Zooplankton of Wellington Harbour, New Zealand
Ctenophora
Ctenophora
Pleurobrachia pileus (O. F. Müller) (Text-fig. 3, C) is dominant in the winter plankton. However, this is one of the most variable planktonic species. In 1961, exceptionally large numbers were recorded, with peak abundance occurring two months earlier than in 1962 and 1963 (Text-fig. 8). Pleurobrachia pileus first appears rarely in April, and few are sampled in May. The species is common in June and abundant in July and in August when it may dominate many samples. In September, October and November, P. pileus is common in all samples, but occurs only rarely in December and January. In February and March the species is absent (Text-fig. 7).