Invertebrates
Brine Fly
Ephydridae · also called alkali fly
Along the shoreline of an extreme saline lake, brine fly larvae develop in water chemistry that would kill nearly any other insect outright. Their sheer numbers, once they emerge, become the reason thousands of migratory birds detour specifically to this one hostile lake each year.
Overview
The brine fly, family Ephydridae, is a small insect capable of developing within extreme saline and alkaline lake water, found at hypersaline lake ecosystems across multiple continents. Its remarkable chemical tolerance and outsized ecological importance as bird food make it one of the more genuinely extreme insect success stories.
Thriving where almost nothing else can
By tolerating water chemistry that excludes nearly all other insect competition, the brine fly has turned one of the most hostile aquatic environments on the planet into a habitat it can dominate in extraordinary numbers, supporting entire bird migrations in the process.
Status
Least Concern — abundant at suitable extreme saline lake habitats worldwide, though concentrated populations remain sensitive to changes at specific key lakes.
Brine Fly: common questions
How can the brine fly survive in such salty water?
Brine fly larvae are capable of surviving and developing within water bodies many times saltier or more alkaline than ordinary seawater, tolerating chemical conditions that are lethal to the vast majority of other insect species, an extreme physiological adaptation that allows the species to exploit habitat essentially free of competition.
How does an adult brine fly walk underwater without getting wet?
Some brine fly species can trap a layer of air around their body, allowing adults to walk beneath the surface of saline water to lay eggs while remaining effectively dry and protected from the surrounding caustic liquid, a remarkable adaptation for surviving direct contact with extreme water chemistry.
Why are brine flies important to migratory birds?
The sheer abundance of brine flies at certain extreme saline lakes makes them a critical food source for large numbers of migratory birds, which rely on this concentrated, reliable protein source during specific, energy-demanding stages of their long-distance migration.
Where can you find brine flies?
Brine fly species are found at extreme saline and alkaline lakes across multiple continents, including several well-known hypersaline lake ecosystems, generally wherever water chemistry is too extreme for most other insect species to establish a breeding population.