|Document Type:||Journal Article|
|Title:||Prey selection patterns of Chrysaora fuscescens in the northern California Current|
|Author:||Samantha M. Zeman, Richard D. Brodeur, Elizabeth A. Daly, Kelly R. Sutherland|
|Journal:||Journal of Plankton Research|
|Keywords:||Jellyfish, diets, prey selection,California Current,|
Chrysaora fuscescens is the most abundant large cnidarian medusa in the northern California Current (NCC), a productive upwelling system. We quantified the diet and prey selection of C. fuscescens at cross-shelf stations off the Oregon and Washington coasts during June, July and September of 2014. The major prey items ingested by C. fuscescens were copepods, cladocerans, and gelatinous taxa. Northern anchovy eggs (Engraulis mordax) were a dominant prey item at stations near the Columbia River. Prey selection indices show that though copepods dominated gut contents, C. fuscescens preferentially ingest slow moving, non-motile prey including fish eggs and gelatinous taxa and negatively selected for more motile prey such as copepods. Clearance rates and ingestion rates varied by orders of magnitude for the different zooplankton taxa and by sampling station, but on average, fish eggs and gelatinous taxa were cleared at higher rates than more commonly ingested prey items such as copepods. Daily carbon ration reached 10% of body carbon but had an average value of 2%, suggesting that medusae are often food limited. At stations with northern anchovy eggs present in the gut, daily carbon ration was significantly larger than at stations without anchovy eggs.
|Theme:||Ecosystem approach to improve management of marine resources|
Characterize ecological interactions (e.g. predation, competition, parasitism, disease, etc.) within and among species.
Characterize the interaction between marine, freshwater and terrestrial ecosystem components.