Heterocentrotus trigonarius

Heterocentrotus trigonarius
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Echinodermata
Class: Echinoidea
Order: Camarodonta
Family: Echinometridae
Genus: Heterocentrotus
Species:
H. trigonarius
Binomial name
Heterocentrotus trigonarius
(Lamarck, 1816)

Heterocentrotus trigonarius, commonly known as the slate pencil urchin or red slate pencil urchin, is found in the tropical waters of the Indo-Pacific region. Heterocentrotus mamillatus is a similar, related species.

Heterocentrotus trigonarius can grow to 30 cm (12 in) in diameter (spine-to-spine). The spines are potentially harmful to humans if trodden on.