Isabella Cowrie, also known as the Isabella Cowry or Mauritia isabella
Phylum: Mollusca, Class: Gastropoda, Order: Littorinimorpha, Family: Cypraeidae, Genus: Mauritia, Species: Mauritia isabella · Cypraeidae (Cowrie family) · Gastropod, whole shell, oval/cylindrical shape
Species
Mauritia isabella
Shell Type
Gastropod, whole shell, oval/cylindrical shape
Family
Cypraeidae (Cowrie family)
Size
Approximately 1.5 to 2 inches in length, which is average for this species. Adults typically range from 1 to 2.5 inches (25-65 mm).
Color & Pattern
The dorsum features a yellowish-brown or greyish-fawn base color overlaid with three longitudinal dark brown bands and numerous fine, irregular dark flecks and dashes. The base and margins are whitish to cream with distinct dark spots along the lateral edges extending onto the base. The aperture is narrow and lined with distinct, contrasting dark teeth.
Rarity
Common, frequently found by snorkelers and beachcombers in suitable tropical reef habitats throughout Hawaii.
Habitat
Found in tropical marine waters, typically in shallow subtidal zones, under coral slabs, in crevices, and among coral rubble on reef flats and benches from the intertidal zone down to about 50 meters depth.
Geographic Range
Indo-Pacific region, spanning from the Red Sea and East Africa across the Indian Ocean to Polynesia and Hawaii.
Description
An oblong, cylindrical, and highly polished shell with a low, rounded dorsum and a flattened base. The surface possesses a natural porcelain-like gloss typical of cowries, completely obscuring the spire in adult specimens. The narrow aperture runs the entire length of the underside, edged with fine, well-defined teeth on both the outer and inner lips.
Key Features
Cylindrical elongated shape, three faint to distinct longitudinal bands on a brownish-fawn background, dark spots along the lower margins, and contrasting teeth along the narrow aperture.
Collector Value
Moderately common and affordable for collectors, usually valued more for aesthetic appeal and perfection of gloss rather than rarity. Typically valued between $2 to $10 depending on size and grade.
Condition Notes
The specimen appears to be in Good to Fine condition with a relatively intact glossy finish, showing minimal beach-wear or fading, likely collected alive or fresh-dead.
Interesting Facts
Like all cowries, the living animal possesses an extensive mantle that covers the shell while active, which continuously deposits calcium carbonate and pigment, keeping the shell permanently glossy and protected from fouling organisms.
Ecological Role
Marine grazers that feed primarily on algae, sponges, and detritus using a radula. They help maintain reef health by controlling algal growth. Predated upon by specialist fish, octopuses, and cone snails.
Similar Species
Mauritia carneola (The Flesh-colored Cowrie), which lacks the distinctive longitudinal dark bands and is generally more reddish-orange.
Beach Finding Tips
Look under large flat coral rocks and in deep crevices during extremely low tides, or search among shell drift and coral rubble on high-energy reef beaches following storms.
Notes
Goat Island Hawaii