AMBRIDGE, Mass. — In 1993, Leonard Zon had 110 fish tanks and an idea.
Zon, a professor of stem cell and regenerative biology at Harvard University, thought to study human diseases in zebrafish. The freshwater fish, native to the streams and rice paddies of India and Myanmar, struck him as an ideal model animal for laboratories: Its eggs are transparent, allowing scientists to observe developing organs just by peering into a microscope, and female fish can lay hundreds of eggs a week.
More than two decades later, he now has thousands of tanks housed in two separate facilities — and zebrafish, alongside fruit flies, worms, and mice, are one of the most ubiquitous lab animals worldwide.
This video shows what it’s like inside Zon’s zebrafish room, one of the largest zebrafish facilities in the world.
“Zebrafish is a wonderful system to study disease,” said Zon. “They’re essentially embryo factories. … [This] allows you to study as many genetic diseases as possible and do it very effectively.”
Zon’s lab is focused on studying blood diseases and cancer.
Through these tiny fish, he’s found genes that cause human diseases and developed drugs that have made their way to the clinic.
Zon said he likes to walk through the rows of tanks and observe the fish swimming, sometimes spotting some “interesting tumors” along the way.
“That’s how I space out.”