Distribution and characteristics of fishes
In the region, there are 7 fish species under two orders, three families and five genera, among which, the Dadu schizopygopsis malacanthus chengi are the most common as it has been found in several survey spots besides Changping Valley, Triplophysa stolickai takes the second place, and the specimens of the rest 5 species were found in the lower reaches of Wori Dayingpan River, which are rare in tributaries.
The fish specimens once were collected from Changping Valley. This time, however, no specimen has been found in the 3 investigation points, and the reason is subject to further investigation. In Haizi Valley, there are a large amount of Dadu schizopygopsis malacanthus chengi, most of which inhabit in Huahaizi and the lower reaches of the river. Huahaizi is an important spawning site, so are Nianyuba in Shuangqiao Valley. This is an important finding of the spawning site of Dadu schizopygopsis malacanthus chengi. Other species are mainly found in the lower reach of Wori Dayingpan River, and rarely found in upstream or other tributaries. The distribution of fish species in this region is shown in the attached diagram: Distribution Diagram of Fishes in Mount Siguniang Region.
The seven fish species are fish species of the Qinghai-Tibet Plateau, except euchiloglanis kishinouyei and pareuchiloglanis robusta. Triplophysa stenura, schizothorax longibarbus, Dadu schizopygopsis malacanthus chengi, euchiloglanis kishinouyei and pareuchiloglanis robusta are endemic species of the upper reaches of Yangtze River, and schizothorax longibarbus and Dadu schizopygopsis malacanthus chengi are the endemic species of Dadu River. Triplophysa brevicauda, triplophysa stolickai and triplophysa stenura are mainly found in Qinghai-Tibet Plateau, of which, triplophysa stolickai are found in plateau rivers at the altitude of about 5,000m but rare in alpine lakes, such as Xihainiuzi (4,500m), and further investigation is pending.
The main habitat of different fish species has a certain range. Usually, the habitat of fish varies with the habitat environment, so does the distribution, especially with the elevation. In this region, the most widely distributed fish species with the highest habitat height is the Dadu schizopygopsis malacanthus chengi, which can be found in the river reach at the altitude of 4,000m at maximum. Next is the triplophysa stolickai, which can be found in the reach at 3,300m, and the other five species are more common in reaches below 3,000m. The fish species in this region are notably different from those in Wolong region. Due to relatively low altitude, Wolong has a large variety, about 11 species characterized by river fishes in mountain areas around the Sichuan basin, while the fishes in the Mount Siguniang region are featured by the fishes on the Qinghai-Tibet Plateau due to its high terrain and cold weather, which is one of the salient features of the fish composition in this region.