Pseudechinus

Pseudechinus is a genus of sea urchins in the family Echinometridae. It is a genus of small, usually dark colored urchins commonly found in the intertidal and shallow subtidal regions of the Indo-Pacific region. These urchins are known for their relatively flat, disc-shaped test (shell) and short spines.

Common Names

Common names for Pseudechinus species include:

  • Flat sea urchin
  • Pancake urchin
  • Keyhole urchin

Characteristics

Pseudechinus sea urchins share a number of characteristics, including:

  • Test (Shell): Relatively flat, disc-shaped test with a diameter typically ranging from 2 to 5 cm. The test is usually covered in short, blunt spines.
  • Spines: Short, blunt, and often dark in color. The spines can be quite variable in size and shape between different species.
  • Tube Feet: Numerous tube feet are present on the oral (bottom) surface of the test, used for locomotion and feeding.
  • Mouth: Located on the oral surface, surrounded by a ring of five teeth.
  • Anus: Located on the aboral (top) surface, usually near the center of the test.

Environments

Pseudechinus species are primarily found in the intertidal and shallow subtidal zones of the Indo-Pacific region. They prefer rocky or coral reef environments and are often found amongst algae and seaweed.

References

For more information, refer to the following reliable references: