Enrichment of Artemia nauplii with essential fatty acids and vitamin C: effect on rainbow trout (Oncorhynchus mykiss) larvae performance

The effect of essential fatty acids (EFA) and vitamin C-enriched Artemia nauplii on growth, survival, and resistance to temperature (high) stress in rainbow trout larvae reared in tanks were investigated. The larvae (average weight 120.43mg±13.5) were fed 6 times daily starting at the onset of exogenous feeding for 1 week. Triplicate groups of fish were offered one of four treatments (1) commercial starter food for rainbow trout, (2) newly hatched Artemia nauplii (unenriched), (3) highly unsaturated fatty acid (HUFA) + vitamin C-enriched Artemia nauplii and (4) combination of 10% HUFA + vitamin C enriched nauplii and commercial starter food. After 1 week, all groups of fish were switched to the commercial diet for an additional period of 3 weeks. Statistical analysis of growth after the first week and at the end of the experiment, showed that growth of larvae in various treatments was significantly different (P<0.05). After 4 weeks, the larvae in treatment 3 with the average weight of 657.50 ± 57.93 mg had the highest body weight (P<0.05). The highest percentage of survival (96%) was observed in treatment 3 (P<0.05). Proximate compositions of trout larvae after one week feeding with experimental diets showed that the protein in the larvae of treatments 3 and 4 was significantly different compared to other treatments (P<0.05). The best result of resistance to temperature (up to 24ºC) was observed in larvae reared on treatment 3 with 91.34 ± 1.52 percent (P<0.05)

Effects of stocking density on survival and growth indices of common carp (Cyprinus carpio)

The effects of social interactions on survival, growth indices and competitive behavior of common cam (Cyprinus carpio) at four stocking densities (350, 400, 450 and 500 fish per hectare) were investigated. A poly-culture of Chinese carps was implemented for 7 months in 12 Culture ponds each 10 hectares in size at Dikjeh area, Golestan province of Iran. Monthly biometrical characteristics such as total length, weight, and condition factor and growth rate were measured. The introduced common carp weighing on average 45g reached 705g after 7 months. With increase in common can) density up to 450 fish per hectare, growth indices including secondary weight, growth rate, SGR and fish biomass showed no significant differences (P>0.05), whereas 500 common carp individuals per hectare caused secondary weight, growth rate and SGR indices decrease significantly (P<0.05). At this density, fish biomass showed significant increase (P<0.05). Based on the results of this study, we conclude that common carp can be successfully cultured up to a density of 450 fish per hectare

Effect of a multi-strain probiotic (Primalac) on growth performance, some blood biochemical parameters, survival and stress resistance on Caspian kutum (Rutilus kutum) fry

This study was conducted to evaluate the effect of probiotic supplementation of Primalac on growth performance, some blood biochemical parameters, survival and salinity tolerance of the Caspian kutum fry. Fish (1.002±0.001 g) were classified to four groups fed on diets containing Primalac in different levels: 0 (control), 0.05, 0.10 and 0.15 % for 45 days. The results showed that there was a significant increase in final weight, weight gain and specific growth rate in those fish fed 0.10% Primalac diets (p0.05). On the other hand, blood cholesterol of the Caspian kutum was significantly increased in control group in comparison with Primalac treatments (p0.05). The results of the present study indicate that the supplement of 0.10% Primalac have a positive effect on the growth performance and blood biochemical parameters of the Caspian kutum fry

Effect of light and music on growth performance and survival rate of goldfish (Carassius auratus)

Environmental enrichment is one of the methods for improving fish growth performance. In the present trial, the effects of both light color and music on growth performance and survival of goldfish (Carassius auratus) (initial mean weight: 4.15±0.08 g) were investigated for 2 months. Two light color treatments (red light and white light) and three music treatments (M0: without music, M30: 30 minutes music and M60: 60 minutes music) were considered. At the end of the rearing stage, growth performance including weight gain (WG), specific growth rate (SGR), daily growth rate (DGR) and food conversion rate (FCR) and also survival rate (SR) were surveyed. Results indicated that the effect of music and interaction effect of light by music were not significant (P>0.05) on growth performance parameters, whereas light significantly (P0.05). Using music in the rearing environment had no positive or negative effect on goldfish growth, revealing that goldfish can distinguish music from other environmental stressful sounds

Effect of herbal supplement of sangrovit on growth, blood biochemical parameters, survival and resistance to salinity stress of Cyprinus carpio fingerlings

This study was conducted to investigate the effects of different levels of sangrovit (0, 0.05, 0.1 and 0.15 %) on growth, some of blood biochemical parameters, survival and salinity tolerance capacity in Cyprinus carpio (2.62±0.117 gr). After 45 days of feeding, results showed that growth performance including of weight gain and % specific growth rate improved which fish fed whit sangrovit compared with to control group, but there was no significant differences in growth parameters which fish fed with herbal supplement compared to control group (P>0.05). There were significant differences in biochemical parameters in fish fed with sangrovit compared to the control group (P<0.05). The lowest level of cholesterol was observed in 0.05 % group and the highest level of total protein was observed in 0.15 % group. The highest levels of glucose observed in control treatment. In order to determine the effect of the herbal supplement on resistance to salinity stress, salinity stress was carried out after 45 days of feeding. Blood samples were obtained at 24, 72, 120 and 168 hours after stress. Hematocrit had significant difference in each groups (P<0.05). On the third day after stress, hematocrit levels were decreased in all treatments. Survival and tolerance to salinity stress challenge remained unaffected by dietary supplementation of sangrovit. The results of this study showed that addition of sangrovit to fish diet can improve growth performance and blood biochemical parameters of common carp fingerlings

