Great Green Turban (or Silver-mouth Turban variant)
Phylum: Mollusca, Class: Gastropoda, Order: Trochida, Family: Turbinidae, Genus: Turbo, Species: Turbo marmoratus · Turbinidae (Turban Shells) · Gastropod (univalve); whole shell with a globose, spiral shape and a turbinate (top-shaped) structure.
Species
Turbo marmoratus (though the green mottling and ribs also suggest a variant of Turbo argyrostomus)
Shell Type
Gastropod (univalve); whole shell with a globose, spiral shape and a turbinate (top-shaped) structure.
Family
Turbinidae (Turban Shells)
Size
Approximately 3.5 to 4.5 inches in diameter. This appears to be a medium-sized specimen; adults of the marmoratus species can reach up to 8 inches.
Color & Pattern
Predominantly lime green and creamy white with dark olive and brownish-black mottled patterns. The shell features strong spiral ribbing. The coloration appears natural but may have been lightly cleaned to reveal the iridescent nacre beneath the outer layer in some spots.
Rarity
Common to Uncommon. While the species is widespread, finding a large, high-quality specimen with vibrant green color on a beach is uncommon as they are heavily fished for the mother-of-pearl industry.
Habitat
Tropical marine environments, typically found on shallow coral reefs and rocky substrates in the intertidal and subtidal zones down to 20 meters.
Geographic Range
Indo-Pacific region, ranging from East Africa to the tropical islands of the Central Pacific, and north to Japan.
Description
This is a heavy, thick-walled turbinate shell with a high spire and deeply incised spiral cords. The surface is characterized by a series of prominent, rounded ridges (ribs) that follow the whorls. The green mottling acts as camouflage in algae-rich reef environments. The aperture (not fully visible) is typically circular and lined with a thick layer of silvery-white nacre.
Key Features
Deeply grooved spiral ribs, globose shape, distinct green-and-white mottled 'camo' pattern, and a heavy calcareous structure. The lack of spines distinguishes it from 'Turbo castanea'.
Collector Value
Moderate ($15 - $45 USD depending on size and luster). It is highly desirable for its aesthetic green color and its potential to be polished down to the pearl layer.
Condition Notes
The shell appears to be in 'Fine' condition. It shows some natural wear at the apex (spire tip), and the surface texture indicates it was likely collected as a beach specimen or lightly weathered before being cleaned. The lip looks relatively intact.
Interesting Facts
The 'Turbo' family is famous for its 'operculum'—a trapdoor used to seal the shell. In this genus, the operculum is a heavy, stony 'button' known as a 'Cat's Eye.' Historically, these shells have been the primary source of commercial mother-of-pearl for buttons and jewelry.
Ecological Role
A primary herbivore that grazes on macroalgae and periphyton on coral reefs. They are a food source for octopuses and large crustaceans. Due to over-harvesting for the pearl trade, some regions have implemented size limits for collection.
Similar Species
Turbo argyrostomus (Silver-mouth Turban) which is smaller and more heavily ribbed, and Turbo setosus (Rough Turban) which has deeper grooves.
Beach Finding Tips
Look in the 'wrack line' after storms on tropical Indo-Pacific beaches. Larger specimens are often found by snorkeling near the reef crest where they graze on algae during the night.
Notes
Pass