Batrachochytrium is a genus of fungi known for causing chytridiomycosis, a disease that affects amphibians, particularly frogs. This pathogen infects the skin of these animals, disrupting their ability to absorb water and regulate electrolytes, which can lead to severe health issues and even death. The most notable species within this genus is Batrachochytrium dendrobatidis, which has been linked to significant declines in amphibian populations worldwide. The spread of this fungus is a major concern for biodiversity, as it poses a threat to many species, contributing to the ongoing global amphibian crisis.