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Found: Tiny Shrimp Hiding in Hot Springs

Also, snails smaller than a grain of sand.

An ostracod.
An ostracod. Anna Syme/CC BY-SA 3.0

Ten years ago, researchers at Hot Springs National Park, located just outside of Hot Springs, Arkansas, surveyed the microscopic life living in the park’s thermal waters. This summer, two interns decided to follow up on that work, The Sentinel-Record reports.

They sought out pools of water throughout the park where they might find evidence of teeny tiny life; one of the most fruitful spots was at the former site of the Government Free Bath House, which was originally funded by Congress in 1878.

The Government free bath house around 1901.
The Government free bath house around 1901. Library of Congress/LC-DIG-det-4a08627

Their search was successful: The two young researchers found five species of tiny “seed shrimp” that were not known to be living in the park. These creatures are called ostracods, and they can be less than 1 mm in size. The ones living in the hot springs are extremophiles that thrive under conditions that most creatures would pass on. (While it’s nice to take a dip in a hot springs, most of us wouldn’t want to live in that steaming water full time.)

The survey turned up more than tiny shrimp, too. According to The Sentinel-Record, the interns also found snails “about the size of the a grain of sand” in the water. That’s very small!