the immunostaining and the renal tubules dilation had direct relation with environmental salinities, and showed the involvement of these proteins in physiological responses to environmental salinity. Furthermore, in the salinities 9 and 12 g/l epithelium of the renal tubules, profound histomorphological alteration was present.

Plasma chemistry, lipid metabolism and vitellogenin gene expression of captive Sterlet sturgeon Acipenser ruthenus were studied in different maturity stages. A total of 32 fish were sampled, and maturity stages were identified on the basis of histological criteria and direct observation. Females were classified to four groups: previtellogenic, vitellogenic, post-vitellogenic, and atresia. Blood, gonad and liver tissue samples were taken through non-lethal biopsy. Our results showed that plasma levels of glucose, cholesterol, triacylglycerol, high-density lipoprotein, low-density lipoprotein, very low-density lipoprotein, calcium, phosphorus, alkaline phosphatase activity, albumin and total protein increased during ovarian development and were highest at post-vitellogenic stage. The lowest amounts in atresia stage demonstrate that lipid and energy imbalance was related to reabsorption and digestion of the yolk. These results suggested that the VLDL was the main plasma lipoprotein component of Sterlet. We determined that lipoprotein lipase and hepatic lipase activity increased during vitellogenesis process which suggested the role of lipase enzymes in regulating blood lipid metabolism. RT-PCR analysis indicates that Vitellogenin (VTG) mRNA could be detected both in livers and ovaries of female Sterlet. Throughout the study, the expression level of VTG gene showed an increase both in ovaries and in livers reaching its peak at late vitellogenesis stage. This strongly indicated a relation between VTG mRNA and ovarian development.

This study was conducted to determine the effects of mannan oligosaccharide (MOS) on growth, some immune responses and gut lactic acid bacteria of common carp. Four experimental diets containing 0%, 0.05%, 0.10% and 0.20% MOS were prepared. Each diet was randomly allocated to triplicate groups of fish with initial average weight of approximately 14 g. After eight weeks, survival rate was high in all treatments with no significant difference (p > 0.05). Growth performance including final weight, weight gain (WG) and specific growth rate (SGR) did not differ among the treatments. Feed conversion ratio (FCR) was better when the fish were fed 0.05 to 0.20% MOS diets. The alternative complement activity, lysozyme activity and serum total Ig were found to be significantly (p < 0.05) greater in fish fed 0.20% MOS diets. Although the total intestinal bacterial counts were not affected by dietary treatment (p > 0.05), the lactic acid bacteria levels were significantly elevated in fi...

Carthamus tinctorius L. (Safflower) is a member of the asteraceae family which is used as a food additive but also has medicinal applications. This study investigated its effects on placental histomorphology and survival of mice neonates. Eighty Balb/C pregnant mice were randomly distributed into one control and three experimental groups (n=20). The control group received only distilled water, whereas experimental groups were administered intraperitoneally C. tinctorius extract at doses of 0.7, 1.4, and 2.8 mg/kg during the organogenesis period (6(th) to 16(th) day of gestation). On the 17(th) day of gestation, half of the animals were euthanized; their fetuses and placentas were removed and histomorphological study was performed. In the rest of the animals after parturition, the number of neonates was counted. Survival rates were periodically calculated for neonates within days 5, 15, 25, and 42 after birth. The results were evaluated by one-way ANOVA. The results showed that treatment with 1.4 and 2.8 mg/kg C. tinctorius extract caused reduction in the trophoblastic giant cells ratio and increasing in the proportion of labyrinthine interhemal membrane (LIM). Moreover, the size of the labyrinthine zone per whole placenta, weight, diameter, and thickness of the placenta in the mice administered with 1.4 and 2.8 mg/kg C. tinctorius extract became lower than those of controls (p<0.05). In addition, in the treated mice with 1.4 and 2.8 mg/kg C. tinctorius extract, the number of neonate was drastically decreased on days 5, 15, 25, and 42 after birth. It is concluded that treatment with C. tinctorius extract in doses of 1.4 and 2.8 mg/kg induces toxic changes in the placental structure so caution should be paid to popular consumption of this plant both as an alternative medicine and as a food additive.

