ツマジロナガウニ / Echinometra tsumajiro

棘の先端が白いのでツマジロナガウニと言います。
The main feature of this sea urchin is that the spine tip is white.

Scientific Name : Echinometra tsumajiro
Family: Echinometridae
Order: Echinoida
Photo taken at Aquamarine Fukushima