四、污水池塘鱼类的生长状况鱼类成长的速度和鱼体肥瘦,主要取决于食料是否充足和其营养价值的高低。在养鱼生产中,鱼类的食料是通过直接投饵或施肥,增加水体中的食料生物的方法来解决。因此饵料供给的丰富与否是决定生产量的关键。这些水体中各种大小的动植物,通常称为鱼类的饵料基础。鱼类的食性,在不同季节,不同生长期和不同地区往往是有变化的,但作为鱼类食物的水生生物等是它所需的外界环境条件之一;它的滋长繁殖和气候 Fourth, the sewage ponds, the growth of fish The speed of fish growth and body fat, mainly depends on the adequacy of food and its nutritional value of the level. In fish production, the foodstuffs of fish are solved by direct feeding or fertilization to increase the food material in the body of water. Therefore, the abundance of food supply is the key to determine the production volume. Animals and plants of all sizes in these bodies of water are often referred to as bait grounds for fish. Fish food habits, in different seasons, different growing periods and different regions are often changing, but as a fish food aquatic organisms and so it is one of the external environmental conditions it needs; its growth and reproduction and climate