Sea Pork

Aplidium solidum

Aplidium solidum is a colonial tunicate that forms distinctive sheets or slabs on hard substrates, reaching sizes of up to 20 cm across. Its tunic is gelatinous yet firm, typically 2 to 3 cm thick, and exhibits a red or pink coloration. The individual zooids are bright red and approximately 12 mm long, arranged in small systems with 13 to 15 rows of gill-like perforations in their pharynx. This species can be found in various marine environments, particularly along the west coast of North America from British Columbia to California, where it thrives on rocks and among kelp forests. It inhabits the intertidal zone and can be found at depths down to 40 metres, although most occurrences are shallower than this range. As a filter feeder, Aplidium solidum draws water through an oral aperture, trapping phytoplankton and other small organisms in mucus threads secreted by the endostyle. Breeding occurs in the spring and summer, with the species brooding its larvae in its atrial cavity. Encounters with this tunicate during dives may reveal its unique sheet-like formations, often nestled in crevices or among kelp, providing a colorful sight against the rocky backdrop. The conservation status of Aplidium solidum has not been evaluated by the IUCN, but it is commonly found in its habitat.