Asian date mussel or bag mussel

Introduction

The Asian date mussel or bag mussel is a relatively small species of saltwater mussel attaining a maximum length of 3cm. It has a smooth, fragile shell, olive green/brown in colour, with unique zigzag markings and iridescent radiating bands.

Its habitat ranges from intertidal to subtidal habitats to depths of 30m, forming dense clumps in soft sediment or on hard surfaces. It can foul artificial structures and compete with native species for food and habitat.

Identification

Asian date mussel

Photo: courtesy Northern Territory Government

 

Asian-Date-Muss-2

Photo: Graham Edgar, Australian Marine Life

Asian date mussel/bag mussel
Musculista senhousia

Key features:

  • Smooth fragile shell up to 3cm long, olive green/brown colour
  • Shell has zigzag markings and iridescent radiating bands
  • Often in clumps of many individuals

Known locations:

  • Found in Vic, SA, Tas and WA
  • Not known to occur in NSW

Habitat:

  • Soft sediment or hard surfaces
  • Occurs just below the low tide level in aggregated clumps

Impacts:

  • Fouls man-made structures
  • Forms dense mats competing with natives for food and space

Similar native species

These native species may be confused with this marine pest.

Asian-Green-Mussel-3

Photo: Graham Edgar, Australian Marine Life

Blue mussel
Mytilus galloprovincialis planulatus

Key features:

  • Large fan shaped shell up to 12cm
  • Blue/black colour
  • Usually found in clumps

Habitat:

  • Sheltered and moderately exposed reefs, pylons and pontoons
  • Up to 15m depth
Asian-Date-Muss-5

Photo: Graham Edgar, Australian Marine Life

Brachidontes rostratus

Key features:

  • Long flat shell up to 4cm
  • Purple colour, regular rounded ribs
  • Usually found in dense clumps

Habitat:

  • Exposed rock platforms
Asian-Date-Muss-4

Photo: Graham Edgar, Australian Marine Life

Hairy mussel
Trichomya hirsuta

Key features:

  • Numerous hairs on lower half of shell
  • Up to 6cm

Habitat:

  • Exposed reef up to 15m depth
  • Common intertidally and subtidally
Asian-Date-Muss-6

Photo: Graham Edgar, Australian Marine Life

Little black horse mussel

Xenostrobus pulex

Key features:

  • Small shiny inflated shell up to 2.5cm in length
  • Black colour
  • Forms dense clumps

Habitat:

  • Exposed rocky shores
  • Mid intertidal

How can you help?

Learn to recognise, and be aware of, the Asian date mussel or bag mussel so that you can report any suspected new sighting.

Report any suspected new sightings on the 24 hour recorded hotline: 02 4916 3877 or email aquatic.pests@dpi.nsw.gov.au.

If you see this pest in NSW, please report it immediately

  • Note the exact location
  • If possible take a photo and/or collect a sample
  • Freeze sample in a plastic bag
  • Report your sighting