جستجوی مقالات مرتبط با کلیدواژه "تکثیر و پرورش" در نشریات گروه "شیلات"

Successful reproduction and rearing of marine ornamental fish significantly depend on capturing, digesting, and assimilating sufficient amounts of live food. The most limiting factor in producing marine ornamental fish is the requirement for appropriately sized live food as a first feed. This issue is due to the small mouth size of many high commercial-value species. Therefore, the need for prey with the right size is one of the necessities in producing marine ornamental fish. In this regard, development and progress in the usage of new live food are required to expand this industry. The most common live food used in the rearing of marine ornamental fish larvae is rotifer and Artemia. These prey are not ideal in terms of size and especially nutritional aspects. Significant improvements in rearing marine ornamental fish larvae can be achieved by providing copepods and ciliates to feed them. Currently, various species of copepods can be successfully cultivated. The participation of copepods in the nutritional scheme of larvae, as exclusive feed or as a supplement to traditional prey such as rotifer and Artemia, is beneficial due to their high nutritional quality and a wider range of available sizes for different stages of larval development. Due to their small size, ciliates are a suitable food source for feeding the larvae of ornamental marine fish with very small mouth sizes. They have the characteristics of an effective live food, such as rapid reproduction, tolerance to high-density cultures, consumption of various food items, and the possibility of enrichment.

Ornamental fish is one of the most important industries in the aquaculture industry, which has international reputation compared to other aquatics. Breeding of ornamental fish has been successful in terms of using internal resources, high profitability, low investment, relative simplicity of production technology, and the possibility of spreading innovation and participation of young people for direct and indirect employment generation. Polypterus fish which is known as Azarakhsh fish in Iran, is one of our prehistoric fish whose history goes back to more than 200 million years ago. In addition to water breathing, this fish has air breathing and is resistant to many diseases and unfavorable environmental conditions. The birthplace of this fish is Africa and the catchment areas of the Nile River, Senegal, Niger, and other countries. The weight of this fish is reported to be about two hundred grams. In nature, these fish use insects, small fish, crustaceans, frog larvae and some molluscs, although some polypterous species are insectivorous and their lifespan reaches 34 years. Although it is very difficult to reproduce polypterus fish inside the aquarium, it can be done using techniques. The best age for polypterus fish reproduction is over 7 years and 30 cm long, otherwise these fish will not spawn. In order to stimulate the spawning of these fishes, it is necessary that the place of the aquarium is quite large and covered with hiding places.

The rapid development of fish farming and the increasing demand for fish have led to the dense cultivation of fish, which in turn has caused stressors for fish and thus increased the risk of disease. until now, the use of chemicals has been widely used for prevention and treatment, however, the use of chemical drugs has several negative effects on the environment (creation of resistant strains of bacteria) and human health (accumulation in tissues). medicinal plant compounds are readily available, especially for small-scale fish farmers, they are easy to use, nature friendly and degradable. since there has been a lot of attention recently to the use of plant compounds as a substitute for chemical hormones, therefore, in this article, the use of medicinal plants in sex reassignment, reproduction and breeding of different species of fish is mentioned. in this study, the library method has been used.

Infusoria are a group of aquatic organisms that are used to feed fish larvae. They are actually small forms of life in freshwater that include: Amoeba, Oglena, Green algae, Paramecium, Rotifer, Vertisella, and Invertebrates are small. Due to its small size, Infusoria can be used to breed newly hatched larvae of many aquarium fish species such as gourami and beta fish. Many home aquarium owners are naturally unable to provide enough infusoria to raise fish larvae. Infusoria can be grown by soaking any decomposing vegetative material such as lettuce and cabbage in an old, chlorinated, glassless water bottle. Depending on the temperature and light received, the infusoria begin to multiply within two to three days after planting. The water is initially cloudy due to the increase in the level of bacteria, but when the infusoria consume them, the water becomes clear. At this stage, infusoria are usually visible to the naked eye as small, white moving spots.

Marine fish cage culture is a fledgling industry in Iran. The continuous supply of juvenile fish is needed for cage farms, and it is the bottleneck of this industry. Therefore, selecting a suitable species for breeding and rearing that guarantees the stable supply of juvenile fish is the key to the continuity and success of this industry. To date, in Iran, several different species of marine fish have been introduced for breeding and rearing, however there have been various opinions among fisheries experts regarding target species selection. In this study, several indicators considered and categorized as principal factors affecting the target species selection, then the characteristics of fish used for breeding and rearing were compared with scientific evidence, and consequently, a species was nominated as the target one. Also, a native proper species for utilization in the marine aquaculture industry in Iran introduced.

The Snow trout, Schizothorax zarudnyi Nikolskii, 1897 belongs to Cyprinidae family, endemic to Hamoun Lake, Sistan, Iran. Female fish mature at 4 years old, a few at 3 years old, and male fish at 3 years old, and live in the rivers and lagoons of Hamoon (stagnant waters) and spawn in the same place. Natural fish populations have declined during the last several years because of environmental degradation due to drought and the introduction of non-endemic fishes to Hamoun Lake. Artificial breeding is an option to preserve and restore Sistan snow trout stocks. Given the successful breeding of this fish in recent years and the susceptibility of this endemic species to breeding, acquisition of its farming biotechnology, while restocking this valuable fish in the country, by entering the aquaculture sector of the region and the country, will increase the diversity of farmed species, provide part of the protein needed by the people and create employment.

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.

The Persian Gulf hosts great biodiversity. With 400-450 species of fish, the Persian Gulf is a unique area in terms of biodiversity. Different systems of aquaculture based on the introduction of native or non-native species have a special place in aquaculture. Species diversity in aquaculture is an attempt to maximize the benefits of species diversity such as resistance to disease, rapid growth, economic production, etc. within the framework of the ecological conditions created in aquaculture. Among species of fish in the Persian Gulf, most species belong to coastal fish, which include 85 species (65.38%), followed by pelagic fish (17 species), flounders (13 species), demersal fish (5 Species), tuna (4 species), cod and fatty fish (3 species), and unidentified marine fish (3 species). In recent years, increasing attention has been paid to marine species in Iran, accompanied by a focus on the development of aquaculture in marine environments. The cobia (Rachycentron canadum) is a fast-growing species native to tropical and semi-tropical regions. This native species of the Persian Gulf and the Gulf of Oman is a rich source of Omega-3. Currently, a large number of fish species are being harvested in the Persian Gulf. Calculation of maximum sustainable harvest quotas for each species is one of the goals of fisheries management, requiring information on fish stock

This study was carried out to evaluate the effects of dietary carbohydrate levels on growth performance and body composition of juveniles Caspian Kutum (Rutilus frisii kutum). Fish with initial average weight of 0.8±0.2g (±SD) were fed five isoproteic and isenergic formulated diets with different carbohydrate levels including 15, 20, 25, 30 and 35% in triplicate groups, 4 times daily according to their satiation for 10 weeks. Results showed that increasing the level of carbohydrate to 35% significantly increase some growth indices such as final weight (Wf), weight gain (WG), body weight increase (BWI), specific growth rate (SGR) and protein efficiency ratio (PER). In addition, result of body composition analysis showed that the increase in carbohydrate level lead to increase of protein level. So, the highest amount of protein was observed in fingerlings fed with diet containing 35% carbohydrate. In conclusion, the results indicate that increase in carbohydrate levels from 15 to 35% have not any negative effect on growth parameters and therefore, the level of 35% carbohydrate in the diet of 1-2g Caspian Kutum fingerlings can lead to better efficient in protein and desirable growth.