Echinometridae

Pencil sea urchin ( Heterocentrotus mammillatus )

The drilling and pencil sea urchin ( Echinometridae ) are a family of very different sea urchins. They are sometimes also referred to as cross- urchins, as they often have an oval dish. This is because of the dense spines but not visible.

At the very differently shaped spines they are distinguished by their German trivial name:

• Thickness, blunt spines ( pencil urchins )
• Strong, sharp spines ( Bohrseeigel )
• Spines as a shield formed (sign - urchins )

The reef - Bohrseeigel ( Echinometra Mathei ), with a shell diameter of up to 7.5 cm, is probably the most abundant sea urchin in the world. Its range extends from the Red Sea and the east coast of Africa to the coasts of Japan, Australia and Hawaii. The stylus urchins Heterocentrotus mammillatus has 8-12 cm long and 1.3 cm thick spines. It is widespread in the Indian and Pacific Ocean. The shield - urchins Colobocentrotus atratus lives in the surf zone of tropical coral reefs. It has a flattened calcareous skeleton and short, widening spines. With the suckers of the bottom it can attach to the hard ground.

Species and genera

• Genus Anthocidaris Lütken, 1864 Anthocidaris crassispina (A. Agassiz, 1863)

• Shield sea urchin ( Colobocentrotus atratus )

• Echinometra lucunter (Linnaeus, 1758)
• Reef - Bohrseeigel ( Echinometra mathaei )
• Echinometra viridis Agassiz, 1863

• Pencil sea urchin ( Heterocentrotus mammillatus ) (Linnaeus, 1758)
• Heterocentrotus trigonarius

Heterocentrotus trigonarius

Shield sea urchin ( Colobocentrotus atratus )