Cryptic diversity in mesopelagic fish is increasingly documented across the Indo-Pacific, but remains understudied in the Red Sea, a region known for its high endemism and unique ecological conditions. We investigated cryptic diversity in Benthosema spp. and population genetic structure in the two most abundant mesopelagic fishes in the eastern Red Sea, the Benthosema pterotum species complex and the endemic Vinciguerria mabah...

Earth's biodiversity is central to ecosystem health and resilience, providing essential functions and services. The Red Sea is a recognised marine biodiversity hotspot with high endemism and unique environmental conditions that support extensive but poorly resolved biodiversity. Here, we applied metagenomic analyses to sediment samples collected from coastal to deep‐sea environments during the Red Sea Decade Expedition 2022 to...

The Antarctic coastal environment, influenced by a dynamic glacial and oceanographic history, hosts diverse benthic invertebrate communities. However, how these communities evolve across ecologically heterogeneous coastal habitats remains poorly understood. Population genomic structure in this extreme region is particularly relevant because pelagic larval stages are not common among polar benthic invertebrates, raising questio...

Introduction Soft corals play key ecological roles in benthic communities by enhancing ecosystem health, providing structural complexity, cycling nutrients, and maintaining symbiotic relationships with diverse microbes. Although their microbiomes are highly structured and species-specific, little is known about their responses to extreme thermal anomalies such as marine heat waves. Methods We analyzed the microbiomes of three...

Antarctic marine invertebrates are sensitive to temperature fluctuations, and therefore vulnerable to ongoing ocean warming. To investigate molecular responses to heat stress, the benthic isopod Spinoserolis beddardi and the asteroid Diplasterias sp., both adapted to ~0 °C conditions, were used. Organisms were exposed to short-term thermal increments of +3 °C and +7 °C in controlled aquarium experiments. After one week, transc...

Marine sediments host diverse benthic prokaryotic communities that are integral to global biogeochemical cycles. However, the spatial distribution and environmental drivers of these communities, particularly in unique environments like the Red Sea, remain largely underexplored. In this study, we examine benthic prokaryotic communities sampled during the Red Sea Decade Expedition (RSDE) using 16S rRNA gene sequencing across fiv...

Pelagic particle‐associated bacterioplankton play crucial roles in marine ecosystems, influencing biogeochemical cycling and ecosystem functioning. However, their diversity, composition, and dynamics remain poorly understood, particularly in unique environments such as the Red Sea. In this study, we employed eDNA metabarcoding to comprehensively characterise bacterioplankton communities associated with pelagic particles in a t...

Rhodaliids, a specific family of siphonophores inhabiting the benthic zone, have remained enigmatic due to their rarity and elusive nature. These unique organisms, primarily found in open ocean habitats, exhibit distinctive features and are characterized by complex structures. During the Red Sea Decade Expedition, two rhodaliid specimens were collected at the sea bed at water depths of 438 and 495 meters. Regardless of challen...

Observations are essential to explore and discover the ocean. The rapid advancements in technology have revolutionized our capacity to document the ocean and its diverse array of species, pushing the boundaries of our understanding further than ever before. The central Red Sea was exposed as part of the Red Sea Decade Expedition , which took place from 04 February to 18 June 2022 aboard the R/V OceanXplorer, using underwater s...

Introduction Sponges are key components of marine benthic communities, providing many ecosystem functions and establishing close relationships with microorganisms, conforming the holobiont. These symbiotic microbiotas seem to be host species-specific and highly diverse, playing key roles in their sponge host. The effects of elevated seawater temperature on sponges and their microbiota are still poorly known, and whether sponge...

Seaweeds contain a wide range of secondary metabolites which serve multiple functions, including chemical and ecological mediation with microorganisms. Moreover, owing to their diverse bioactivity, including their antibiotic properties, they show potential for human use. Nonetheless, the chemical ecology of seaweeds is not equally understood across different regions; for example, Antarctic seaweeds are among the lesser studied...

Antarctic marine benthic invertebrates are an underexplored source of natural products for biodiscovery. Bioactive marine natural products from Antarctica are reviewed here for their potential use as drugs, considering the main examples in Porifera (15 species), Cnidaria (eight species), Mollusca (one species), Bryozoa (one species), Nemertea (one species), Echinodermata (six species), and Tunicata (five species). A wide varie...

Sponges have recently been proposed as ideal candidates to act as natural samplers for environmental DNA due to their efficiency in filtering water. However, validation of the usefulness of DNA recovered from sponges to reveal vertebrate biodiversity patterns in Marine Protected Areas is still needed. Additionally, nothing is known about how different sponge species and morphologies influence the capture of environmental DNA a...