Iranian Scientific Fisheries Journal
Year:2017 | Volume:26 | Issue:1|Papers Count:21

In this study effect of different levels of Ascorbic acid (AA) on growth, survival attributes in fingerling common carp were studied and optimum range of the vitamin was calculated in cultural condition. Thus, fingerling carps in 6.85±0.16g weighted were feed by SFC feed with 4 levels of AA (0, 100, 300 and 500 mg/Kg) during 8 weeks. The results showed that there were different between treatments in aspects of fish length and weight (P<0.05), but there wasn' t in survival (p>0.05). The fish were fed with 300 mg/Kg AA showed maximum weight and length gain and the minimum weight and length gain were showed in control and treatment of 500 mg/Kg AA (p<0.05). The results also showed that SGR, WG, DGR and BWi% were highest in treatment of 300 mg/Kg AA and also lowest FCR has obtained in same treatment. There were no different in condition factor (CF) between treatment (p>0.05). According to results optimal level of AA to improve of growth performance for fingerling carp feed is 300 mg/Kg.

The present study aimed to investigate the effects of different digestible and metabolizable energy to protein ratio to obtain optimum ratio in diet. This experiment was carried out with 2600 (control), 2900, 3200, 3500 and 3800 kcal/kg digestible energy (DE) that equal to 2250, 2500, 2750, 3000 and 3300 kcal/kg metabolizable energy (ME) with 35 % protein (CP) in diet. The DE/CP ratios were 74, 83, 92, 100, 108 and for ME/CP 64, 71, 78, 86 and 94. Five treatments were compared in a completely randomized design with 200 fish (average weight 195±5 g) and 4 replicates for 9 weeks. According to the results, the higher growth rate was observed, when the energy to protein ratio increased compared to control group. Fish fed DE/CP=100 (ME/CP=86) dietary content significantly showed the highest weight gain compared to other treatments and improved feed conversion ratio (FCR) and specific growth rate as well (P<0.05). In all treatments, no significant differences were observed for dry matter and ash content of flesh compared to control group (P>0.05). Moreover, fat content significantly increased, but protein content significantly decreased when DE/CP increased (P<0.05). Therefore, it is recommended that diet contains 35 % CP and 3500 or 3000 kcal/kg DE and ME, respectively (DE/CP=100 and ME/CP=86) at the finishing stage of rainbow trout is more effective.

Aquatic organisms present, not only simple sources of accumulated metal, but can interact with metals, altering their toxicity. Due to exposition of biosphere with metals, organisms have developed various defense mechanisms to protect themselves against adverse effects of these ions and their compounds.MT is one of that which represent a critical mechanismfor detoxificationof metals.The Sterlet (Acipenser ruthenus) is a bottom-feeding sturgeon specie and because the fish are dependent on invertebrate species for food throughout their life cycle, the Sterlet could be a good indicator of the quality state of water ecosystem. Addition of copper to water leads to the induction of metallothionein. The present study analyzed metallothionein gen that (MT) excreted from liver of Sterlet (Acipenser ruthenus) exposed to sub-lethal copper concentrations (0.075mgL (-1).To begin to elucidate molecular mechanism (s) of sensitivity of sturgeons to metals a RNA encoding metallothionein (MT) was purified from livers of Sterlet then a cdna was synthetized and the MTgene was amplified. The primary structure of Sterlet metallothionein (S-MT) contained 20 cysteine residues, which is the same as MTs of teleost fishes. However, the primary structure of Sterlet metallothionein contained 63 amino acids, which is longer than any MT identified in teleost fishes but similar to Lake sturgeon and White sturgeon. The complete nucleotide sequence of the Sterlet metallothionein gene has been detected. We have determined the structure of the fish copper-binding protein by DNA sequence analysis of the gene.

Yersinia ruckeri is one of the most important causative agents of economic losses in fish farms in Iran. During April-August 2012, sampling was done from 285 unhealthy rainbow trout weighing from 1-200 g up, from 19 coldwater farms that located in west-Azerbaijan province in order to isolate and identify the pathogenic bacterium Y. ruckeri, as causative agent of enteric redmouth disease. Samples from the fish's mouth, kidney tissue and the last third of intestine were cultured on Yersinia selective agar media and then incubated at the 25oC for 48-72 hours. Using gram staining, biochemical tests and molecular assay (PCR) from 285 studied samples, 110 samples were infected to Y. ruckeri in the intestine (with an average of 59.38% contamination), 76 in mouth (with an average of 25.66% contamination), and 25 in kidney tissue (with an average of 8.77% contamination). Moreover, Y. ruckeri were isolated from 12 farms out of 19 studied farms so the contamination rate about 36.84 percent was estimated. The results show that the average amount of contamination in west-Azerbaijan is higher than other provinces in the country. Regarding different weights, the samples in finger size weighing 1-20 g were the most infected ones (52.63%) and the market size weighing up to 200 grams (24.56%) had minimal contamination with bacteria. This result revealed that fish with fingerling size are the most sensitive compare to higher weights. Also, significant correlation was observed between high rate of nitrite and disease occurrence (r=870 and p=0.03). It seems that amount of nitrite more than 0.1 ppm in water of farms could be played important role as susceptibility factor in occurrence of ERM disease. So, proper health management could control the rate of disease outbreak in west-Azerbaijan’s fish farms.

