A New, Unique new species – Hemimyzon yushanensis, endemic to Taiwan, was discovered in Yushan National Park 
Yushan National Park Headquarters (referred to as YSNPH below), of National Park Service, Ministry of the Interior, commissioned Professor Chen I-Hsiung and his research team from the National Taiwan Ocean University's Institute of Marine Biology to implement the “Ecological Survey of aquatic biological resources of freshwater fishes and crustaceans in all river basins of the Yushan National Park during 2022-2023.” During this period, the team focused on the diversity of high-mountain stream fish and crustaceans and explored the Nanzihsian River and Laonong River in the upstream area of the Gaoping River watershed. They discovered and then formally published the world's first new species of Taiwan endemic freshwater fish, the Hemimyzon yushanensis (Photo 1), representing a distinctive species in the high-mountain streams of the Park's southern foothills near Yushan's main peak. The newly discovered species has a slender body with numerous white spots, and its dorsal fin differs in structure and characteristics from the Hemimyzon formosanus (Photo 2). Professor Chen I-Hsiung's team obtained research results, and the new species was officially published and named in the international journal Zootaxa.
The Hemimyzon belongs to the fish genus known as sucker loaches in Chinese water systems. These fish species occupy the ecological niche of insect-eating fish in stream ecosystems, due to their adaptability to the high-flow, high-dissolved-oxygen areas. Therefore, these fish species depend on stable, unpolluted stream ecosystems with constant water flow. The well-preserved forest ecology of water systems like those in the southern foothills of Yushan has therefore nurtured stable populations, which has demonstrated the importance of forest ecology conservation.
Rich Ecological Diversity in Yushan National Park's Three Major River Systems, with Excellent Water Quality
In the survey and research of the diversity in the three major river systems within Yushan National Park, 24 sample stations were set up along the Jhuoshuei River, revealing 9 fish species from 4 families and 7 genera as well as 2 crustacean species from 2 families and 2 genera. In the Xiuguluan River,13 fish species from 4 families and 9 genera, and 3 crustacean species from 2 families and 2 genera were discovered in 28 sample stations. Along the Gaoping River, 8 fish species from 3 families and 7 genera, and 2 crustacean species from 2 families and 2 genera were found in 16 sample stations. Basic hydrological measurements and monitoring were conducted in the main stream environments of these major river systems. Overall, water quality ratings were excellent, with more significant environmental fluctuations during periods of high turbidity in the main stream, while the smaller tributaries maintained a more stable environment.
Protecting the Ecological Stability of High-Mountain Streams in Yushan – a Collective Responsibility
The opening of mountain areas to a large number of visitors has caused significant impacts on both the "original" inhabitants of the mountains and the environment. The stability of the high-mountain stream ecosystem, with its diverse and intact fish populations, is crucial for sustaining various types of fish communities and serving as a vital food source for mammals or reptiles in the riparian zones. While the YSNPH has long been committed to ecological conservation, the protection of mountains and rivers requires collective attention and action. Hikers and outdoor enthusiasts are reminded to refrain from littering during mountain activities to reduce the disturbance to wildlife in the park. For more information, interested individuals can visit the official website (https://www.ysnp.gov.tw/) to explore reports on research investigations commissioned over the years and gain a deeper understanding of Yushan National Park's high-mountain stream ecology.