Scientists isolated a fungus from the gut of deep-sea amphipods in the Mariana Trench and discovered how it uniquely adapts to low-salt conditions. Unlike other fungal strains from different habitats, this gut fungus showed special abilities to survive and even thrive when salt levels dropped dramatically. The researchers found that the fungus rapidly rewired its genes and cellular structures to maintain water balance and protect itself, revealing how life in extreme deep-sea environments drives evolution of novel survival strategies.