Borax Lake chub is only found in - and is the only fish who lives in - Borax Lake of southeastern Oregon. The lake is fed by geothermal hot springs full of dissolved minerals + heavy metals that most fish can’t tolerate - not to mention water temps that can reach over 100°F/37°C #25DaysofFishmas

The Alaska blackfish is found only in Alaska and Siberia, usually in heavily vegetated lakes and ponds. While native to much of Western/Interior Alaska, they were introduced to the Anchorage area in the 1950s and the Kenai Peninsula in the 1990s #25DaysofFishmas

The Alaska blackfish is the Arctic’s only air-breathing fish - they have the ability to breathe atmospheric oxygen through a modified esophagus. This party trick helps them live in habitats unsuitable for other fish like seasonal tundra ponds + even wet mud during periods of drought #25DaysofFishmas

While “large minnow” sounds like an oxymoron on par with “jumbo shrimp”, the Colorado pikeminnow historically grew nearly 6 ft/2 m long and could weigh over 80 lbs/40 kg. These days, however, the largest individuals are typically less than 4 ft/1.2 m long #25DaysofFishmas

Colorado pikeminnow was one of the first fishes put on the federal Endangered Species list in 1973 due to a combo of overharvest by settlers, introduction of nonnative species + most significantly, large dams and human water use that altered river flows + restricted their movement #25DaysofFishmas