Tricolor Frog Shell, also known as the Parthenope Triton or Pygmy Frog Shell
Phylum: Mollusca, Class: Gastropoda, Order: Littorinimorpha, Family: Bursidae, Genus: Bursa, Species: Bursa corrugata · Bursidae (Frog Shell family) · Gastropod (snail/univalve), whole shell, spiral shape
Species
Bursa corrugata
Shell Type
Gastropod (snail/univalve), whole shell, spiral shape
Family
Bursidae (Frog Shell family)
Size
Approximately 1 to 1.5 inches in length. This is average for a smaller frog shell species, which typically mature between 1 and 2 inches.
Color & Pattern
Vibrant alternating bands and blocks of creamy white and deep reddish-orange or rust brown. The colors are natural and exceptionally well-preserved with high contrast, showing no signs of fading or sun-bleaching.
Rarity
Uncommon, as these shells tend to inhabit rocky and coral-rich microhabitats where they are less frequently washed ashore intact.
Habitat
Inhabits shallow to moderately deep sub-tidal waters, typically found hiding among coral rubble, rocky reefs, and coarse sandy substrates in tropical marine environments.
Geographic Range
Widely distributed throughout the tropical waters of the Indo-Pacific region, including the Red Sea, East Africa, and across to Southeast Asia and Australia.
Description
A remarkably attractive and stout marine snail shell featuring a distinctive knobby or nodular texture with strong axial ribs and spiral cords. The spire is elevated with distinct whorls, and the surface displays a striking, high-contrast plaid or banded pattern of rich orange-red and white.
Key Features
Characterized by its stocky, heavily sculpted shape, prominent varices on opposite sides of the whorls, nodular sculpture, and striking orange and white coloration.
Collector Value
Moderately high collectible value due to the exceptional color preservation and pristine condition. While common frog shells are readily available, specimens with such vivid, unbleached orange-and-white contrast are prized by display collectors.
Condition Notes
Gem condition. The shell is fully intact with no chips, cracks, or significant wear. The apex is sharp and undamaged, and the vibrant color pattern is pristine.
Interesting Facts
Frog shells get their common name from their bumpy, warty surface texture which resembles the skin of a toad or frog. Like other members of the Bursidae family, they are carnivorous predators that feed on other bottom-dwelling invertebrates.
Ecological Role
Plays an important role as a marine carnivore helping to regulate populations of benthic invertebrates. They serve as prey for larger fish and crustaceans, and their empty shells frequently provide homes for hermit crabs.
Similar Species
Other members of the Bursidae family, such as Bursa granularis or Bursa rhodostoma, which can be distinguished by differences in aperture coloration, varice placement, and nodule arrangement.
Beach Finding Tips
Finding intact frog shells requires searching among shell grit and coral rubble on tropical beaches after storms, or snorkeling around shallow rocky reefs and reef drop-offs during exceptionally low tides.