Pseudoplanktonic

organism An organism is any life, living thing that functions as an individual. Such a definition raises more problems than it solves, not least because the concept of an individual is also difficult. Many criteria, few of them widely accepted, have be ...

s are those that attach themselves to

planktonic Plankton are the diverse collection of organisms that drift in water (or air) but are unable to actively propel themselves against currents (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they pro ...

organisms or other floating objects, such as drifting wood,

buoyant Buoyancy (), or upthrust, is the force exerted by a fluid opposing the weight of a partially or fully immersed object (which may be also be a parcel of fluid). In a column of fluid, pressure increases with depth as a result of the weight of t ...

shells of organisms such as '' Spirula'', or man-made flotsam. Examples include

goose barnacle Goose barnacles, also called percebes, turtle-claw barnacles, stalked barnacles, gooseneck barnacles, are filter-feeding crustaceans that live attached to hard surfaces of rocks and flotsam in the ocean intertidal zone. Goose barnacles form ...

s and the bryozoan '' Jellyella''. By themselves these animals cannot float, which contrasts them with true planktonic organisms, such as '' Velella'' and the

Portuguese Man o' War The Portuguese war (''Physalia physalis''), also known as the man-of-war or bluebottle, is a marine hydrozoan found in the Atlantic Ocean and the Indian Ocean. It is the only species in the genus ''Physalia'', which in turn is the only genus in ...

, which are buoyant. Pseudoplankton are often found in the guts of filtering zooplankters.

References

Biological oceanography {{ocean-stub