Spider Conch, Common Spider Conch
Phylum: Mollusca, Class: Gastropoda, Order: Neogastropoda, Family: Strombidae, Genus: Lambis, Species: Lambis lambis · Strombidae (True Conchs) · Gastropod (Univalve); Spiral shell with large digitations (fingers)
Species
Lambis lambis
Shell Type
Gastropod (Univalve); Spiral shell with large digitations (fingers)
Family
Strombidae (True Conchs)
Size
Approximately 180mm to 220mm (7-9 inches). This is a large, mature adult specimen, fitting well within the standard species range of 6-11 inches.
Color & Pattern
Base color is a creamy white or light beige, heavily mottled and banded with rich caramel, chestnut, and dark brown blotches. The digitations show distinct brown spiral banding. The interior aperture (not fully visible but inferred) is typically smooth and cream to orange-pink.
Rarity
Common; one of the most widespread and frequently encountered species in the Lambis genus.
Habitat
Shallow tropical marine waters, typically in the intertidal and subtidal zones. Found on sandy bottoms, reef flats, and among coral rubble or seagrass beds at depths of 1 to 20 meters.
Geographic Range
Indo-West Pacific: ranging from East Africa and the Red Sea to Micronesia, north to Japan, and south to Queensland, Australia.
Description
A heavy, sturdy shell characterized by a large body whorl and a flared outer lip that extends into seven distinct, curved, hollow digitations or 'fingers.' The dorsal surface is rugose with coarse spiral ribs and nodules. The siphonal canal is long and slightly curved. The shell's architecture is designed for stability in turbulent shallow waters.
Key Features
Seven digitations including the siphonal canal; the labrum (lip) fingers are typically more curved in females than males; heavy spiral sculpture; presence of a 'stromboid notch' near the anterior end.
Collector Value
Low to Moderate ($10 - $30 USD). While visually striking and iconic, their abundance makes them very accessible. Value increases for exceptionally large specimens (over 250mm) or those with vibrant, unfaded aperture colors.
Condition Notes
Fine to Good condition. The shell is mostly intact with all major digitations present, though the tips show minor erosion. The color is well-preserved but slightly faded on the dorsal side, suggesting it may have been exposed to sunlight. No significant encrustations or predator bore holes are visible.
Interesting Facts
Spider conchs are known for their unusual 'leaping' motion. The animal uses its claw-like operculum to dig into the sand and pole-vault itself forward. Historically, they have been used as a food source in many Indo-Pacific cultures and as decorative ornaments.
Ecological Role
Herbivorous grazer, feeding primarily on algae and detritus. They play a vital role in controlling algal growth on reef flats. They are preyed upon by large crustaceans, octopuses, and predatory fish.
Similar Species
Lambis truncata (much larger and heavier with shorter spikes) and Lambis chiragra (which has digitations that appear to emerge from both sides of the lip).
Beach Finding Tips
Look in shallow reef flats during low tide, particularly in the Indo-Pacific region. They are often camouflaged by algae on their dorsal side, so look for the distinctive shape of the spikes protruding from the sand.
Notes
No idea