Sea mice

Pacific Northwest coastal waters provide habitat for several species of sea mice (Family Aphroditidae), stout, solid worms with oval-shaped bodies. Many species have a thick, often highly iridescent coat of “felt” covering their backs. Spiny notochaetae (upper appendage bristles) and fine silky fibres mesh together to produce the felt. Spinning glands weave these silky fibres, which in turn entrap silt particles or encrusting organisms, making the worms look dirty. Probably solitary, sea mice live at a slow pace that contrasts with their aggressive feeding habits. Known to be active carnivores, they prey on large worms, small crustaceans, molluscs and even sea cucumbers. Without well-developed jaw structures, they use a muscular, eversible proboscis for feeding.