title: First evidence for zooplankton feeding sustaining key physiological processes in a scleractinian cold-water coral.
abstract: Scleractinian cold-water corals (CWC) represent key taxa controlling deep-sea reef ecosystem functioning by providing structurally complex habitats to a high associated biodiversity, and by fuelling biogeochemical cycles via the release of organic matter. Nevertheless, our current knowledge on basic CWC properties, such as feeding ecology and key physiological processes (i.e. respiration, calcification and organic matter release), is still very limited. Here, we show evidence for the trophic significance of zooplankton, essentially sustaining levels of the investigated key physiological processes in the cosmopolitan CWC Desmophyllum dianthus (Esper 1794). Our results from laboratory studies reveal that withdrawal (for up to 3 weeks) of zooplankton food (i.e. Artemia salina) caused a significant decline in respiration (51%) and calcification (69%) rates compared with zooplankton-fed specimens. Likewise, organic matter release, in terms of total organic carbon (TOC), decreased significantly and eventually indicated TOC net uptake after prolonged zooplankton exclusion. In fed corals, zooplankton provided 1.6 times the daily metabolic C demand, while TOC release represented 7% of zooplankton-derived organic C. These findings highlight zooplankton as a nutritional source for D. dianthus, importantly sustaining respiratory metabolism, growth and organic matter release, with further implications for the role of CWC as deep-sea reef ecosystem engineers.
authors: Centre Scientifique de Monaco, Avenue Saint Martin, 98000 Monaco, Principality of Monaco. mnaumann@uni-bremen.de
authors: Malik S
authors: MS
authors: Naumann
authors: Covadonga
authors: C
authors: Orejas
authors: Christian
authors: C
authors: Wild
authors: Christine
authors: C
authors: Ferrier-Pagès
mesh_terms: D000704:Analysis of Variance; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D037421:Anthozoa / Q000502:physiology*; D001156:Artemia; D002113:Calcification, Physiologic / Q000502:physiology; D002244:Carbon / Q000378:metabolism; D003080:Cold Temperature; D005247:Feeding Behavior / Q000502:physiology*; D020387:Food Chain; D008522:Mediterranean Sea; D010101:Oxygen Consumption / Q000502:physiology; D013050:Spectrometry, Fluorescence; D015048:Zooplankton
chemical_list: D002244:Carbon