The World Around Us

Vilankulo, Good Times, Lots of Sun and One Curiosity

Country: Mozambique by Marlowe

28-12-2012

Sand dollar

The enigmatic (at least for me) Sand Dollar.

No doubt Lisette will give a full report on our goings-on in Vilankulo, but I prefer to talk about the nature and curiosities found there (one of which is pictured here).

First of all, Vilankulo is located some 700 kilometers northeast of Maputo City, along the coast on the Mozambique Channel that separates them from nearby Madagascar. This equates to a roughly 10-hour bus ride with Intercape and takes you about a quarter of the way up to country’s coast.

Lis and I had a fantastic time, in spite of a rather frenzied return that she will discuss in her post. In any case, we chartered a very authentic (and authentic also means falling apart) dhow to the island of Bazaruto. There we found giant sand dunes, wonderful vistas and something that made me very curious.

Pictured to the right is what is called a Sand Dollar, embedded in sand. This is the skeleton of an organism that lives in the sand and is from the Echinoderm family Clypeasteroida (related to sea cucumbers and starfish).

Sand dollar "flower" detail

Three-dimensional “etchings” on the surface of this amazing animal’s skeleton.

The thing that blew me away was how manufactured it looked. Looking closely at the star pattern on it’s back you can see what look like tiny ink hatchings arranged in a five-pointed star. For this reason I thought this could not possibly be natural and these white “tokens” were actually some kind of discarded scuba equipment (the slits look like they could support a strap or something). Upon breaking one open I saw a lattice work of soft bone-like material. I was amazed. How could nature create such a symmetrical object. There seemed no place for an animal to exist in this plain, flat disc. Apparently in life most of the organism lives on the outside of this skeleton in the form of a thin skin with cilia for locomotion.