Investigation on replacement of fish oil by vegetable oils (rice bran, soybean and linseed) in diet of rainbow trout (Oncorhynchus mykiss)

The aim of the present study was to determine the impact of replacing the fish oil by alternative lipid sources in diets for rainbow trout (Oncorhynchus mykiss) on growth, fatty acid profiles of muscle. Five isonitrogenous and isoenergetic semipurified diets were formulated containing 100% rice bran oil (RBO), 100% linseed oil (LO), 100% Soybean oil (SO) and a 1:1:1:1 rice bran, linseed, soybean and fish oil mixture (MX) were compared to a pure fish oil (FO) diet. The diets were fed to apparent satiation twice a day to triplicate groups of 30 rainbow trout with an initial weight of 90g for 15 weeks at 12°C.At the end of the experiment, fillet samples were collected from fish for the measurement of fatty acid profile and fillet composition. Fish fed the FO diet had the highest weight gain over the experimental period (280.28 g), However no differences in growth rate and CF were observed across diet groups. Feed conversion ratios (FCR) ranged from 1.12 to 1.24. Significant difference in FCR was found in the group fed an FO diet. The fillet lipid concentrations and fatty acid composition of the fish were significantly affected by the experimental diets. Fish fed the FO diet contained significantly lower lipid levels (20.18%) than those fed the 4 other diets. The highest level of n-3 PUFA concentrations were recorded in fish fed the LO diet (21.8) with significant difference than other diets and the lowest were in those fed the RBO diet (7.84). Fish fed the SO diet contained significantly higher level of n-6 PUFA concentrations (31.72) than other diets and the lowest were in those fed the FO diet (19.15). Fish on the FO diet had a significantly greater percentage of DHA (10.10%) in muscle tissue compared with fish on all other diets and the lowest was in those fed the RBO diet (2.81%). However, the highest level of eicosapentaenoic acid (EPA) concentrations was recorded in fish fed the SO diet (1.84%) and the lowest in those fed the diet (0.67%). This study showed considerable reductions (about 3-fold) in the n-3/n-6 ratio when FO in the fish diet was replaced by rice bran and soybean oils, which may be extremely negative from a nutritional point of view. In other hand linseed oil had the highest n-3/n-6 ratio (0.91) that was comparable with fish oil n- 3/n-6 ratio (0.89). The results in this study imply that an appropriate mix of vegetable oils and FO can replace the sole use of FO in fish feeds

Study on the growth parameters of Capoeta trutta (Heckel, 1843) in Shour River, Iran

In this study growth characteristics of 815 tuwini (Capoeta trutta) in Shour River were investigated during July 2010 through June 2011. The population was composed of 62.94% females and 32.02% males. Sex ratio was 1: 1.96, with significant differences observed at 1:1 (x^2= 150.6; df= 1; p<0.05). The age distribution of this population ranged from <1 to 6 years. The distribution of length and weight was between 95 and 300 mm. The average length, except in <1 year olds, was statistically significant between sexes and average weight in all age groups was statistically significant between sexes (p<0.05). Weight-length relationship was determined as W=0.0115L^2.9475 (R=0.91) in males and W=0.0096L^3.0025 (R= 0.88) in females. Von-Bertalanffy growth equation was Lt= 24.5(1-e^-0.333(t+2.54)) for males and Lt= 36.4 (1- e^-0.129(t+4.02)) for females. Growth performance index was also estimated as Φ=2.301 in males and Φ=2.223 in females

Study of Spirulina platensis meal effectin diet for growth and survival of Litopenaeus vannamei Larvae

This survey was conducted to survey the substition effect of Arthrospira platensis and Chaetoceros muelleri as food for feeding Litopenaeus vannamei during zoea and mysis stage. Larvae were cultured in 30 L containers filled by 10 L at a density of 100 Larvae. During the experiment salinity was 30 ppt and the average of temperature , pH and DO were 31.4ºC ,8.03 and 5.3 mg/l respectively .Three diet treatment and three replicates consist of twomonospecific and 1 combination of two algae were designed. All treatments received Artemia naupli at 5/ml from M1 and micro bound diet at 6 mg/l/d. Survival and total length were measured in zoea and mysisstage.The result indicate that highest survival rate in Zoea (63.17±1 %) and mysis (45.3±1.2 %) was obtained in Chaetoceros (P0.05)but In mysis stage (4.44±0.09mm ) was obtained in combination of Chaetoceros muelleri and Arthrospira platensis ( P<0.05 ).The result of this survey indicated that combination of Chaetoceros and Arthrospira platensis is better for feeding Litopenaeus vannamei during zoea and mysis stage

Investigating the role of organic matter in the variation of concentration of nickel, mercury and cadmium in sediment and leaf Avicenna marina on the coast of Bandar-e-Eman Khomeini

