show Abstracthide AbstractAustrofundulus limnaeus is an annual killifish that inhabits ephemeral ponds in coastal desert and savanna regions of Venezuela. These fish survive in ephemeral habitats by producing drought-tolerant embryos that can enter into a state of metabolic depression termed diapause. The adults are highly hypoxia tolerant and eurythermal. The embryos are tolerant of extreme environmental stresses and can survive for months without oxygen or water. This species is an excellent model for studying the mechanisms that control cellular growth and proliferation, phenotypic plasticity during development, and tolerance to environmental stress. Studies of this organism could lead to new strategies for preventing cellular damage associated with heart attack and stroke, and provide novel insights into stem cell biology and regenerative medicine.