Lipid content of diet is very susceptible to oxidation, especially when stored for a long time, so for evaluating protective effects of green tea in fish received oxidized oil this study was done. Lipid content of diet was replaced by oxidized fish oil (OFO) in 0, 50 and 100%. Green tea extract (GTE) was added to diet in 3 levels, 0, 5 and 100 mg/kg giving a total of 9 experimental diets. Two hundred and seventy sturgeon hybrid of Sterlet (Huso huso ♀ × Acipenser ruthenus ♂) with initial weight of 212.6±0.7 g after 2 weeks adaptation randomly divided in 27 fiberglass tanks with 700 L volume. Fish were fed satiated three times daily. After 6 weeks, biometry was done to evaluate growth performance and blood samples were taken for biochemical analysis. The result showed that feeding with oxidized oil had no effects on growth. However, in fish fed GTE growth indices improved slightly. Feeding with OFO reduced serum total cholesterol, triacylglycerol, low density lipoprotein, while increased high density lipoprotein. Dietary GTE moderated the effects of OFO on lipid metabolism. Feeding with the OFO increased activity of serum superoxide dismutase, catalase, glutathione peroxidase and malondialdehyde contents. In fish received both OFO and GTE reduced activity of serum antioxidant enzymes and malondialdehyde content was recorded in compare to fish fed only OFO. According to the result of the present study, it can be argued that feeding of sturgeon hybrid of Sterlet with OFO has negative effects on lipid metabolism and antioxidant status, whereas GTE dosages used in this study has protective effect on fish from the adverse effects of oxidized oil.

For evaluating effects of green tea in fish received oxidized oil this study was done. Lipid of diet was replaced by oxidized fish oil (OFO) in 0, 50 and 100%. Green tea extract (GTE) was added to diet in 3 levels, 0, 5 and 100 mg/kg giving a total of 9 experimental diets. Two hundred and seventy sturgeon hybrid (Huso huso ♀ × Acipenser ruthenus ♂), mean weight of 211.71 ± 0.23 g randomly divided in 27 fiberglass tanks with 700 l volume after 2 weeks adaptation. After 6 weeks, biometry was done to evaluate growth performance and blood samples were taken. The result showed that feeding with OFO had no effects on condition factor and specific growth rate. However, in fish fed GTE feed efficiency ratio and protein efficiency ratio improved slightly. Red blood cells were not affected by OFO and GTE while in fish received GTE and both GTE and OFO white blood cells increased significantly (P<0.05). Immunological parameters, (IgM, ACH50 and Lysozyme) showed significant increase in compare to control (P<0.05). Our findings showed that feeding of sturgeon hybrid with OFO had no effects on growth but GTE improved feeding performance. Also OFO had no effects on immune function.

The aim of the present study was to evaluate the effects of dietary vitamin E, nanoselenium (nanoSe), and their combination on growth and acute stress responses in rainbow trout previously subjected to chronic stress. The fish were divided into five groups according to stocking density and diet: Normal (20 kg m −3 ; basal diet), Dense (80 kg m −3 ; basal diet), Vit E (80 kg m −3 ; 500 mg kg −1 vitamin E-supplemented diet), NanoSe (80 kg m −3 ; 1 mg kg −1 nanoSe-supplemented diet), and Combination (80 kg m −3 ; 500 mg kg −1 vitamin E and 1 mg kg −1 nanoSe-supplemented diet). The fish in each group were weighed after 60 days. The best growth under high density condition was observed in fish fed on vitamin E-supplemented diets (Vit E and Combination groups). Following high stocking rearing, fish were subjected to an acute confinement stress by decreasing water volume in the tanks (200 kg fish m −3) for 45 min and sampled at 0, 2, 4, 8 and 24 h post-stress to evaluate the fish performance to additional stressors. The levels of serum cortisol, glucose, lactate, alanine aminotransferase, as-partate transaminase, and alkaline phosphatase were significantly higher in the Dense group at most of time points after initiation of acute stress. The results showed that rainbow trout can reach adaptation to chronic stress conditions, resulting in intensified stress responses to an acute stressor. The data also showed that vitamin E-supplemented diets can exert positive effects on the welfare of chronically stressed rainbow trout subjected to an additional acute stressor.

