Published In

Marine Biology

Document Type

Article

Publication Date

4-1-2025

Subjects

Marine ecosystems -- Filter feeding, Gelatinous grazers -- Plankton

Abstract

Mucous mesh grazers including pelagic tunicates and thecosome pteropods play a key role in oceanic food webs. They are taxonomically and morphologically diverse and can be highly abundant. Using their fine mucous meshes, these pelagic grazers ingest a wide range of plankton prey and link pelagic and benthic marine ecosystems. Characterizing the diet of this group is central to fully understanding marine food webs and developing accurate food web models. However, gelatinous grazers are challenging to study owing to their physically delicate composition so studying their feeding ecology requires numerous complementary techniques. Microscopy has largely been supplanted by other methods, but it remains valuable for its precision in determining cell size and morphology, which are key to characterize the diet and feeding mechanics of grazers. We use environmental scanning electron microscopy (ESEM) to examine the gut contents of several mucous mesh grazers from the Northern California Current (NCC) including Dolioletta gegenbauri, Limacina helicina, Pegea socia, Pyrosoma atlanticum, and Thetys vagina. Our findings provide taxonomic resolution of the prey of these grazers, which includes dinoflagellates, silicoflagellates, centric and pennate diatoms, coccolithophores, tintinnids, foraminiferans, and copepods. Our results show that these gelatinous grazers ingest prey ranging in size from 0.4 µm to 91.0 µm and expands the known prey size range for Thetys vagina. This work underscores the advantages of using microscopy, including insights into prey morphology and integrity, which enhances our understanding of feeding selectivity, prey defenses, and the pathways of grazed plankton through the marine ecosystem.

Rights

Copyright (c) 2025 The Authors Creative Commons License This work is licensed under a Creative Commons Attribution 4.0 International License.

Locate the Document

https://doi.org/10.1007/s00227-025-04615-6

DOI

10.1007/s00227-025-04615-6

Persistent Identifier

https://archives.pdx.edu/ds/psu/43487

Publisher

Springer Science and Business Media LLC

Included in

Biology Commons

Share

COinS