نشریه بهره برداری و پرورش آبزیان
سال یکم شماره 2 (تابستان 1391)

The present study was done to investigate the effect of color of cultural environment on growth and color changes intensity of guppy's skin (Poecilia reticolata). Guppy's larva (360 specimen, weight 100 mg), as a completely randomized design, were reared in red, black and white aquariums for 76 days and at the end of each experiment, their growth and color skin, by tree factors L*, A* and B* and by Hue indices in 3D circular model and ECI as new indices were considered. The results showed that red and black colors had a negative effect on growth performance than white one (P<0.05). Brightness value (L*) of skin for black aquarium fishes was less than red and white aquariums (P<0.05) and skin redness (A*) of various treatments were similar (P>0.05). Also, the skin of red aquariums fishes have less yellowness (B*) than black and white aquariums (P<0.05). According to these results, cultural environment color influences on growth performance and skin color of guppy

The effects of tank color background on the growth performances (weight gain, protein efficiency ratio, average daily growth, feed efficiency, and specific growth rate and condition factor) and body composition (protein, fat, moisture and ash) of juvenile’s common carp were studied. Seventy two fish (average weight 30±1.42g) were introduced into white, blue and black tanks (with 3 replicates) and fed for 8 weeks to saturation level. The results showed that fish was grown in the blue tanks had better condition in terms of growth performances and carcass protein significant difference was observed in this treatment compared with two other treatments (P<0.05). This study showed us using blue color tank is more effective than white and black color, in regarding growth performances that is may be due to more and better physiological adaptation of fish to this color.

Among anthropogenic pollutants, the aim concern has been directed to organochlorine (OCs) such as polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDTs) because of their persistency, bioaccumulative nature and potential toxic affects to wild life and human. Animal diet is generally one of the major routes of contaminats into the human body. In particular, an important significance in this context has been attributed to fish and seafood. In this study, the levels of organochlorinated contaminats, such as organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) were measured in three species, Carassius auratus, Cyprinus carpio Esox lucius, for the two season (winter and spring) from the international Anzali wetland, Iran. These species were selected for their feeding behavior, condition habitat and their importance to local human fish consumption and the two seasons were selected for the difference in the agriculture actions and atmospheric rains. The results indicated that the levels of these pollutants in the Cyprinus carpio (omnivorous feeding mode and bentho plagic condition habitat) were higher than in the other species and this was related to higher lipid content, difference in the their feeding behavior, condition habitat. DDTs were the predominant organochlorinated contaminats in all species. Also in the almost of samples levels of this pollutants lowered than global standard

The objective of this study was to introduce a simple method for identification of caviar species in caspian sea sturgeons. For this purpose, caviar samples of Acipenser gueldenstaedtii, A. percicus, A. stellatus, A. ndiventeri and Huso huso were collected from fishery stations, Khajenaphas, Torkaman and Chalasht in Golestan province and propagation center of sturgeons in Aghalla city. The extracted DNA from caviars were amplified using three primers termed R1, F2a and F1a, which were designed for cytb gene in the mtDNA. The primers of R1 and F1a were universlly introduced for all corresponding species in this study whereas R1 and F2a were spesific for A. stellatus. In addition, the results of sequencing obtained in cytb gene showed that the region studied here can be successfully utilized for identification of A. stellatus, A. ndiventeri and Huso huso species. phylogenetical study and the sequential corrolation among species studied verified the results obtained in this investigation. The results of this study can be perfectly used for identification of caviar in forensic,import and export issues.

Aim of this study was to evaluate proximate analysis and physicochemical changes in fish sausage made from unwashed and washed mince during refrigerated storage. Sausages produced from unwashed and washed mince and kept refrigerated and subsequently chemical, physical and sensorial analysis were performed. The results showed that the impact of washing process on trial factors (P<0.05). Sausage made from unwashed mince had the higher amount of protein, fat and ash in comparison with sausage made from washed mince (P<0.05). Total moisture in unwashed mince group was lower than washed mince group (P<0.05). Released water and expressible moisture increased during the trial period (P<0.05). Released water in washed mince group was higher than mince group (P<0.05). However, hardness and chewiness changes during time did not have statistical differences in trial groups (P>0.05), but amount of these factors in unwashed mince was higher than washed mince (P<0.05). Washed mince had the higher whiteness and Hue* than mince (P<0.05). TBA in washed mince depicted lower intensity increasing during time but did not exceed allowed limit at the end of experiments (P<0.05). pH in washed mince was higher than unwashed mince (P<0.05). Overall results proved in order to produce silver carp sausage washing process is not needed.

In this study the effects of toxic pesticide, Diazinon (60% emulsion) on the some tissues male brood stocks of (Rutilus frisii kutum, Kamensky, 1901) were studied. The test was studied under static water quality conditions at 15°C±2ºC during winter and spring of 2009. The effectiveness of water physical and chemical parameters of water were pH=7-8.2, dh=300mg/L (Caco3), DO=7ppm and T=15±2ºC. LC50 96h of diazinon was determined according to 0.4 mg/L and the fishes were exposed to the toxin with 3 concentrations, MAC value, LC1, LC5, and a control with three replicates for 45 days. Pathological results showed that diazinon had no effect on the average weight and body length, the average weight of spleen, liver, kidney and liver index, however diazinon exposure caused complications such as tissue necrosis, vascular congestion, inflammation in the liver, a sharp reduction in the number of glomeruli, necrosis, vascular congestion and haemorage in the kidney, capsule thickening and fibrosis, atrophy, vascular congestion, macrophages release increase, sediment hemosiderine increase and thickening of artery walls in the spleen of kutum male brood stocks.

The effect of zeolite (Clinoptilolite) and clove oil (Eugenia caryophyllata) has assessed in this study to investigate survival, physicochemical water factors transportation of rainbow trout (Oncorhynchus mykiss). 13 fish with an average weight about 80 ± 4.4 in 10 liters reservoir with a dewatering volume equal to eight liters was stored randomly. In this study, it was performed, four treatments and three replications for each treatment including control, clove oil (25 parts per million), zeolite (concentration 14 g per liter) and clove oil (40 parts per million) +zeolite (14 g per liter) treatment and survival factors of the final fish and quality of transportation water reservoirs including (ammonia (NH3), ammonium (NH4+), the degree of acidity (pH), carbon dioxide (CO2) and water temperature in the interval of 0.00, 6.00, 12.00, 18.00 hours was measured. Survival rate in the control treatment experiment was 97.44 percent at last and 100 percent in the rest of the treatments. Ammonia value in treatments during the interval had significant difference (P<0.05), so that at the times of 12.00 and 18.00 hours, ammonia in zeolites and clove oil + zeolite treatments was less and it had significant differences with control treatment (P<0.05). Zeolites and clove oil + zeolite treatments had the lowest ionized ammonium and it did have a significant difference with other treatments (P<0.05). Carbon dioxide value of water in clove oil treatments at the time 12.00 and 18.00 hours was more than other treatments and it showed a significant difference (P<0.05). PH levels were lower in the zeolite treatment but it didn’t have a significant difference among treatments (P>0.05). in this study, the usage of zeolite material to improve transportation water quality but clove oil was not effective