Freshwater gold clam

• Inflated, round to triangular shell is yellowish brown to black with evenly spaced ridges.
• Can grow to a shell length of 50–65mm, although it is usually less than 25mm.

• Tolerates a wide variety of substrate/habitat types.

• Limited locations along the Brisbane River in the Ipswich region.
• Established in New Zealand, and North and South America.
• Spreads when it is:
  • attached to boats or carried in ballast water
  • used as bait
  • sold through the aquarium trade
  • carried with water currents.

• Fertilised eggs form larvae, which exist in plankton for up to 55 days before settling.
• Lives up to 7 years.
• Generally thought to reproduce twice a year, but this may depend on climatic and ecological factors.

Environmental

• Highly invasive
• Can displace native clams and diminish water quality

Economic

• Can block plumbing, heat exchangers and other water infrastructure

Slipway operators, vessel inspectors and vessel owners should thoroughly check, clean and, where possible, dry vessel hulls and niche areas such as internal seawater systems.

If you think you have seen a freshwater gold clam, report it to Biosecurity Queensland online, by phone or in person. Take reasonable and practical measures to prevent gold clams from spreading until an authorised officer contacts you.

• The freshwater gold clam is not a prohibited or restricted matter under the Biosecurity Act 2014. However, by law, everyone has a general biosecurity obligation (GBO) to take reasonable and practical measures to minimise the biosecurity risks associated with invasive species under their control.
• Local governments must have a biosecurity plan that covers invasive species in their area. This plan may include actions to be taken on freshwater gold clams. Some of these actions may be required under local laws. Contact your local government for more information.