1st Record: Auckland, North Island/New Zealand/Waitemata Harbor (1957, Gordon 1989; Gordon 1992); Watersipora arcuata has been replaced by W. subtorquata at many locations. Gordon and Matawari (1992) found living poulations at Taurange Harbor and the Bay of Islands, near the northern peninsula of the North Island, but not in locations further south.
Whangarei Heads, North Island/New Zealand/Whangarei Harbor (Gordon 1989); Leigh, North Island/New Zealand/Hauraki Gulf (Gordon 1967); Auckland, North Island/New Zealand/Waitemata Harbor (Gordon 1989); North Island/New Zealand/Maurangi Estuary (Gordon 1989); New Plymouth/North Island/New Zealand/Tasman Sea (Gordon 1989); Napier, North Island/New Zealand/Bay of Plenty (Gordon 1989); Nelson, South Island/Tasman Bay (Gordon 1989); North Island/New Zealand/Tauranga Harbor (Gordon and Matawari 1992); Opua/North Island/New Zealand/Bay of Islands (Gordon and Matawari 1992)
|'An important fouling species' (Gordon 1989).|
|It 'became one of the dominant intertidal organisms at several locations' in Auckland Harbor, and spread to other harbors, but in the 1980s was largely repressed by W. subtorquata.|