Answers are grounded in this paper and cite their sources.
Feeding currents of free-swimming calanoid copepods, observed through an expanded krypton laser beam and a back-focus dark-field optical system, show that these planktonic animals generate a double shear field to help in detecting food. The interrelation between flow field, perception of food items, and body orientation explains why these animals are generally negatively buoyant.
No takes yet. Share an insight, caveat, or question.
J. Rudi Strickler (1982) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: