Vertical distribution of Paralabidocera antarctica (Copepoda : Calanoida) in Ace Lake, Antarctica, in summer

Abstract

In an ice-covered (thickness 1.68 m) meromictic lake, in early January 1982, a vertical profile of the population density of P. antarctica showed two peaks: from 7 to 130 cm beneath the ice, and just above the anoxylimnion at 10.0-10.5 m. Copepodite stages 111 and IV were dominant in the first (shallow) peak and stage CV was dominant in the second (deep) peak. Significantly more adult males than females were present within an entire vertical column of oxylimnion, but more adult females than males were present in a stratum 30 cm thick immediately beneath the ice.