فهرست مطالب mohammadhossein khanjani

Over the last few decades, the aquaculture industry has grown and developed as one of the major food production industries. Increased stocking density and cultivated area are two ways to increase aquaculture production. Stocking density increases result in a decrease in water quality and the spread of pathogens. As a chemical substance, antibiotics are not widely accepted by consumers as a means of reducing pathogenic agents in aquaculture. Nowadays, probiotics are crucial to maintaining the health of farmed aquatic animals and increasing production performance without negatively affecting consumers. Probiotics are being used in more studies to achieve environmentally friendly sustainable aquaculture goals. Probiotics have been shown to improve water quality, feed efficiency, growth performance, digestive enzyme activity, immunity, and resistance to pathogens in shrimp aquaculture. The presence of probiotics helps shrimp under stressful conditions, such as handling, grading, transportation, vaccination, and disease treatment. In the aquaculture industry, probiotics are mostly Bacillus, Lactobacillus, Micrococcus, Enterococcus, Lactococcus, Streptococcus, and Carnobacterium species. This study examines the use and importance of probiotics in shrimp aquaculture, as well as their effects on water quality, growth performance, and immunity.

Aquaculture of ornamental fish is today a global industry worth several billion dollars. Nutritionally, ornamental fish are different from edible fish, so body color is more important in ornamental fish than meat production, and in terms of price, ornamental fish and edible fish are different. Aquaculturists strive to use food efficiently and at a reasonable price. Recently, efforts have been made to develop different diets for aquarium fish, and the use of invertebrates such as insects, Artemia, polychaetes, and worms has been studied. Polychaetes are among the live foods with high nutritional value that are approved for use in ornamental fish diets. Polychaetes (protein, fat, and carbohydrates) possess a biochemical composition that is suitable for feeding ornamental fish, resulting in better growth performance, survival, and color quality compared to concentrated diets. Ornamental fish farmers increasingly use polychaetes as sources of long-chain unsaturated fatty acids (such as docosahexaenoic acid, eicosapentaenoic acid, linoleic acid, and arachidonic acid) in order to improve growth performance, sexual maturity, and color quality. The importance of polychaetes as live food for ornamental fish is discussed in this promotional study.

An introduced species is one that enters and occupies a habitat where it does not naturally occur. We have reviewed articles and media sources to shed light on the introduced vertebrate species (hereafter IVS) of Iran. Here, we present a list of IVS in Iran which have the potential to become invasive and are the ones that can harm biodiversity. We aggregated information on their approximate range in the country, origin, probable means of introduction, as well as conservation status based on the IUCN Red List of Threatened Species. Based on the results of this study, 63 such species were recognized as introduced. Human population size in each province was a correlate of the number of introduced species. We suggest that this correlation exists because human demand for exotic species as pets orlivestock may result in the release of invasive species into the wild. Further investigations on the root causes of their emergence, their range in Iran, and their ecological interactions are urgently needed. Finally, we propose educating the public, and government authorities about IVS in order to encourage better management and prevent future introductions. We recommend that species with a high levelof invasiveness should be targeted foreradication.

Aquaculture is one of the fastest growing sectors of agriculture in the world today. The intensive development of the aquaculture industry has been accompanied by an increase in environmental impacts. The production process generates substantial amounts of polluted effluent, containing uneaten feed and feces. Discharges from aquaculture into the aquatic environment contain nutrients, various organic and inorganic compounds such as nitrogenous compounds (ammonium, nitrite, and nitrate), phosphorus, dissolved organic carbon and organic matter. Ammonia (NH3) is the product of fish respiration and decomposition of excess organic matter. Chemoautotrophic bacteria (Nitrosomonas and Nitrobacter) tend to oxidize ammonium ions to nitrite and nitrate ions. Interest in closed aquaculture systems is increasing, mostly due to biosecurity, environmental and marketing advantages over conventional extensive and semi-intensive systems. When water is reused, some risks such as pathogen introduction, escapement of exotic species and discharging of waste water (pollution) are reduced and even eliminated. In current review, we will discuss on inorganic nitrogen removal techniques in aquaculture.

