نشریه آبزیان زینتی
سال دهم شماره 2 (تابستان 1402)

Spirulina is a cyanobacterial photosynthesis that is grown commercially in many tropical and subtropical countries and temperate regions for human and animal nutrition. This commercial product is used as a rich source of protein and vitamins in the pharmaceutical, food and chemical industries due to its valuable nutrients. In the last two decades, the production of microalgae for food has increased more than five times and now algae are consumed in about 80 countries. Also they are produced in 22 countries, where the European market consumes lonely 32% of total production. Based on the observations made, one of the highest growth rates the fastest growing market, with an annual growth rate of 15%, has been recorded in this area. The algae has been introduced by the US space agency (NASA) as a superfood and tries to provide a healthy diet for astronauts with the help of Spirulina. The aim of this study was to investigate and identify spirulina algae as food for the next generation of humans.

In line with the growth of the aquaculture industry, the reproduction and cultivation of ornamental fish has developed significantly due to its high economic importance. One of the most important challenges in the aquaculture industry is the improvement of formulated diets to improve the growth efficiency, nutrition and immunity of fish. In recent years, many efforts have been made in connection with nutritional strategies and optimization of feed compositions in different fish species. The use of microbial feed additives (probiotic, prebiotic and synbiotic) through different mechanisms can lead to increased growth, survival, immunity, improvement of reproductive functions and maintenance of water quality in breeding environments. Therefore, according to the successful results of using microbial feed additives in different species of fishes, the use of these additives is considered as an important strategy for better production of aquatic products in breeding systems and helps the sustainable development of the aquaculture industry.

The present study was conducted in order to review the biological characteristics and breeding and maintenance methods of common platy (Xiphophorus maculatus) as one of the popular aquarium species in the world. The literature review showed that this species is native to subtropical and tropical regions including Mexico, Guatemala, Belize and Honduras. In terms of diet, common platy is omnivorous, and in terms of reproduction, if the water temperature is optimal, it leads to almost continuous reproduction in this species. X. maculatus is known as a peaceful fish, therefore, it is considered a very suitable option for keeping in social aquariums. In general, in terms of the physico-chemical properties of the habitat, platy fish prefer water with a high degree of hardness, which is similar to their natural habitat. The researchers stated that keeping the pH of the water in the range of 6.8 to 8.5 is very suitable for the life of these fish. According to the reports, the lifespan of common platy is three to five years, if it is properly cared for. Fin rot, Ich and velvet are among the most common diseases of platy fish in the aquarium environment. The overall findings showed that common platy (X. maculatus) due to having a series of special features such as small size, omnivorous diet, no need for a special bed and environment for spawning, as well as its high potential in tolerating a wide range of environmental conditions can be considered as an ideal and suitable option for breeding in home aquariums.

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.

In the culture and breeding of aquatics, establish the conditions as close as possible to those of the natural habitat, it is more likely to succeed. One of the most important challenges in this regard has always been the type of food and the feeding method of aquatics. Attempts have been made to make artificial foods for all types of aquatic animals, but due to the diversity of farmed fish, especially marine fishes, providing a balanced diet for all types of aquatic animals has faced difficulties. Therefore, using live foods in aquaculture has always had a special importance. The most important characteristics of a suitable live food are high nutritional value, free from contamination and pathogens, and easy, economical and sustainable production. White worm is one of the best options in farming a variety of aquatic animals, considering the above characteristics and compared to other live foods. This worm has been used for feeding of different marine and freshwater fishes, and different species have showed different responses, that indicate using this worm has high potential, and in the other hand, there are need supplemental investigation on feeding of different fish species. Therefore, it seems accessing basic data about this worm is very necessary. This paper presents the biology, nutritional value and enrichment, reproduction, and harvesting methods of this worm.

Beta fish with the scientific name of Betta splendesns and the so-called names of warrior fish and Siamese warrior is one of the most famous freshwater aquarium fish in the world that in recent years its maintenance, reproduction and breeding has expanded significantly in the world and as good in Iran. This fish has an elongated and scaly body with a round cross section that has a maximum overall length of 6.5 cm. The hallmark of the Beta fish or fighter fish, as its name implies, is its aggressive behavior. Beta has a carnivorous diet and in nature feed on animal plankton or zooplankton, insects and insect larvae. The best temperature for keeping Beta in the aquarium and multiplying it is 26 to 30 degrees Celsius. These fishes reach sexual maturity in less than a year and possibly up to six months, depending on temperature and living conditions such as nutrition, water quality and other factors. By selecting suitable breeders and providing suitable environmental conditions, this fish can be mated and reproduced. 36 to 48 hours after the Beta fish spawns, the eggs hatch and give birth to tiny larvae with an average length of 2 mm that have a yolk sac and no swimming ability. Finally, by following a proper diet and other biological and environmental factors, these fishes at about five months of age will reach the appropriate size to be presented to the ornamental fish market.