Species - Magallana (Crassostrea) gigas


  • Magallana (Crassostrea) gigas (Thunberg, 1793)
  • Pacific oyster
  • In Australia, it has been predicted that M. gigas may displace Saccostrea glomerata (Gould, 1850), the native Sydney rock oyster, in both mid- and low intertidal zones (Krassoi et al. 2008) where it is also known to alter native species assemblages (Wilkie et al. 2012).

    In the Northern Hemisphere, M. gigas continues to spread toward the poles, facilitated by the warming of sea surface waters (Rinde et al. 2016; Thomas et al. 2016; Townhill et al. 2017).

  • The Pacific oyster, Magallana gigas, has a white and purple elongated shell, with an average shell length of 15 – 20 cm. It is among the largest of all oyster species globally, with extreme examples reaching up to 450 mm in length (Huber 2010: 180). M. gigas, as with many other ostreid species, possess shells that are morphologically highly variable, often as a function of their substrate (Poppe and Goto 2000). This variability can make species identification challenging (Dridi et al. 2008).

    M. gigas is an important aquaculture species throughout the world. Native to Japan, it was introduced intentionally to, North America, Europe, New Zealand, and Australia to establish oyster aquaculture industries. M. gigas was intentionally introduced to southern Tasmania, Western Australia, and Victoria in the mid-1900s, and was found in New South Wales in the 1960s. It is well established in Tasmania, South Australia and parts of NSW. It did not establish in Western Australia and is not common in Victoria.

  • Established
  • New South Wales
    South Australia
    Tasmania
    Victoria
  • Non-native
  • Native to Japan and southern China, where it occurs in shallow-water habitats.

    Substantial M. gigas industries exist in New South Wales, South Australia, and Tasmania. However, commercial M. gigas numbers have been substantially reduced in areas of Tasmania and New South Wales due to mass mortality events caused by Pacific oyster mortality syndrome (Ostreid herpesvirus 1 microvariants).

    Magallana gigas has been introduced to every continent, with the exception of Antarctica, and it has become established in all major oceans and seas of the world (Padilla, 2010).

Expand all
Collapse all
Auto collapse
Identification
Similar species
Reproduction and growth
Competitors
Predators
Controls
Additional information
References
Location
Images
  • Crassostrea gigas - NIMPIS.
    Crassostrea gigas - NIMPIS.
    Copyright Notice: Karen Gowlett-Holmes, CSIRO Marine Research. Acknowledge: true
  • <p><em>Magallana&nbsp;gigas</em> diagram &amp; key features. Cement one valve entirely to the substrata. Presence of a promyal chamber (visible only under microscope). Radial grooves present. Lacks chomata (small bumps near hinge ligamant). Outside shell colour is white-purple (as in interior colour).</p>

    Magallana gigas diagram & key features. Cement one valve entirely to the substrata. Presence of a promyal chamber (visible only under microscope). Radial grooves present. Lacks chomata (small bumps near hinge ligamant). Outside shell colour is white-purple (as in interior colour).

    Copyright Notice: CRIMP, CSIRO Marine Research. Acknowledge: true
  • <p><em>Magallana&nbsp;gigas,</em> Cloudy lagoon, Tasmania - NIMPIS.</p>

    Magallana gigas, Cloudy lagoon, Tasmania - NIMPIS.

    Copyright Notice: CRIMP, CSIRO Marine Research. Acknowledge: true

Was this page helpful?

Yes No