Allometric growth pattern is a phenomena during early development of fishes. This research was conducted to study the allometric growth patterns of a hybrid triploid sturgeon (Acipenser baeri♂ x Huso huso♀) during early developmental stage up to 50 day post hatching (dph). Morphometric parameters of this study obtained from 2D pictures of specimens using the software ImageJ and allometric growth pattern was calculated as a power function of total length using non-transformed data: Y=axb. The results revealed that during early development of the triploid sturgeon after hatching, head and tail regions have positive allometric growth pattern that can be as result of importance vital functions, including swimming, respiration and sensory systems during this period. The inflexion points of the most body parts have been occurred prior 25 dph and afterward their growth patterns were isometric. Despite the genetic difference between the hybrid triploid sturgeon with its parents, the results showed that its allometric growth patterns have many similarities with them. This results, also, provide evidence that the phenotypic plasticity plays important role in regulation of the body shape during early development.

The aim of this study was to determine the concentrations of heavy metals Nickel and Cadmium in muscle and liver tissues of Pomadasys kaakan in Bushehr seaport during 2015.20 samples of Pomadasys kaakan were caught completely at random from Bushehr seaport by the area local fishermen should be omitted. After biometry of the samples, the muscle and liver tissues of the samples were separated and chemical digestion of the samples was done by MOOPAM, then Nickel and Cadmium accumulation levels in tissues were measured using Graphite furnace atomic absorption instrument (VARIAN AA 100). Based on the obtained results the mean concentrations of Nickel in muscle and liver tissues of Pomadasys kaakan were calculated 0.284±0.074 and 0.344±0.081 mg/kg dry weight respectively and showed that there were no significant differences (P>0.05). Moreover, based on the obtained results the mean concentrations of Cadmium in muscle and liver tissues of Pomadasys kaakan were calculated 0.118±0.011 and 0.132±0.021 mg/kg dry weight respectively and showed that there were significant differences (P<0.05). The results of this study revealed that the Nickel and Cadmium metals concentration in edible tissues (muscle) of Pomadasys kaakan in study station are lower than the levels permitted within the standards of WHO, FAO, NHMRC, UK (MAFF) and FDA. So the use of these species for human consumption from the perspective of public health will not create a problem.

Yellowfin tuna (Thunnus albacares) is one of the most important apex predator species that currently catch by Iranian purse seiners in the Indian Ocean and Oman Sea. This study considered the possible relationship of spatial, temporal and some satellite derived environmental variables on yellowfin tuna distribution to finally help implementing of ecosystem based fisheries management for stock recovery program and management of yellowfin tuna. Results of generalized additive model (GAM) (by assuming two distribution; binomial and Gaussian) revealed spatial and temporal explanatory variables plus sea surface temperature (SST), sea surface salinity (SSS), mixed layer depth (MLD) and net primary production (NPP) have the greatest impact on yellowfin tuna distribution in both cold and warm season. In addition, the results revealed that latitude had stronger effect on deviance explanation of model in warm season. On the other hand, in cold season, the effect of longitude and environmental variables was clear. In warm season, binomial distribution was explained higher deviance of model, though in cold season deviance explanation of best model was lower than warm season but no significant difference has detected. Since the early step in ecosystem management is the sufficient knowledge on ecosystem and distribution of target species in relationship to environmental variables, therefore this research could help Iranian purse seiners to improve the catch efficiency in order to help to implementing of ecosystem based management in the Indian Ocean.

An 8- week feeding experiment was conducted to evaluate the effect of dietary betain as a feed attractant on growth, survival, body composition and resistance rate on kutum (Rutilus frisii kutum) fingerling.225 fish by the initial weight of 2.26±0.2 g and density of 15 fish per tank. Five treatments of different levels of betain including 0 (control), 0.5%, 1%, 1.5% and 2% added to diet containing 40% protein and 8% lipid. According to the results of this study, no significant differences in growth performance and feeding parameters observed between fish fed control and betain supplementation diets. No significant differences in survival rate among all treatment groups. There were no significant differences in body composition among all treatment groups. Resistance rate were not influenced by the levels of betain. Totally considering betain did not show significant effect on the growth, surviving and resistance to stress in kutum fingerling.

