Polarised light micrograph of a sea urchin (Gracilechinus acutus). The test and spines of sea urchins are composed of calcium carbonate. Each spine articulates with a tubercle on the test. The elaborate structure of the spines when seen in cross section has made them a popular subject for microscopists. Horizontal object size: 2.0 mm. | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Pasieka, Alfred |
Taille de l’image : | 5472 px × 3648 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |