Cidaroida
Cidaroida is an order of sea urchins, known for their distinctive long, sharp spines. These spiny sea urchins are found in a variety of marine environments, from shallow coastal waters to the deep sea. They are commonly referred to as “slate pencil urchins” due to the shape and texture of their spines. Cidaroids are important members of marine ecosystems, playing a role in maintaining the balance of algae and other organisms.
Characteristics
Cidaroid sea urchins are characterized by their long, slender spines, often tipped with a sharp point. These spines can be incredibly diverse in shape and color, ranging from smooth and cylindrical to ridged and branched. The test, or shell, of a cidaroid is typically robust and covered in small, rounded tubercles that support the spines. The mouth, located on the underside of the test, is surrounded by five teeth arranged in a circular pattern. These teeth are used for scraping algae and other food sources from rocks and other surfaces.
Environments
Cidaroids have a wide geographical distribution, inhabiting a variety of marine environments. They can be found in both tropical and temperate waters, from shallow intertidal zones to the deep sea. Some species prefer rocky reefs, while others live on sand or mud bottoms. Some species even burrow into the substrate, using their spines for support and protection.
Common Names
Cidaroid sea urchins are known by a variety of common names, including:
- Slate pencil urchins
- Spiny sea urchins
- Long-spined sea urchins
References
For more information about Cidaroida, refer to the following online resources: