Phyllacanthus imperialis
(Lamarck, 1816)
Enter the name for this tabbed section: Description
This is the second species and a lot less common representative of the family Cidaridae. Phyllacanthus imperialis is a large urchin, the test the size of a tennis ball with spines the diameter of pencils. The test, the most recently developed primary spines and the flattened secondary spines are dark purple in color. The spines are characterized by longitudinal grooves, contrary to the small thorns characteristic of P. baculosa. Older spines are covered with numerous encrusting organisms, algae, barnacles, bryozoans and sponges
Enter the name for this tabbed section: Distribution
Phyllacanthus imperialis is rare in Oman. Only few specimen were observed in Dhofar, near Mirbat in a protected bay around 10m in depth.
Enter the name for this tabbed section: Ecology and Biology
Like Prionocidaris baculosa and other Cidaridae, P. imperialis is carnivorous, feedings on the small animals found on the reef. During the day, it is often found hidden in crevices and below overhangs in which it locks itself using their mutable collagen to block the movement of the spines. They are nearly impossible to dislodge without breaking the spines or the test.