Cidaridae

Cidaridae is a family of sea urchins in the order Cidaroida. They are commonly known as “slate pencil urchins” due to the shape and texture of their spines. Cidarids are found in all oceans, generally in shallow water, and are often associated with rocky or coral reefs. They are distinguished by their long, slender spines, which are often tipped with a sharp point. The spines of some species can be quite fragile and break easily, while others are very robust and can be used for defense.

Characteristics

Members of the Cidaridae family share several characteristic features:

  • Spines: Long, slender spines, often tipped with a sharp point. These spines are typically arranged in a radial pattern around the test (body).
  • Test: Relatively small and compact, usually covered in small, granular tubercles.
  • Tube Feet: Simple and short, used for locomotion and feeding.
  • Aristotle's Lantern: A complex jaw apparatus used for scraping algae and other food particles from surfaces.

Environments

Cidaridae are typically found in shallow water, often in association with rocky or coral reefs. They can be found in a variety of habitats, including:

  • Intertidal zones: Some species are adapted to living in areas that are exposed to air at low tide.
  • Subtidal reefs: Many species are found on reefs below the low tide mark.
  • Seagrass beds: Cidaridae can be found in seagrass beds, where they feed on algae and other invertebrates.

Examples of Cidaridae

There are many species of Cidaridae, including:

  • Cidaris cidaris (Common slate pencil urchin)
  • Echinometra lucunter (West Indian sea urchin)
  • Diadema antillarum (Long-spined sea urchin)
  • Phyllacanthus imperialis (Imperial urchin)

References

For more information on Cidaridae, refer to the following reliable resources: