For decades, there are severe disputes on the approaches and actions of aquatic wildlife conservation, such as in situ protected area, ex situ conservation, domestic preservation, domestication, artificial breeding, aquaculture, artificial releasing, ecological restoration, and so on. These indicate that for both professionals and the publics there are some differences and even contraries on the goals and methods of aquatic wildlife conservation. Lack of a theoretical discourse system, which is suited and matched to the needs and features of aquatic wildlife conservation, is the main reason that causes the problem. In this paper, we proposed a theoretical discourse system framed by the “conservation of species vs conservation of ecosystem” and the “suppressive protective actions vs active protective actions”, based on the differences on the goals of aquatic wildlife conservation and the differences on the methods of artificial involvement in aquatic wildlife conservation. Then, we summarized the status and effects of suppressive protective actions and active protective actions in aquatic wildlife conservation, and indicated that the effects of suppressive protective actions (in situ conservation) of aquatic wildlife were not good enough in part of protected areas, because the aquatic ecosystem patterns had been changed or still were deteriorating, and the human activities and impacts could not be removed or avoided. In contrast, the species with domestic preservation, artificial breeding, and aquaculture completely had avoided the risk of extinction; even the reintroduction and wild population restoration could be implemented. In this paper, we carefully showed the dramatic conservation results of three sturgeon species in Yangtze River, Psephurus gladius, Acipenser sinensis, Acipenser dabryanus, which vividly showed the significance of active protective actions for aquatic wildlife conservation. Here, we strongly suggested that we needed to advance the in situ conservation which would provide a space for wildlife, moreover, domestic preservation, artificial breeding, and aquaculture needed to be advocated, which would provide the last defender for withstanding species extinction.