This study evaluated the effects of diets including different levels of oregano (Origanum vulgare L. (essential oil on growth indices and fillet quality of rainbow trout (Oncorhynchus mykiss) during refrigerated storage (4±1°C). For this purpose, rainbow trout with an average weight of 69.38±0.44 g were fed with diets containing 0, 250, 500 and 750 mg kg-1 oregano essential oil for 48 days. After the end of 48 days, growth parameters were measured and also some fishes of experimental groups were filleted and stored at refrigerator (4±1oC) for 21 days due to quality investigation. Total psychrophilic counts, TBA and TVB-N analyses were done every 7 days (day 0, 7, 14 and 21). The results showed significant differences in some growth parameters including final weight, weight gain, weight gain percent and feed conversion ratio among experimental groups (P<0.05).The results also showed lower amount of total psychrophilic counts and TBA in rainbow trout fillet from oregano groups than control group, during refrigerated storage (P<0.05). As on day 21, the highest amount of PTC was obtained in control (14.39±0.12 log cfu/g) and the least amount of that was obtained in 250 mg kg-1 (12.38±0.09 log cfu/g).The highest amount of TBA was also observed in control (1.57±0.05 log cfu/g) and the least amount of that was observed in 750 mg kg-1 (1.20±0.08 log cfu/g) (P<0.05). No significant differences were observed among essential oil treatments. Overally, it could be say using500 mg oregano essential oil can cause improvement of growth and rainbow trout fillet quality during refrigerated storage (4±1oC).

This study was conducted to determine statement of some metals and oil pollutants in the southern Caspian Sea (Kelarabad-Mazandaran).Seventy five Surface sediments samples (Triplicate) were collected at three stations from autumn of 2011 to winter of 2012. All samples were prepared by digesting and extracting processes and then determined using Atomic Absorption Spectroscopy and High Performance Liquid Chromatography instruments. Results showed that annual mean contents and standard error (±SE) of surface sediments were observed 59 (±3), 25 (±1), 42 (±2), 28 (±1), 14 (±1), 0.16 (±0.06), 0.020 (±0.005) and 2.81 (±0.73) mg/kg.dw for Zn, Cu, Cr, Ni, Pb, Cd, Hg and PAHs, respectively. Also, sediments samples based on Enrichment factor (EF) and Ggeoaccumulation index (Igeo) were showed no polluted conditions for this region, but sediments were classified low polluted based on CF, Cd and PLI. In addition, Hazard Quotation (HQs) of most of PAHs compound were calculated more than unit in surface sediment which according to results of the evaluation’s risks to health of 16PAHs suggest that there is risk for biota. In a conclusion, according to anthropogenic sources of some metals and PAHs of sediment, it is essential that the management and development of the aquaculture industry in the Mazandaran Coast to be made with environmental considerations and cautions.

This study was performed in order to evaluate the effects of chronic stress (density) and acute stress (handling) existed in culture environments on stress and hematological parameters of beluga sturgeon (Huso huso) under winter condition (below 10oC) after application of anesthesia. Fish with mean (±SE) weight of 399±1.4 g were kept in the low (1 kg/m2) and high densities (8 kg/m2) in three replicates for a week. Then, fish were held under stress condition so that they were quickly removed from the rearing tank and then anesthetized for 2 minutes in container (50 I) includes 400 mg/l clove powder extract. They were then returned to the original tanks. Blood samples were taken before the stress, 1, 3, 6, 12, 24 and 48 hours after application of the stress and stress indicators (cortisol, glucose and lactate) and hematological parameters (hematocrit, hemoglobin, number of red blood cells, MCV, MCH, MCHC, number of white blood cells, lymphocytes, neutrophils, eosinophils and monocytes) were measured. No differences in measured parameters were observed after one week of holding fish at low and high densities. The results of stress indicators, one hour after acute stress and anesthesia showed a significant difference with resting time (P<0.001). Also significant difference was observed on lactate levels between the low density and high density at 3 h after acute stress and anesthesia (P=0.032). Number of white blood cell at 1 and 6 h after acute stress and anesthesia in high density showed significant difference with resting time (P<0.001). MCV showed significant difference between two treatments at 48 h after the stress and anesthesia (P=0.016). The other parameters did not show any significant difference between treatments (P>0.05). The results revealed that beluga has high resistance against chronic and acute stressors and anesthesia. However, it seems that anesthesia could not control the low negative effects of stress even in this condition of low temperature.

