Extremophile
Guides
Artemia monica
Mono Lake brine shrimp
Artemia monica is a brine shrimp species endemic to Mono Lake, California. It is a sibling species of the widespread A. franciscana, with which it is reproductively isolated due to different water requirements. The species exhibits strong salinity-dependent life history traits, with higher salinities reducing hatching success, survival, growth, and reproductive output while prolonging developmental timelines.
Cicindelidia haemorrhagica
Wetsalts Tiger Beetle
Cicindelidia haemorrhagica is a tiger beetle species notable for its ability to inhabit extreme thermal environments. In Yellowstone National Park, it is exclusively associated with hot springs ranging from pH 2.7 to 9.0 and temperatures from 29.1 to 75.0°C, where it functions as the apex invertebrate predator. The species exhibits remarkable thermal tolerance, with adults observed on substrates exceeding 50°C and showing minimal behavioral thermoregulation compared to populations in milder habitats. Outside Yellowstone, it occurs in wet salt lakes, ponds, rivers, and tidal flats across the western United States.
Cicindelidia haemorrhagica haemorrhagica
Wetsalts Tiger Beetle
Cicindelidia haemorrhagica haemorrhagica is a subspecies of tiger beetle known for its remarkable tolerance of extreme thermal environments. Populations in Yellowstone National Park inhabit hot springs with water temperatures exceeding 70°C (158°F) and pH ranging from highly acidic (2.7) to strongly alkaline (~9), making them among the most thermally tolerant insects known. The subspecies exhibits unique physiological and behavioral adaptations that allow it to function as an apex predator in these extreme habitats, including heat-reflective ventral plates and an apparent lack of cooling behaviors despite high ambient temperatures.
Ephydra
brine flies, alkali flies
Ephydra is a genus of shore flies (Ephydridae) with cosmopolitan distribution. Several species are notable for inhabiting extreme environments, including hypersaline lakes and hot springs. The genus includes the alkali fly (Ephydra hians), which forms dense populations in alkaline lakes such as Mono Lake, California, and serves as a critical food source for migratory birds. Larvae are aquatic or semi-aquatic, with morphological adaptations for feeding and respiration in mineral-rich waters.