9 research outputs found

    An investigation of Capoeta capoeta feeding in Makoo Dam Lake

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    Makoo dam lake made up in 1998, to providing agriculture water, prevention of flood water and production of electric power. It is placed in 12 km to south of Makoo city 29° 44' minute E and 39°11' N). Feeding studies occurred by using of fishing gear, include of electro fishing, gill net and beach seine, seasonally. Fish caught was in size range of 27-290 mm and 0.4- 327.7g. Maximum and minimum of feeding intensity was in winter and spring, respectively. Its average was 360, that showed feeding of this fish was approximately optimum in this lake. Whereas maximum and minimum of K-factor was in summer and winter, respectively. C. capoeta is a detritovorous. Therefore, it consumed from so much other food items, a.g. phytoplankton and benthos in this lake. From phytoplankton, phylum Chrysophyta and genus cyclotella from benthos; Chirooomidae and Ephemeroptera have the most important food sources. With attention to limitation of food organisms of benthos, it is not recommended introducing of other benthopelagic fishes in Makoo lake

    Study on bioaccumulation of Aldrin, Diazinon and Endrin pesticides in the edible muscle tissues of commercially important fish species of the Anzali Wetland

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    The objectives of the present investigation were to study the bioaccumulation of Aldrin, Diazinon and Endrin pesticides in the edible muscle tissues of Tinca tinca, Rutilus frisii kutum, Carassius auratus, Cyprinus carpio, Silurus glanis and Esox lucius that were caught at various stations in the west, east and center of the Anzali Wetland and to compare the results with the standards of the World Health Organization (WHO). The concentration of organochlorine pesticide was determined using Gas Chromatography (GC) equipped with an electron capture detector. The concentration of organophosphorus pesticide was determined using Gas Chromatography/Mass Spectrometry (GC/MS). The highest concentration of Diazinon was detected in Esox lucius from the wetland east station (20.25 ppb). Significant differences were not observed in the amounts of Diazinon and Aldrin pesticides in the muscles of fish samples in various stations (P>0/05). The highest amounts of Endrin were observed in the muscle of Cyprinus carpio from the wetland east and west stations which were significantly different compared to that of other fish species (P<0/05). The amount of Aldrin in the Carassius auratus was significantly different compared to that of other fish species (P<0/05). According to the results, the amounts of Aldrin, Diazinon and Endrin were lower than the detection limits of the WHO standards. Therefore, consumers are not at risk from the point of view of food safety

    Effects of probiotic (Pediococcus acidilactici) on growth and survival of kutum (Rutilus kutum) fingerlings

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    In the present study effects of different levels of probiotic Pediococcus acidilactici, on growth performance and survival rate of Rutilus kutum fingerlings were investigated. Kutum fingerlings with a mean weight of 1±0.235 g were reared for 8 weeks in 500-l fiberglass tanks (15 fish per tank) with 4 diet treatments (3 replicates for each). Treatments included 1×10^9, 2:1×10^9, 3×10^9 CFU kg^-1 dry food and a control without probiotic. At the end of the study, specific growth rate (SGR) and survival rate (SR) were significantly higher in treatments supplemented with probiotic compared to the control (p<0.05), while the fish fed with probiotics showed lowest food conversion ratio (FCR) (p<0.05). The results indicated that the use of 3× 109 CFU kg^-1 dry food probiotics improved growth parameters and survival rate in R. kutum fingerlings

    The effect of various concentrations of dietary calcium and phosphorus on biological and culture characteristics of juvenile freshwater crayfish, Astacus Leptodactylus

