Bacterial communities associated with scyphomedusae at Helgoland Roads
Different modes of asexual and sexual reproduction are typical for the life-history of scyphozoans, and numerous studies have focused on general life history distribution, reproductive strategies, strobilation inducing factors, growth rates and predatory effects of medusae. However, bacteria associated with different life stages of scyphozoa have received less attention. In this study, bacterial communities associated with different body compartments and different life stages of two common scyphomedusae (Cyanea lamarckii and Chrysaora hysoscella) were analyzed via automated ribosomal intergenic spacer analysis (ARISA). We found that the bacterial community associated with these two species showed species-specific structuring. In addition, we observed significant differences between the bacterial communities associated with the umbrella and other body compartments (gonads and tentacles) of the two scyphomedusan species. Bacterial community structure varied from the early planula to the polyp and adult medusa stages. We also found that the free-living and particle-associated bacterial communities associated with different food sources had no impact on the bacterial community associated with fed polyps.