Aporocidaris
Videos
Aporocidaris is a genus of sea urchins in the family Ctenocidaridae. Several species are found in deep water in circum-Antarctic locations.
Test (biology)
Videos
In biology, a test is the hard shell of some spherical aquatic animals and protists, notably sea urchins and microorganisms such as testate foraminiferans, radiolarians, and testate amoebae. The term
Test of a shingle urchin (Colobocentrotus atratus)
Test of a sea urchin.
Sea urchin test detail. External plates made of carbonate, silica, and chitin create a dense protective layer that is often covered in serrations, ridges and spines.
Foraminiferan tests.