Application of Spirulina in Aquaculture
October 21 06:01:56, 2018
Spirulina belongs to the genus Cyanophyta, Cyanophyceae, Oscillatoria, and Spirulina, which are helical under the microscope. The Spirulina algae species are mainly derived from Spirulinum maxima in Lake Tecos, Mexico, and Spirilinaplatensis in Lake Chad, Africa. At present, the spirulina industry is rapidly developing in China. Through the continuous renewal of the Spirulina breeding technology, the production cost has been greatly reduced, providing good conditions for the development and application of aquaculture and aquatic food bait. Spirulina is rich in nutrients, of which the protein content is 55%-70%, 1 gram of Spirulina is equivalent to 1 kilogram of the total nutrition of all kinds of vegetables and fruits, and contains 8 essential amino acids. Since Spirulina is a native plant and has no cell wall, the digestion and absorption rate of humans and animals is over 75%. Spirulina can be widely used in aquaculture, in addition to the cost of algae powder has decreased, the more important reasons are: 1, small particle diameter, usually 5 - lOum wide algae, 200-500um long. Application is often more than 120 mesh, algae powder is not easy to sink when put into water, not easy to corrupt water quality. 2. Spirulina is not only nutritious but also balanced and reasonable in composition. 7—Unsaturated fatty acids such as linolenic acid can promote the reproduction and development of aquatic animals, increase the survival rate and the metamorphosis rate of larvae, especially the high content of carotenoids. Its main components are p-carotene and lutein in aquatic products. Animals are metabolized into astaxanthin and spotted chelating jasminoids, which have significant color-enhancing effects and effectively increase the value of the products. At the same time, carotenoids are precursors of vitamin A and can be converted into vitamin A at any time in the body, which can enhance cell toughness and free radical activity, thereby enhancing resistance to bacterial and fungal diseases. Mikuton and Soin (1983) found that The consumption of carotenoids in yolk sac is quite large during embryonic development, and the high percentage of carotenoids increases the hatching rate. 1 Application of Spirulina in Crab Breeding Shengli Oilfield Shengda Group Fisheries Corporation observed that after the Spirulina was fed to the crab larvae, the water quality remained good, the larval metamorphosis rate increased by 18.4%, and the culture time was shortened by more than one day. In 1991, the Zhanjiang Fisheries Research Institute researched the growth of Scyllaserro (ta). It was found that the growth and development of larvae was 1-2 days faster than that of conventional foods, and the larvae were lively. The experimental conclusion of the Nantong Fisheries Technology Extension Station was that the Spirulina was fed as an open feed diet. The larvae metamorphosed to Z2 very neatly, and the survival rate of Z, metamorphosis to Z: increased by 14.2%, and the nursery time was shortened by 13%. The cost is reduced by 34.9%. The experiments conducted by Jiangsu Dongfang Agrobiochemical Co., Ltd. in a pond of a nursery household in Qidong showed that the spirulina powder can completely replace the rotifers and most of the annual insects. The larvae have a deep body color, and the individuals are slightly smaller. Strong ability, survival rate increased by 20.5%. 2 Application of Spirulina in shrimp aquaculture Spirulina has been widely used as a shrimp bait throughout the country. Experiments conducted by the Institute of Mariculture in Shandong Province showed that Spirulina powder can increase the seedling production of shrimp by 54.47% and increase the efficiency of water per cubic meter. Nearly 200 yuan. At the same time, the disease resistance was significantly enhanced. No antibiotics were used in the whole process of cultivation, and no disease and bacterial proliferation were found. Two years of experiments in the agricultural area of ​​Tanghai County, Hebei Province have proved that Spirulina as a bait has the best effect in the quail-like period and the oyster-shrimp period, and the increase in the survival rate of 8.3%-17.3% reduces plant costs by 58%. The experimental result of Beijing Agricultural University is that Spirulina can substitute for egg yolk and soybean milk to feed juvenile shrimp at the metamorphosis stage, and can promote growth and development more than egg yolk and soybean milk. Wen-Liandjao, a scholar at the University of Tokyo in Japan, has fed 3% spirulina bait on P. monodon and has the best effect. Zcaxanthin, one of the major carotenoids in Spirulina, has rapidly been transformed into astaxanthin. 3 Application of Spirulina in Macrobrachium rosenbergii The Guizhou Fisheries Research Institute conducted experiments on Macrobrachium sulphureus nursery in Beihai, Guangxi. It was found that after 10 hours of feeding Spirulina, the larvae of Macrobrachium rosenbergii were observed under the microscope and the stomach was visible. The intestine is filled with blue-green spirulina, and the color is clearly different from the color of eggs, Artemia and other feeds, indicating that Spirulina has been ingested by Macrobrachium rosenbergii. The statistical data of this experiment showed that the survival rate of Spirulina + Artemia cultured in Macrobrachium rosenbergii was 75.5%, which was 13.8% higher than that of the control group fed eggs + Artemia, thus changing the original Single production feeding mode. 4 Application of Spirulina in juvenile breeding Aquaculture trials of Jiangsu Jinhu special aquatic product seedlings were conducted on 3-5g hatchlings hatched during the same period. The results showed that they contained 0.9%-1.0% Spirulina diet is not easy to degenerate, feeding from the climate, does not pollute the water, not only improve the survival rate of earthworms, specifications have increased, and reduced feed costs. 5 Application of spirulina in abalone farming The Chinese Academy of Sciences Institute of Oceanology began to develop spirulina compound feeds in 1985, including nursery, industrialized abalone and sea cage feeds. Compared with Japanese feed, the water resistance of spirulina abalone complex feed in China Well, the mortality rate of young fish is low, and the shell is thicker and less likely to be damaged. And the unique shell color is black and green, close to wild abalone. It is more popular among manufacturers and consumers, and the feed cost is only half that of Nissan feed. The overheating experiment of abalone with waste heat at the Qingdao Power Plant showed that the survival rate was increased from 37.4% for winter to 85% for the feeding of Spirulina, and the growth period was extended by 5 months. 6 Application of Spirulina in Ornamental Fish Culture The ornamental value of fish depends on the shape of the fish and the vividness of the color. In the same species, in addition to water temperature, water quality, and light conditions, the feed has a more prominent effect on body color. Generally, red worms, krill meat, small fly algae, synthetic carrots, and other substances are added to the diet to increase fish. Body color. Spirulina is rich in carotenoid L, and it can be metabolized into axtaxanthin in animals to make body color more vivid. Japan (Shenya Koji, 1982) fed spirulina, goldfish, crescent fish, and tilapia with spirulina in the 1970s and found that their body color was brightened and their growth and reproduction capacity increased. Shanghai Fisheries University used Spirulina to feed Koi for 60 days. It showed that Spirulina can increase the surface coloration. With the increase of Spirulina content, the color of the fish body is more beautiful. Among them, the color of the fresh algae bait is the most obvious, and the vigor of the Koi also follows. Spirulina content increased and enhanced. 7 Conclusions In summary, as a natural feed resource, the feeding effect of Spirulina in aquaculture, especially in aquatic breeding, is very significant. However, the formation of large-scale, serialized products is not much, feeding technology remains to be further studied. We believe that the application of Spirulina in feed will be very bright.