Food selectivity and processing by the cold-water coral Lophelia pertusa
Van Oevelen, D.; Mueller, C.E.; Lundälv, T.; Middelburg, J.J. (2016). Food selectivity and processing by the cold-water coral Lophelia pertusa. Biogeosciences 13: 5789–5798. https://dx.doi.org/10.5194/bg-13-5789-2016
Additional data:
In: Gattuso, J.P.; Kesselmeier, J. (Ed.) Biogeosciences. Copernicus Publications: Göttingen. ISSN 1726-4170; e-ISSN 1726-4189, more
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| Authors | | Top |
- Van Oevelen, D., more
- Mueller, C.E.
- Lundälv, T., more
- Middelburg, J.J., more
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| Abstract |
Cold-water corals form prominent reef ecosystemsalong ocean margins that depend on suspended resourcesproduced in surface waters. In this study, we investigatedfood processing of 13C and 15N labelled bacteria and algaeby the cold-water coral Lophelia pertusa. Coral respiration,tissue incorporation of C and N and metabolically derivedC incorporation into the skeleton were traced followingthe additions of different food concentrations (100, 300,1300 μg CL?1/ and two ratios of suspended bacterial andalgal biomass (1 V 1, 3 V 1). Respiration and tissue incorporationby L. pertusa increased markedly following exposureto higher food concentrations. The net growth efficiency ofL. pertusa was low (0.08?0.03), which is consistent withits slow growth rate. The contribution of algae and bacteriato total coral assimilation was proportional to the food mixturein the two lowest food concentrations, but algae werepreferred over bacteria as a food source at the highest foodconcentration. Similarly, the stoichiometric uptake of C andN was coupled in the low and medium food treatment, butwas uncoupled in the high food treatment and indicated acomparatively higher uptake or retention of bacterial carbonas compared to algal nitrogen. We argue that behavioural responsesfor these small-sized food particles, such as tentaclebehaviour, mucus trapping and physiological processing, aremore likely to explain the observed food selectivity as comparedto physical–mechanical considerations. A comparisonof the experimental food conditions to natural organic carbonconcentrations above CWC reefs suggests that L. pertusais well adapted to exploit temporal pulses of high organicmatter concentrations in the bottom water caused byinternal waves and downwelling events |
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