 This research is in terms of the nature of the review, which has studied the subject by reviewing scientific sources.

The most common way to remove nitrogenous waste material in aquaculture system, is including; water exchange, aeration, cut off feeding, use of zeolite mineral and the biological control.

the most suitable method for controlling inorganic nitrogen compounds is consumption and reduction of nitrogen in the same place by bacteria (biochemical method).

Ornamental fish keeping is the second most popular hobby in the world, and its popularity is growing every day. The ornamental fish farming industry provides entrepreneurship and income generation opportunities, so it is important to focus on various aspects of ornamental fish farming. Several physical and chemical parameters of water are discussed in this study, including pH, hardness, ammonia, nitrite, and nitrate, as well as optimal water conditions. The physical, chemical and biological parameters of water are interrelated in aquatic ecosystems. Thus, physical and chemical parameters of water must be analyzed together. The ornamental fish production centers have greater expertise than edible farmed fish in terms of water quality management since ornamental fish are sensitive to low water quality. Water quality management is more critical when it comes to ornamental fish since they are kept in greater densities than edible fish. In tanks that hold a large number of fish, water quality factors such as pH, water hardness, and excess nitrogen compounds must be measured daily, so the producer needs to take measures to manage them. It is essential for high density aquarium fish rearing tanks to monitor water quality daily, change the water regularly, and ensure adequate aeration.

In current study, the effect of different times of molasses addition on water quality and immune performance of Nile tilapia (Oreochromis niloticus( mucus in biofloc system with limited water exchange was investigated. Nile tilapia with an average weight of 1.53 g was cultured in fiberglass tanks (circular cross section) with a volume of 130 liters of water at a density of one fish per liter for 37 days. Five experimental groups were considered including a control (without biofloc) group without carbonaceous substance addition and four biofloc treatments with molasses added daily (biofloc 1), once every two days (biofloc 2), once every three days (biofloc 3) and once every four days (biofloc 4). 2.5 ml/l microbial mass was added as a starter to biofloc treatments. Also, molasses carbonaceous material (65% of the input feed) was used to adjust the carbon to nitrogen ratio. According to the results, water quality in biofloc treatments showed that the lowest amount of total ammonia nitrogen (0.23 mg/l) and the highest amount of nitrate (25.5 mg/l) were obtained in biofloc 1 treatment (daily molasses addition), that showed a significant difference with other treatments (p<0.05). Based on the results of immune function of tilapia mucus, the lowest amount of total immunoglobulin (43.66 mg/100 ml) and lysozyme activity (17.33 ml/min) were observed in the control (without biofloc) group (p<0.05). Generally, the current research showed that the water quality in the biofloc system is improved with the addition of molasses on a daily basis and also the immune function of Nile tilapia mucus in biofloc system is more active than the normal system without microbial floc.

The aquaculture industry has grown dramatically in recent years, with a multimillion-dollar market. There are a variety of freshwater fish, marine fish, mollusks, and ornamental fish cultivated in this industry. The pigment and coloring of ornamental fish are important characteristics for marketing. In edible fish, carotenoids are responsible for the pigmentation of body tissue, while in ornamental fishes, they are responsible for the coloring of the skin. Fish are unable to synthesize carotenoids and are dependent on their diets to obtain the pigments they require. In closed environments, artificial and formulated feeds play a critical role in successful fish farming. A variety of natural carotenoid sources are widely used for enhancing the pigment of ornamental fish, including non-photosynthetic tissues of higher plants, microalgae, seaweed, red yeast and crustacean by-products (shells, carapace). Aquaculture farmers prefer natural carotenoid sources over artificial sources. For farmers, the amount of benefit gained from skin color after the end of fish feeding is important. The importance of carotenoids in ornamental fish culture has been discussed in this review.

