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Spatial changes in environmental characteristics strongly influence the structure of benthic communities on sandy beaches, where the patterns of occurrence are mainly controlled by morphodynamic characters and biological interactions. Despite being very abundant and extensive, the Amazonian sandy beaches are among the coastal environments less well known to science. On these beaches, the ghost shrimp Lepidophthalmus siriboia Felder and Rodrigues, 1993 is an important component of the intertidal macrofauna. The present study describes the small-scale distribution patterns of L. siriboia and of the macrobenthic communities in a dissipative macrotidal Amazonian sandy beach. Samples were collected in the intertidal zone of two areas: Area 1, next to a tidal channel; and Area 2, away from the tidal channel. In Area 1, with finer sediments, there was a higher burrow density of L. siriboia and higher density and species richness of macrofauna. In both areas, the burrow density of L. siriboia increased towards the sea. The faunal distribution patterns can be explained by changes in flooding and the type of substratum across the shore and alongshore. These findings add to our knowledge of tropical sandy beach ecology and reinforce the idea that tropical macrotidal beaches have a complexity of morphological features, which are drivers of macrofaunal structure. [ABSTRACT FROM AUTHOR]

Site‐occupancy modelling is widely used in ecology for understanding species distribution, habitat‐use and community changes but its application is still limited in paleoecology, where incomplete detection is also routine. Here, we make extensive expansions to an earlier multispecies occupancy model used to estimate the dynamics of relative species abundance in fossil communities. These expansions include incorporating counts of individuals at sites, explicitly allowing for the inclusion of specimens assignable to genus – but not species‐level, a situation common in paleontology, and modelling regional presence/absence. We provide simulations to check the performance of this new model, as well as simulations to quantify the benefits of using individual count data versus subsample occupancy data, and model estimates versus face‐value (raw) estimates, respectively. We also provide an empirical case study using occupancy data from a community of marine benthic colonial animals preserved in the Pleistocene of New Zealand. We find that the new model performs well, especially when it comes to recovering relative abundance dynamics and that it is well worth the effort to both collect individual count data and to include individuals unidentified to species‐level in the site‐occupancy modelling framework. This extended model can be widely applied in paleoecological settings and is necessary when both the average and uncertainty values of relative abundance dynamics need to be robustly estimated. [ABSTRACT FROM AUTHOR]

Gastrotricha are microscopic benthic animals found in almost all water bodies. To date, over 890 species distributed in 71 genera, 18 families, and two orders are known. There are 376 freshwater species, and several are also found in Italy; however, a compendium of the studies carried out so far, and a georeferenced distribution of the species, still need to be provided. This project summarizes information about the diversity and geographic distribution of Italian gastrotrichs. Diversity data, acquired over 239 years, were reviewed and corrected based on taxonomic and nomenclatural updates and, in addition to distribution information, were organized into a data matrix valuable for statistical analysis. The data were fed into geographic information system software to understand the overall figures more easily. The results indicated that Italy is one of the best-known countries regarding freshwater gastrotrichs. With 92 species in 17 genera and three families from 61 investigated localities, Italy counts 17 type localities and 19 endemic species. Despite this high biodiversity, many Italian regions still need to be investigated, and should, therefore, be the focus of future research. The implementation of a web-mapping plugin enabled the creation of interactive maps for an easy and modern method for sharing the work done, and the information acquired. [ABSTRACT FROM AUTHOR]

A new filamentous cyanobacterial strain (CHAB 4127) was successfully isolated from the algal mat during the field investigation of the open channel from Luanhe River to Tianjin, China. The polyphasic approach combining morphological, ultrastructural, ecological, and molecular features was used to characterize this studied strain. The strain is morphologically similar to the Microcoleus-like cyanobacterial taxa under light microscopy, and the radial arrangement of thylakoids is also consistent with that of Microcoleus-like groups. The phylogenetic position of CHAB 4127 based on 16S rRNA gene sequences, is shown to be clearly clustered into an independent clade with the newly established genus Microcoleusiopsis. The maximum similarity of 16S rRNA gene of the studied strain with other existing related cyanobacterial taxa is 93.97%, and the ITS secondary structures is also obviously different from other members of Microcoleaceae. Based on all the above evidence, we proposed the establishment of this novel cyanobacterial genus as Neomicrocoleus, with its type species, Neomicrocoleus tianjinensis. [ABSTRACT FROM AUTHOR]

