Jellyfish mucus-derived organic matter as a source of labile nutrients for the ambient microbial community

Author(s)
Nathan Hubot, Sarah L.C. Giering, Neža Orel, Katja Klun, Gerhard J. Herndl, Felix Hohaus, Cathy H. Lucas, Tinkara Tinta
Abstract

Jellyfish are increasingly recognized as a significant contributor to marine organic matter (OM) on a global scale, with implications for ecosystem dynamics. While the role of jellyfish detritus in microbial nutrient cycling has been explored, the contribution of OM released by live jellyfish—primarily as mucus (hereinafter referred to as mucus-associated OM, or MAOM)—remains understudied. This study investigates the release of organic and inorganic nutrients through MAOM from live jellyfish and their effects on ambient microbial communities in the northern Adriatic Sea using a series of leaching and short-term microcosm experiments. Our results show that per gram of MAOM dry weight from the jellyfish Aurelia spp, approximatively 2 µmol of phosphate, 4 µmol of dissolved inorganic nitrogen, 18 µmol dissolved organic nitrogen, 134 µmol of dissolved organic carbon and 15 µmol of dissolved free amino acids can be released in the ambient seawater in 24 h. Almost half of the OM is released as dissolved OM (DOM), of which a substantial part is low molecular weight (<1 kDa) molecules. During the first 20 h, the DOM fraction of MAOM was rapidly consumed by the ambient microbial community without a corresponding increase in biomass, likely due to nitrogen limitation. In the subsequent 22 h, microbial growth accelerated to 0.19 ± 0.03 h−1 until phosphate became limiting, leading to a sharp decline in microbial production. Our metagenomics analysis revealed that the MAOM-degrading microbial community, dominated by Gammaproteobacteria opportunistic copiotrophs, exhibited increased functional capacity for nutrient assimilation and OM degradation, particularly in the transport and metabolism of amino acids (particularly glycine and taurine) and phosphorus. These traits mirror those found in detritus-degrading microbial communities, suggesting that jellyfish blooms promote the emergence of specialized microbial consortia with shared metabolic capabilities. Taken together, our findings highlight that live jellyfish, through the release of OM, play an active and previously underappreciated role in shaping ambient microbial community dynamics and nutrient fluxes in marine systems affected by jellyfish blooms.

Organisation(s)
Functional and Evolutionary Ecology, Department of Evolutionary Biology, Teaching Affairs and Student Services
External organisation(s)
National Oceanography Centre Southampton, National Institute of Biology, South Westphalia University of Applied Sciences, University of Southampton
Journal
PeerJ
Pages
1-27
No. of pages
27
ISSN
2167-8359
DOI
https://doi.org/10.7717/peerj.20784
Publication date
2026
Peer reviewed
Yes
Austrian Fields of Science 2012
106021 Marine biology
Keywords
ASJC Scopus subject areas
General Neuroscience, General Medicine, General Biochemistry,Genetics and Molecular Biology, General Agricultural and Biological Sciences
Portal url
https://ucrisportal.univie.ac.at/en/publications/ed315ecb-43e2-44be-8ed5-25d594f537ef