Aloe vera has been used worldwide in pharmaceutical, food and cosmetic industries due to the plethora of biological activities of its constituents. This study was done to evaluate the effects of dietary aloe vera on growth and lipid peroxidation in rainbow trout (Oncorhynchus mykiss). A total number of 480 O. mykiss (mean weight 9.50 ± 0.85 g) were randomized into four experimental groups including one control and three experimental groups that aloe vera was incorporated in their diet at 0.5, 1.0 and 2.0 g kg-1. Trial was done for eight weeks. Then biometry and blood sampling were done. Plasma malondialdehyde, ferric reducing ability of plasma and growth index were estimated at the end of study. The results showed that aloe vera extract did not affect growth indices. Malondialdehyde was increased in the experimental group compared to the control group but ferric reducing ability of plasma showed a decrease in experimental groups (p &lt; 0.05) compared to the control group. Our findi...

144 juvenile Sobaity, Sparidentex hasta, after acclimation to laboratory conditions in sea water (40ppt) for one week, sea water was replaced with different salinities (5, 20 and 60ppt) and seawater (40ppt) as control. Samplings were performed at 6 and 12 hours, 1, 2, 7 and 14 days after the time of changing in environmental salinities. Blood samples were collected for plasma cortisol, glucose and electrolytes analysis. According to the results, plasma levels of cortisol showed significant increases in 5 and 60 ppt environment in relation to control and 20ppt groups 12 hours from the beginning of the experiment. However in 24h samples up to the end of the experiment (14days) there were no significant differences among treatments. Plasma glucose levels showed a significant increase only at 12h sampling time in relation to 6 and 24hours in fish adapted to 5 and 60ppt. Plasma Ca ++ concentrations had no significant changes during experiment. Plasma Mg ++ amounts decreased significantly...

Asian sea bass, Lates calcarifer is one of the most valuable marine fish species that is known to be tolerant to wide range changes of salinity. The species is able to live in freshwater, brackish and marine water, being an ideal model species for studying the effects of salinity on physiological responses. The present study is aimed to evaluate the changes in expression levels of Na+ -K + ATPase (NKA) and Na+/K+/2Cl– (NKCC) genes in gill tissue of L. calcarifer kept in a range of salinities including freshwater (0 ppt), brackish water (15 ppt) and saline marine water (35 and 50 ppt). Totals of 180 individuals were randomly distributed into 12 fiberglass tanks (volume 300 L) that contained different water salinity variants. After 30 days of experimental captivity, fish were euthanized and gill tissues were collected for NKA and NKCC mRNAs expression analysis. The U shape expression pattern for both NKA and NKCC was recorded. The highest brachial expression was seen in 50 ppt that wa...

This study was undertaken to investigate the effects of feeding rainbow trout (Oncorhynchus mykiss) broodstocks with different ratio of plant oils to evaluate the changes in antioxidant defense status in the progenies. In the experimental diets, fish oil was replaced with different combination of plant oils including corn oil, olive oil, sunflower oil, and coconut oil, to gain different levels of polyunsaturated fatty acids (PUFA) and highly unsaturated fatty acids (HUFA) in the experimental diets. Fish fed eight weeks with experimental diets before reproduction. After spawning, samples were taken on days 0, 5, 10, 15, 20, 25, 30 and 35 after fertilization. The samples were homogenized, centrifuged and the supernatant was removed for determination of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) activity and malondialdehyde (MDA) content. Results showed that SOD activity was significantly increased from the first sampling to day 35 in all treatment grou...

Effects of different levels of dietary nucleotides (NT) were studied on growth indices and body composition of rainbow trout with average weight of 11.35±0.32 during 8 weeks. This experimental was carried out in 700 L circular tanks with 40 fishes per tank. NT was added to the diet at a rate of 0.0, 0.05, 0.1, 0.15 and 0.2 percent. Fish were fed 5 times daily at a rate of 3-5% body weight per day. At the end of feeding trial, the fish fed 0.2% NT showed higher whole body protein, and lower lipid and ash levels compared to the control group. Administration of dietary NT at the level of 0.2% seems to positively influence the proximate composition of fingerling rainbow trout.