Effects of plant proteins as food on growth performance, carcass quality and plasma biochemical parameters of Beluga juvenile (Huso huso)

The possibility of replacing fish meal with plant protein sources (soybean meal and corn gluten) for beluga (initial body mass 159.55±2.14g) was studied in autumn 2009. Experimental feeds with 46.5% of crude protein, GE: 5.4 Cal g -1 in four replacement levels: 0, 270, 450 and 660 gr kg 1 were prepared and fish were fed on the diets for 60 days. Significant differences were found in growth performance (P0.05). Moisture of beluga carcass fed with diet 4 was significantly higher (P0.05) among diets. The hematocrit percentage was significantly higher in experimental treatments 1 and 2 than 3 and 4 and the plasma glucose was significantly different between diets 1 and 4 (P<0.05). With decreased fish meal, significantly (P<0.05) decreased plasma cholesterol was found in diet 1 compared to the diets 3 and 4. Results showed that combination of soybean meal and corn gluten is not a good substitute for fish meal and deceased growth performance of the fish

The effect of dietary nucleotide on the haematological and serum biochemical parameters of Persian sturgeon (Acipenser persicus) juveniles

This study was aimed to examine the impact of different levels of dietary nucleotides (Vannagen) on serum biochemical and blood parameters of Persian sturgeon (Acipenser persicus). Fish (42.37± 2.12 g and 23.67± 0.61 cm) were divided into four treatments with different levels of dietary nucleotides (0, 0.25, 0.35 and 0.5 percent of diet). There were three replicates with a density of 12 fish per tank. After 10 weeks of feeding, serum biochemical and blood parameters were measured. Among the measured factors, blood glucose, triglycerides, cholesterol, erythrocyte and heterophil showed significant differences between the groups fed with nucleotides and the control group (P ≤ 0.05). By increasing the nucleotide levels, the mean heterophil and serum glucose showed significant increase and decrease, respectively. The highest and lowest values of cholesterol and triglyceride were found in groups fed with 0.25% and 0.35% nucleotides, respectively. The other measured factors had no significant difference (P≤0.05). Therefore, it could be said that with regard to the limited capacity of cells to synthesize nucleotides, external preparing of nucleotides could result in the production of needed nucleotides and an increase of its production speed, especially during stress. Such preparation can also improve fish physiology and health status

Effect of chitosan diet on intestinal histology, body composition and salinity and thermal stresses resistance in Caspian kutum (Rutilus frisii kutum, Kamenskii 1901) fingerlings

This study was conducted to evaluate the effect of the chitosan diet on the intestinal histology, body composition and resistance towards salinity and thermal stresses in Caspian kutum (Rutilus frisii kutum) fingerlings. This research, using a completely random design, consisted of 0.25, 0.5, 1, and 2 g levels of chitosan per kg for each commercial diet of the Caspian kutum in three repetitions. The Kutum fingerlings, with an average weight of 1.76 ± 0.15 g, were fed with the experimental diets for 8 weeks. At the end of the experiment, tissue sections were prepared by cutting 5mm-thick samples from the intestines of the fish. To evaluate the resistance to salinity and thermal stresses, the fingerlings were exposed to a salinity stress of 11 ppt and 13 ppt and temperatures of 30 °C and 34 °C, after which the survival rate was calculated. Microscopic observations showed that the intestinal villi height in the fish fed with the diet containing 1 g kg-1 of chitosan significantly increased to 319.93 µm compared to the control group (P0.05). Fish survival rate after 11 ppt and 13 ppt salinity stress showed no statistically significant difference (P>0.05), but the survival rate of the fish fed with the diet containing 1g kg1 of chitosan after experiencing the 34 °C thermal stress significantly increased to 70% (P<0.05). The results suggest that a chitosan level of 1g kg-1 in the diet can not only affect the survival rate and resistance of kutum fingerlings against thermal stress, but can also affect the height of the intestinal villi

Effects of organophosphate, diazinon on some haematological and biochemical changes in Rutilus frisii kutum (Kamensky, 1901) male brood stocks

The acute toxicity and effects of diazinon on some haematological parameters of kutum (Rutilus frisii kutum, Kamensky, 1901) weighing 613.33 ± 157.06 g were studied under static water quality conditions at 15 °C ± 2 ºC. These experiments were carried out based on the standard TRC, 1984 method over 4 days, and controlled for the effective water physicochemical factors having pH ranges of 7-8.2, total hardness 300 mgl^-1 (CaCO3), dissolved oxygen 7 mgl^-1. The results showed that the 96h LC50 value of diazinon was 0.4 mgl^-1 and that the maximum allowable concentration (MAC) value of this toxin was 0.04 mgl^-1. The second stage of experiments consisted of four treatments: LC0: 0 as blank, treatment A with a concentration of LC1: 0.107 mgl^-1, treatment B with a concentration of LC5: 0.157 mgl^-1, treatment C with a concentration of MAC value: 0.04 mgl^-1. Male brood stocks of R. frisii were treated with these concentrations for 45 days. The results showed that long-term exposure to diazinon causes a decrease in the erythrocyte count (RBC), haemoglobin (Hb), haematocrit (PCV), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), leucocyte count (WBC), lymphocyte, testosterone, iron (Fe), sodium (Na), lactate dehydrogenase (LDH) and cholinesterase (CHeS) (P0.05). The results showed that long-term exposure to low concentrations of diazinon causes changes in some haematological and biochemical parameters of R. frisii male brood stocks