【摘要】 <正> 非洲鲫鱼(Tilapia mossambica)是广盐性鱼类,不仅可在淡水养殖,而且在盐碱地区的水池或海水中都能进行养殖。其自然繁殖习性已有不少报道,但有关其人工繁殖的研究工作仅见Show,Valenti,金德沂等有过报道。 1975年,我们进行非洲鲫鱼的人工授精及口腔外孵化的试验,初步获得成功,1976和1977两年间又进行了多次重复,方法上进一步完善。更多还原

【Abstract】 Tilapia mossambica belongs to the mouth hatching fishes, which makes it rather difficult to observe its embryonic development and cell division. Therefore, we have to carry on artificial fertilization and the out-of-mouth hatching experiment for this kind of fish.1. The experiments were made on individuals of both sexes of Tilapia mossambica reared in a cement tank. They were caught when they were strongly displaying sex behavior and their eggs or sperm were lightly squeezed out by pressing their abdomens with a thumb and a forefinger. It should be pointed out that sperm should be squeezed out first and then eggs. Artificial fertilization were carried out in sea water with different salinities. The eggs and sperm showed higher fertilization rates over a salinity range of 8.25 to 33‰ sea water, the highest in 8.25‰ sea water. We have found that fertilization rates are closely related to the state of maturation of the eggs. Mature eggs can be kept for six hours at 30℃ without deleterious effect.2. The out-of-mouth hatching experiments were made in sea water with different salinities. The fertilized eggs were hatched in 8.25 to 33‰ sea water. Better results were found in 10 to 20‰ sea water, the worst in fresh water. When a proper quantity of antibiotic was added to the culture medium, the results of experiments were much improved.3. In fresh water sperms remained viable for no more than five minutes. In 10% sea water their fertility was much greater and they showed fertilizing potency even after thirty minutes.更多还原