Hydropotes inermis, also known as the water deer, is native to China and Korea. It lacks antlers, a rarity among deer, but features prominent canine tusks. This small, solitary species thrives in wetlands, feeding on grasses and aquatic plants, and plays a vital role in maintaining the ecosystem balance.

Hydropotes inermis, commonly known as the water deer, is native to eastern Asia. Its primary geographical distribution includes China and Korea. In China, it is found in the eastern provinces, specifically in the Yangtze River basin and regions such as Jiangsu and Zhejiang. It is also present on the Korean Peninsula.

The water deer typically inhabits riparian zones, marshlands, and wetlands. These areas are characterized by their proximity to water bodies, and they often feature dense vegetation such as reeds, tall grasses, and shrubs. The climate in these regions ranges from temperate to subtropical, with distinct seasonal variations including cold winters and warm, humid summers.

Water deer are adapted to environments with ample water sources and thick vegetation, which provide both food and cover from predators. Their ecological niche includes foraging on a variety of plants, especially grasses and sedges, and they are well-suited to wetland ecosystems where their swimming ability aids in escape from threats. Their adaptations to a semi-aquatic lifestyle are unique among deer species.