What do glass sponges do when no one is looking? Vazella pourtalesii: Responses to sediment deposition, passive locomotion, and contracting behavior

11 pages, 8 figures, 1 table, supplementary data https://doi.org/10.1016/j.dsr.2024.104388.-- Data availability: Data will be made available on request

Behavioral response of deep-sea sponges can provide crucial insights into the mechanisms shaping energy fluxes and ecosystem functioning. Although some advances have been made, the behavior of deep-sea Hexactinellid still remain widely unknown. In the present study we address the glass sponge Vazella pourtalesii behavior. High-temporal resolution imaging and environmental data were acquired with an autonomous lander deployed in the Sambro Bank Sponge Conservation Area (Scotian Shelf) at a depth of 150 m, representing the upper limit of this deep-sea species' distribution and what is commonly regarded as the deep sea. For 94 days, a V. pourtalesii individual was monitored, providing quantitative information on its response to sediment deposition triggered by a storm, as well as on its passive locomotion and contractive behavior. Sediment was cleared from its surface within 72 h, which is highly relevant for its filtering capacity, indicating that this sponge species can cope with high suspended sediment concentrations. This enables it to occur on sedimentary environments like the Scotian Shelf. As observed in other deep-sea hexactinellids, the monitored individual engaged in rhythmic contractions, which appear to be driven by physiological process/es rather than environmental factors. During the study period, strong bottom currents (>37 cm/s) toppled and displaced the monitored individual several times. Despite changes in position and orientation that can negatively impact the filtering capacity of sponges, no signs of deterioration were observed. V. pourtalesii's vase-like body morphology and attachment to cobbles, as a gravitational center, may allow it to have a more homogeneous interaction with currents which may permit them to better cope with positional changes. Overall, this study highlights that deep-sea Porifera display a wide array of phenological changes in response to both biotic and abiotic factors

This study is part of the SponGES project, which received funding from the European Union's Horizon 2020 Research and Innovation Program under grant agreement no. 679849. Cruises were funded by Fisheries and Ocean's Canada's (DFO) International Governance Strategy awarded to EK, Bedford Institute of Oceanography, and supported by Hans Tore Rapp (University of Bergen, Norway). Dr. Jordi Grinyó has received funding form the European Union's Horizon 2020 research and Innovation program. Action MSCA-IF-EF-ST fellowship, CWCC-Dynamics project under the grant agreement no. 101028621. Dr. Luciano Ortenzi acknowledges the Ministry of University and Research (MUR) initiative “Departments of Excellence” (Law 232/2016) DAFNE Project 2023-27 “Digital, Intelligent, Green and Sustainable (acronym: D.I.Ver.So). Dr. Jacopo Aguzzi acknowledges that the researh has been carried out within the framework of the project “Severo Ochoa Center of Excellence” financially supported by ICM-CSIC (CEX2019-000928-S) and the Research Unit Tecnoterra (ICM-CSIC/UPC) of the Spanish Government

Peer reviewed