### Identification The Arabian Cowry (*Mauritia arabica*) is a masterpiece of natural calligraphy. Its heavy, inflated shell (40–100mm) features a dorsal pattern of intricate, longitudinal brown lines broken by pale, irregular spots, strikingly reminiscent of Arabic script. Look closely at the "callus"—the thickened margins of the shell; they are distinctly flattened and adorned with large, dark-brown spots. The base is creamy-tan with a long, narrow aperture lined with dark-brown "teeth." To distinguish it from the similar *Mauritia eglantina*, look at the shape: *M. arabica* is stouter and more humped, lacking the tiny dark spire-blotch often found in its cousin.
### Habitat & Range This species is a quintessential resident of the Indo-Pacific, ranging from the Red Sea and East Africa to the shores of Australia and Japan. You’ll find them in the high-energy zones of coral reefs, typically from the low-tide mark down to about 10 meters. They favor rocky crevices, under-slab environments, and coral rubble where the surge provides oxygen-rich water.
### Behaviour A shy, nocturnal wanderer, the Arabian Cowry spends its daylight hours tucked deep into reef fissures. If you find one at night, you might not recognize it; the snail extends two lobes of a dark, fleshy mantle that completely envelop the shell. This mantle is covered in tiny, branched papillae (skin flaps), which provide camouflage and assist in respiration. Like many cowries, they are solitary and highly sensitive to light—touch one, and it will instantly retract its mantle to reveal the glossy porcelain beneath.
### Diet These are specialized grazers. Using a radula (a tooth-lined tongue), they scrape algae, sponges, and tiny encrusting organisms like bryozoans off the reef surface. They act as "gardeners" of the reef, keeping algae from smothering the coral polyps.
### Fascinating Fact The Arabian Cowry is a self-polishing marvel! Unlike most mollusks, its shell has no dull outer layer (*periostracum*). Because the living mantle covers the shell whenever the snail is active, it constantly secretes fresh calcium carbonate, polishing the surface to a mirror-like lustre and preventing barnacles or algae from ever gaining a foothold on its back.