The rock units in the Gawran Gorge, Sagirma Mountains (from the High Folded Zone), near the Sulaimaniyah city, in the Kurdistan Region, NE Iraq, were investigated in order to describe and biostratigraphically date the sedimentary succession. Twenty-seven species of larger benthic foraminifera were identified belonging to 16 genera. Several other fossil groups were also recognized, including echinoid, bryozoan, bivalve, gastropods and coral remains. Two biozones were recognized--the Praerhapydionina delicata-Austrotrillina asmariensis/Peneroplis evolutus Assemblage Zone and the P. delicata/Austrotrillina howchini Interval Zone, which indicate a late Oligocene-lowermost Miocene age for the succession. This section was correlated to the surrounding successions having a similar age in the High Folded Zone of Iraq, and to sediments in other countries, so as to indicate the wider distribution of the lithostratigraphic unit. [ABSTRACT FROM AUTHOR]

Given the limited understanding of benthic fauna along the Algerian coast, this study was conducted to explore the diversity of bivalve mollusks specifically on the Algerian west coast. The primary objectives of this study were to create a comprehensive but not exhaustive inventory of bivalve species in this region and to analyze the distribution of these species within the study areas and neighboring regions. The research involved the investigation of numerous sandy beaches across four sectors of the Algerian west coast: Tlemcen, Béni-Saf, Ain-Temouchent, and Oran. Between June 2019 and April 2020, a random collection of empty bivalve shells was carried out in the foreshore zones of 16 beaches within these sectors. This extensive collection of 10,076 shells resulted in the identification of 56 bivalve mollusk species, categorized into 22 families. Among these families, the most prominent were Cardiidae, Donacidae, Glycymerididae, and Veneridae, serving as the most representative families across all four sectors. Notably, the Glycymerididae family was the most abundant along the Oran coast, with nearly 2,000 individuals, although they were less prevalent on the beaches of the Béni Saf sector. In contrast, the Veneridae family was prevalent on the beaches of the Tlemcen, Béni Saf, and Aïn-Témouchent sectors. Within the Veneridae family, there was remarkable diversity, featuring 11 species, followed by the Cardiidae family with 6 species, and the Limidae and Pectinidae families with 5 species each. Finally, among the identified species, the most abundant ones included Acanthocardia tuberculata (Linnaeus, 1758), Chamelea gallina (Linnaeus, 1758), Glycymeris nummaria (Linnaeus, 1758), and Donax trunculus (Linnaeus, 1758), each belonging to the Cardiidae, Veneridae, Glycymerididae, and Donacidae families, respectively. [ABSTRACT FROM AUTHOR]

Benthic food‐web structure and organic matter (OM) utilization are important for marine ecosystem functioning. In response to environmental changes related to the ongoing climate change, however, many benthic species are shifting their ranges to colder regions, which may lead to altered community composition, but it remains largely unknown how it will affect ecosystem functioning. Here, stable isotope analysis was used to study benthic OM utilization and food‐web structure and to assess whether their spatial patterns reflect today's community differentiation among biogeographic regions and depth zones. Benthic fauna and OM mixtures were collected from two depth zones (100–150 m vs. 200–250 m) within a temperate, two sub‐Arctic, and an Arctic fjord along a latitudinal gradient (59–78° N) that was used as a space‐for‐time substitution to assess the impact of climate change. Our results showed that Arctic and temperate communities are functionally different. Arctic communities were characterized by a strong resource partitioning among different feeding types, irrespective of depth zone. In contrast, all feeding types in temperate communities seemed to rely on sedimentary OM. The sub‐Arctic presented a transition zone. In the sub‐Arctic, shallower communities resembled Arctic communities, suggesting a functional transition between temperate and sub‐Arctic regions. Deeper sub‐Arctic communities resembled temperate communities, suggesting a functional transition between the sub‐Arctic and Arctic regions. This implies that the regions north of the current transitions (deep Arctic and shallow sub‐Arctic) are most likely to experience functional changes related to an altered OM utilization in benthic food webs in response to climate change. [ABSTRACT FROM AUTHOR]

