Swarm of Paralabidocera antarctica (Calanoida, Copepoda) under sea ice near Syowa Station, Antarctica

• Main Authors: Atsushi Tanimura, Takashi Minoda, Mitsuo Fukuchi, Takao Hoshiai, Hideaki Ohtsuka
• Format: Article in Journal/Newspaper
• Language: English
• Published: National Institute of Polar Research 1984
• Subjects: geo; Syowa Station; Kita-no-seto; Antarc*; Antarctica; Sea ice
• Online Access: https://doi.org/10.15094/00008406; https://doaj.org/article/67cf0ad6e8e04cc693b8a3946fb4a3e0

A monospecific swarm of a calanoid copepod Paralabidocera antarctica was observed under the fast ice in the Kita-no-seto Strait near Syowa Station, Antarctica. During the day on January 22 to 23,a swarm appeared just beneath the undersurface of the fast ice. It was primarily composed of adults. P. antarctica seemed to have aggregated horizontally in an extremely narrow layer against the undersurface of the sea ice with density of roughly 2-6×10^4ind./m^3. Swarming may be associated with reproduction because almost all of adult females were carrying the spermatophores. P. antarctica was probably attracted to the undersurface brightness of the sea ice. At night, a swarm disappeared from the whole water column and the zooplankton composition differed from that during the day. It was assumed that the disappearance of the swarm was due to P. antarctica's entering into the loose lower part of the fast ice.