Fish school swims on ladders instead of diamonds

For half a century, marine biologists believe they have figured out the fish. This genre of thought would slide into water in flat diamond formations to save the most energy, such as fighter jets sailing through the sky.

But after tracing six giants, Danios for ten hours in a row, researchers at Princeton and Harvard University discovered something unexpected: fish don’t swim in diamonds at all.

Instead, they moved in what scientists call “ladder formation”, a three-dimensional pattern in which fish have increasingly more ladders on ladders that are tilted in water. This discovery overturns decades of assumptions about one of nature’s most fascinating glasses.

The current situation that goes against scientific beliefs

Diamond Formation Theory comes from elegant mathematical models of the 1970s. Scientists suggest swimming side by side in synchronous formations can reduce drag and improve efficiency, just as cyclists draft each other. This idea seems logical enough to spawn countless research and even inspire the design of underwater robots.

But there is a problem: Most experiments force fish into shallow cans, essentially turning their natural three-dimensional world into two-dimensional. “When swimming, fishing averages produces planes driving back and forth,” explains Hungtang Ko, a postdoctoral researcher at Princeton, the study’s lead author and postdoctoral researcher at Princeton. Because of this jetting effect, the fish benefit from avoiding positions between each other.

The KO’s team used computer vision software (original design used to track individual animal movements) to capture the first comprehensive 3D data about the fish school formation. They collaborated with Harvard biologist George Lauder to analyze the circulating flow of giant Danios swimming in tanks, making the river state mimic the river.

Ladder Revolution

The results are surprising. Among the 264,173 video frameworks analyzed, famous diamond formation appeared in less than 0.1% of observations. Meanwhile, newly discovered ladder formation accounts for 79% of all fish pairs.

Key findings from a ten-hour marathon swimming course:

• Only 25.2% of the pairs of fish swim in the same horizontal plane
• Of those planes, 54.6% are inline, 30.0% are interleaved, and only 15.4% are side by side
• The position of the fish is constantly rearranged, and the formation changes every 32-48 seconds
• At higher speeds, the trapezoidal formation becomes more slender and proclaimed

KO points out that ladder patterns have similar hydrodynamic benefits for the shape of theoretical diamonds, but require less precise coordination between individual fish. “They can lay multiple planes on multiple planes,” he said, with his construction being more practical.

Meaning outside the fish tank

The discovery was immediately applied to underwater robotics. Nagpal Laboratories are developing fish-inspired robotic populations that can eventually patrol coral reefs and kelp forests. Understanding how real fish schools navigate across three dimensions can make these mechanical swimmers more effective.

This study also reveals the profound role of scientific hypotheses. The formation of diamonds seems so logical for decades that few people question whether the fish actually used it. New discoveries show that the solutions found by nature are more elegant and practical than human theory predicts.

“Cooperation is a two-way street,” Ko reflects. “We can use computer vision to discover how and why animal groups do things together.

The study, published in the journal Scientific Reports, opens new questions about collective behavior in marine environments with three-dimensional spatial freedom in marine environments. After 50 years of swimming, swimming with the current activities of established wisdom, science finally caught up with the knowledge of fish.

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