Sea Urchins

My biggest and oldest collection I have is all the treasure I have picked up mostly from the Kenyan beaches. As kids we used to have beach art competions for which we would earn chappie money for prizes.

We would spend endless hours beachcombing and the joy of finding any member of the urchin family was fantastic – we don’t get nearly as many on the southern coast beaches as more often than not they get smashed up on the reef, its always a bonus to find one still perfectly intact. They are incredibly fragile and all too often I have experienced the disappointment on arriving home only to find shattered remains.

In my third year of studying jewellery design I finally discovered and came up with a process to preserve and reinforce the shells so that they can last forever and be used a cabochons in jewellery. (see PumPoiki Cabochons)


The Facts

· Sea urchins are small, spiny sea creatures of the class Echinoidea found in oceans all over the world. (the name urchin is an Old English name for the round spiny hedgehogs sea urchins resemble.)

· The spines give both the sea urchins and the Echinoderms, their names. The Greek word, ‘echinos,’ refers to both the spiny European hedgehog and to sea urhins.

· The globular shaped fragile shell we find on the beaches is also called the ‘test’.

· Regular sea urchins are strongly pentamerous; that is they have a five-star symmetry. When viewed from either the top or bottom, the spines will be seen to be arranged in five or ten rows spaced regularly and evenly around the body.

· On a sea urchin test each of the whiter bands is called an ‘ambulacrum.’ There are five such ‘ambulacra’; the five-fold symemetry reveals a kinship with starfish and sand dollars.

· On the oral surface of the urchin which is at the bottom of the shell is a centrally located mouth made up of five united calcium carbonate teeth which we can see in the test. This is named Aristotle’s lantern after his accurate description in “History of Animals”