Deep-sea diagrams

Divers off the coast of Japan began noticing "mystery circles" on the seabed in 1995. Unsure whether they were the result of a natural phenomenon or the work of an organism, scientists began observing the 2 m geometric structures and finally had results in 2011. They are in fact nest sites made by male pufferfish (Tetraodontidae), who spend 7 to 9 days constructing them and create a new one with their fins for each reproductive cycle. Characteristics like size, symmetry, number of peaks and valleys, peak height, ornaments, and the amount of fine sand particles play an important role in female mate choice. But once they are selected, the male pufferfish don't just fertilize and go on their way. After spawning, males remain in the circular structure for 6 days to care for the eggs.

Posted with Blogsy