Marine and coastal ecosystems have many benefits and different services for humans that marine aquaculture is one of the most important of these services. Southern coast of Caspian Sea particularly Mazandaran coast have great potential for development of marine aquaculture. Now, there are 9 fish farms with different production capacities in Mazandaran coast. In this study, the growth of specie of fish Rainbow trout (Oncorhynchus mykiss) was modeled using the marine aquaculture model based on daily temperature, rate of metabolism and mortality rate. Finally calculated the harvest weight and net present value (Net Present Value: NPV) for this this specie in each farm was calculated by considering two scenarios: 1) Development and 2) BAU (Business as Usual) that in each scenario equal to 2786 and 1121 tons with the NPV 11158 and 15788 million toman in total mazandaran coast during 1 years. So production of Rainbow trout is more economic. Results show that growth cycle fom the release (200 g) to harvest for Rainbow trout and is 2 cycle in 1 year. Also, duration of growth cycle decreases when temperature increases such that at 14, 16 and 18 degrees Celsius was142, 124 and 110 days, respectively. Since aquaculture farms on the Mazandaran coast had been grownd mostly Rainbow trout so this study is evaluated the production and NPV for this specie. Rainbow trout is a non-native specie in South Caspianso so is necessary that be studied effects and consequences of production the specie in this area.

The aim of the present study was to investigate the effect of probioenzyme on the control of yersiniosis as well as to assess the impact of probioenzyme on the expression of immune-related genes in the head kidney of rainbow trout (Oncorhynchus mykiss). Probioenzyme was supplemented at 0.3, and 0.5g/kg diet and fed to fish (average weight: 26 g) in 200l tanks for 60 days. At the end of the feeding period, fish were challenged with yersinia ruckeri. Only the fish fed the diet containing high dose of probioenzyme showed significantly (P<0.05) improved protection against y. ruckeri compared to the low dose and control groups. Subsequently, real-time PCR was employed to determine the mRNA levels of IL-1β and TNF-α cytokines in the head kidney of the control and probioenzyme groups. High dose of probioenzyme significantly (P<0.05) up-regulated the TNF-α transcription in the kidney compared with low dose and control groups. Meanwhile, the probioenzyme didn, t change nterleukin-1β mRNA level in the kidney in treatment groups compared with control group (P>0.05). Only, high dose of probioenzyme noticeably differs IL-1β and TNF-α gene expressions. Based on results, expression levels of studied cytokines were different, dose-dependent and tissue-specific. Results showed that cytokine gene expressions, especially TNF-α, in kidney may affect fish disease resistance. Present study suggests that probioenzyme especially at 0.5g/kg feed may effectively stimulate the immune system and enhance disease resistance in rainbow trout. Meanwhile, it is necessary to study effects of probioenzyme on cytokines in various tissue and different growth period of breeding species.

To determine the fecundity and population composition of Gammarus (Pontogammarus maeoticus (Gurianova, 1951)) in coast line of the Caspian Sea, monthly sampling was conducted in ten stationg (between Babolsar to Fereydunkenar) from August 2013 to April 2014.A total of 1906 P.maeoticus speciments, male populationcomposition (673), female (873) and immature (360), respectively. Kruskal-Wallis test based on the average number of Gammarus in stations (c2=14.8; p<0.011) and months (c2=17.6; p<0.040) showed significant different. The average length of immature, male and female was 4.1, 8.5 and 8.3 mm and weight 0.0068, 0.0303 and 0.0282, respectively. Males have more weight and length than the female and the mean length and weight of the two sexes was statistically significant (length: t-test=2.05; p<0.041 Weight: t-test=2.81; p<0.005, respectively). Gammarus Length and weight equation was very strong based on exponential relationship (p<0.001; R2=0.80) and slope of line b was 2.1205. The minimum average fecundity was 59.0±0.6 and a maximum of 71.0±4.16. Kruskal-Wallis test between the mean fecundity in different months showed a significant difference (p<0.001).The results show that the overall ratio of male: female was 77.0: 1 which showed completely dominant of females (p<0.001).Also compared the frequency of male and female at different months showed that only in August and March females are dominant statistically (p<0.05).

The objective of this study is to evaluate and compare the concentration of heavy metals, lead, nickel, iron and copper in muscle tissue of White shrimp (Metapenaeus affinis) in three regions (Qeshm, Khamir port and Laft port) in Hormozgan Province. Sampling was conducted in summer and winter 1394. After the 180- captured biometric sample, muscle tissue were isolated. The preparation and analysis of samples was performed according to standard methods MOOPAM. The results indicated that the studied concentration in muscle tissue of White shrimp at sample locations showed significant difference statistically. In terms of concentration in the muscle tissue of White shrimp in the study area between summer and winter significant difference was observed, statistically (p<0.05). As both in summer and winter concentrations of lead, nickel, iron and copper in muscle tissue of White shrimp in Qeshm is greater than the other two regions. The studied concentration in muscle tissue of White shrimp in Qeshm, Khamir port and Laft port international standards is less than the limit which indicates that the health of aquatic ecosystems contamination is not a problem.