The 10th International Symposium on Sturgeon (ISS10)

Freshwater ecosystems, despite occupying less than 1% of Earth’s surface, harbor a disproportionately high share of aquatic biodiversity, yet they are experiencing catastrophic declines under accelerating human pressures. Conservation assessments for critically endangered species often rely on outdated data that fail to reflect ongoing anthropogenic impacts. Here, we provide a comprehensive reassessment of two endemic and critically endangered Amu Darya Shovelnose Sturgeons (Pseudoscaphirhynchus kaufmanni and P. hermanni) by integrating field surveys, morphometric measurements, mitogenomic analyses, and sociocultural data. Contemporary fieldwork (2019–2024) reveals drastic range contractions and population collapse, with the long-snouted form of P. hermanni likely extinct and the short-snouted form persisting only in fragmented habitats. Morphological data show ecotype-specific degradation: wide-snouted P. kaufmanni exhibit declining body mass despite increased length, suggesting stress-induced metabolic trade-offs, while narrow-snouted forms display growth release amid demographic collapse. Mitochondrial diversity has declined sharply since the 1990s, likely driven by habitat fragmentation and poaching-induced bottlenecks. Social surveys and trade records expose culturally entrenched beliefs in the sturgeons’ medicinal properties, fueling targeted poaching and illegal trade. Our findings reveal a multidimensional extinction trajectory, encompassing range loss, phenotypic miniaturization, genomic erosion, and cultural overexploitation. These results highlight the urgent need for coordinated regional and international conservation strategies to halt the collapse of these evolutionary relicts and safeguard the ecological integrity of the Amu Darya River Basin.

 

Pseudoscaphirhynchus, Anthropocene freshwater crisis, Population collapse, Illegal poaching, Conservation strategy