Just when you think you’ve seen everything amazing that animals can do to attract a mate, you find something even more bizarre. This short video from BBC Earth shows a male pufferfish off Japan working tirelessly to build a stunning “sand castle” to attract females. Narrated by David Attenborough (of course), this video blew me away.
As National Geographic reports, the circles are two meters wide, take ten days to build, and, if one pleases a female, she lays her egg in the nest, and then the male fertilizes them and guards them till they hatch six days later. Then the male builds a new nest all over again. The discovery was made by Hiroshi Kawase et al. and published in 2013 in Nature Scientific Reports (reference and free link below).
A beautiful nest:
Kawase, H., Y. Okata, and K. Ito. 2013. Role of huge geometric circular structures in the reproduction of a marine pufferfish, Nature Scientific Reports 3, Article number: 2106 (2013) doi:10.1038/srep02106