Photo by Eliot Rotford | Info
Cliona delitrix is a species of burrowing demosponge belonging to the family Clionaidae. It is found in shallow water in the Caribbean Sea and the Gulf of Mexico. It usually grows on a massive coral, not only covering its surface but also burrowing into its interior, though is sometimes found on other calcareous substrate such as a shell or a limestone rock. It can grow to a diameter of up to a meter (1 yard) and has several large openings called osculi, 10-30 mm (0.4 to 1.2 in) wide, surrounded by projecting rims and many small raised papillae 2-5 mm (0.1 to 0.2 in) wide. The color is usually red or dark orange.
Demosponges (Class Demospongiae) are the most diverse class in the phylum Porifera. They include 76.2% of all species of sponges with nearly 8,800 species worldwide. They have a soft body that covers a hard, often massive skeleton made of calcium carbonate.