Mytilidae: Arcuatula senhousia (Benson, 1842) (‘Asian bag-mussel’)

Synonym(s): senhousia Benson in Cantor, 1842.

Typical shell-length 30 mm. Lives intertidally and subtidally amongst seaweed and seagrass within a ‘nest’ of its own byssal threads, in estuarine and other sheltered environments. Non-native. Occurs in southeastern and southwestern Australia (TAS, VIC and WA); also northeast Asia (native) and widely introduced elsewhere. In Tasmanian waters, this species is currently found only in the NE, following unintentional introduction from Japan.