In the waters of Hainan's southern rivers, where currents carry silt and leaves, scientists have encountered a fish previously mistaken for a known species. It has now been identified as a distinct member of the genus Pseudobagrus, named 琼州拟鲿 (Qióngzhōu nǐcháng) after the island's ancient designation.
This discovery was made during routine surveys of the Nandu and Changhua river basins.
Researchers from the Hainan Institute of Marine and Fishery Sciences compared the morphological characteristics of the new fish with descriptions of other species in the genus. Significant differences were noted in the length of the maxillary barbels, fin shape, and body proportions, none of which matched any known species.
Molecular analysis further confirmed that this is a separate species, not merely a variation of an already described one.
Previously, this fish was often confused with the longitudinally striped Pseudobagrus. However, it has now been determined that the true longitudinally striped species inhabits only a narrow range within the Wanquan River.
All other findings in different Hainan rivers and on the mainland were attributed to distinct, as-yet-undescribed forms. This clarification of species boundaries allows for a more accurate assessment of population statuses.
Visually, 琼州拟鲿 resembles species from the Pearl River and Red River basins, but statistical analysis of its three-dimensional features and barbel length ratios reliably distinguishes it from its relatives. These differences likely developed due to the island's isolated river systems, where conditions such as current, temperature, and food sources vary from those on the mainland.
The findings have been published in the journal Animals. Scientists plan to further investigate its habitat preferences, life cycle characteristics, and population numbers. Such data will form the basis for conservation measures aimed at preserving Hainan's freshwater biodiversity, where each river represents a unique ecological niche.
Island rivers often harbor species found nowhere else, and their disappearance can go unnoticed until systematic monitoring efforts begin.
