Scientists Were Puzzled for Years by Mysterious Seafloor ‘Crop Circles'
By Darren Orf - 7/2/2026, 1:00 PM - 650 words
Faulty reasoning signals
- Confirmation Bias - 10.8% (70 hits)
- Anchoring Bias - 8.5% (55 hits)
- Availability Heuristic - 16.9% (110 hits)
- Representativeness Heuristic - 10.5% (68 hits)
- Hindsight Bias - 11.4% (74 hits)
- Overconfidence Bias - 19.8% (129 hits)
- Framing Effect - 10.2% (66 hits)
- Loss Aversion - 0%
- Status Quo Bias - 4.8% (31 hits)
- Sunk Cost Effect - 3.8% (25 hits)
- Optimism Bias - 8% (52 hits)
- Pessimism Bias - 0%
Article text
Scientists Were Puzzled for Years by Mysterious Seafloor ‘Crop Circles'
Here’s what you’ll learn when you read this story:In 1995, divers off the coast of Japan discovered strange, circle designs on the seabed that resemble the famous “crop circles” that mysteriously appear in farmers’ fields.More than 15 years later, scientists discovered that these creations were the work of a new species of pufferfish (Torquigener albomaculosus).
Although they’re made by a fish that’s only five inches long, the crop circles stretch as wide as seven feet in diameter and take up to 9 days to complete.Few creatures are stranger than the pufferfish.
As the name suggests, their claim to fame is the ability to become a puffball of deadly, poisonous barbs that scream “don’t mess with me.”
To pull off this feat, they’ve evolutionarily ditched the need for ribs or even a pelvic bone.
Incredibly, people actually eat pufferfish (a delicacy known as fugu) even though the animal contains a poison known as tetrodotoxin, which is 1,200 times stronger than cyanide.
In Japan, chefs have to take national written and practical exams to learn how to prepare the fish safely.In addition to these weird traits, pufferfish are also underground artists…of a sort.
In the 1995, divers discovered strange formations on the ocean floor off the coast of Japan.
From a distance, the aquatic works of art looked like a child’s drawing of a sun—a perfect circle roughly seven feet in diameter with small fissures around its circumference.
They’ve often been compared to the mysterious crop circles that have been found in farmers’ fields for decades.
This head-scratching display stumped scientists for decades until 2011, when a team of Japanese scientists spotted a new species of pufferfish, Torquigener albomaculosus, hard at work on what they theorized was an elaborate mating ritual.Elaborate mating rituals aren’t uncommon in the animal kingdom.
Bowerbirds, for example, construct intricate display avenues decorated with natural and man-made debris to entice a female, and fish species like the featherfin cichlids of Africa’s Lake Tanganyika build small bowls of sand as part of their mating ritual.
However, according to a 2013 study in the journal Scientific Reports, the seabed sand circles are the first display that uses radially aligned valleys, fragments of sea shells, and fine sediments to set itself apart from the competition.
Once a female selects its preferred site (a process scientists still don’t understand), it lays its eggs in the center of the circle while the male fertilizes them externally before standing guard at the site for at least six days.“
It is quite obvious that the cost of constructing the nest site is extremely high in the species in our study because it took 7–9 days to complete the structure.
In that case, why do males not reuse nests for the next reproductive cycle but always construct a new circular structure at a huge cost?”
the authors wrote.
“Males could construct new structures because the valleys may not contain sufficient fine sand particles for multiple reproductive cycles; a single reproductive cycle consumes a large proportion of the available fine sand particles.”
Years after their discovery, scientists assumed that these circles were only found around the coasts of Japan, but in 2020, another team of scientists spotted similar “crop circles” in Australia’s North West Shelf, near subsea gas infrastructure.“
Immediately, I knew what it was,” University of Western Australia’s Todd Bond, a co-author of a study on the circles in Journal of Fish Biology, told Science News at the time.
“It’s kind of humbling to know that there’s so much out there that we don’t know.”
A paper published in the journal Geosciences a year later also theorized that the design of the nest may not be entirely aesthetic.
The fissure may promote the movement of oxygen-rich waters toward the center of the nest no matter what direct currents are flowing.Pretty impressive work for a five-inch fish.