First New Zealand record of the Australian bridled goby, Arenigobius bifrenatus (Pisces : Gobiidae)

Arenigobius bifrenatus (Kner 1865) is a burrowing coastal and estuarine gob y from temperate areas of Australia. One specimen was captured from the Wha ngateau Harbour, north-eastern New Zealand, on 1 April 1998, constituting t he first record of this species from New Zealand. Further intensive beach s eining at Pollen Island, within the Waitemata Harbour (Auckland), yielded t wo further specimens which were females in breeding condition. We suggest t hat the species is an adventive, and its presence in northern New Zealand w aters is the result of accidental transport in shipping ballast water.