Biology subjects

Simon-Lledo, E.

Publications and source records attributed to Simon-Lledo, E..

3 recordsLinked to original sources

bioRxiv2025

Ecology of Echinodermata in the Clarion-Clipperton-Fracture Zone (Central Pacific)

Abyssal seascapes between 3,000 and 6000 m water depth represent over 50% of the Planets surface, but the species, functions, and particularly the life history traits that these ecosystems harbour remain poorly understood. Brittle stars (Ophiuroidea) contribute about one third to the invertebrate megabenthos assemblage between 3,800 m and 4,800 m water depth in the Clarion-Clipperton Fracture Zone (CCZ, Northeast Pacific). Starfishes (Asteroidea) are present in lower densities. In the CCZ, Ophiuroidea are often seen near Xenophyophoroidea and attached to glass sponge (Hexactinellida) stalks. We hypothesize that (1) the observed relationship between Ophiuroidea, Xenophyophoroidea, and Hexactinellida is a predator-prey relationship, where Ophiuroidea feed on foraminifera- and sponge-derived organic matter. (2) Ophiuroidea have a reduced dependency on fresh phytodetritus. (3) Brisingida (order of Asteroidea), often clings to stalks to have easier access to particulate organic matter sinking to the seafloor. To test these three hypotheses, we combined bulk and compound-specific stable isotope analyses of fauna (Ophiuroidea, Asteroidea) and sediments with the analyses of seafloor images from the eastern CCZ. Faunal specimens and sediments were collected during three research expeditions between 2019 and 2022, and previously collected seabed images were re-analysed to quantify the major behaviours in which Ophiuroidea and Asteroidea engage. All investigated Echinodermata species had a high trophic level. Phospholipid-derived fatty acids (PLFAs) used as biomarkers suggest that Silax daleus consumes sedimentary detritus that is processed by its gut microbiome. Ophiacantha cosmica is likely a top consumer or scavenger, Ophiosphalma glabrum is an opportunistic omnivore ingesting phytodetritus, bacteria, Crustacea, and Foraminifera, while Ophiuroglypha cf. polyacantha is a more selective omnivore. Freyella benthophila sits mostly on stalks of Hexactinellida and uses this elevated position to catch phytodetritus and zooplankton. Freyastera cf. tuberculata, in comparison, sits mostly on polymetallic nodules from where it preys upon Crustacea moving on the sediment surface. This study confirmed the hypothesis that Ophiuroidea in the CCZ are less dependent on phytodetritus than Holothuroidea in the Peru Basin. It was confirmed that Ophiuroidea consume foraminifera- and sponge-derived organic matter, but Brisingida cling to stalks of Hexactinellida to prey upon Crustacea living in the benthic boundary layer.

ecology↗

bioRxiv2022

A review of the International Seabed Authority database DeepData: challenges and opportunities in the UN Ocean Decade

1.There is an urgent need for quality biodiversity data in the context of rapid environmental change. Nowhere is this more urgent than in the deep ocean, with the possibility of seabed mining moving from exploration to exploitation, but where vast knowledge gaps persist. Regions of the seabed beyond national jurisdiction, managed by the International Seabed Authority (ISA) are undergoing intensive mining exploration, including the Clarion-Clipperton Zone. In 2019 the ISA launched its database DeepData, publishing environmental (including biological) data; and since June 2021, DeepData records have been harvested by OBIS (Ocean Biodiversity Information System) via the ISA node. Here we explore how DeepData could support biological research and environmental policy development in the CCZ (and wider ocean regions); and whether data are Findable, Accessible, Interoperable and Reusable (FAIR). Given the direct connection of DeepData with the regulator of a rapidly developing potential industry, this review is particularly timely. We found evidence of extensive duplication of datasets; an absence of unique record identifiers and significant taxonomic data quality issues, compromising FAIRness of the data. The publication of DeepData records on the OBIS ISA node has led to large-scale improvements in data quality and availability. However, limitations in usage of identifiers and issues with taxonomic information were also evident in datasets published on the node, stemming from mis-mapping of data from the ISA environmental data template to the data standard Darwin Core prior to data harvesting by OBIS. While notable data quality issues remain, these changes signal a rapid evolution for the database and significant movement towards integrating with global systems through usage of data standards and publication on global aggregators. This is exactly what has been needed for biological datasets held by the ISA. We provide recommendations for future development of the database to support this evolution towards FAIR.

bioinformatics↗

bioRxiv2022

Habitat types and megabenthos composition from three sponge-dominated high-Arctic seamounts

Seamounts are isolated underwater mountains often stretching >1,000 m above the seafloor. They are usually identified as biodiversity hotspots of marine life, and host benthos assemblages that may vary on regional (among seamounts) and local (within seamounts) scales. Here, we collected seafloor imagery of three seamounts at the Langseth Ridge in the central Arctic Ocean to assess habitats and megabenthos community composition at the Central Mount (CM), the Karasik Seamount (KS), and the Northern Mount (NM). The majority of seafloor across these seamounts comprised bare rock, covered with a mixed layer consisting of sponge spicule mat intermixed with detrital debris composed primarily of polychaete tubes as well as sand, gravel, and/ or rocks. The megabenthos assemblages consisted of in total 15 invertebrate epibenthos taxa and four fish taxa, contributing to mean megabenthos densities of 55,745 ind. ha-1 at CM, 110,442 ind. ha-1 at KS, and 65,849 ind. ha-1 at NM. The faunal assemblages at all three seamounts were dominated by demosponges of the order Tetractinellida that contributed between 66% (KS) and 85% (CM) to all megabenthos. Megabenthos assemblages living on bare rock or on mixed substrate differed among seamounts and across individual seamounts.

ecology↗