High trophic plasticity in the mixotrophic Mastigias papua-Symbiodiniaceae holobiont: implications for the ecology of zooxanthellate jellyfishes

Djeghri, Nicolas; Pondaven, Philippe; Le Grand, Fabienne; Bideau, Antoine; Duquesne, Nolwenn; Stockenreiter, Maria; Beh, Stephan; Huang, Jessica Y-T; Hansen, Thomas; Patris, Sharon; Ucharm, Gerda und Stibor, Herwig (2021): High trophic plasticity in the mixotrophic Mastigias papua-Symbiodiniaceae holobiont: implications for the ecology of zooxanthellate jellyfishes. In: Marine Ecology Progress Series, Bd. 666: S. 73-88

Abstract

The trophic ecology of mixotrophic, zooxanthellate jellyfishes potentially spans a wide spectrum between autotrophy and heterotrophy. However, their degree of trophic plasticity along this spectrum is not well known. To better characterize their trophic ecology, we sampled the zooxanthellate medusa Masligias papua in contrasting environments and sizes in Palau (Micronesia). We characterized their trophic ecology using isotopic (bulk delta C-13 and delta N-15), elemental (C:N ratios), and fatty acid compositions. The different trophic indicators were correlated or anti-correlated as expected (Pearson's correlation coefficient, r(P) > 0.5 or < -0.5 in 91.1 % of cases, p < 0.05), indicating good agreement. The sampled M. papua were ordered in a trophic spectrum between autotrophy and heterotrophy (supported by decreasing delta C-13, C:N, proportion of neutral lipid fatty acids (NLFA:TLFA), n-3:n-6 and increasing delta N-15, eicosapentaenoic acid to docosahexaenoic acid ratio (EPA:DHA)). This trophic spectrum was mostly driven by sampling location with little influence of medusa size. Moreover, previous observations have shown that in a given location, the trophic ecology of M. papua can change over time. Thus, the positions on the trophic spectrum of the populations sampled here are not fixed, suggesting high trophic plasticity in M. papua. The heterotrophic end of the trophic spectrum was occupied by non-symbiotic M. papua, whereas the literature indicates that the autotrophic end of the spectrum corresponds to dominant autotrophy, where more than 100% of the carbon requirement is obtained by photosynthesis. Such high trophic plasticity has critical implications for the trophic ecology and blooming ability of zooxanthellate jellyfishes.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Biologie
• Themengebiete: 500 Naturwissenschaften und Mathematik > 570 Biowissenschaften; Biologie
• ISSN: 0171-8630
• Sprache: Englisch