The study was carried out in Ottu reservoir, which is situated in Sirsa city of Haryana, India. Collection and identification of benthos of Ottu reservoir were monitored from March 2021 to June 2021. A total of 17 benthic species of benthos identified belongs to 2 phylum viz. annelida (3 species) and mollusca (14 species) and in mollusca 2 class viz. gastropoda and bivalve recorded. Maximum benthic fauna recorded in June. The maximum 219 benthos/m2 found in month of June and total benthos found in reservoir was 527 benthos/m². [ABSTRACT FROM AUTHOR]

Copyright of Sultan Qaboos University Journal for Science is the property of Sultan Qaboos University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Eighteen Cibicidoides Rotaliid benthic foraminiferal species were erected from three localities in the Southern Tethys Chile, Egypt and Pakistan. An American diagnostic west hemisphere species C. vulgaris is added to the assemblage, which was later is also recorded from another localities in the eastern hemisphere in the Southern Tethys: Egypt and Iran . One of the identified species is believed here to be new: C. chilensis. Environmental conditions of the identified species of the genus Cibicidoides represent middle-outer neritic environment (100- 200 m) and show an affinity with Midway-Type Fauna "MTF". [ABSTRACT FROM AUTHOR]

Simple Summary: Geloina erosa, an important animal in mangrove ecosystems, possesses both economic and environmental value. However, to date, there has been no research conducted on its miRNA. This study utilized high-throughput sequencing to identify 1412 miRNAs in three tissues: the gills, hepatopancreas, and muscles. Among these, 1047 miRNAs were identified as known conserved sequences. In conjunction with mRNA research, it was observed that approximately 33% of the transcripts were predicted to be predicted targets for miRNAs. Building upon our team's previous research on mRNA, it is worth noting that the majority of genes suppressed by miRNAs in different tissues align with their respective organ functions. Specifically, in gills, miRNAs predominantly regulated immune-related genes, substance transport, and cytoskeletal organization. In the hepatopancreas, miRNAs suppress genes involved in shell formation while also influencing cellular motor activity and metabolism. In muscle tissue, miRNAs were found to participate in metabolism, photoreceptive processes, and immune regulation. These findings suggest that miRNA regulation is finely tuned to swiftly respond to environmental changes. Overall, these discoveries provide significant insights into the molecular mechanisms and biological processes of miRNA within G. erosa. They serve as a foundation for further validation and elucidation of these regulatory relationships. Geloina erosa is an important benthic animal in the mangrove, serving as an indicator organism for coastal environmental pollution. This study aimed to investigate the tissue-specific expression of miRNAs and their regulatory roles in predicted targets in G. erosa. Through miRNA sequencing and co-expression network analysis, we extensively studied the miRNA expression in three tissues: gills, hepatopancreas, and muscle. The results revealed a total of 1412 miRNAs, comprising 1047 known miRNAs, and 365 newly predicted miRNAs. These miRNAs exhibited distinct tissue-specific expression patterns. In the miRNA target gene prediction, a total of 7404 potential predicted targets were identified, representing approximately 33% of all unique transcripts associated with miRNAs. Further co-expression network analysis revealed nine modules, each showing a positive correlation with specific tissues (gills, hepatopancreas, or muscle). The blue module showed a significant correlation with gills (r = 0.83, p-value = 0.006), the black module was significantly related to the hepatopancreas (r = 0.78, p-value = 0.01), and the purple module was significantly correlated with muscle (r = 0.83, p-value = 0.006). Within these modules, related miRNAs tended to cluster together, while their correlations with other modules were relatively weak. Functional enrichment analysis was performed on miRNAs and their predicted targets in each tissue. In the gills, miRNAs primarily regulate immune-related genes, substance transport, and cytoskeletal organization. In the hepatopancreas, miRNAs suppressed genes involved in shell formation and played a role in cellular motor activity and metabolism. In muscle, miRNAs participate in metabolism and photoreceptive processes, as well as immune regulation. In summary, this study provides valuable insights into the tissue-specific regulation of miRNAs in G. erosa, highlighting their potential roles in immune response, metabolism, and environmental adaptation. These findings offer important clues for understanding the molecular mechanisms and biological processes in G. erosa, laying the foundation for further validation and elucidation of these regulatory relationships. [ABSTRACT FROM AUTHOR]

The deep sea (>200m depth) off South Africa is largely unexplored, with most benthic macrofauna samples limited to depths shallower than 100m. The benthic infaunal diversity of the Agulhas Bank shelf edge has not yet been studied. We analysed seven grab samples that were opportunistically collected along the shelf edge at depths of 290-533 m. A total of 136 macrofauna items representing 75 species were identified, and the first species list of the infauna of the shelf edge was compiled, Polychaetes comprised 48% of total abundance, and the sites had an average similarity of 7% based on species abundance, Spearman rank correlation showed that depth and sediment particle size are important environmental drivers of community abundance and biomass variation on the shelf edge, Habitat heterogeneity is likely high along the Agulhas Bank shelf edge, Greater sampling effort in habitats for which data are scarce provides crucial information for offshore biodiversity assessment and management [ABSTRACT FROM AUTHOR]

Simple Summary: This investigation delves into the intricate world of aquatic life, specifically zoobenthos, and how they respond to a combination of environmental challenges: climate change, eutrophication, and pesticide contamination. These organisms play a vital role in aquatic ecosystems, affecting energy flow, nutrient cycling, and sediment decomposition. Unfortunately, these challenges have led to a decline in their numbers and changes in community structure. Notably, the warmer temperatures associated with climate change promote the abundance and diversity of zoobenthos while making these communities more similar across different sites. Pesticides like imidacloprid negatively impact the survival and growth of zoobenthos. Interestingly, when combined with warming, imidacloprid seems to mitigate its adverse effects, increasing species diversity. However, when nutrient loading is part of the equation, imidacloprid negatively affects species diversity. These findings reveal the intricate responses of zoobenthos to multiple stressors, offering valuable insights for ecosystem conservation and management. In simpler terms, this study explores how tiny underwater creatures react to a changing environment, which has consequences for our ecosystems. Multiple stressors, including climate change, eutrophication, and pesticide contamination, are significant drivers of the decline in lake zoobenthos. Zoobenthos play a crucial role in aquatic ecosystems, impacting energy dynamics, nutrient cycling, and sediment degradation. However, these stressors have led to a decrease in the abundance and diversity of zoobenthos, resulting in notable changes in species composition and structure. Eutrophication typically increases zoobenthos abundance while reducing taxonomic diversity. Climate change, such as warming and heatwaves, also affects the zoobenthos community structure, with different species exhibiting varying levels of adaptability to temperature changes. Additionally, pesticides like imidacloprid have negative effects on the survival and growth of zoobenthos. However, the interactions between imidacloprid and other stressors remain understudied. Here, we used 48 mesocosms (2500 L) to simulate shallow lakes. We combined nutrient loading, sustained warming, and the imidacloprid pesticide to test how these stressors interactively influence the survival and community of zoobenthos. The experimental results demonstrate that elevated temperatures have a significant impact on aquatic benthic organisms under different treatment conditions. The increase in temperature led to a notable rise in species richness and α-diversity, primarily attributed to the stimulation of metabolic activities in zoobenthos, promoting their growth and reproduction. This finding underscores the potential influence of climate change on aquatic benthic ecosystems, particularly in terms of its promoting effect on α-diversity. However, it is essential to note that elevated temperatures also reduced β-diversity among different sites, implying a potential trend toward homogenization in zoobenthos communities under warmer conditions. Moreover, this study revealed the interactive effects of multiple stressors on the diversity of aquatic benthic communities. Specifically, the pesticide imidacloprid's impact on zoobenthos is not isolated but demonstrates complex effects within various treatment interactions. In the presence of both temperature elevation and the addition of imidacloprid, the presence of imidacloprid appears to counteract the adverse effects of temperature elevation, resulting in increased species diversity. However, when imidacloprid coincides with nutrient input, it significantly affects α-diversity negatively. These findings highlight the complexity of zoobenthos responses to multiple stressors and how these factors influence both α-diversity and β-diversity. They provide valuable insights for further research on the conservation and management of ecosystems. [ABSTRACT FROM AUTHOR]