Limited water exchange system is an environmentally friendly system that pursues the goals of sustainable aquaculture and is used in modern aquaculture. In the present study, the effect of different levels of dietary protein on water quality, growth performance and biochemical composition of microbial mass in the system with limited water exchange was investigated. Western white shrimp juveniles with an average weight of 2.5 g were studied in fiberglass tanks with a volume of 160 liters and a density of 1 fish per liter for 5 weeks. Four experimental treatments with different levels of dietary protein including 40, 36, 33 and 30% were considered in the system with limited water exchange. The results of the present study showed that the amounts of dissolved oxygen, pH, total ammonia nitrogen (1.11 mg/l) are higher in the treatment of diet with 40% protein. Growth performance in 33% and 36% protein showed a significant difference compared to 30% and 40% level of protein (P<0.05), so that higher values were observed in 33% and 36% protein treatments. The biochemical composition of the microbial mass was affected by different dietary proteins (P<0.05) and higher amounts of lipid (2.17%) and ash (35.44% of dry weight) were observed in the treatment with 30% protein. According to the present study, it was found that different dietary proteins affect water quality, growth performance of western white shrimp and microbial mass composition and the optimal values in the diet are 33% and 36% of protein.

The performance of Pacific white shrimp broodstocks is affected by several factors including different environmental conditions, feeding type, size, and the cultivation site. In the present study, two different reproduction systems were used to investigate the reproductive performance of Pacific white shrimp broodstocks: conventional (water exchange) and limited water exchange Female broodstocks having an average weight of 38.6 ± 6.8g were obtained from Chabahar Reproduction Center located in Konarak and experimented in 2000-liter tanks. Two treatments in three replications in a completely randomized design were considered for the current research, including: control group (conventional rearing system) in which 90% of the water was replaced and limited water exchange treatment in which 2 to 3% of the water was exchanged daily. The results of this study showed no significant difference in the growth performance of broodstocks between two cultivation systems (p > 0.05), but the survival rate in the limited water exchange system were measured higher (97.57%). Moreover, the number of eggs in each spawning stage for shrimps under conventional farming system and limited water exchange 47,500 and 60,800 were obtained, respectively, a significant difference (p < 0.05). Furthermore, the number of shrimp eggs in each spawning stage varied significantly in the conventional system and in the limited water exchange treatment, with 49,300 and 60,800 eggs, respectively (p <0.05). A higher number of eggs converted to nauplius by the limited water exchange system than by the conventional system. In general, this study found that the reproductive performance of Pacific white shrimp broodstocks in the system with limited exchange of water is better than the conventional system.

At reproduction centers, using live food is important, especially when it comes to the first feeding of aquarium fish larvae. Live foods commonly used in the aquarium aquaculture industry include rotifers in two sizes, small types with a size of 50-110 microns, and larger types with a size of 100-200 microns, Artemia, and copepods. Fish larvae in marine aquariums primarily consume copepods. However, there is still need to develop protocols to produce this tiny live food in propagation facilities. This is because the food consumption and digestive system of copepods are different from other live foods such as rotifer and Artemia. Copepods are nutritionally valuable due to the fact they contain long-chain unsaturated fatty acids including docosahexaenoic acid, eicosapentaenoic acid, and arachidonic acid. There is an insufficient amount of long-chain unsaturated fatty acids in both Rotifers and Artemia nauplii, a deficiency that can be rectified through dietary enrichment. In this study, live foods are discussed as an important component of feeding aquarium fish larvae.

