Mytilidae: Gibbomodiola albicosta (Lamarck, 1819) (‘white-sided horse-mussel’)

Synonym(s): albicosta Lamarck, 1819 delinifica Iredale, 1924.

Typical shell-length 130 mm. Periostracum bristly; flakes off when worn. Interior of shell pearly-white. Lives subtidally embedded in sponges in exposed environments. Native. Endemic to southeastern and southwestern Australia (QLD, NSW, TAS, VIC, SA and WA). In Tasmanian waters, this is a widespread and common species.