According to a recently presented bioenergetic model for the weight-specific growth rate of jellyfish, Aurelia aurita, fed brine shrimp, Artemia salina, specific will remain high and constant at prey concentrations > 6 l?1. The aim present study was verify this statement by conducting controlled feeding experiments on small jellyfish in tanks. It found that organisms offered 25, 50, 100 l?1 ...

26 Gelatinous zooplankton populations are well known for their ability to take over perturbed 27 ecosystems. The ability of these animals to outcompete and functionally replace fish that 28 exhibit an effective visual predatory mode is counterintuitive because jellyfish are 29 described as inefficient swimmers that must rely on direct contact with prey in order to 30 feed. We show that jellyfis...

There has been a dramatic increase in jellyfish biomass over the eastern Bering Sea shelf since the early 1990s, which was previously hypothesized to have been triggered by changing climate and ocean conditions. We examine the hypothesis that the presence of these large carnivores has affected fisheries resources, either through direct predation on larval stages, or through competition for zoop...

Jellyfish possess venomous cnidae on their tentacles to capture and consume marine zooplankton. Nevertheless, the planktonic larvae of the smooth fan lobster (Ibacus novemdentatus), known as phyllosoma, prey on jellyfish and successfully ingest both tentacle tissue as well as constituent cnidae, despite the presence of the venom-filled explosively penetrant cnidae or nematocysts. In the present...

A temporal change in the stable isotope (SI) composition of jellyfish in the Kiel Fjord, Western Baltic Sea, was documented by analyzing δ13C, δ15N and δ34S of bell tissue of Aurelia aurita and Cyanea capillata in the period between June and October 2011. A strong and significant temporal change in all SI values of A. aurita was found, including an increase of ~3 ‰ in δ13C, a decrease of ~4 ‰ i...

Gelatinous zooplankton populations are well known for their ability to take over perturbed ecosystems. The ability of these animals to outcompete and functionally replace fish that exhibit an effective visual predatory mode is counterintuitive because jellyfish are described as inefficient swimmers that must rely on direct contact with prey to feed. We show that jellyfish exhibit a unique mecha...

The Pacific population of leatherback sea turtles (Dermochelys coriacea) has drastically declined in the last 25 years. This decline has been linked to incidental capture by fisheries, egg and meat harvesting, and recently, to climate variability and resource limitation. Here we couple growth rates with feeding experiments and food intake functions to estimate daily energy requirements of leath...

Leatherback turtles (Dermochelys coriacea) are capital breeders that accumulate blubber (33 kJ g-1 wet mass) by hyperphagia on a gelatinous diet at high latitudes; they breed in the tropics. A jellyfish diet is energy poor (0.1-0.2 kJ g-1 wet mass) so leatherbacks must ingest large quantities. Two published estimates of feeding rate [50% body mass day-1 (on Rhizostoma pulmo) and 73% body mass d...