河蟹的栖息地常选在水质清澈,水草丛生的河湖地带,喜欢在岸边掘穴而居,其洞口多呈扁平状,比身体稍大些,深约20—100厘米。白天,河蟹躲在家中休息,晚上则外出觅食。河蟹的主要食物是螺蛳、河蚌、水生昆虫、小鱼虾以及各种水生植物等,个体较大的雄蟹有时也捕食青蛙。在自然条件下,由于动物性食物不易获得,所以河蟹更多是吃水草及植物种子等。河蟹吃食贪婪且争抢凶猛,几只河蟹常为争食一条死鱼而大打出手,胜利者有时会将受伤者一块吃掉。但河蟹忍饥挨饿的能力也是很强的,在正常摄食季节,即使一个月吃不到食物也不会饿死。在养殖密度较大的池塘里,如果投食不足,个别体弱力小的河蟹,由于抢不到食物,长期处于饥饿状态,个体发育迟缓,形成瘦小的“懒蟹”。懒蟹个 Habitat habitat Crab in the clear water, grass and river rivers and lakes, like digging in the shore and living, the hole was flat, slightly larger than the body, about 20-100 cm deep. During the day, crab hides at home to rest, at night go out for food. The main food crabs are snails, mussels, aquatic insects, small fish and aquatic plants, etc., the larger individual male crabs sometimes prey on frogs. In natural conditions, animal food is not easy to get, so the crabs are more plants and grass and other seeds. Crab eats greedy and fierce competition, a few crabs often fight for a dead fish and fight, the winner sometimes will be a piece of the wounded ate. But the crab’s ability to starve is also strong, and in the normal feeding season, even a month to eat food will not starve to death. In the more densely populated ponds, if insufficient feeding occurs, individual crabs, who are weak and weak, have been starved for a long time due to lack of food, and the individual is sluggish to form a lazy “lazy crab.” Lazy crab