Those in nature have much greater adaptability to disease and to the environment. Those raised in fish ponds are weaker, and need frequent infusions of fish from nature in order to upgrade their quality.
由於野外族群對疾病、環境有更高的適應力，當抗病力弱的養殖品種逐漸衰弱，常需要採取野外族群來改善品質。