PLANKTONIC TUNICATES (CHORDATA, TUNICATA) OF THE RTMA

DAPONTE, M.C; CAPITANIO, F.; MACHINANDIARENA, L.; ESNAL, G.

IHERINGIA. SéRIE ZOOLOGIA

FUNDACAO ZOOBOTANICA RIO GRANDE SUL

Año: 1993 vol. 74 p. 71 - 80

0073-4721

The planktonic tunicates from the samples collected by the RTMA "EVRIKA" in the southwestem Atlantic in 1988 were studied. For the salps Ihlea magalhanica and a clear association with waters of subantarctic origin was once more found, while Ciclosalpa bakeri, Iasis zonaria, Ritteriella retracta ; the aggregates of Thalia democratica group, the doliolidae nurses and the appendicularia Oikopleura albicans were found associated with subtropical waters. For the salps Salpa aspera and S.fusiformis, species previously considered associated with Brazil current waters, the distribution is extended further South in mixed subtropical-subantarctic waters or with predominantly subantarctic features, which shows a wider tolerance to environmental change. Thetys vagina extends its southern limit of distribution of the Atlantic Ocean from 5" S to 40S. In only one station specimens were found which could be attributable with high probability to Pegea socia species which had not been previously mentioned for the southwestern Atlantic. Since only fixed specimens were available worthy identification is not possible so we refer to the taxon as Pegea sp. and the corresponding morphormetric data are included.