Showing 4 results for Tilapia
Akram Bemanikharanagh, Morteza Alizadeh, Mohammad Hossein Khanjani,
Volume 7, Issue 4 (4-2018)
Abstract
The aim of the present study was the environmental impact assessment of tilapia (Oreochromis niloticus) farming in suitable areas of Yazd province. This research was conducted to achieve appropriate use of these resources, employment and development of central less developed regions of Iran along with identifying the human and ecological effects of its implementation in order to minimize environmental impacts as well as economic and social justification. A total area of about 100 ha including 6 farms was selected. Matrix method was utilized for the environmental impact assessment. Considering the executed studies and results of operation phase matrix, no considerable destructive impacts were observed related to the project. Due to the fact that 50% of means in rows and columns of the matrix were not less than -3.1, we proposed execution of this project with rehabilitation plans.
Mohammad Hossein Khanjani, Morteza Alizadeh,
Volume 11, Issue 3 (12-2021)
Abstract
The use of modern systems in the cultivation of economical fish such as tilapia is important. In the present study, the effect of conventional and limited water exchange systems on water quality, growth, nutritional performance, and the economic aspect of farming systems were investigated in Nile tilapia. For this purpose, juvenile tilapia with an average weight of 1.79 g were reared in fiberglass tanks with a volume of 170 liters of water at a density of one fish per liter of water for 5 weeks. Two treatments were considered in three replications. In the system with limited water exchange, molasses carbonaceous material was added to develop biofloc and maintain optimal water quality. The results showed a significant difference between water quality parameters in the two cultivation systems (P <0.05) so that a lower amount of total ammonia nitrogen (1.07 mg /L) was observed in the system with limited water exchange. The highest increase in body weight, biomass and survival ratio (98.82%) were obtained in the treatment with limited water exchange. The economic evaluation showed that water consumption is lower (61.47 L/ Kg), less food is required (1042.5 gr), higher production is obtained and thus limited water exchange had better profitability in the system. In general, the present study showed that the system with limited water exchange is more economical than the conventional system for the cultivation of Nile tilapia on the mentioned scale.
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Volume 12, Issue 3 (12-2022)
Abstract
The aim of this study was to evaluate the effect of substituting the dietary fish meal with blood powder on some blood immune factors of Nile tilapia. 150 speciemns of tilapia (30 ± 0.5 g) were fed diets containing 0 (control group), 25, 50, 75, and 100 % of blood powder, each in three replicates for 8 weeks. After this period, fish were anesthetized and the blood samples were taken from the caudal peduncle of fish with a heparinized syringe for evaluating the blood immune indicators. No significant differences were observed in ACH50, glucose, and triglyceride among the blood powder-fed fish and the control group (P>0.05). The highest reported value of ACH50 (148.36±23.13), was observed in 75% treatment and the highest values of glucose (145.72±21.44) and triglyceride (451.68±49.61) were observed in 100% blood powder fed treatment. However, there were significant differences in the activity of lysozyme, immunoglobulin, total protein, and cholesterol in the groups receiving blood powder with different percentages compared to the control group (P<0.05). The results of this research showed that it is possible to replace fish meal with blood powder in the diet of Nile tilapia due to its strengthening effect on immune system.
Asghar Abdoli, Maryam Peymani, Hussein Valikhani, Seyed Darioush Moghaddas,
Volume 13, Issue 4 (12-2023)
Abstract
The introduction of non-native species causes a variety of negative ecological and economic-social impacts on aquatic ecosystems. One of the first studies conducted on these species was the study of their composition and abundance in recipient ecosystems. The present study aimed to investigate the distribution, composition, and abundance of non-native fishes in the lower Tigris basin in a fishing year from fall 2014 to summer 2015. To update and compare the information, the latest fishing situation in the fishing year 2022-2023 was also examined. In total, 31 species from 15 families, including eight non-native species were caught from the studied water bodies. According to the results, non-native species are widely spread to the most aquatic ecosystems of the studied area, among which tilapia, including the redbelly tilapia Coptodon zillii (Gervais, 1848) and the blue tilapia Oreochromis aureus (Steindachner, 1864) were the most abundant species. The redbelly tilapia showed the most distribution in the studied area. According to the local fishermen, the amount of catch in many areas of inland waters of Khuzestan province has decreased compared to 2014-2015, and their statements indicate that they are not satisfied with the state of fishing.
