Three faunistic areas were identified along a transect off the Argentine coast (38º11'S 55º11'W to 39º20'S 55º07W) based on the distribution of copepod taxa: coastal, transitional midshelf and outershelf-oceanic in summer, autumn and winter 1987. The copepods formed different assemblages depending on the season, with a certain overlapping among some of them. Calanus propinquus, Clausocalanus brevipes and Oithona atlântica a group identified in March, appeared in other assemblages during the studied period. Calanus australis, Calanoides carinatus and Centropages brachiatus, a group also formed in summer, continued together in the following two seasons in other groups. The oceanic species were only found in March and May, excepting Clausocalanus laticeps which was present in July (winter). The number of recorded taxa decreased from 19 to 12 along the studied period.
