Predation on pelagic coelenterates: a review

Abstract

Coelenterates (cnidaria and ctenophores) are well recognized as predators in food webs of marine ecosystems but are less often considered as prey. This is partly because they are digested very rapidly. In studies based on predator stomach contents the measured masses of different prey organisms are rarely scaled by their relative rates of digestion. Predators that are frozen and thawed, or for which whole stomachs are placed in preservatives, may have already lost much of their coelenterate content when they are examined. There is also a tendency to assume that gelatinous organisms, with their high water and salt content relative to organic content, are poor food. However, given the high rates of digestion (and presumably of assimilation) coelenterates may provide sources of energy comparable to better recognized prey such as arthropods. It is already becoming well documented that a number of cnidaria and ctenophores as well as fish utilize gelatinous organisms as prey. Data is accumulating more slowly on predation by a wide range of other carnivores such as molluscs, arthropods, reptiles and birds.

Does prey size matter? Novel observations of feeding in the leatherback turtle ( Dermochelys coriacea ) allow a test of predator–prey size relationships

“…Despite the low calorific value of jellyfish [9], their high digestibility [15] may explain the adoption of this specialized diet by the leatherback turtle. In addition, this particular feeding strategy may be facilitated by the relatively low metabolic rate of this marine reptile [10,11] and the slow-moving nature of its prey (i.e.…”

Preservation methods alter stable isotope values in gelatinous zooplankton: implications for interpreting trophic ecology

“…Gelatinous zooplankton or jellyWsh (here considered as Phylum Cnidaria, Class Schyphozoa) have been viewed as peripheral and transient components within marine ecosystems, constituting little more than a carbon sink or a trophic dead end (Hansson and Norrman 1995;Arai 2005). This perception now appears outdated and international eVorts are underway to redress this long-standing gap in our knowledge (Mills 2001;Purcell and Arai 2001).…”

Benthic scavengers and predators of jellyfish, material for a review

“…Arai 2005). Evidence had become available countering the previous prejudiced ideas about the negligible number of animal species preying on jellyfish.…”