ABSTRACT
The ecology of marine planktonic assemblages depends, in essential, intricate ways, on the behavior of individual zooplankters. Swarming behavior is among the most crucial, and also least charted, of the territories that span population and organismal biology in this way. On large scales in the ocean, and possibly in some small-scale environments like frontal zones, aggregation into patches is probably a physics-driven, passive process. At the same time, active swarming behavior — that is, a type of motion that resists dispersion without orienting or distributing animals in an organized way — is well known,
and controls small-scale zooplankton distribution in the ocean to an unknown extent. Passive and active aggregations are essential for setting encounter rates between predators and prey, between grazers and patchily distributed food sources (Lasker, 1975; Davis et al., 1991) and between conspeciÞcs in search of mates (Brandl and Fernando, 1971; Hebert et al., 1980; Gendron, 1992).
