Life cycle and morphogenetic differentiation in heteromorphic cell types of a cosmopolitan marine microalga.

Gephyrocapsa huxleyi is a prevalent, bloom-forming phytoplankton species in the oceans. It exhibits a complex haplodiplontic life cycle, featuring a diploid-calcified phase, a haploid phase and a third 'decoupled' phase produced during viral infection. Decoupled cells display a haploid-like phenotype, but are diploid.

Recurrent association between colonies and calcifying amoebae.

Colonies of the N-fixing cyanobacterium spp. constitute a consortium with multiple microorganisms that collectively exert ecosystem-level influence on marine carbon and nitrogen cycling, shunting newly fixed nitrogen to low nitrogen systems, and exporting both carbon and nitrogen to the deep sea. Here we identify a seasonally recurrent association between puff colonies and amoebae through a two-year survey involving over 10 000 colonies in the Red Sea.

Desert dust improves the photophysiology of heat-stressed corals beyond iron.

Desert dust is an important source of essential metals for marine primary productivity, especially in oligotrophic systems surrounded by deserts, such as the Red Sea. However, there are very few studies on the effects of dust on reef-building corals and none on the response of corals to heat stress. We therefore supplied dust to two coral species (Stylophora pistillata and Turbinaria reniformis) kept under control conditions (26 °C) or heat stress (32 °C).

Ecological succession on 3D printed ceramic artificial reefs.

The global degradation of natural coral reefs requires innovative approaches to their conservation and restoration. This study investigates the efficacy of using parametric design tools in 3D software and 3D-printed terracotta structures in artificial reef (AR) design. Three ARs were deployed in the northern Gulf of Aqaba in 2019.

Life cycle strategies in free-living unicellular eukaryotes: Diversity, evolution, and current molecular tools to unravel the private life of microorganisms.

An astonishing range of morphologies and life strategies has arisen across the vast diversity of protists, allowing them to thrive in most environments. In model protists, like Tetrahymena, Dictyostelium, or Trypanosoma, life cycles involving multiple life stages with different morphologies have been well characterized. In contrast, knowledge of the life cycles of free-living protists, which primarily consist of uncultivated environmental lineages, remains largely fragmentary.

Impacts of Desalination Brine Discharge on Benthic Ecosystems.

Seawater reverse osmosis (SWRO) desalination facilities produce freshwater and, at the same time, discharge hypersaline brine that often includes various chemical additives such as antiscalants and coagulants. This dense brine can sink to the sea bottom and creep over the seabed, reaching up to 5 km from the discharge point. Previous reviews have discussed the effects of SWRO desalination brine on various marine ecosystems, yet little attention has been paid to the impacts on benthic habitats.

Taxonomic distribution of metabolic functions in bacteria associated with consortia.

Colonies of the cyanobacteria act as a biological hotspot for the usage and recycling of key resources such as C, N, P, and Fe within an otherwise oligotrophic environment. While colonies are known to interact and support a unique community of algae and particle-associated microbes, our understanding of the taxa that populate these colonies and the gene functions they encode is still limited. Characterizing the taxa and adaptive strategies that influence consortium physiology and its concomitant biogeochemistry is critical in a future ocean predicted to have increasingly resource-depleted regions.

Acclimatization of a coral-dinoflagellate mutualism at a CO vent.

Ocean acidification caused by shifts in ocean carbonate chemistry resulting from increased atmospheric CO concentrations is threatening many calcifying organisms, including corals. Here we assessed autotrophy vs heterotrophy shifts in the Mediterranean zooxanthellate scleractinian coral Balanophyllia europaea acclimatized to low pH/high pCO conditions at a CO vent off Panarea Island (Italy). Dinoflagellate endosymbiont densities were higher at lowest pH Sites where changes in the distribution of distinct haplotypes of a host-specific symbiont species, Philozoon balanophyllum, were observed.

Exploring the phycosphere of Emiliania huxleyi: From bloom dynamics to microbiome assembly experiments.

Coccolithophores have global ecological and biogeochemical significance as the most important calcifying marine phytoplankton group. The structure and selection of prokaryotic communities associated with the most abundant coccolithophore and bloom-forming species, Emiliania huxleyi, are still poorly known. In this study, we assessed the diversity of bacterial communities associated with an E.

Phycobilisome light-harvesting efficiency in natural populations of the marine cyanobacteria Synechococcus increases with depth.

Cyanobacteria of the genus Synechococcus play a key role as primary producers and drivers of the global carbon cycle in temperate and tropical oceans. Synechococcus use phycobilisomes as photosynthetic light-harvesting antennas. These contain phycoerythrin, a pigment-protein complex specialized for absorption of blue light, which penetrates deep into open ocean water.

Selective deep water coral bleaching occurs through depth isolation.

Climate change is degrading coral reefs around the world. Mass coral bleaching events have become more frequent in recent decades, leading to dramatic declines in coral cover. Mesophotic coral ecosystems (30-150 m depth) comprise an estimated 50-80 % of global coral reef area.

