A major new UN assessment finds that the world’s great freshwater fish migrations are rapidly collapsing, threatening ecosystems, fisheries, and the livelihoods of hundreds of millions of people. Being released by the Convention on the Conservation of Migratory Species (CMS) at its COP15 in Brazil, the Global Assessment of Migratory Freshwater Fishes identifies 325 species requiring coordinated international conservation action, their declines driven by dams, habitat fragmentation, pollution, overfishing, and climate change. Migratory freshwater fish populations have fallen by about 81% since 1970, making them among the most imperiled wildlife on Earth. Because many species migrate across national borders through shared river basins such as the Amazon, Mekong, Danube, Nile, and Ganges–Brahmaputra, the report stresses that effective protection depends on countries managing rivers as connected systems. At CMS COP15, governments will consider new basin-scale action plans, conservation listings, and other initiatives to protect iconic long-distance migrant species such as the massive Amazonian catfish.

TCF3::HLF-positive B cell acute lymphoblastic leukemia is a rare and highly aggressive childhood cancer that causes severe damage to bones through mechanisms that remain unclear. To tackle this gap, researchers from Japan have developed a new mouse model that closely mirrors the disease as seen in humans. With it, they uncovered an inflammatory feedback loop that accelerates leukemia growth and bone destruction, highlighting a potential therapeutic target to combat disease progression and protect bone health.

A single-celled predator maintains stolen chloroplasts with its own proteins, linking the host cell and stolen organelles at the molecular level. This process, now supported by biochemical evidence, may offer clues to early steps in the evolution of plant cells.