نشریه آبزیان زینتی
سال سوم شماره 4 (زمستان 1395)

The removal process of ammonia (NH3) to replace the bacteria in environments with a suitable substrate is better than systems based on bacteria suspended in the water column. Thus, the aim of this study was to study the efficiency of the wheat stem as a substrate to accelerate the consolidation of ammonia (Denitrification) and increase the chances of survival of Koi fish (Cyprinus carpio carpio) faced with the acute concentrations of ammonia. 8 glass aquariums were selected (the volume of 50 liters) and divided into two groups: control (no wheat stem) and treatment (with wheat stem, equivalent to 10% of the total volume of the tank) with four replications. 10 ml/l ammonia was added to each aquarium and its amount in the treatment and control groups were calculated after 24, 48, 72 and 96 hours. In the second stage, after adjustment stage, 24 Koi were divided into 8 new aquariums with an average weight of 6±2 g (different from the first stage). Fish were faced with a concentration of 10 ml/l ammonia for 96 hours. The mortality in the control group (have not wheat stem and have Koi fish) and the treatment group (have the wheat stem and have Koi fish) were counted in intervals of 24, 48, 72 and 96 hours. Results showed that the concentration of ammonia at the end of 96 hours in the treatment group compared to control group there was a significant difference (P>0.05). Also, the number of mortality in the treatment group compared to control group there was a significant difference (P>0.05); the lowest mortality related to treatment. The results of this study demonstrate the use of wheat stem in addition to increasing the efficiency of established systems of ammonia; increase the chances of survival of koi fish in the face of acute concentrations of ammonia.

This study was conducted to evaluate the effect of substitution of fish meal with poultry waste byproducts in the diet of gold severum (Cichlasoma severum). In this regard, four experimental groups, each with three replicates, introduced and specimens being reared for 93 days. Four diets contain different levels of poultry by-product meal (25, 50, 75 percentages of fish meal were being replaced). 144 Severum juveniles with an average initial weight of (1/39±0/17) and initial length (1/15±0/71) were stocked 12 aquariums, specimens were fed every six hours a day and biometry conducted every fourteen days. At the end of the 97 days, the results were being analyzed by use of one- way ANOVA routine and growth performance indices and FCR revealed that the replacement of 50 percent of fish meal with poultry by-product meal significantly impact the gold severum and shows that this ingredient could be used effectively in fish feed formulation process.

Successful reproduction in captivity of aquatic animals is one of the key issues this industry. Today hormones are an employed process of duplicating. But because of the long-term accumulation in the body, are adversely affected in the reproductive tract. Considering the disadvantages of hormones and benefits of phytoestrogens Use of natural exogenous estrogens, such as phytoestrogens were common in the industry. Phytoestrogens are classified into two main groups: flavonoids and non-flavonoids. Isoflavones are weak oestrogen agonists that tendency of oestrogen receptor band is lower than estradiol and due to the relative concentrations of internal oestrogen and phytoestrogens show agonist and antagonist properties. This study is a review of the introduction of phytoestrogens, performance and their application in aquaculture. The results show that consumption of phytoestrogens has been effective in maintaining aquatic and consumer health in aquaculture and the products derived from them has a good marketability. So it can be stated that phytoestrogens can be a good alternative to synthetic estrogens.

In recent years, the global trade of ornamental fish has been a significant growth, so that Asia and other countries such as Sri Lanka and South-east Asian countries could use this potential to export this type of fish to other countries. Considering the importance of ornamental fish, the efforts to reduce stress is one aim of the ornamental fish farmer to reach more growth and production. Besides using the other new technology for alleviating the effects of stress through changes in physiological parameters related to blood and body tissues of fishes, music as stress reducer factors is more considered, recently. Music as a controllable factor in cultivating is reported by many researchers, to achieve more benefits by lower cost. This article reviews the effects of music on some ornamental fish species.

The aim of hybridization is to get the generation which has better characters than the parent. Because of pretty apparent and different species, ornamental fish attract peoples, attention over the world and there was the limited study about them so the purpose of this study was to investigate the hybridization between guppy and molly, growth performance and reproduction indices next generation. Virgin females and males aged 2 weeks were used in the experiment. 4 females and 2 males were stored per a glass aquarium (40×30×30). Fish were randomly stored in 4 treatments and 3 repeats including male guppy and female molly, male molly and female guppy, male guppy and female guppy and male molly and female molly and fed biomar. At the end of the trial, the possibility of molly and guppy hybridization was evaluated. The results indicated that no pregnancy and larva were seen in prospective treatments.

Ornamental fish farming has been as a matter of priority production activities and it has followed a growing trend in recent years. Based on last studies in the world estimated that there are about100 million interests Aquarium fish. In order, FAO reports international trade ornamental fish since 1985 annual growth rate of 14 percent (FAO, 1999).The economic value of the ornamental fish market in the world, estimated to be several billion dollars annually(Watson & Moreau,2006). Iran annually produces 200 million pieces of ornamental fish and about 11 million pieces of ornamental fish has imported from the biggest producer of ornamental fish in the world on South-east Asian countries such as Thailand, Malaysia and Singapore last year (Rahmany, 2015). There are 300 species of 1500 species of global ornamental fish as native in Iran country that we could propagation more than 80 species of 300 species now. If the condition of production ornamental fish to be prepared in Iran, we could become simply to a serious competitor for global ornamental fish production (Rahmany, 2015). Ornamental fish production does in the big farm with high products and too in the small farm by the family operating system but all of them to need individual and special requirements that taking them can create new opportunities for employment. To achieve this noble objective should be provided activity and sustainable jobs. On the other attention to ornamental fish, production could be the as expanding trend in the popular hobby. So that we can organize this section and compilation created between ornamental fish production units and entertainment units in a complex by propose of the development of hobby area in each region. Manufacturing and Entertainment Ornamental Fish Complex of Mahallat city design and study by propose of to create a model complex site for production of ornamental fish and hobby area for people and in the second proposed for to aggregation of Ornamental Fish Farming Units In Mahllat City on Markazi Province of Iran.