Particulate matter ingestion and associated nitrogen uptake by four species of scleractinian corals

• Published in: Coral reefs 2004-09, Vol.23 (3), p.311-323
• Main Authors: MILLS, Matthew M, LIPSCHULTZ, Fredric, SEBENS, Kenneth P
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Coral reefs; Diploria strigosa; Fundamental and applied biological sciences. Psychology; Ingestion; Isotopic tracers; Madracis mirabilis; Marine; Marine biology; Montastrea franksi; Morphology; Nitrogen; Particulate matter; Scleractinia; Sea water ecosystems; Siderastrea radians; Synecology; Variance analysis
• ISSN: 0722-4028; 1432-0975
• DOI: 10.1007/s00338-004-0380-3

The ingestion of two size classes of natural particulate matter (PM) and the uptake of the associated nitrogen by four species of scleractinian corals was measured using the stable isotopic tracer ^sup 15^N. PM collected in sediment traps was split into 105 µm size fractions and labeled with (^sup 15^N-NH^sub 4^)^sub 2^SO^sub 4^. Siderastrea radians, Montastrea franksi, Diploria strigosa, and Madracis mirabilis were incubated in flow chambers with the labeled PM in suspension (105 µm). Ingestion was detected for all four species (98-600 µg Dry wt. cm^sup -2^ h^sup -1^), but only for D. strigosa was any difference detected between suspended and deposited PM. Only the three mounding species, S. radians, M. franksi, and D. strigosa showed uptake of suspended and deposited particulate nitrogen (PN); whereas, the branched coral M. mirabilis had no measurable PN uptake. Only coral host tissues were enriched with ^sup 15^N, with no tracer detected in the symbiotic zooxanthellae. Uptake rates ranged from as low as 0.80 µg PN cm^sup -2^ h^sup -1^ in S. radians to as high as 13 µg PN cm^sup -2^ h^sup -1^ in M. franksi. M. franksi had significantly higher uptake rates than S. radians (ANOVA, p