Hercules Club Whelk (also known as the Black Creeper or Swollen Creeper)
Phylum: Mollusca, Class: Gastropoda, Order: Cerithiidae, Family: Potamididae, Genus: Pyrazus, Species: P. ebeninus · Potamididae (Mud Whelk family) · Gastropod (snail); shell fragment (specifically a remaining whorl segment with a prominent tubercle/spike)
Species
Pyrazus ebeninus (Confidence Level: 95%)
Shell Type
Gastropod (snail); shell fragment (specifically a remaining whorl segment with a prominent tubercle/spike)
Family
Potamididae (Mud Whelk family)
Size
The fragment appears to be approximately 15-20mm across. A complete adult shell would typically measure between 60mm and 100mm in length.
Color & Pattern
Dense black to dark charcoal grey exterior with a vibrant, contrasting orange or yellowish tint on the weathered/exposed internal layers. The dark coloration is natural for this species, while the bright orange highlights the 'burned' or mineralized interior often seen in weathered specimens from Moreton Bay.
Rarity
Very Common. These are one of the most abundant shells found on the mudflats of Sandgate and Brighton Beach, though finding bright orange weathered fragments is more common than finding perfectly intact live-collected specimens.
Habitat
Estuarine environments, particularly intertidal mudflats, mangrove swamps, and seagrass beds in salt marshes. They are marine/brackish water animals.
Geographic Range
Endemic to the east coast of Australia, ranging typically from Queensland (including Brisbane/Moreton Bay) down to New South Wales.
Description
This is a fragment of a heavy-set, spirally coiled gastropod. The full shell is known for its rugged, bumpy texture with large nodules (tubercles) on the whorls. This specific piece shows a singular, sharp-edged tubercle and the thick, dense shell wall characteristic of the species. The contrast between the obsidian-black outer layer and the orange internal calcification makes it a visually striking beach find.
Key Features
Heavy, thick shell walls; prominent pointed nodules or 'spikes' on the shoulder of the whorls; dark black/brown periostracum; often shows orange/brown internal weathering in Brisbane's local sand.
Collector Value
Minimal monetary value (less than $1). Its value is primarily sentimental or decorative as part of a local beachcombing 'treasure' collection due to its unique color contrast.
Condition Notes
Poor to Fair (fragmentary). This is a weathered beach-worn piece rather than a whole shell. However, the vivid orange coloration suggests it has been naturally polished by the tide, which increases its aesthetic appeal to beachcombers even if it lacks scientific value.
Interesting Facts
The Hercules Club Whelk is one of the largest mud-dwelling snails in Australia. Indigenous Australians historically used these as a food source, and large 'middens' of these shells can be found at various historical sites along the Queensland coast.
Ecological Role
They are detritivores, playing a vital role in the ecosystem by consuming decaying organic matter on the mudflats and recycling nutrients. They are not currently a protected species, but they are important indicators of healthy mangrove ecosystems.
Similar Species
Telescopium telescopium (Telescope snail), which is more conical and lacks the large spikes, and Cerithidea antarctica, which is much smaller.
Beach Finding Tips
Wander the mudflats at low tide at Brighton or Sandgate. Look near the roots of mangroves or in the debris lines after a high tide. The orange fragments stand out sharply against the grey-brown silt of the bay.
Notes
Brighton beach Sandgate Brisbane