Abstract:
In recent years, the wild fishery resources of Schizothoracinae fishes in the plateau have been declining. Understanding the potential distribution and driving factors for these fish species can provide important references for the conservation in China. Up to now, species distribution models (SDMs) have been wildly used to predict the geographic distribution of different terrestrial species, including plants and animals. Among these, the Maximum entropy (MaxEnt) model is the most commonly used, with significant potential for identifying wildlife distribution and habitat selection. In this study, the MaxEnt model Ⅰ, Ⅱ, and Ⅲ were constructed based on 3 groups of selected environmental factors (i.e., Group 1: climatic and topographical factors for the model Ⅰ; Group 2: freshwater environmental factors for the model Ⅱ; Group 3: climatic, topographical, and freshwater environmental factors for the model Ⅲ). These models were applied using 58 recorded occurrences of
Gymnocheilus pachycheilus to study the current potential habitat distribution of
G. pachycheilus in the Yangtze River and Yellow River basins. The study also analyzed the main environmental factors affecting its potential distribution and discussed the future prospects of applying the MaxEnt model to inland freshwater fish species. The results indicated that: (1) MaxEnt model Ⅰ, Ⅱ, and Ⅲ demonstrated high reliability in predicting the current suitable distribution of
G. pachycheilus in the Yangtze and Yellow River basins. The inclusion of freshwater environmental factors further improved the reliability and accuracy of the models based on climatic and topographic factors; (2) the predicted potential geographical distributions of
G. pachycheilus predicted by MaxEnt model were consistent with the current existing distributions; (3) in the Yangtze and Yellow River basins,herbaceous vegetation-range across sub-catchment (Hb-rang), average elevation across sub-catchment(Up-ele), and temperature seasonality(Bio4) were the main environmental factors affecting the distribution of
G. pachycheilus. This study provides a theoretical basis for the conservation of wild
G. pachycheilus populations and their habitat protection. It also highlights the potential for the further application of MaxEnt model in studying other rare and endangered fish species of China. Moreover, the MaxEnt model holds broad prospects for applications in habitat protection of inland fish species, predicting drivers of fish displacement and extinction, monitoring and assessing fish community biodiversity, and evaluating the risks posed by nonnative (or invasive) fish species in China.