Scanning Electrons



So far we have been venturing deeper into the details of the two Cidaridae species.

Some of these details are minuscule traits that cannot be observed by even 100x magnification.

We therefore, have to make use of modern, technically very sophisticated methods. In our case, we are lucky! We have a scanning electron microscope (SEM) at our disposal.

Let's prepare samples, and analyze them with the TESCAN VEGA3. It's powerful electron gun provides us with high definition pictures, with up to 1000x magnification.

It's not only the magnification...

...that is impressive,

but the quality of the...

... surface structures details.

Secondary spine of Cidaris cidaris

Secondary spine of Stylocidaris affinis

Above we see a most impressive close up picture of a sample of secondary spines. The differences might appear minor at the first glance. But a closer look permits the distinction of the pictures by two striking features.

  • The grooves of S. affinis are following a pattern of right angles

  • The minispines of the C. cidaris are less narrow than the ones on S. affinis


These two differences emphasize the amount of information we can gain from the magnification levels as can be seen above. We have never imagined that a magnification of 450x the real size would provide us with such information. Information that could not be accessed by conventional methods.

We have encountered many interesting surface traits. Let's sum up what we have found so far.