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    This study was performed to investigate the effect of Ca and P on rearing and biological indices of crayfish (Astacus leptodactylus). Twenty-five isonitrogenous and isoenergetic diets were used. The experimental diets were made of the basal diet that was contained casein and gelatin. The basal diet was supplemented with five levels of calcium (0, 1, 2, 3, 4 %) from calcium chloride and five levels of phosphorus (0, 0.5, 1, 1.5, 2%) from natrium phosphate monobasic. The study was conducted in two phases and four experiments. In each experiment the diets with three replicates, totally in the 75 culture tanks containing 100l were used for feeding crayfish with average weights 1-2g and 8-9g for 80 days. In the first and second experiments, 5 and 3 indivisiual crayfish (miniatures) with average weights 1.22±0.21g and 1.31±0.29 g respectively and during the third and fourth experiment 10 and 4 indivisiuals crayfish with the average weights 8.48 ±1.03g and 9.06±1.41g respectively were stocked in each cultural tanks. The physicochemical factors of water (temperature, dissolved oxygen, pH as daily and hardness, nitrite, nitrate and phosphate as weekly) were measured for monitoring the condition of farming. The crayfish were fed about 5% of body weight for 3 times per day. The graded levels of Ca did not affect the growth indices. In crayfish (1-2g), weight gain and specific growth rate was significantly affected by the phosphorus levels. The average weight gain, survival, biomass increment in the different treatments was significantly affected by the graded levels of phosphorus. The crayfish were fed with diet containing calcium with 3-4% and phosphorus 1% showed the better growth. In the both group of experimental crayfish, were showed the graded levels of dietary Ca were caused the reduction the body ash and P values were increased. The clear correlation was not observed between the dietary levels of P and body ash and phosphorus in crayfish (1-2g). However, high levels of dietary phosphorus developed the body calcium. In Crayfish (8-9g) showed strong and negatively correlation between the dietary P levels and body ash and calcium. The graded dietary levels of Ca and P were caused increase in molting frequency and weight increment in molting. The optimum dietary levels of Ca and P were analyzed by broken –line regression showed 3-4%, 1% for crayfish 1-2g and 2-3, 1 -1.5% for crayfish 8-9g respectively. The results showed the presence of Ca and P are necessary for normal growth and molting in both group of crayfish. The proper growth was obtained at levels of 2-3% Ca and level of 1% P. Furthermore, the Ca and P ration in diet could not describe the interaction between Ca and P levels on growth function. So the determined Ca and P ratio were not obtained base of growth indices in the freshwater crayfish, Astacus leptodactylus

    The study on culture of rainbow trout (Oncorhynchus mykiss) by new design of foster-lucas ponds

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    Intensive culture of rainbow trout, usually done using several different methods. The objective of this study was to compare fish performance and welfare in a new design of Foster-lucas ponds (FLP) and a raceway ponds (RP) under field conditions. Currennt study was designed in two treatment with three repeats. Each pond was randomly stocked by rainbow trout fish with initial average weight of approximately 51±5 g. stocking density was 120n/m3 during study. After 10 months of trial, fish fed diets with commercial diet (Chineh Company). Feeding operation conducted according to the manuals by consideration of water temperature, fish weight and biomass. During the 10 months experiment, the fish survival rate was high (97.39 and 98.05%). No significant differences in growth parameters were observed between RP and FLP, but in all parameters FLP was higher than RP Final weight was 0.99% higher in FLP than in RP. Water quality factors (Dissolved oxygen, PH) was better in FLP. The results confirm that when water quality is maintained in safe level ranges, growth rate of rainbow trout attained in FLS are comparable to those in RP

    Experiments on polyculture of pike, Esox lucius, with carps

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    The Goal of project implementation was survey of biological roles of Northern pike, Esox lucius, in decreasing of Coarse fish and other un economics organisms in carps ponds and also increasing of final crops in hectare and determination of Suitable ration of pike in ponds. This project implemented by 5 treatment with 3 replicates for every ones in 2 years. The pike density was 200, 350, 500 and 650 fish individuals per hectare for 1, 2, 3 and 4 treatment, respectively, and fifth treatment was without pike. The treatments of 1 and 3 conducted in first year and other in second year of test period. At first, about 26 brooders Caught from Anzali Lagoon, and reproduced by artificial and semi - natural methods in Sefidroud Fisheries Research Station in 12–14 °c temperature. Produced larvae reared in earthen ponds and fries reached to weight of 10 -12 g after 45 days. Mean weight, length and survival rates of fish was 12.27 and 32.5 g, 11.44 and 15.83 cm, and 40 and 21% after 45 and 60 days, respectively. The carp density in ponds was 3500 fish individuals per hectare and stocking rates were 55 % silver carp, 20 % common carp, 10 % bighead carp and 15 % grass carp. In throughout of the experiment period, physico– chemical factors measured and plankton (phyto and zoo), benthos, un wanted fish and other organisms investigated. The biomass of unwanted fishes reduced to 76/81 and 60/6 % in first and second year of experiments respectively. The results showed that Esox lucius had effect in increasing of objective fish produce about 17.9 % and 3.9 % in first and second period of project implementation respectively. The average of fish produce in pond unit (2400 m^2)was 842 kg (3508 kg/ha ), 825 kg (3439 kg/ha) and 776 kg (3232 kg/ha) in first , second and control treatments first year of test period , and also in second year was 865 kg (3603 kg/ha), 877 kg (3652 kg/ha) and 848 kg (3531 kg/ha) in second , fourth and control treatments , respectively. A significant different found in final weight mean of common carp between treatments and Control ponds (P <0/05), as the weight of common carp in treatments ponds was 220 % in first year and 191 % in second year more than control pond. In end of the trial, the mean weight of Esox lucius was 265 ± 74, 276 ± 104, 159 ± 33 and 265 ± 89 g in 1, 2, 3 and 4 treatment, respectively. Survival rate of Northern pike in 1 to 4 treatment was 43.8, 55.2, 40 and 35.6 %, respectively

