SYMBIOSIS OF PLANKTONIC COPEPODS AND MYSIDS WITH EPIBIONTS AND PARASITES IN THE NORTH PACIFIC: DIVERSITY AND INTERACTIONS BY

Planktonic crustaceans such as copepods and mysids are two of the most abundant components of the marine zooplankton community and, although they harbor a diversity of symbionts, their real interactions have been poorly understood. We have been investigating planktonic symbiosis and briefly review the biology of symbionts on planktonic crustaceans based mainly on our research conducted in the North Pacific. Symbiotic histophagous apostome ciliates probably have a significant negative impact on their coastal copepod hosts in view of their high prevalence and their worldwide distributions in the coastal ecosystems. Such symbionts are also likely to impact the populations of the copepod’s predators such as chaetognaths. In contrast, symbiosis between copepods and epibionts such as diatoms and suctorian ciliates may be more or less harmless to the host