Tiger Cowry

Roughly egg-shaped and dextral, the glossy shell is large and heavy for a cowry. It measures up to 15 cm (6 in) in length, and the upper or dorsal side is white, pale bluish-white, or buff, densely covered with dark brown or blackish barely circular spots. Akin to many other Cypraea snails, the shells surface is notably effulgent, as if it were deliberately polished. There is sometimes a blurred red line along the length of the shell at the midline on the dorsal surface. The lower margins are rounded (that is, there is no sharp margin between the upper and lower surfaces of the shell as is found in some other cowries). The ventral side is white or whitish, and the shell opening is lined with tooth-like serrations.

The tiger cowrie is found on the ocean floor in the Indo-Pacific region, from the eastern coast of Africa to the waters of Micronesia and Polynesia, the Coral Sea and around the Philippines. Along the Australian Coast it is found from northern New South Wales to northern Western Australia, as well as Lord Howe Island, and along the east coast of Africa including Madagascar. Found between depths of 10 and 40 metres (35–130 ft), it is often associated with live coral colonies, such as the table-forming Acropora, either found on the reefs themselves or the sandy sea bottom nearby. Once common, it is now much less abundant due to shell collecting and the destruction of its habitat by such processes as dynamite fishing, especially in shallower areas. Carnivorous, the adult tiger cowrie eats coral and various invertebrates, while juveniles eat algae.

The Hawaiian subspecies C. t. schilderiana naturally preys on invasive sponges, including Dysidea spp., Mycale grandis, M. parishii, Haliclona caerulea, H. coerulea, Cladocroce burapha, and Gelliodes wilsoni. (Compounds in Monanchora clathrata acted as a repellent, so C. t. schilderiana avoided them.) Thus, C. t. schilderiana was found to be controlling invasive populations, which shows its importance in maintaining the normal variety of life in Hawaiian marine habitats by constraining invasive species in Hawaii.

Despite this species not occurring in the Mediterranean Sea, shells of the tiger cowrie and the related panther cowrie, Cypraea pantherina, have been unearthed at Pompeii, the ancient Roman city near Naples, Italy, where these shells may have been used as some form of ornament.The shells also were conceivably part of a natural history collection. An interest in natural history existed at the time, as exemplified by Pliny the Elder, who wrote extensively about seashells in his book Natural History and who died investigating the eruption of Vesuvius.

The shells of this species of cowry are still popular among shell collectors, and are also used as a decorative object, even in modern times.

The shell of C. tigris is believed to help to facilitate childbirth; some women in Japan hold a shell of this species during childbirth.