From the Department of Awesome Natural Wonders come these mysterious patterns on the ocean floor off the southern coast of Japan. Japanese scuba diver and photographer Yoji Ookata, who has spent the last 50 years exploring and documenting his underwater discoveries off the coast of Japan, spotted these beautiful and puzzling patterns in the sand, nearly six feet in diameter and 80 feet below sea level, during a dive near Amami Oshima at the southern tip of the country.
So what happened next? Are these rippling geometric patterns the equivalent of crop circles on the seafloor? Not quite, but the answer is still a good one. Colossal explains:
“He soon returned with colleagues and a television crew from the nature program NHK to document the origins what he dubbed the “mystery circle.”
Using underwater cameras the team discovered the artist is a small puffer fish only a few inches in length that swims tirelessly through the day and night to create these vast organic sculptures using the gesture of a single fin. Through careful observation the team found the circles serve a variety of crucial ecological functions, the most important of which is to attract mates. Apparently the female fish are attracted to the hills and valleys within the sand and traverse them carefully to discover the male fish where the pair eventually lay eggs at the circle’s center, the grooves later acting as a natural buffer to ocean currents that protect the delicate offspring. Scientists also learned that the more ridges contained within the sculpture resulted in a much greater likelihood of the fish pairing. To learn more about the circles check out the full scoop over on Spoon and Tamago, and you can see two high resolution desktop photos courtesy of NHK here.”
Busy little pufferfish boys wooing potential mates by sculpting the sand with their bodies. As far as we’re concerned, that’s pretty awesome!
[via Colossal]
Some nautiloid shell vocab
- Phragmocone basically the shell in general I think? The larger and heavier it is the more disadvantageous it is to catching prey.
- Septa the walls that divide the shells into camerae. As the nautiloid grows it moves forward in the shell to a new living chamber. Where the septa meets the shell it forms a suture that reinforces structure without compromising weight.
- Camerae the spaces in between septa, they help regulate buoyancy with gas delivered through the siphuncle.
- Siphuncle a long strand of threadlike tissue, passes through all the camera chambers. It can change the salinity in its blood and absorb more dilute water into the siphuncle. Then gas is diffused from the blood. It cannot rapidly expel water from the chambers. The openings for the siphuncle cn be clearly seen in the above photo.
- Living Chamber outermost or last chamber in a nautiloid shell.
Ammonites
Ammonoidea
- More closely related to coleoids (octopuses, squid, and cuttlefish) than nautiloids.
- Name derived from Pliny the Elder’s ammonis comua (Horns of Ammon/Amun) an egyptian god depicted with ram horns.
- Ammonite septa are convex as opposed to the slight concave nature of nautiloid septa; results in more defined sutures on the outer portions of the shell.
- Ammonite siphuncles are much narrower and run along the outer rim of the phragmocone.
- First appeared in the devonian period (c. 400 mya) and went extinct with the dinosaurs at the end of the cretaceous (65.5 mya).
- Divided into three orders and eight known suborders by virtue of their sutures, septa, and shell shapes.
- Little is known about their life, virtually no soft tissue preserved in fossils
- There might have been a range of ammonites which were good and bad swimmers.
- Ammonites and modern nautiloids are sexually dimorphic in size with females (macroconch) being larger and thinner than their male counterparts (microconch).
- Ammonite shell shapes are super diverse, man! Majority are the typical planispiral shape, but there are some that are nearly straight, coiled helically, superficially like a gastropod, some that are partially coild and partially straigh. This diversification occurs mainly during the early cretaceous and are called heteromorphs.
- Nipponites are crazy!
- During the middle jurassic they reached a size of 23 cm up to 2 meters during the cretaceous.
- Distributed worldwide.
Belemnite
Belemnitida
- Superficalliy squid-like
- Ten arms of equal length with small inward curving hooks, no specialized arms like modern squids
- Possessed a hard inner calcite or aragonite skeleton
- Possessed an ink sack
