Gelatinous Zooplankton and Their Trophic Roles

Abstract

The ecological role of gelatinous zooplankton is as diverse as the taxa that composed this watery group. The most abundant gelatinous zooplankton in coastal waters are a few species of ctenophores and cnidarians that feed primarily on crustacean zooplankton or, in some cases, other gelatinous zooplankton. A few species of pelagic tunicates, including salps, doliolids, and larvaceans/appendicularians, which feed on very small particulates, can also be present in large numbers. All of these taxa are characterized by conspicuous annual and inter-annual variability. In productive coastal waters, gelatinous zooplankton exhibit high rates of growth and reproduction resulting in seasonally high abundances (blooms) when conditions are favorable. Direct consumption of prey by these large populations has been documented in several studies to significantly decrease prey abundance. Additionally, gelatinous zooplankton are themselves prey for a variety of other taxa, including both invertebrates and vertebrates. The role of gelatinous zooplankton as competitors, however, is poorly quantified, as are their symbiotic associations. Here we review the current understanding of the trophic role of gelatinous zooplankton in coastal marine ecosystem.