    Feasibility study on semiintensive polyculture of chainess and Indian carps in I.R.IRAN (Guilan province)

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    15000 juvenile Indian majour carps (Labeo Rohita,Cirhinus merigala, Catla catla) imported (200 ) and transferred to the earthen ponds in Astaneh Fisheries Research Station , In order to assess the viability of rearing under the climatic condition of north part of Iran and also achieve some growth parameters from the larval stage to market size.The fry with 300 mg weight, were released in to 12 ponds. Specimens were separated to tree experimental categories: 1= (30%indian carp and 70% chinees carp) , 2= (50%indian carp and 50% chinees carp) , 3= (70%indian carp and 30% chinees carp) .single chinees carp production were used as control . fishes were fed with artificial food and also with the natural products of the ponds which were enriched with organic fertilizers, after being equally stocked in the ponds .During the experiment, oxygen level ,PH, turbidity, and temperature were measured. Monthly fry samples were taken, for weight and length biometrical analysis and also determination of the weight gain percentage, average daily growth rate, specific growth rate. Results have indicated adaptations and considerable growth in this species, with an increase from the initial weight of 300 mg to an average of 13.5±1.6 mg in 50 days period until the end of November for fingerlings. Also the average weight of growing phase (second year of production ) was 647g for Labeo Rohita ,420 g. for Cirhinus merigala and 734g for Catla catla. The special growth rate (SGR)in Roho was 4.51 %.and 3.9 % for merigal and6.2 % for Catla while for Chinees carps SGR was 4.9, 6.7, 7.6 and 5.8 for silver carp,grass carp, common carp and big head respectively. Results revealed that the Indian majour carps compatibility with the condition in Gilan province was succesfull and the combination of species and optimization of their compatibility were remind for futhre studies

    Determination of optimum dosage of Ovaprim injectionon artificial spawning efficiency of Esox lucius

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    This project was conducted to goal of optimum dosage determination of ovaprim injection to artificial spawning efficiency of Esox lucius. The research implemented by 4 treatments with 3 replicates for each ones. 3 female and 6 male brooders injected in each replicate. The animals in 1, 2 and 3 treatments injected by 10, 20 and 30 µg/kg BW, respectively, and 4th treatment as a control injected with 4 mg/kg BW pituitary gland extract. Average weight of brooders were 1361±521, 1376±954, 1009±160 and 1100 ±422 g in 1, 2, 3 and 4 treatments in females and 689±145, 734±197, 547±118 and 794±238 g in males, respectively. In addition, positive response percent to hormone injection were measured 77.8 ±19.24 , 88.9 ± 19.24 , 55.5 ±50.91 and 55.5 ± 19.24 % in 1, 2, 3 and 4 treatments in female and 94.4 ± 9.58, 88.9 ±19.26 , 83.3±28.86 and 88.9 ± 19.26 % in male brooders, respectively, but there was no significant different between all of treatments (p<0.05). Incubation period from fertilization till hatching step in 7 to 15 ˚C was 5 to 10 days with average of 7±1.5 days. Fertilization content was in 1 to 4 treatments measured 87.1±10, 88.04±7.7, 83.9±5.2 and 72.4±19.7 %, respectively and also the treatments didn’t show any different significantly together (p<0.05). Average percentage of eyed eggs 66.6±15.9 in treat 1, 61.2±22.3 in treat 2, 58.3±10.7 in treat 3 and 56.1±15.04 in treat 4, without any significant different between of them (p<0.05). Hatching of eggs mean were measured 27.41±19.8 in treat 1, 39.53±26.9 in treat 2, 95.18±5.6 in treat 3 and 26.78±12.4 in treat 4, and significant different observed between of them too (p<0.05).In the other hand, mean percent of larvae with active feeding in these treatments were measured 18.77±14.6, 20.1±8.51, 55.6±11.6 and 14.51±7.72 as the treatments had significant different (p<0.05). Also, the best temperature and dosage injection of ovaprim hormone was 9 to 12.5 ˚C and 20µg/kg BW, respectively. The end of trial, from 103740 larvae introduced to earthen pond obtained 8000 fingerlings with weight of 2.68±0.6 g and length of 6.96±0.51 cm
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