Black-Spined Murex (also known as the Root Murex or Radix Murex)
Phylum: Mollusca, Class: Gastropoda, Order: Neogastropoda, Family: Muricidae, Genus: Hexaplex, Species: H. radix · Muricidae (Murex family/Rock snails) · Gastropod (univalve); whole shell exhibit; globose spiral shape with multiple varices.
Species
Hexaplex radix
Shell Type
Gastropod (univalve); whole shell exhibit; globose spiral shape with multiple varices.
Family
Muricidae (Murex family/Rock snails)
Size
Approximately 3.5 to 4.5 inches (9-11 cm) in height. This is a medium-to-large adult specimen for the species, which typically grows between 2 and 6 inches.
Color & Pattern
Striking high-contrast appearance featuring a chalky white base color. The varices (growth ridges) are adorned with dense, jet-black to dark chocolate brown spines and scales. The spines are short, blunt, and arranged in concentric rows following the whorls. The interior aperture (not fully visible) is typically white, sometimes with a dark stained edge along the outer lip.
Rarity
Common to Uncommon. While widely distributed in its range, finding a specimen with all spines intact and without heavy erosion on a beach is uncommon.
Habitat
Shallow tropical waters, typically in the intertidal and subtidal zones. Prefers rocky substrates, coral reefs, and occasionally sandy patches near reef edges.
Geographic Range
Eastern Pacific Ocean, ranging from the Gulf of California (Mexico) south to Peru.
Description
A robust, heavy-bodied gastropod shell characterized by its rugged and 'thorny' texture. The shell features several prominent varices per whorl, each bristling with short, sturdy black spines. The spire is moderately elevated, and the body whorl is large and globose. The texture between the black-spined ridges is relatively smooth but matte white. It represents one of the most iconic 'rock shells' of the Panamic province.
Key Features
Distinguished by the high number of varices (varies from 6 to 11) and the characteristic monochromatic black-on-white color scheme. The spines are generally shorter and sturdier than those of the Indo-Pacific Murex species.
Collector Value
Desirable but affordable. Retail value for a specimen of this quality ranges from $10 to $25 USD. Large ('monstrose') or exceptionally black specimens carry higher value for specialists.
Condition Notes
Good condition. The spines show some minor blunting/wear consistent with a beach-collected or naturally aged specimen. The white areas appear clean with minimal encrustation. Collectibility grade: Fine.
Interesting Facts
The Black-Spined Murex is a carnivorous predator that uses its radula and muscular foot to drill into or pry open bivalves (clams and oysters). Historically, members of the Muricidae family were famous for the 'Tyrian purple' dye, though this specific species was more likely used for food by local coastal populations.
Ecological Role
Apex invertebrate predator in reef ecosystems. They control bivalve populations and provide empty shells for large hermit crabs once they pass away.
Similar Species
Hexaplex nigritus (Black Murex) is very similar but usually has more numerous, finer spines and a more elongated shape. Muricanthus princeps has longer, more curved spines.
Beach Finding Tips
Best found during extreme low tides in rocky tide pools along the Pacific coast of Central America. Look for the black spines protruding from sand or wedged between volcanic rocks.
Notes
Pass