نشریه آبزیان زینتی
سال هشتم شماره 1 (بهار 1400)

Ornamental fish are the most popular pets in most parts of the world. The trade in ornamental marine fish began around 1930, and has expanded significantly in recent years, with the maintenance of home aquariums and public spaces. International ornamental fish trade is a multibillion-dollar global industry, much of which is in coral reefs caught in the Indo-Pacific and Caribbean and marketed in the United States and Europe. To increase marketability and improve the quality of color and health in ornamental aquatic animals, it is necessary to use healthy and natural diets. Algae, due to the presence of chlorophyll pigments, carotenoids and astaxanthin and other beneficial compounds such as unsaturated fatty acids and high protein are a very good source for use as a main food or supplement in ornamental aquatic feed. In this review study, we will try to review the studies on the effect of the use of algae in the diet of ornamental aquatic animals.

Successful reproduction in captivity is one of the most important issues in the aquaculture industry. Due to the disadvantages of  using hormones and the fact that plants containing phytoestrogens do not have negative effects of synthetic estrogens, the use of natural estrogens such as phytoestrogens has become common in this industry. Natural plant products are very rich sources of compounds with various properties, including enhancing the reproductive performance of aquatic animals, and due to their positive effects on aquatic animals, they can be used as a suitable alternative to synthetic estrogens and should also be used to achieve sustainable and environmentally friendly aquaculture. In this article, we investigated the role of phytoestrogens in enhancing ornamental fish reproductive performance, using review of related articles, evaluated in recent years.

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.

The ornamental fish farming industry, which in the past was monopolized by a few countries in the world, has now expanded to 125 countries and our country is developing rapidly. The purpose of writing this article is to evaluate the situation of Iran in the world and future research of ornamental fish using Environmental Scanning model and strategic radar method. A balanced scorecard developed by Kaplan and Norton was also used to evaluate activity analysis. In the short-term strategy of improving the situation of :union:s and private organizations in ornamental fish in Iran can improve the balance and improve the situation of production and exports. It is important in the medium-term strategy to increase technology and use new equipment and facilities and specialized research centers for ornamental fish. In the long-term plan, competition with other countries in the field of reducing prices and improving quality and increasing global marketing capacity has a greater share in the field of ornamental fish. The results show that in the measurement and analysis obtained from the Environmental Scanning model and the BSC first generation balanced scoring card, our countrychr(chr('39')39chr('39'))s ability to trade ornamental fish is 34.28%, Malaysia with a long history of 74.28% and Singapore with extensive trade and technology. Shows 92.85%. This shows that the ornamental fish trade is a young activity that requires extensive changes that must be developed in the coming years in order to gain a special place in the world compared to other leading countries in the field of ornamental fish production.

Pollutants lead to undesirable changes in aquatic physiology. One of these changes is the expression of cytochrome P450 enzymes (CYPs) that are found in various organisms, including aquatic organisms. CYPs are too diverse and metabolize many substrates, but their structure is highly protected. CYP1 is one of the first enzymes produced in the first phase of the response to contaminants in the detoxification of extracellular compounds such as toxins, heavy metals, carcinogenic chemicals, drugs and petroleum contaminants. This enzyme is also expressed in stress-free conditions, but its expression changes in the presence of contaminants and stressors, which is affected by the aquatic species, age, sex, type of contaminant, concentration and duration of exposure to the contaminant and these changes can be used as biomarkers of pollution in aquaculture. Increasing its level can increase the resistance, growth and survival of aquatic animals against environmental pollutants. In this study, we investigate the role, importance and function of cytochrome p450 oxidase in fish.

Nowadays, releasing of heavy metals to aquatic systems is increasing due to development of various industries and factories. Heavy metals are highly resistant to degradation and could accumulate in ornamental fish and other fish body as a human food chain and be dangerous for human health. Removing of these pollutants from water using common methods are very time-consuming and sometimes expensive. Thus, nanotechnology introduced to solve this problem, recently. Nanotechnology plays a key role in pollution prevention, identification, measurement and treatment of heavy metals. Reactivity properties of nanoparticles in converting harmful pollutants to harmless substances due to small size, high surface area, crystalline form and unique network has been proved. Nanoparticles mechanisms are very different according to their structures. This  study was investigated types of nano-adsorbents and their application in removing heavy metals from aquatic ecosystems and aquariums.