Corbicula fluminea
Invasive freshwater clam
Also known as:
Freshwater gold clam (note that this term is no longer being used)
Family: Corbiculidae
Origin: Asia
General description
There are no other New Zealand freshwater shellfish that look anything like the invasive freshwater clam.
The adult clams are 2-3cm in length and are typically dirty white, yellow or tan in colour.
They have an obvious ribbed texture on the shell.
They are found in freshwater or brackish water, sitting on top of sandy or muddy substrates or buried shallowly within them.
It was first found in the Waikato River in May 2023. These clams have not yet been found in the Auckland Region.
What you need to know
To help protect our environment:
- You must not distribute or release any invasive freshwater clam within the Auckland region.
If you swim, boat or row in the Waikato River, follow the Check Clean Dry guidelines to help stop the spread of this clam to other rivers and lakes.
Habitats
Lakes, rivers, estuaries.
Impact on environment
This shellfish is native to eastern Asia but has become widespread in North and South America and Europe where it has become a pest.
Invasive freshwater clams are prolific breeders, able to produce large populations that can clog electric generation plants, irrigation systems and water treatment plants.
Their shells will wash up and smother sandy lakeside beaches.
They can potentially compete with native species for food. However, we do not yet know how this species will respond in New Zealand conditions.
Control
Check equipment and vessels for freshwater pests, clean everything that has been in contact with the water and dry everything thoroughly.
For more information about the freshwater invasive clam or to report a sighting contact Biosecurity New Zealand 0800 80 99 66.
Invasive freshwater clams are prolific breeders, able to produce large populations that can clog electric generation plants, irrigation systems and water treatment plants.
