Soft shell or long-necked clam (Mya arenaria)

Key features

  • Very different shells; one has a distinctive large scoopedout projection & the other a pit. They fit together but gape at both ends when closed
  • Shell is thin, oval, chalky, white with rough exterior & uneven growth lines
  • Up to 15 cm long


  • Buried up to 30 cm deep in sand, mud, clay & gravel mixes
  • Mainly upper intertidal; also in shallow subtidal


  • Outcompetes native bivalves, changes characteristics of sediments & composition of bottom dwelling communities

Known locations

  • Not yet in Australia

Known locations

  • Not yet in Australia

What you can do

  • Inspect & clean niche areas & antifoul your vessel regularly
  • Clean & dry equipment before transporting & using in a different location

Learn more

Read the national biofouling management guidelines for your sector.

Report immediately Outside known locations!

  • Note the exact locations
  • If possible, collect a sample and freeze in a plastic bag or take a photo
  • See for your state contacts

Report a sighting

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