frilled venus shell of sheltered sandy bays
- Size
- Shell: 5–7 cm, Weight: 15–30 g
- Lifespan
- 10–15 years
- Diet
- Phytoplankton and organic particles. Filters food from the water using its gills. Draws water in through its siphon and extracts microscopic algae. Feeds continuously when submerged.
- Habitat
- Sandy and muddy bottoms in sheltered bays, harbours and estuaries from the low tide mark down to 30 metres depth. Burrows into sediment with only its siphon showing. Prefers areas with clean, stable sand and moderate currents.
- Range
- Coastal waters of the North and South Islands from Northland to Otago. Most common in sandy bays and harbours. Also found in southern Australia and the Southwest Pacific.
- Endemism
- Native
- Main Threats
- Habitat loss from coastal development and dredging. Water quality degradation in estuaries. Bycatch in trawl fisheries. Climate change affecting estuarine habitats. No targeted commercial fishery for this species.
- Population
- Populations are considered stable across most of the species' range. The frilled venus shell is not commercially harvested in New Zealand. Its attractive, frilled shell is popular with collectors. Its preference for sheltered bays makes it vulnerable to habitat loss from coastal development.
- Conservation Status
- Not Threatened
Named for the delicate frills along the edge of its shell. A clam that is too beautiful to eat.
The frills are not just decorative. They strengthen the shell, making it more resistant to the crushing attacks of crabs and other predators. The frills also help anchor the shell in the sand, preventing it from being washed away by currents. A shell that is beautiful and functional.
The shell is thick and heavy for its size, with a beautiful creamy-white colour often tinged with pink or purple. The surface is covered in fine concentric lines, the growth rings that mark the clam's age. The frills are most prominent in young shells, becoming worn and rounded in older individuals.
It lives buried in the sand of sheltered bays and estuaries. The frilled venus shell is not a fast burrower. It relies on its thick shell and its frilled edge for protection, rather than speed. When threatened, it closes its shell tightly and waits. The predator, unable to break the shell, eventually gives up and moves on.
Its attractive shell means it is more often collected for display than for eating. The flesh is sweet but small, and the shell is too beautiful to crack open for a meal. Collectors prize the frilled venus shell for its lacy edge and its creamy colour. A perfect specimen, with all its frills intact, is a treasure.
It is found washed up on beaches after storms, where its frilled edge makes it easy to recognise. The beach is quiet after the storm. The frilled shell lies in the sand, creamy white with pink tinges, frills catching the light. It does not know it is a treasure. It does not know it is too beautiful to eat.
It just wanted to filter water. The frilled venus shell is a clam that demands to be noticed. And it is.