ghd outlet Cement pond aquaculture greenhouse argu

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Cement pond aquaculture greenhouse argus Causes of early sexual maturity

, The mortality rate is low, easy to transport live fish,[link widoczny dla zalogowanych], and welcomed by the farmers. Currently, the argus ditch by the rural culture is semi-intensive culture pond intensive approach to the development of cement pool. It is reported that under natural conditions, female argus General 2 winter age, body length of about 30cm when the gonadal development and maturation, but also the individual has at age 1 female gonad maturation. Found in the breeding process,[link widoczny dla zalogowanych], greenhouse farming argus cement pool in the age of sexual maturity has advanced. Less than 1 age, body length more than 30cm, weighing 500g or more individuals, all gonad maturation, artificial oxytocin to lay eggs. Causes of precocious puberty caused, generally there are three aspects: first, the long-term ingestion of high protein, high fat diet, the body length, body weight rapidly, while speeding up the development of the gonad. Because food provides a large number of germ cell development of the necessary nutrients, so that rapid increase in the number of germ cells, volume increased rapidly, so early gonadal development and maturation. Pre-breeding, because the incidence of disease, has repeatedly long-term indigestion, indigestion during the greater part of individuals with similar individual to eat less, weight rapidly, the same species, the largest individual is the smallest individual 5O times. Before the spawning season by 2 months, feeding chilled sardines, its high content of protein and fat,[link widoczny dla zalogowanych], feed conversion ratio of 2.5 to 3.0, not only to meet the needs of fish growth, but also effective in promoting the gonads mature. Second, light and temperature differences with the natural state is a major factor causing precocious puberty. In natural water, Channa argus like clusters of bottom habitat in the aquatic environment, the distinct seasonal changes in water temperature, the rapid development of germ cells during the temperature and light intensity is higher in the spring and summer. Cement pond in the greenhouse, the argus higher stocking densities, habitat in the water layer,[link widoczny dla zalogowanych], the pool was no shade plants, high light intensity, water temperature has been maintained at high levels, stimulating gonadal development. Third, regular renewal of water stimulated gonadal development. Channa argus cement pool in the breeding, feeding rate of the high organic content in water rich in plankton growth and reproduction of fast. Dominant species of the pool, such as the Chlorophyta Scenedesmus, Chlamydomonas reinhardtii, the Transfer of algae, and soon formed blooms. 20 ~ 25 �� in temperature when changing the water every 7 days 1, for water, 9O. New water filling simulation of natural precipitation, so that the living conditions of Channa argus rapid gonadal development closer to spring and summer, accelerated through the neural regulation of gonad maturity. Presumably, Channa argus gonadal development and body length, weight and nutrition, environmental conditions are closely related, and relationship with age is not very close. Snakehead fry rearing in the production, just select the appropriate diet for broodstock enhancement training and maintain appropriate environmental conditions, early breeding species is feasible. (Fisheries College, Yantai University, 264001) * 23 *
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