Metagenomes of Red Sea Subpopulations Challenge the Use of Marker Genes and Morphology to Assess Diversity.

are filamentous cyanobacteria of key interest due to their ability to fix carbon and nitrogen within an oligotrophic marine environment. Their blooms consist of a dynamic assemblage of subpopulations and colony morphologies that are hypothesized to occupy unique niches. Here, we assessed the poorly studied diversity of in the Red Sea, based on metagenome-assembled genomes (MAGs) and gene-based phylotyping.

Coral fluorescence: a prey-lure in deep habitats.

Fluorescence is highly prevalent in reef-building corals, nevertheless its biological role is still under ongoing debate. This feature of corals was previously suggested to primarily screen harmful radiation or facilitate coral photosynthesis. In mesophotic coral ecosystems (MCEs; 30-150 m depth) corals experience a limited, blue-shifted light environment.

Intensified microbial sulfate reduction in the deep Dead Sea during the early Holocene Mediterranean sapropel 1 deposition.

The hypersaline Dead Sea and its sediments are natural laboratories for studying extremophile microorganism habitat response to environmental change. In modern times, increased freshwater runoff to the lake surface waters resulted in stratification and dilution of the upper water column followed by microbial blooms. However, whether these events facilitated a microbial response in the deep lake and sediments is obscure.

Effects of prey density and flow speed on plankton feeding by garden eels: a flume study.

Feeding by zooplanktivorous fish depends on their foraging movements and the flux of prey to which they are exposed. While prey flux is a linear function of zooplankton density and flow speed, those two factors are expected to contribute differently to fish movements. Our objective was to determine the effects of these factors for garden eels, stationary fish that feed while anchored to the sandy bottom by keeping the posterior parts of their bodies inside a burrow.

Trophic guilds of suction-feeding fishes are distinguished by their characteristic hydrodynamics of swimming and feeding.

Suction-feeding in fishes is a ubiquitous form of prey capture whose outcome depends both on the movements of the predator and the prey, and on the dynamics of the surrounding fluid, which exerts forces on the two organisms. The inherent complexity of suction-feeding has challenged previous efforts to understand how the feeding strikes are modified when species evolve to feed on different prey types. Here, we use the concept of dynamic similarity, commonly applied to understanding the mechanisms of swimming, flying, walking and aquatic feeding.

Colonies of the marine cyanobacterium optimize dust utilization by selective collection and retention of nutrient-rich particles.

, a globally important, N-fixing, and colony-forming cyanobacterium, employs multiple pathways for acquiring nutrients from air-borne dust, including active dust collection. Once concentrated within the colony core, dust can supply with nutrients. Recently, we reported a selectivity in particle collection enabling to center iron-rich minerals and optimize its nutrient utilization.

A Review on Species: Ethnopharmacology, Nutritional Properties, Phytochemistry, Biological Activities and Propagation.

A. J. Scott is a halophytic edible succulent plant belonging to the family.

Divergent fate of coccolithophores in a warming tropical ecosystem.

Rising ocean temperatures will alter the diversity of marine phytoplankton communities, likely leading to modifications in food-web and biogeochemical dynamics. Here we focus on coccolithophores, a prominent group of calcifying phytoplankton that plays a central role in the global carbon cycle. Using both new (2017-2020) and historical (1975-1976) data from the northern Red Sea, we found that during 'mild summers', the most common coccolithophores - Emiliania huxleyi and Gephyrocapsa ericsonii - co-exist at similar densities.

Untangling the molecular basis of coral response to sedimentation.

Urbanized coral reefs are often chronically affected by sedimentation and reduced light levels, yet many species of corals appear to be able to thrive under these highly disturbed conditions. Recently, these marginal ecosystems have gained attention as potential climate change refugia due to the shading effect of suspended sediment, as well as potential reservoirs for stress-tolerant species. However, little research exists on the impact of sedimentation on coral physiology, particularly at the molecular level.

Fishmeal replacement by periphyton reduces the fish in fish out ratio and alimentation cost in gilthead sea bream Sparus aurata.

Aquaculture threatens natural resources by fishing down the sea to supply fishmeal. Alternative protein sources in aquafeeds can provide a solution, particularly those that are waste from other operations and thereby reduce feed production costs. Toward this goal, we examined the waste biomass of marine periphyton from biofilters of an integrated multi-trophic aquaculture (IMTA) system as a replacement for fishmeal in diets of gilthead seabream (Sparus aurata).

Biogeography, reproductive biology and phylogenetic divergence within the Fungiidae (mushroom corals).

While the escalating impacts of climate change and other anthropogenic pressures on coral reefs are well documented at the coral community level, studies of species-specific trends are less common, owing mostly to the difficulties and uncertainties in delineating coral species. It has also become clear that traditional coral taxonomy based largely on skeletal macromorphology has underestimated the diversity of many coral families. Here, we use targeted enrichment methods to sequence 2476 ultraconserved elements (UCEs) and exonic loci to investigate the relationship between populations of Fungia fungites from Okinawa, Japan, where this species reproduces by brooding (i.

Iron transport in cyanobacteria - from molecules to communities.

Iron is an essential micronutrient for the ecologically important photoautotrophic cyanobacteria which are found across diverse aquatic environments. Low concentrations and poor bioavailability of certain iron species exert a strong control on cyanobacterial growth, affecting ecosystem structure and biogeochemical cycling. Here, we review the iron-acquisition pathways cyanobacteria utilize for overcoming these challenges.