Uncovering hidden structures: previously undescribed pseudopodia and ectoplasmic structures in planktonic foraminifera

• Published in: Journal of Plankton Research
• Main Authors: Greco, Mattia, Westgård, Adele, Sykes, Freya E., Ezat, Mohamed M., Meilland, Julie
• Other Authors: Tromsø Research Foundation, European Commission, Agencia Estatal de Investigación (España)
• Format: Article in Journal/Newspaper
• Language: English
• Published: Oxford University Press 2023
• Subjects: Planktonic foraminifera; Ectoplasmic roots; Trophic strategy; Laboratory observations; Conserve and sustainably use the oceans; seas and marine resources for sustainable development; Baffin Bay; Cierva; Greenland; Tromsø; Baffin; Greenland Sea; Neogloboquadrina pachyderma
• Online Access: http://hdl.handle.net/10261/334273; https://doi.org/10.1093/plankt/fbad031

9 pages, 5 figures, 1 table, supplementary data https://doi.org/10.1093/plankt/fbad031.-- Data Availability: Video in supplement to this article is available on FigShare (10.6084/m9.figshare.22665031) The trophic strategies of cold-water planktonic foraminifera are not well understood due to the challenge of culturing them in polar conditions. Here, we identify previously unknown ectoplasmic and cytoplasmic projections in three species of planktonic foraminifera thriving in polar and subpolar marine environments: Globigerina bulloides, Neogloboquadrina incompta and Neogloboquadrina pachyderma. These structures were observed during routine monitoring of cultured specimens sampled from the Norwegian coast, Greenland Sea and Baffin Bay. Two types of projections were discovered, including permanent and non-permanent structures such as ectoplasmic roots, twigs and twig-like projections, similar to those observed in benthic taxa Cibicides and Cibicidoides. Additionally, a previously undescribed filopodia-like projection was observed in N. pachyderma. We discuss the function, the ecological significance and the potential impact on pelagic processes of the presence of these structures in foraminifera species that occupy diverse niches in the water column. Our findings suggest that these structures may play an important role in the trophic strategies of cold-water planktonic foraminifera, and further research and observations are necessary to fully comprehend their significance in the carbon cycle A.W, F.S and M.M.E are supported by the Tromsø Research Foundation [Grant Number A31720 awarded to M.M.E.]. J.M. was funded through the Cluster of Excellence “The Ocean Floor – Earth’s Uncharted Interface”. MG was supported by a Juan de la Cierva-formación 2021 fellowship (FJC2021–047494-I/MCIN/AEI/10.13039/501100011033) from the European Union “NextGenerationEU”/PRTR With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S) Peer reviewed