Cross-hatched Lucine
Phylum: Mollusca, Class: Bivalvia, Order: Lucinida, Family: Lucinidae, Genus: Divalinga, Species: Divalinga quadrisulcata · Lucinidae (Lucine Clams) · Bivalve (clams/two-shelled); this specimen is a single valve (right valve). It is fan-shaped/subcircular.
Species
Divalinga quadrisulcata
Shell Type
Bivalve (clams/two-shelled); this specimen is a single valve (right valve). It is fan-shaped/subcircular.
Family
Lucinidae (Lucine Clams)
Size
Approximately 0.75 to 1 inch (19-25mm) in diameter. This is a very typical adult size for the species, which rarely exceeds 1 inch.
Color & Pattern
Pure white to creamy white. This specimen exhibits a natural matte-to-slightly-glossy white finish. It lacks colored bands or spots, as is characteristic of the species. The exterior shows faint yellowish aging, while the interior (partially visible at edges) is usually polished white.
Rarity
Very Common. These are frequently washed up on Atlantic beaches after storms or high tides.
Habitat
Marine; found in shallow subtidal waters and intertidal zones. It prefers to burrow deep into sandy or muddy substrates, often in areas with low oxygen where it utilizes specialized symbiotic bacteria.
Geographic Range
Western Atlantic, ranging from Massachusetts down to the West Indies, the Gulf of Mexico, and Brazil. Extremely common along the South Carolina coast, including Myrtle Beach.
Description
A small, sturdy, circular bivalve shell distinguished by its unique sculptural pattern. The surface is covered in fine, sharp, chevron-like (V-shaped) ridges that cross the growth lines at an angle. The shell is moderately inflated with a small, pointed beak (umbo) that curves slightly forward.
Key Features
The 'Divaricate' sculpture: fine ridges that form a distinct V-shape or cross-hatched pattern across the shell's surface. Also, the circular shape and the presence of a small, distinct lunule (heart-shaped impression) near the hinge.
Collector Value
Minimal monetary value (typically $0.50 - $2.00) due to its abundance. However, it is a 'must-have' for a regional Atlantic collection because of its unique texture. Specimens with both valves attached (paired) are more desirable.
Condition Notes
Good condition. The sculpture is crisp and well-defined. Notably, there is a small 'drill hole' near the umbo, likely caused by a predatory snail (such as a Moon Snail or Drill). Collectibility Grade: Good (due to the predator hole).
Interesting Facts
Members of the Lucinidae family are famous for chemosymbiosis. They host sulfur-oxidizing bacteria in their gills, which provide the clam with nutrients, allowing them to thrive in environments where other mollusks might struggle to find food.
Ecological Role
Functions as a filter feeder and a host for symbiotic bacteria. They help process sulfides in the sand. The hole in this specific shell shows its role as a prey item for carnivorous gastropods.
Similar Species
Divalinga dentata (Imperial Lucine), which is much larger (up to 3 inches) and found in more tropical waters; Lucina pensylvanica, which lacks the V-shaped cross-hatching.
Beach Finding Tips
Look in the 'shell hash' or drift lines at low tide on Myrtle Beach. Because they are small and white, they are best spotted on overcast days or by sitting and scanning the tide line carefully. They often wash up in large numbers after a heavy swell.
Notes
Myrtle Beach SC