Document Type
Article
Department/Program
Virginia Institute of Marine Science
Publication Date
2011
Journal
Limnology And Oceanography
Volume
56
Issue
2
First Page
666
Last Page
672
Abstract
The environmental conditions inside the gut of Calanus hyperboreus and C. glacialis were measured with microelectrodes. An acidic potential hydrogen (pH) gradient was present in the gut of C. hyperboreus, and the lowest pH recorded was 5.40. The gut pH of a starved copepod decreased by 0.53 after the copepod resumed feeding for a few hours, indicating the secretion of acidic digestive fluid. A copepod feeding on Thalassiosira weissflogii (diatom) had slightly lower pH than that feeding on Rhodomonas salina (cryptophyte). Oxygen was undersaturated in the gut of both C. hyperboreus and C. glacialis, with a steep gradient from the anal opening to the metasome region. The central metasome region was completely anoxic. Food remains in the gut led to a lower oxygen level, and a diatom diet induced a stronger oxygen gradient than a cryptophyte diet. The acidic and suboxic-anoxic environments of the copepod gut may support iron dissolution and anaerobic microbial activities that otherwise are not favored in the well-buffered and oxygenated ambient ocean.
DOI
10.4319/lo.2011.56.2.0666
Keywords
Plankton Community Structure; Fecal Pellets; Crustacean Zooplankton; Pelagic Ecosystems; Biogenic Silica; Acartia-Tonsa; Bacteria; Ph; Methane; Finmarchicus
Recommended Citation
Tang, KW; Glud, RN; Glud, A; Rysgaard, S; and Nielsen, TG, Copepod guts as biogeochemical hotspots in the sea: Evidence from microelectrode profiling of Calanus spp. (2011). Limnology And Oceanography, 56(2), 666-672.
10.4319/lo.2011.56.2.0666