Without abstract

AACL BIOFLUX Aquaculture, Aquarium, Conservation &amp; Legislation International Journal of the Bioflux Society Effect of vacuum packaging on quality changes of refrigerated Jinga shrimp Metapenaeus affinis muscle

Abstract. Metapenaeus affinis is one of the economically valuable species of Persian Gulf and Oman Sea and is of high nutritional value. In this research chemical composition and spoilage indicators of vacuum packed shrimp muscle including total lipids (TL), moisture, total protein, total ash, peroxide value (PV), thiobarbituric acid (TBA), total volatile bases nitrogen (TVN), and pH during a period of 18 days were examined at a cold temperature. To carry out the experiment sampling was done in seven steps (0, 3, 6, 9, 12, 15, 18 days) and the results showed that the rate of PV index in the first day increased from 0.93 meq/kg to 2.09 meq/kg. TVN indicator increased from 10.02 mg/100 g muscle to 26.83 mg/100 g muscle in the 18 th day. Lipid and protein content significantly decreased during the period (P&lt;0.05). Thiobarbituric acid (TBA) index increased from 0.59 mg MDA/kg to 1.53 mg MDA/kg in the 18 th day. In general, according to the results, the maintenance period of vacuum-packed muscles at cold temperature was determined to be 12 days

Effect of vacuum packaging on the shelf-life and quality of Hypophthalmichthys molitrix fillets during storage in refrigerator temperature

Vacuum packaging is one of the appropriate methods in packaging and storage of fish products. In this study, chemical changes including pH, thiobarbituric acid (TBA), total volatile basic nitrogen (TVN) and microbial counts such as coliform bacteria, fecal coliform, salmonella and Escherichia coli in vacuum packed fillet of silver carp (Hypophthalmichthys molitrix) was performed during 30 days storage at 4 ± 1 °C. Fresh silver carp fish samples (ranged 900 to 1200 g) were obtained and transported to the laboratory. Data were analyzed using SPSS 18 software. Results showed that the highest levels of TVN and pH were determined as 63.33 ± 1.82 mg/100 g and 6.81 ± 0.04 in the day 30, respectively. According to the results, TBA, TVN and pH values were increased during 30 days storage. Moreover, total bacterial count increased during the 30 days of storage. Results revealed that coliform counts were less than 2 log cfu/g during the 30 days of storage. Increasing trend of faecal coliform at the end of storage period was estimated as 2.38±0.01 log cfu/g. Considering the microbial populations and the chemical spoilage indicators (TBA and TVN), the shelf life of 15 days was established for the vacuum packaged fillet stored at 4±1°C

Lipid quality in benni (Barbus sharpeyi) fillets during ice storage

Abstract This research was conducted to evaluate qualitative changes of Benni Fish (Barbus Sharpeyi) during its maintenance in ice storage for 20 days. To do so, chemical spoilage indicators including peroxide (PV), thiobarbituric acid (TBA), free fatty acids(FFA), total lipid (TL), moisture (M), heme iron (HI), and also organoleptic parameters (tissue, gill appearance, gill smell, general appearance, and eyes) were measured. Fat quality of sample fish (in terms of oxidative and hydrolytic rancidity) showed a significant reduction during the maintenance period (p&lt;0.05). Peroxide index changes from 3.73 to 7.52 (meq/kg) and TBA from 0.5 to 6.6 (mg MDA/kg) was recorded as markers of oxidative spoilage and FFA changes from 2.05 to 6.58 (expressed as % of oleic acid) were recorded as indicator of hydrolytic rancidity. Each one of sensory tests were rated as excellent to good until the fourth day and their quality was acceptable until the tenth day and then organoleptic results dropped significantly. In general, the best time of fish Shelf life in ice storage was determined to be 7 to 10 days

Association of Mercury, Cadmium and Arsenic bioaccumulation with the chemical compositions of Liza auratus muscle in Anzali Wetland

This study aimed to evaluate protein, fat and ash contents as well as the concentrations of As, Hg and Cd in muscle tissues of Liza auratus cached from Anzali Wetland. Eighteen samples of Liza auratus were collected using gill net. Heavy metals were extracted using wet digestion method and the concentrations were measured by Atomic Absorption Spectrophotometer. Concentration of Hg, As and Cd in the muscle of mullet was 57.20±7.56, 97.29±13.27 and 200.80±31.39 µg/Kg. Moreover, the percentage (mean±SD) of protein, fat and ash in the muscle of the samples were determined as 17.69±0.42, 0.74±0.08 and 1.37±0.12%, respectively. The positive and significant relationship was observed between the concentration of Hg, As and Cd in the muscle of mullet (