نشریه بهره برداری و پرورش آبزیان
سال سوم شماره 1 (بهار 1393)

This study investigates the effects of garlic extract on salinity and PH stress resistance of white leg shrimp post larvae (0.1±0.01 g). The experiment was carried out on the basis of completely random model with 5 dietary treatments which include 0 (control treatment), 1cc (treatment 1), 2cc (treatment 2), 4cc (treatment 3) and 8cc (treatment 4) per 100g food in triplicate. 1500 shrimps were randomly stocked in 15 tanks (100 shrimps in each tank). Shrimps were fed 4 times a day for 7 weeks. At the end of this period, growth and nutritional indices were measured. Salinity and PH stress experiment was done. The results showed that use of 4cc and 8cc of garlic extract for each 100 gr in White leg shrimp’s post larvae improve growth indices of shrimps with regard to control treatment. Results showed that mortality started in 70 and 80ppt salinity, treatment 2 showed significant difference with control, and treatments 3 and 4 had significant difference with control and treatments 1 and 2. In 90ppt salinity treatments 2, 3 and 4 showed significant difference with control treatment. In PH stress, at pH 9 and 10 significant difference was not observed among treatments but in PH 10.5 significant difference showed between treatment 2 and control and treatments 3 and 4 with control and treatment 1. The results show that the economy could be due to diets containing garlic extract 4cc making diets for shrimp larvae posts be considered.

In present study, it was determinated LC50 96-h and toxicity degree of diazinon in Huso huso, then were evaluated effects of sub-lethal concentrations on tow general enzymatic indices including Alanine and Aspartate aminotransferase of plasma and one specific enzymatic index including tissue AChE enzyme. The median lethal concentration, lowest observed effect concentration and maximum allowable toxicant concentration was measured 5.47, 4.28 and 0.54 mg.L-1, respectively. Also, diazinon according by amount of LC50 was classified in “moderate toxicity degree” for this sturgeon. The test results showed that with increasing sub-lethal concentrations of diazinon in water, AST and ALT enzyme activity in experimental fish were increased, Thus, a direct relationship seen between the concentration of diazinon with the public indices. However, increased concentrations of diazinon, causing a decrease in cholinesterase activity in both brain and muscle tissues. In other words, inhibition of AChE is directly related to the concentration of pesticide.The diazinon pesticide concentrations for non-target specieses which were ineffective and allowable according to the lethal test can lead to their enzymatic indicies of serum and AChE responses.

In this investigation, the effects of the precooking (cooking with saturated steam, microwave and oven) and sterilization (115, 120 and 130 ° C, with same sterilization value) on the amount of iron, zinc, copper, calcium, sodium, of silver carp was studied during canning process. The results of measuring elements in the raw and precooked fish were ranged from 3.05 to 4.19 for copper, 71.45 to 82.85 for zinc, 32.18 to 40.70 for Iron, 425.6 to 529.46 for sodium and 315.5 to 534.76 ppm for calcium, respectively. The results showed that different precooking treatments had no significant effect on the amounts of copper, zinc, calcium and sodium. After comparing different methods of precooking, steam cooking was recognized as the best way to preserve the mineral nutrient. In the final stage, with two kinds of filling media, canned samples were processed under three different temperatures (115, 120 and 130 ° C) with same sterilization value (7 min). Results showed, the amount of sodium was increased after canning process. Amounts of other elements were changed heterogeneously in all treatments. Using 120°C and 130°C thermal regimes, achieved better results in maintaining the mineral nutrients. Based on these results, the thermal regime of 115 ° C is not recommended for production canned silver carp.

In this study of common carp surimi produced under the influence of different concentration of thyme (0, 2 and 4%) was investigated. The samples were stored in a refrigerator for 15 days and the three days of the microbial tests include measurement of total bacterial load, Enterobacteriaceae and Pseudomonas bacteria and the total volatile nitrogenous bases was performed on the samples. The results showed that the total bacterial load in any of the treatments until the end of the storage period did not exceed the limit. In such a way that the maximum value of the total bacterial load in control samples 5.11 and the samples treated with thyme extract 5.03 log cfu per g. Enterobacteriaceae bacteria levels at the end of the storage period between treatments did not show significant differences, except day of 9 that the amount of bacteria in the control sample, significantly more samples treated with the extract. Pseudomonas bacteria levels between different treatments until the end of the storage period but did not show a significant difference between days 1 and 6, that's two times the amount of bacteria in control samples was significantly more than treatment with 4%, However, the samples treated with the extract showed no significant difference of 2%. The total volatile nitrogenous bases in samples treated with the extract were less than the control sample until the end of the storage period except the first day. Based on the findings of this study can be stated Thyme extract has anti-bacterial compounds will be retained for a short period of surimi from bacterial spoilage during refrigerated storage used.

