ノコギリウニ / Prionocidaris baculosa

• ノコギリウニ

ノコギリウニは、ウニの中でも原始的な種類です。
どの辺が原始的なのかは知りませんが。

Prionocidaris baculosa is a primitive species among the sea urchins.
I don't know which part is primitive, though.

Scientific Name : Prionocidaris baculosa
Family: Cidaridae
Order: Cidaroida
Photo taken at Okinawa Churaumi Aquarium