### Identification Commonly known as the Red-lined Chiton, this "armored tank" of the intertidal zone is a master of camouflage. Reaching lengths of 25–40mm, its oval body is composed of eight overlapping valves (plates). Look for the namesake crimson pinstripes—fine, longitudinal red lines that streak across a background of mottled olive, grey, or tan. The most reliable field mark, however, is the fleshy girdle surrounding the plates. In this species, the girdle is "hairy," covered in minute spines and featuring 18 distinct tufts of glassy, translucent bristles (spicules) that look like tiny explosions of silk along the margin.
### Habitat & Range You’ll find *Acanthochitona rubrolineata* clinging to the undersides of boulders or wedged into damp crevices within the mid-to-low intertidal zones. They are prominent across the Northwest Pacific, particularly along the rocky coastlines of Japan, Korea, and Vietnam. They thrive where wave action is high but seek shelter in the "micro-canyons" of the reef to avoid desiccation during low tide.
### Behaviour & Diet These mollusks are nocturnal "homebodies." While they appear sedentary, they emerge at night or during high tide to graze. They exhibit remarkable homing behaviour, using chemical sensors to navigate back to the exact same depression in a rock after a night of foraging. Their diet consists of microscopic algae, diatoms, and encrusting bryozoans, which they scrape off the stone using a specialized, tongue-like ribbon called a radula.
### Fascinating Fact The teeth on this chiton’s radula are capped with magnetite—the hardest mineral produced by any living organism. This iron-based coating is so durable it allows the chiton to literally grind away at solid rock to reach the nutrients within, making its mouth essentially a biological magnetic saw!