Zooplankton — The Connecting Link: A Historical Perspective

Abstract

Marine Zooplankton, like most other marine animals including fish, produce many more offspring than eventually grow to maturity. Zooplankton encompass a wide range of taxonomic diversity. We know little about their early life history during which most of their mortality occurs, because they are very small (less than 1 mm), transparent and very difficult to observe. By definition, they cannot navigate or traverse significant distances at will. They have widely ranging fecundities from tens, hundreds, thousands to millions. The early life history stages of Zooplankton are almost universally microscopic, indistinguishable from related species, are dependent on adequate food supplies within hours to a day or two at most for survival, and have innumerable predators. Very little is known of the ecology and behavior of most of these early life history stages, yet they provide the food, and in some cases are the predators, for virtually all larval and post-larval fish. I review, from a historical perspective, the slow development of our understanding of this connecting link, attributable to the enormous difficulties in working both in the laboratory and the environment with a huge diversity of very small and very delicate organisms for which an adequate sampling technology has yet to be developed.