New sustainable aquaculture technology which is called biofloc technology (BFT) that consumed food waste, organic matter and compounds produced during the production by aquatic animals. Biofloc has two major roles: maintenance of water quality, by the uptake of nitrogen compounds and generating microbial protein which results in reducing feed conversion ratio and a decrease in feed costs. Biofloc is a rich natural source of protein and lipid available 24 hours per day for aquatic animals. The current problem in biofloc system is the difficulty in controlling and management of bacterial community composition for achieving optimal water quality and aquatic species health. More than 2000 bacterial species developed well in water containing biofloc., That most include photoautotrophic, chemoautotrophic and heterotrophic communities and heterotroph bacterium plays a key role in BFT. This review gives descriptive information about a bacterial community associated with biofloc, and its influences on aquatic species intestinal microbiota, which can further be applied to research on immunity, disease resistance and nutrition in aquaculture.

In recent years, the shrimp farming industry has been one of the most influential sectors in food production and has grown rapidly into a dynamic and growing industry over the past few decades. Declining shrimp and fish stocks that are being traded and exploited on the one hand, and growing population on the other hand, have increased demand for marine protein sources. In such a situation, increasing the efficiency of aquaculture production is one of the important goals of the aquaculture industry. With the use of new technologies obtained until 2019, today it is possible to increase the density and amount of production in production units. These technologies include the implementation of modern recirculating aquaculture and biofloc systems, which is growing and developing around the world. Therefore, it is very important to provide useful aquaculture engineering solutions for use in the shrimp farming industry and the use of new technologies in this industry. In this study, various shrimp farming systems and research on the use of biofloc and recirculating systems were reviewed. The study also examines the challenges of the biofloc system and the prospects facing the shrimp industry.

It is important to know the nutritional requirements of ornamental fish to achieve better growth and production performance. In recent years, nutritional information has been obtained about some aquarium species. Also, in some cases, the diet information of these fish can be extracted from the results obtained from farmed fish. Having the right dietary formula for the complementary needs of aquarium fish improves the digestibility of nutrients, meets metabolic needs, and reduces maintenance costs and water pollution. And at the same time feeds the complete formula of sustainable aquaculture goals.  In addition, a complete diet follows the goals of sustainable aquaculture. So far, a variety of foods such as milk powder, flakes, slaughterhouse waste, dry food and a variety of live foods including rotifers, Artemia nauplii, Moina, daphnia, Ceriodaphnia and algae have been widely used to feed aquarium fish; each has its own nutritional and production value. Considering that the coloring of ornamental fish species is important in the trade of these fish, it is recommended to add pigments and carotenoids to the diet of aquarium fish. The aim of this study was to investigate the specific nutritional requirements to improve production and thus more economical fish farming.

In the current study, economic performance and production of Pacific white shrimp (Penaeus vannamei) were studied in conventional and biofloc aquaculture systems. Shrimp juveniles with a weight of 2.56±0.33 g (M ± SD) were fed for 5 weeks in fiberglass tanks with 180 liters volume and density of 1gr shrimp per liter in four treatments including one control group with water exchange (100% artificial feed) and three biofloc treatments, 100%, 66.6% and 33.3% artificial feed (without water exchange). According to the results, considering the values of water quality parameters and production and economic performances of Penaeus vannamei, there were significant differences between two systems (P <0.05). The highest increase in body weight, growth rate (0.136 g per day), specific growth rate (3 %/day), survival rate (90.48%) and feed efficiency were obtained in biofloc treatments (P<0.05). The maximum level of profitability obtained in biofloc systems, that showed significant difference compared with conventional system (P<0.05). Results of this study highlights the production and economic performance of Penaeus vannamei in juvenile stage could be improved with biofloc system; and the presence of biofloc improves economic performance of Penaeus vannamei in zero water exchange system.

