Amami night-sky pufferfish / Torquigener albomaculosus / Amami hoshizora fugu / アマミホシゾラフグ
Scuba divers exploring reef life just off the southern tip of Amami-Oshima had for years come across mysterious three-dimensional circles in the sand on the sea floor. It wasn’t until 2011, when an underwater photographer witnessed a stunning performance by a unique sea denizen, that the origins of the markings became clear. The circular geometric patterns were spawning nests made by the Amami night-sky pufferfish as part of a unique mating ritual that has only been recorded in this spot. The small, 12-centimeter-long male uses its fins to create intricate round designs approximately 2 meters in diameter, at depths ranging from 10 to 20 meters. It then collects shellfish and coral, breaks them into manageable pieces, and decorates the nest.
A big job for a little fish
The entire job can take over a week of nonstop effort. If a female finds the nest’s appearance appealing enough to mate in it, the spawning takes place in the center of the circle. After laying her eggs, the female leaves the nest and the male looks after the eggs. After a few days they hatch, and the male heads off to start work on another nest and a new design. The same nest is never used again. In 2014, this unusual, hardworking fish was registered as a new species. Its name is a reference to the many silvery white spots on its back.
