|Pelagic cnidarians and ctenophores as predators: Selective predation, feeding rates, and effects on prey populations|
Purcell, J.E. (1997). Pelagic cnidarians and ctenophores as predators: Selective predation, feeding rates, and effects on prey populations. Ann. Inst. Océanogr. 73(2): 125-137
In: Annales de l'Institut Océanographique. Institut Océanographique: Monaco. ISSN 0078-9682, more
Ichthyoplankton; Prey selection; Zooplankton; Cnidaria [WoRMS]; Ctenophora [WoRMS]; Hydroidolina [WoRMS]; Scyphomedusae [WoRMS]; Siphonophorae [WoRMS]; Marine
Siphonophores; Feeding rates
The following paper reviews predation by the pelagic ctenophores and cnidarians (Hydromedusae, Siphonophores, and Scyphomedusae). In spite of the difficulties in studying gelatinous zooplankton, much has been learned about the trophic ecology of the gelatinous predators. Their feeding is characterized by selectivity; some species specialize on fish larvae, and some specialize on other gelatinous species. Most species have broader diets, but some selection still occurs. Such selectivity in feeding depends on many factors: prey size and swimming speed; predator tentacle width and spacing; predator swimming behavior and resulting water flow, nematocyst/colloblast structure affecting adhesion or penetration, and toxins; sensitivities to chemical and mechanical discharge affecting nematocyst or colloblast discharge, prey escape abilities; and attraction between predator and prey. Feeding rates and effects on prey populations (copepods, fish eggs and larvae, and ctenophores) of the scyphomedusan Chrysaora quinquecirrha are given as examples of the potential importance of predation by gelatinous species. At high densities, gelatinous predatora can seriously affect populations of zooplankton and ichthyoplankton, and may be detrimental to fisheries through competition for food with fishes as well as direct predation on the eggs and larvae of fish.