Pencil urchins are known for their distinct thick, blunt spines. The spines allow urchins to wedge into rocks during the day and in areas with a strong current. Mostly nocturnal, pencil urchins can be found in shallow, rocky-bottomed areas in the western Atlantic from South Carolina to the Caribbean, as well as the eastern coast of Mexico to Brazil.
  • Size

    2-4 inches (5-10 cm)
  • Diet

    Moss-like bryozoans, sponges, and corals
  • Range

    Western Atlantic coastal areas
  • Habitat

    Shallow waters, including coral reefs and rocky-bottomed areas

Physical Characteristics

  • Common width range is 2-4 inches (5-10 cm).
  • Tan to dark reddish-brown in color, the pencil urchin has distinct thick, blunt spines that move in any direction. The spines are often coated with sponges or coralline algae.

Animal Fact

Pencil urchins have five similar parts that make up their test, or rigid skeleton, called pentamerous radial symmetry. These are five skeletal plates that equally cover their body.

Diet / Feeding

  • Diet consists primarily of moss-like bryozoans, sponges, and corals.
  • Feeding involves biting and gnawing with a five-pointed chitin beak. The underside beak can push outward or retract inward from the body.

Range / Habitat

  • Occurs in Western Atlantic coastal areas from South Carolina to Florida and the Caribbean, as well as the eastern coast of Mexico to Brazil.
  • Found in shallow waters, including coral reefs and rocky-bottomed areas near the low tide line and below.

Additional Information

  • Mostly nocturnal, using its heavy spines to wedge itself into rocks during the day. This behavior also helps in areas with a strong current.
  • Pencil urchins have five similar parts that make up their test, or rigid skeleton, called pentamerous radial symmetry. These are five skeletal plates that equally cover their body.

Sources

  • Meinkoth, N. National Audobon Society field guide
  • www.sanctuaries.noaa.gov
  • Ruppert, E. and Fox, R. Seashore Animals of the Southeast
Buy Tickets