Heterocentrotus trigonarius,[1] commonly known as the slate pencil urchin or red slate pencil urchin,[2] is found in the tropical waters of the Indo-Pacific region.[1] Heterocentrotus mamillatus is a similar, related species.[2]

Heterocentrotus trigonarius can grow to 30 cm (12 in) in diameter (spine-to-spine). The spines are potentially harmful to humans if trodden on.[2]

References

  1. ^ a b Kroh A, Mooi R, eds. (2023). "Heterocentrotus trigonarius (Lamarck, 1816)". World Echinoidea Database. World Register of Marine Species. Retrieved 22 October 2023.
  2. ^ a b c "Critter of the Week: The tropical slate pencil urchin". NIWA. Retrieved 22 October 2023.