The aquaculture industry has experienced the fastest growth in the food industry with an annual growth of 8.9% since 1970. This industry has grown steadily over the last five decades, supplying nearly half of the fish consumed by human. As the population grows, one of the major challenges ahead will be human nutrition. Aquaculture can play a key role in tackling poverty and hunger. In sustainable aquaculture, the water source (quantity and quality) is important so that optimal fish production depends on the physical, chemical and biological quality of the water. The limitation and reduction of fresh water resources, population growth and increasing demand for fishery products have led to unconventional waters to be used in the aquaculture industry. Unconventional waters include recycled water, wastewater, and saline water. In different countries, these water resources have been used for producing aquatic species to provide food and protein. The most important limiting factor for the use of unconventional waters is their quality which can be used for aquaculture after physical, chemical and biological treatment. Due to the limited water resources of the country, the use of unconventional waters is very effective and efficient in drought management and is also one of the ways of developing the fisheries sector. In this paper, the necessity of using unconventional waters in the aquaculture industry (fish, shrimp, algae, and Artemia) will investigate.

Carbonaceous organic matter and water salinity are the key factors in zero water exchange system with biofloc production. In the present study, production of biofloc in different water salinities and carbon sources was investigated in zero water exchange system. For this purpose, three levels of salinity (10, 21 and 32 ppt) and two types of carbon source (molasses and wheat flour) were considered in zero water exchange system. The experiment was conducted in tanks with water volume of 300L for 4 weeks in propagation and cultivation aquatics center located in Bandar Kolahi, Minab, Hormozgan province. Minimum dissolved oxygen (5.68 mg/l) and NH3 (0.29 mg/l) and maximum NO3 (12.68 mg/l) obtained in the tanks with molasses, as carbon source, and 32ppt water salinity. Some of water phsicochemical parameters including dissolved oxygen, pH, NH3 and NO3 were measured regularly and significant differences were observed among the different treatments (p<0.05). The analysis of the biochemical composition of the bioflocs showed a decrease in protein and an increase in ash content along with increase in water salinity. Lipid content in molass biofloc was significantly lower than the wheat flour biofloc (p<0.05). The results showed that type of carbon source and value of salinity would be effective on water quality parameters and nutrition value of bioflocs in zero water exchange system.

Biofloc technology (BFT) is a relatively new biotechnological means to support high density culture, maintain water quality, biosecurity, reduce the need for water exchange, reutilize the feed and reduce the production cost. This technology is mainly based on the principle of waste nutrients recycling (particularly nitrogen) into microbial biomass that can be used in situ by the cultured animals. In ornamental fish culture, rearing of larvae are the difficult-phase where the commercial ornamental fish farmer face a lot of difficulties due to low survival rate, water quality management and incidence of disease, these problems could be easily averted through Biofloc technology. Biofloc system is a new alternative that can be used in the culture of different ornamental species produced in country, if the nutritional requirements for each species are considered. In this review study, we will discuss on biofloc technology in Aquaculture with an emphasis on ornamental fish.

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.

Eeffect of different dietary carbon sources on water quality, growth performance and survival of western white shrimp Litopenaeus vannamei post larvae was investigated in zero-water exchange system. Shrimp postlarvae with mean weight of 98.47±8.60 mg and mean length of 22.39± 1.70 mm were fed for 32 days in fiberglass containers with 130 liters volume of water and density of 1 individual per liter in five treatments including one control with water exchange and four biofloc treatments with adding different carbon sources including molass, starch, wheat flour and mixture of them at equal weight ratios with 15% to 9% of body weight. In the values of water quality parameters including temperature, salinity, dissolved oxygen and pH, no significant differences were observed among the biofloc treatments (P>0.05). Maximum pH (8.27 ± 0.09) and maximum dissolved oxygen (6.37 ± 0.56 mg/lit) was in water exchange treatment. Maximum and minimum level of ammonia was 0.43± 0.34 and 0.09± 0.07 mg/lit in water exchange treatment without floc and biofloc treatment with adding starch of carbon sources, respectively and showed significant difference between treatments (P <0.05). The highest increase in body weight (1640.43± 231.28 mg), growth rate (51.26± 7.23 mg per day), specific growth rate 8.97± 0.42 %/day) and biomass (190.29± 26.83mg) was observed in biofloc treatment with adding molass and the highest survival rate (90± 0.77%) was obtained in biofloc treatment with adding mixture of carbon sources. The highest feed conversion ratio (1.52±0.23) and the lowest feed efficiency (66.81±7.95) were obtained in water exchange treatment without floc, showing significant difference compared to the other treatments (P <0.05). The results showed that using biofloc technology with zero- water exchange system and adding carbonaceous organic matter could help to recycle waste and improve the water quality. Moreover, the presence of biofloc improved growth performance, feed utilization and production of western white shrimp in zero water ecxhange rearing system.

Growth performance, food efficiency and body composition of pikeperch (Sander lucioperca) were investigated with 1 or 2 g/kg L-carnitine added to the diet. Control diet did not contain L-carnitine. Two hundred pikeperch fingerlings (1.63 g, mean weight) were stocked in each 1 m3 concrete tank and fed equally 6 meals per day for 6 weeks. Higher increment in body weight (5.92 ± 0.37 g), the highest specific growth rate (3.75 ± 0.17) and food efficiency (98.04 ± 4.56), the highest crude protein (64.53 ± 0.84), the lowest crude lipid (21.59 ± 0.23) and significant (P<0.05) lowering in food conversion ratio (1.02 ± 0.05) were obtained with 2 g/kg L-carnitine diet. The greatest survival rate (84.88 ± 0.92) occurred when fingerlings were fed with 1 g/kg L-carnitine. Both treatments with L-carnitine showed lesser rate of cannibalism than in control (1.25± 0.09). Use of dietary L-carnitine improved growth performance and body composition of pikeperch fingerlings.

The most important factors controlling cladocerans production, growth, and morphometric characters are temperature, food quantity and quality and photoperiod. Effects of temperature and photoperiod on production, and morphometric characters of cladoceran, Ceriodaphnia quadrangular, were examined by culturing on green algae Scenedesmus quadricauda in 250 ml conical flasks (150 ml water). Treatments used for temperature (˚C)and photoperiod (light hours:dark hours) were 20,25,30 (˚C) and 12:12,24:0 and 0:24, respectively. The maximum population density (5.51 ind./ml) obtained at 24:0 and 30 (˚C), while maximum body length (731 µm) and maximum body width (491 µm) obtained at 0:24 and 20 (˚C). Correspondingly, the maximum adult (61 %), maximum neonate (39 %) and young (9 %) in population under culture conditions of 0:24, 12:12,24:0 (L: D) and 20 (˚C) obtained, respectively. Overall, this research showed that growth and reproduction of Ceriodaphniaquadrangula gave better performance at 25 (˚C)and 24:0, light: dark photoperiod.

Temperature and photoperiod are important parameters in zooplankton culture, particularly in cladoceran culture due to their significant effect on growth and reproduction. Effects of temperature and photoperiod on the growth and fecundity of a cladoceran, Moina macrocopa was examined by culturing and feeding it with green algae Scenedesmus quadricauda in 500 ml conical flasks. Treatments used for temperature (0C) and photoperiod were 25, 30, 35 (0C) and 12:12, 24:0 and 0:24(light:dark hours), respectively. The maximum population density (310.5 individuals/flask), maximum specific growth rate (SGR) (0.387 individuals /day), shortest population doubling time (Dt) (1.79days) and highest fecundity (8.5 offsprings/ female) obtained at 30(0C). Correspondingly, the maximum population density (320.7 ind/flask), maximum SGR (0.538 ind/day), shortest Dt (1.28 days) and highest fecundity (7.54 offsprings/ female) determined at 24:0 light:dark photoperiod. Overall, this research showed that growth and reproduction of M. macrocopa at 30 (0C) and 24:0 light:dark photoperiod gave significant performance (P<0.05) compared to other examined treatments. Mass culture of this species under the mentioned conditions of temperature and photoperiod could provide suitable live food for use in fish larvaiculture.