| Popis: |
The Italian Progetto Antartide conducted cruises to Terra Nova Bay and the Ross Sea in 1987–1988 and 1989–1990; planktonic halocyprid ostracodes were among the groups sampled as part of the zooplankton programs. Four species: Alacia belgicae (Muller, 1906), A. hettacra (Muller, 1906), Meta conchoecia isocheira (Muller, 1906) and M. skogsbergi (lles, 1953) were identified in 1987–1988 samples; Boroecia antipoda (Muller, 1906), Conchoecissa symmetrica (Muller, 1906) and Proceroecia rivoltella Benassi et al. 1994 were added in 1989–1990. The latter two species comprised single records only, well south of their known latitudinal ranges, but the other species represent the characteristic planktonic ostracode faunule to 1000 m in the western Ross Sea. A. belgicae is regarded as a facultative Antarctic species at midwater depths. We discuss the spatial distribution of species particularly with regard to their highest densities at the stations, sampling limitations, vertical migration, possible hybridization in A. belgicae; and deal briefly with important associated environmental factors such as the Antarctic Convergence, the water masses of the Ross Sea, the clockwise summer gyre in Terra Nova Bay and associated turbulence zones, the role of the Antarctic Circumpolar Current, melting ice; then draw some conclusions re the planktonic Ostracoda for any continuing program of investigations in the Ross Sea under the aegis of the Italian Progetto Antartide. |
