collector urchin; Tripneustes gratilla
A species of sea urchin. The name literally means 'white-beard sea urchin'.
Collector urchins are often seen in the shallow waters of Okinawa.
There are three collector urchins in this tank.
Katakana spelling is common for this species name; usually written in kana.
Kanji spelling is rare; the word is usually written in kana.
Compound of 白髭 (しらひげ, 'white beard') and 海栗 (うに, 'sea urchin'), referring to the white spines that resemble a beard.