This study was conducted to investigation and determine of cadmium (Cd) concentration in the liver of Platycephalus indicus (flathead) in Minab, Qeshm Island and Khamir Port (Persian Gulf). Moreover, the effect of season (winter and summer) and sex (male and female) on Cd concentration in flathead were investigated. Cd concentration sampling was done in two station (Minab, Qeshm Island and Khamir Port) and two seasons (winter and summer) (n= 30 for each season in each station). After biometry of flathead, the concentration of cadmium was measured using Atomic Absorption Spectrometry (AAS). The results showed that, there were significant differences between stations (Minab, Qeshm Island and Khamir Port) for the concentration of cadmium in liver of P. indicus (P

In this study the acute toxicity of organophosphorous pesticide in four native fishes of Khouzestan province including: barbus sharpeyi, Barbus grypus, Barbus barbulus and Barbus xanthopterus were investigated. The acute toxicity test was conducted following the Organization for Economic Cooperation and Development (OECD) under static-renewal test. Each fish species exposed to serial dilution of Diazinon in triplicate for 96 hours, daily mortality were recorded and analysed. Lethal concentration to induce 10%, 20%, 50% and 90% mortality after 24, 48, 72 and 96 h exposure were calculated using Probit software. Results showed that Diazinon is toxic for all fish species and the mortality rate enhanced along with increasing Diazinon concentration. Mortality pattern was similar in all fish species. Diazinon 96 h LC50 in B. sharpeui and B. xanthopterus were 1.805±0.12 and 2.775±0.23 mg l-1 which was significantly (P

With regard to bycatch problem, this is the first study of the shrimp trawl bycatch in different depth variation in Hormuzgan coastal waters. Samples were collected during shrimp season in October 2011 and November 2012. The study area was divided into two regions: Hormuz-Keshtisoukhte (56°, 27ʹ E/27°, 07ʹ N) to (56°, 18ʹ E/27°, 06ʹ N) and Keshtisoukhte-Toola (56°, 18ʹ E/27°, 06ʹ N) to (55°, 58ʹ E/26°, 58ʹ N). To compare the mean CPUE of bycatch among different depths, sampling zone were divided into 3 depths: 1 to 10, 10 to 20 and 20 to 30 m. In 30 hauls, 1028.2 Kg of shrimp and 3388 Kg of bycatch were caught in the trawl net. Bycatch-to-shrimp ratio was calculated 2.80:1 and 3.77:1 in 2011 and 2012 respectively. Bycatch-to-shrimp ratio in 2011 was less than 2012, in all depth category. In the depth of 10 to 20 m, the less bycatch and Bycatch-to-shrimp ratio in two years of study be obtained. Also, the CPUE and mean CPUE of bycatch in 2012 was higher than 2011. In investigation of the mean CPUE of bycatch between seasons 2011 and 2012 (F=2.544; P>0.05) also, among different depths (F=2.264; P>0.05) and in depths in combination with seasons (F=0.579; P>0.05) with using Two-factor analysis of variance (ANOVA), no significant difference were detected.

In this study the effects of the most popular anaesthetics including: MS222, Clove oil (Eugenia caryophyllata) and 2-Phenoxyethanol, on some haematological and serum enzymes of Cyprinus carpio were investigated. Firstly the effective dose of each anaesthetics (3 minutes for anesthesia and 5 minutes for recovery) and LC50 of them were calculated in C. carpio. Fish were anaesthetized with the effective dose of each anaesthetic. Then blood samples were taken at 0, 1, 12, 24 and 72 hours after anaesthesia. Haematologcal parameters (Packed cell Volume, Hemoglobin, Red blood cell count, White blood cell count, differentiated count, MCV,MCH, MCHC), serum enzymes, ALT,AST,ALP,LDH were compared among the groups. MS222 were more effective and safer than other anaestetics (Lve dose 1C50 7 timlarger than effecties). Induced anaesthesia by Clove oil, 2-Phenoxyethanol and MS222 did not show any significant change in haematological parameters of C.carpio in various sampling times(P>0.05). Besides serum enzymes: ALT, AST, ALP, LDH did not affected by three Anaesthetics(P>0.05). Although anaesthesia with MS222 showed the best efficacy and safty, non of studied anaesthetics were adverse effects on hematological and serum enzymes of Cyprinus carpio. The results showed that the evaluated anaesthetics in this study can be used in hematological and biochemical study in C. carpio.

The aim of this study was to investigate on obtained caviar quantity status of sturgeon at fishing grounds of the southwestern Caspian Sea. Data of catches by means of fixed gill nets in sturgeon fish fishing grounds and beach seine were used during 5 years survey (2005-2009). A total of 1361 female sturgeon was caught including: 788 Acipenser persicus, 410 A. stellatus, 60 A. guldenstaedti, 70 A. nudiventris and 33 Huso huso. The total amount of obtained caviar declined from 1652 kg (in 2005) to 925.06 kg (in 2009) that this reduction was about 44%. Based on Pearson test, the relationship between caviar amount and time was linear and had negative and significant correlation (p= 0.015). Additionally, the trend of obtained caviar amount reduced highly in the west coasts of Guilan province (P= 0.016), but it was almost fixed in the east coasts of Guilan province (P= 0.514). Furthermore, the maximum and minimum of obtained caviar amount were 66.60% and 4.19% that belong to A. persicus and A. guldenstaedti, respectively. The maximum and minimum of relative frequency caviar (%) were 72.90 and 3.27 for high quality caviar and compressed caviar respectively that differed significantly (P