Aloe vera has been used worldwide both for pharmaceutical, food and cosmetic industries due to the plethora of biological activities of some of its constituents. The aim of this study was to evaluate the effects of Aloe vera on the antioxidant defense and growth index in rainbow trout. 480 Rainbow trout, weighing 9.50 gr were divided into four group, group 1: normal group, group 2: 0.5 mg/kg Aloe vera concentration, group 3: 1 mg/kg Aloe vera concentration, group 4: 2 mg/kg Aloe vera concentration. Serum catalase, superoxide dismutase, glutathione peroxidase and growth index were estimated. Our results showed that growth was not significantly affected by Aloe vera extract. In experimental control groups, 0.5 and 2 concentration enzyme activities were significantly lower compared with control group. In conclusion, Aloe vera is not recommended for strengthen of antioxidant defenses.

Fish larvae experience major cellular and biochemical changes during their early life stages.The aim of the present study was to evaluate alterations in the antioxidant status and values oflipid peroxidation and vitamin C content during the different life developmental stages ofHypophthalmichthys molitrix. Eggs and larvae were sampled at fertilization, organogenesis,eyed egg, hatch, active feeding, and 14 and 21 days after active feeding. An age dependentsignificant variation in SOD activity was seen during the period of study as the highest activityrecorded at the eyed egg stage (P 0.05). The overall trend of MDA concentration showedsignificant increase from fertilization toward 21 days after fertilization (P&lt;0.05). Vitamin Ccontent showed an opposite pattern and decreased during the period of study (P&lt;0.05). It can beconcluded that vitamin C plays a crucial role in the antioxidant defence system during the earlylife stages of H. molitrix as could prevent from increase of MDA...

This study was conducted to evaluate the effects of purple coneflower (Echinacea purpurea) (EP) on growth and blood parameters in juvenile sterlet (Acipenser ruthenus). One hundred and eighty fish (mean weight 75±1SDg) divided into 12 tanks (n=15) after adaptation period. Base diet was supplemented with 0 (control), 0.5, 1 and 2g/Kg EP to formulate experimental diets. Fish were fed daily at a rate of 3% of body weight. After 60 days, all fish were weighted for growth analysis and blood samples were collected to assess hematological parameters. Results showed that growth indices were not significantly affected by EP extract (p&gt;0.05). There was no notable differences in hematological parameters, including red blood cell, white blood cells, hemoglobin, lymphocyte and neutrophil percentage in treatments compared to the control group (p&gt;0.05). Total protein, albumin, globulin and albumin to globulin ratio did not reveal any differences between experimental and control groups (p&gt;...

This experiment was conducted to examine the effect of dietary Immunogen prebiotic on growth, hematological indices and body composition of rainbow trout fingerlings. A basal diet supplemented with 0 (control), 0.05, 0.1, 0.15 and 0.2 percent prebiotic to formulate five experimental diets. Each diet was randomly allocated to triplicate groups of fish with initial average weight of approximately 13.76±0.54 g. After 8 weeks of feeding trial, fish fed diets with prebiotic showed the highest final weight and SGR, and lowest in fish fed the control diet (P&lt;0.05). The feed conversion ratio (FCR) was better when the fish were fed with 0.15 percent prebiotic. There were significant differences in hematological parameters including hematocrit, RBC, WBC, HB, lymphocyte and neutrophil counts in fish fed by dietary prebiotic (P&lt;0.05). At the end of feeding trial, the fish fed 0.1% diet showed higher whole body protein. The fish fed with 0.15% diet exhibited lower levels of lipid and ash. ...

Fish oil in the diet of fish is constantly at the risk of oxidation. In this study, the effects of feeding sturgeon hybrid (Huso huso ♂ ×Acipenser ruthenus ♀) with different levels of oxidized fish oil (OFO) on thyroid hormones were investigated. Three experimental diets were made by replacing 0 (control), 50 and 100% OFO were made. Ninety hybrid sturgeon, with the initial weights of 212.6 ± 07g were distributed in 9 fiberglass tanks (2 m3) randomly after 2 weeks of adaptation with experimental conditions. Feeding was done three times daily (08:00, 14:00 and 20:00) for 6 weeks for satisfaction. At the end of the period, blood samples were taken and their serum was separated. Serum thyroxine and triiodotyronine were measured by radioimmunoassay in blood samples. Serum thyroxine, triiodotyronine and thyroxine/triiodotyronine level showed no significant changes related to dietary OFO. Our findings showed that dietary-OFO had no effect on blood thyroid hormones levels.