Prionocidaris
Prionocidaris is a genus of sea urchins in the family Cidaridae. They are commonly known as “slate pencil urchins” due to the shape and texture of their spines. These urchins are characterized by their large, robust spines that are typically black or dark brown, and their test (body) which is often covered in a dense layer of small, fine spines. They are found in various marine environments, primarily in the Indo-Pacific region.
Characteristics
Prionocidaris species have several distinct features:
- Large, robust spines: These spines are typically long and pointed, with a slightly flattened or rounded cross-section, resembling a slate pencil. They are often black or dark brown, but some species exhibit color variations.
- Dense, fine spines covering the test: The test, or body, of the urchin is covered in a layer of small, fine spines that give it a rough texture.
- Five-pointed symmetry: Like all sea urchins, Prionocidaris species exhibit radial symmetry with five distinct sections radiating from the center of the test.
- Tube feet: These are small, tentacle-like appendages that help the urchin move and feed. They are located on the underside of the test.
Environments
Prionocidaris species are found in a range of marine environments, primarily in the Indo-Pacific region. They prefer rocky reefs, coral rubble, and seagrass beds, where they can find shelter and access food.
References
For further information on Prionocidaris, refer to these reliable sources: