Isotopic and elemental compositions reveal density‐dependent nutrition pathways in a population of mixotrophic jellyfish

Type Article
Date 2020-11
Language English
Author(s) Djeghri Nicolas1, Pondaven Philippe1, Stockenreiter Maria2, Behl Stephan2, Huang Jessica Y. T.2, Hansen Thomas3, Patris Sharon4, Ucharm Gerda4, Stibor Herwig2
Affiliation(s) 1 : Laboratoire des Sciences de l'Environnement Marin, LEMAR Institut Unversitaire Européen, IUEMUniversité de Brest, UBO Rue Dumont d'Urville Plouzané 29280, France
2 : Department Biologie II, Aquatische Ökologie Ludwig‐Maximilians‐Universität München Großhaderner Str. 2 Planegg‐Martinsried 82152, Germany
3 : Department of Marine Ecology GEOMAR Helmholtz Centre for Ocean Research Kiel Experimental Ecology‐Food Webs Düsternbrooker Weg 20 Kiel24015, Germany
4 : Coral Reef Research Foundation PO Box 1765 Koror PW96940, Palau
Source Ecosphere (2150-8925) (Wiley), 2020-11 , Vol. 11 , N. 11 , P. e03295 (9p.)
DOI 10.1002/ecs2.3295
Keyword(s) density dependence, jellyfish, marine lakes, mixotrophy, stable isotopes, symbiosis, zooxanthellae
Abstract

Mixotrophic organisms are increasingly recognized as important components of ecosystems, but the factors controlling their nutrition pathways (in particular their autotrophy–heterotrophy balance) are little known. Both autotrophy and heterotrophy are expected to respond to density‐dependent mechanisms but not necessarily in the same direction and/or strength. We hypothesize that the autotrophy–heterotrophy balance of mixotrophic organisms might therefore be a function of population densities. To investigate this relationship, we sampled mixotrophic jellyfish holobionts (host, Mastigias papua etpisoni; symbiont, Cladocopium sp.) in a marine lake (Palau, Micronesia) on six occasions (from 2010 to 2018). Over this period, population densities varied ~100 fold. We characterized the nutrition of the holobionts using the δ13C and δ15N signatures as well as C:N ratios. δ13C values increased and δ15N values decreased with increasing population densities (respectively, R2 = 0.86 and 0.70, P < 0.05). Although less distinct, C:N ratios increased with increasing population densities (R2 = 0.59, 0.1 > P > 0.05). This indicates that the autotrophy–heterotrophy balance tends toward autotrophy when population densities increase. We propose that the availability of zooplanktonic prey is the main driver of this pattern. These results demonstrate that the autotrophy–heterotrophy balance of mixotrophic jellyfishes can be tightly regulated by density‐dependent mechanisms.

Full Text
File Pages Size Access
Publisher's official version 9 939 KB Open access
Appendix S1 pdf 1 171 KB Open access
Appendix S1 doc 143 KB Open access
Top of the page

How to cite 

Djeghri Nicolas, Pondaven Philippe, Stockenreiter Maria, Behl Stephan, Huang Jessica Y. T., Hansen Thomas, Patris Sharon, Ucharm Gerda, Stibor Herwig (2020). Isotopic and elemental compositions reveal density‐dependent nutrition pathways in a population of mixotrophic jellyfish. Ecosphere, 11(11), e03295 (9p.). Publisher's official version : https://doi.org/10.1002/ecs2.3295 , Open Access version : https://archimer.ifremer.fr/doc/00663/77469/