About Phyllodesmium horridum (Macnae, 1954)
Phyllodesmium horridum, commonly called the coral nudibranch, grows to a total length of 30 to 40 mm along the South African coast. It is a slender aeolid nudibranch with a pale body and long paired pinkish cerata. Both the cerata and the body have a bluish-white stripe running along their length, and its rhinophores are smooth. This species does not host zooxanthellae. This species is distributed along the South African coast from False Bay to Sodwana Bay, occurring from the intertidal zone down to at least 30 m depth. Reports of its presence in Australia and Japan are erroneous, caused by confusion with the species Phyllodesmium serratum. In ecological terms, Phyllodesmium horridum feeds on sea fans (gorgonians) that belong to the genus Melitodes, in the family Melithaeidae. It has also been recorded feeding on gorgonians of the genus Acabaria, which is also part of the family Melithaeidae. Its egg ribbon is a gelatinous mass that holds many small white eggs.
