Antigona Rigida (formerly Princess Venus or Rigid Venus)
Phylum: Mollusca; Class: Bivalvia; Order: Venerida; Family: Veneridae; Genus: Antigona; Species: A. rigida · Veneridae (Venus Clams) · Bivalve (single valve, fan/sub-circular shaped)
Species
Antigona rigida (Confidence: 95%)
Shell Type
Bivalve (single valve, fan/sub-circular shaped)
Family
Veneridae (Venus Clams)
Size
Approximately 1.25 inches (3.2 cm). This is a juvenile to sub-adult specimen; adults typically reach 2 to 4 inches.
Color & Pattern
Creamy white base with faint, tan mottling and a few darker brown spots. The patterns appear somewhat sun-bleached but natural. The interior is likely white with a hint of violet or purple near the posterior muscle scar.
Rarity
Common to Very Common. Frequently found on beaches throughout the Yucatan Peninsula and Caribbean islands.
Habitat
Found in shallow water (subtidal) down to depths of about 50 meters, usually buried in sandy or coral rubble substrates near reefs.
Geographic Range
Western Atlantic, ranging from North Carolina and Florida through the Caribbean (including Cancun) to Brazil.
Description
A robust, globose bivalve characterized by its heavy shell and intricate 'waffle-like' sculpture. The surface is adorned with prominent concentric ridges that are crossed by finer radial ribs, creating a distinct cancellate texture. The margin is finely crenulated, and the hinge is thick and well-developed.
Key Features
Heavy, thick shell for its size; cancellate (grid-like) surface sculpture; strong concentric ridges; curved umbo (beak) pointing forward; and internal crenulations on the ventral margin.
Collector Value
Minimal monetary value ($1-$5) due to its abundance; however, it is highly desirable for beginner collections due to its beautiful geometric sculpture and durability.
Condition Notes
Good condition. It is a single valve rather than a paired set. The sculptural details are crisp and well-preserved, though the color is slightly faded from exposure to the sun and sand. No obvious predator drill holes are visible.
Interesting Facts
The Venus family is named after the Roman goddess of love and beauty. These clams are active burrowers that use a muscular 'foot' to pull themselves under the sand. Historically, shells from this family have been used globally as a food source and occasionally for decorative inlay.
Ecological Role
An important filter feeder that helps clear plankton and organic particles from the water column. It serves as a prey item for crabs, rays, and predatory gastropods like whelks.
Similar Species
Chione cancellata (Cross-barred Venus) is much smaller with fewer, more prominent concentric ridges. Mercenaria mercenaria (Quahog) lacks the intricate grid-like sculpture.
Beach Finding Tips
Look in the 'shell hash' lines after a high tide or storm in Cancun. Because they are heavy, they often settle in the deeper pockets of shell debris rather than the surface of the dry sand.
Notes
Cancun