If you’re a geologist, Nicaragua’s Lake Apoyeque is quite interesting because it formed when a volcano erupted and then filled with water over the course of 1800 years. If you’re an aquarist or an evolutionary biologist however, the lake is downright fascinating because of the almost impossible way in which its population of fish got there.

Although Lake Apoyeque is over 300 feet deep, the walls of the crater that form its circumference are still over 1200 tall. As such, the volcanic cliffs that ring the lake and the dense forests that surround it together form a formidable barrier, serving to isolate the lake from any other bodies of water nearby. But when scientists from the University of Konstanz in Germany mounted an expedition to study the evolution of the lake’s population of cichlids, they were in for a shock. After sequencing the DNA of the fish in Lake Apoeque and comparing it to that of cichlids in other lakes, the data revealed that the Apoeque fish actually came from nearby Lake Managua only 100 years ago.

The problem was that are no rivers or streams connecting the two lakes and there are no records of people deliberately transplanting fish from one to the other around 1900, so the scientists were stumped. Indeed the question of how the fish managed to travel across dense forests and traverse towering cliffs was a total mystery until the meteorology of the area offered an unexpected – and almost unbelievable explanation.

One of the quirks of Nicaragua’s weather is that it sometimes experiences waterspouts – twisting columns of air that form over bodies of water almost exactly like tornados. The whirling waterspouts are powerful enough to literally suck water hundreds of feet into the air, hoovering fish up from one lake and dropping them again great distances away. Most of the time, the hapless fish are dumped miles inland, but very rarely (every few thousand years or so) they’re dropped into another lake. It’s an amazing airborne journey for any fish to make, and it gives Nicaragua its very own species of freshwater “flying fish”.

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