نشریه آبزیان زینتی
سال هفتم شماره 4 (زمستان 1399)

The genus Carassius is a genus of the family Cyprinidae, that its species are important part of the ornamental fish industry in Iran. Due to the recent changes in the taxonomic status of the genus Carassius, it is necessary to review the taxonomic statues of its recorded populations in Iran. Therefore, the present study was conducted to provide an overview of the taxonomic status of the genus Carassius and also to provide some of the most important biological and ecological features of the species of this genus in Iran. Three species of the genus Carassius have been recorded in the inland waters of Iran, including C. auratus, C. gibelio and C. langsdorfii thatthei biological features and distribution were reviewed. Morphological differentiation between Carassius species, especially C. auratus and C. gibelio is difficult, because there is a high degree of morphological overlapping. This indicates that the taxonomic status of this genus should be reviewed based on molecular studies.

Parrotfish is a beautiful hybrid of the family Scaridae and the order Perciformes that is created by genetic manipulation of the fish cichlid (Amphilophus citrinellus) and the female red-headed cichlid (Paraneetroplus synspilus). Parrotfishes by chewing grasses and coral reefs and preventing their overgrowth are considered as a determining factor in the structure and bioerosion of marine diversity. Six genders have been reported from the parrot family of fish in the waters of the Persian Gulf and the Sea of Oman. They have structural abnormalities (curved and round vertebrae, always open mouth) and sexual (inability to fertilize eggs). Due to the aggressive behavior of the fish and the restrictions, they are difficult to maintain in the aquarium and should not be adjacent to very small or very peaceful fish. Parrotfishes are omnivorous and feed on triangular mouths and beaks, as usual, on algae and invertebrates, live corals, and shellfish. These fish are male to female hermaphrodites and usually change sex at 7 years of age. Their eggs are pelagic and do not take care of them. No obvious secondary sexual characteristics are seen in these fish. After spawning, the eggs or parents can be moved. By mating a male Texas cichlid with a red femalechr('39')s original can, red Texas, which is very rare, can be created, or beautiful rays can be propagated by mating a male flower horn with a femalechr('39')s redchr('39')s.

Production and trade of ornamental aquatics in countries with natural resources of these aquatics have made significant progress. Out of 1500 species of ornamental fish in the world, Iran has 80 species natively. The coasts in the south of the country have several coral islands and the location of various marine ornamental aquatics. Despite the growing demand for the marine ornamental aquatics  and the countrychr(chr('39')39chr('39'))s natural potential, multinational exploitation and political conflicts and security instability in the Persian Gulf have led to insufficient knowledge and planning for the protection and utilization of these resources. Lack of specialized knowledge and the lack of knowledge of ornamental aquaculture and lack of consulting in the design of production farms and/or aquarium of ornamental aquatics, lack of financial, equipment, cultural, extension, marketing and insurance support lead to failure in the cultivation and continuous trade  of ornamental aquatics at the national and international level and Producers and consumers are deprived of  sustainable using these natural gifts so that other pets, despite some health and even moral warnings, have replaced the aquarium and the ornamental aquatics hobbies. The aquarium industry and the production and trade of ornamental aquatics beyond traditional methods have become technologically global in recent years. Most countries with natural resources of ornamental aquatics, whether marine or fresh water (more or less like Iran) in production and trade have been leaders. But for the reasons mentioned, the country (Iran) has shortcomings in the development of this industry. Acquisition of technology for reproduction and breeding of scarce and limited reserves species with an aesthetic value among ornamental aquatics, especially marine species, is the most important factor for the success of leading countries in the future.

The presence of pharmaceuticals as trace pollutants in natural surface water bodies, ground water anddrinking water has recently led to some concern special for helth of aquatic organisms. Since sewage is the main source of this type of pollution, some attempts have been made to remove pharmaceuticals by advanced physical, chemical and biological techniques which go further than the conventional treatment. In this study has considered the ways enter pollutions and measurement of toxicity eleven different pharmaceuticals and municipal sewage and pharmaceuticals treatment plant effluents case acute and chronic on some aquatic organisms. In this study has proved this pollutants give harmful effect on aquatic ecosystem and reminded in nature by reason high stability and none of the techniques could guarantee a hundred percent removal and questions about possible toxic by-products and the behavior of metabolites remain.

The study of inland waters ichthyofauna and introduction of native fishes as ornamental fishes is importance issue; but it requires sufficient knowledge of Ichthyology and understanding of their ecological and biological characteristics. Recently, several articles have been published regarding ichthyofauna of inland waters of Iran, which have scientific errors. Among these cases is an article entitled " Introduction of some ornamental fish in the waters of Sistan and Baluchistan Province, by Doustdar and Hashemi (2019) in Journal of Ornamental Aquatics. Vol. 7, No. 1, pp: 1-5” which has been aimed to identify ichthyofauna of the Sistan and Baluchestan Province and introduction of those proper fishes to ornamental fish industry of Iran. This article aimed to criticize the above-mentioned article in two parts (1) notifying the authors to ecological issues of introducing non-natives fishes as ornamental species and (2) explaining the taxonomic errors of the identified fish species.