In yesterday’s post we looked at The Tower, a new building in Arles, part of the Parc des Ateliers. While we mainly looked at the outside of the building, the inside is also intriguing: a picture shows indeed a spiral and spirals are incredibly exciting structures as we have seen in previous posts.
There is actually nothing more exciting than spirals found in nature in particular in shells, but there are spiral snails that are also capable of building equally striking structures.
Have you ever seen on a beach in summer around June (roughly) 6cm x 3cm ruffle-like strips that look as if they were made of a rubbery sand material?
If you did, but never picked them up being afraid they were parts of some kind of toxic material abandoned on the beach, well, you shouldn't have been afraid at all. In fact these strips aren't toxic at all but they are fragile collar-shaped egg-masses produced by the Neverita Josephinia, also known as Josephine's Moon Snail for its smooth shell (or Moon Shell, Moon Snail, Necklace Shell, Naticid Snail or Neverita Josephine).
The egg casings of this predatory snail are indeed as intriguing as the texture of Murex seashell egg casings: basically during the breeding season, the female moon snail lays an egg mass mixed with sand and with the snail's own mucus (this material is a sort of mucous concrete, characterised by a rubbery consistency, but sandy to the touch and a bit slippery as well).
The result is a spiral semi-circle with a ruffled edge, also known as "sand collar" as the shape of the egg casings look like old-fashioned collars of the type you may see in paintings.
If you put the ribbon against the sun you will see thousands of tiny cells filled with tiny protoconches (essentially micro shells) forming a pattern similar to that of lace.
Despite producing such a fragile egg structure with the precision of an artisan and having such a poetical name, the Neverita Josephinia is a predatory snail, capable of some, er, shell atrocities.
These snails attack indeed other molluscs, digging a hole through the shell with the radula and then consuming the flesh of their prey.
And while you may be sorry for the prey, if you find several empty shells with Neverita Josephinia's perfect holes, you will be able to do some great necklaces, bracelets and earrings with them and the Moon Shell will have done half the job for you (you will just have to thread a string through the shells.
To see the ruffle-shaped ribbons of eggs underwater, just peel your eyes and try to spot the circular frilly structures from the surface (see last picture in this post). Don't pick them to avoid disturbing the eggs (in my case my brother found some casings on the beach during a walk), but have a look on the beach and try and find older and dried up egg casings. Put them in the water to allow them to get back their original elasticity and smoothness and observe them a bit better, enjoying a completely free creative class in biomimicry inspired by spirals and ruffles found in nature.
Comments