The shrimp stop swimming at dusk and gather near the river’s edge. After sunset, they begin to climb out of the water. Then they march. All night long, the inch-long crustaceans parade along the rocks.
The parading shrimp of northeastern Thailand have inspired legends, dances and even a statue. (Locals also eat them.) During the rainy season, between late August and early October, tourists crowd the riverbanks with flashlights to watch the shrimp walk.
Watcharapong Hongjamrassilp first learned about the parading shrimp, and the hundred thousand or more tourists who come each year to see them, about 20 years ago. When he started studying biology, he returned to the topic. “I realized that we know nothing about this,” he said: What species are they? Why and how do they leave the safety of the water to walk upstream on dry land? Where are they going?
Mr. Hongjamrassilp, a graduate…
