Discovery of Alcyonidium verrilli Osburn, 1912 (Bryozoa: Ctenostomata) in Aotearoa New Zealand: first record of established colonies outside its native range

The first confirmed record is reported concerning established colonies of the bryozoan Alcyonidium verrilli outside of the species’ native range in the Northeast USA (Northwest Atlantic). Two specimens collected from the Port of Lyttelton (Lyttelton Harbour/Whakaraupō, South Island, Aotearoa New Zealand) have been determined as A. verrilli by genetic and histological analysis. The presence of gametogenesis indicates that the species actively breeds in the austral winter, conforming to data on winter breeding and colony growth in the Atlantic. Owing to the difficulty of species-level identification within the genus Alcyonidium , it is likely that A. verrilli has been overlooked elsewhere outside of its native range. This is the ninth species of the genus, and the first genetically confirmed alien Alcyonidium species, to be recorded in New Zealand.