Freshwater lakes are subjected to increasing eutrophication and algal blooms worldwide, which have dramatically impacted the aquatic biodiversity. This situation is especially true in the Yangtze River Floodplain, China. However, few researches have been focused on differences in the spatial and temporal patterns of benthic macroinvertebrates assemblages between the two adjacent lakes in this floodplain. In this study, we conducted seasonal investigations in 2021 to compare the spatial and temporal patterns of macroinvertebrates in Lakes Taihu and Lake Chaohu. Non-metric multidimensional scaling (NMDS) analyses showed Lake Taihu was found to have differences in assemblages within the lake, but Lake Chaohu was found to have uniform assemblage across the entire lake. Macrophyte-dominated lake regions (eastern Lake Taihu) were characterised by the highest species richness and diversity indices than those in other lake regions. The pollution sensitive species (e.g. EPT: Ephemeroptera, Plecoptera and Trichoptera) were only distributed in the macrophytic areas of Lake Taihu. Corbicula fluminea, polychaetes Nephtys oligobranchia and Capitella sp. were dominant in the middle central lake regions in Lake Taihu. Lake Chaohu and the northern Lake Taihu, with turbid algal-dominated state, were characterised by dominance of Oligochaetes and Chironomids. These differences were attributed to varying habitats and environmental parameters among different lake regions. Canonical correspondence analysis (CCA) demonstrated that macrophytes, chemical oxygen demand (CODMn), temperature, ammonium (NH3-N) and electric conductivity (EC) were detected as important factors influencing such macroinvertebrate assemblage patterns between these two lakes. This study contributes to the scientific knowledge of within lake habitats, community assemblages, nutrients and pollution within these lakes. [ABSTRACT FROM AUTHOR]

The determination of potentially toxic element concentrations in fish is an important topic from the point of view of both nature conservation and human consumption. The aim of this study was to assess the concentrations of S, K, Ca, Cr, Mn, Fe, Zn, Rb, Sr, Mo, and P in benthic and pelagic fish species in the Karatal river, which is fed by melting glaciers from the Dzungarian Alatau in Kazakhstan. In September 2022, 48 fish samples were collected. It has been demonstrated that the accumulation of chemical elements in fish species can be explained by both the physiological parameters of the fish species and the influence of glaciers that feed river habitats. The data presented in this study provide a synergistic view of pollutants affecting fish populations. Benthic fish contained more manganese and strontium than pelagic species, while the mutual accumulation of potassium, chromium, rubidium, and molybdenum was higher in pelagic fish. The synergistic concentration of calcium and phosphorus in pelagic fish was higher than that in benthic species, while the amount of zinc and sulfur was higher in benthic animals. Relatively elevated levels of mercury in fish were found. The study contributes to the discussion about the role of glacial environments in loading pollutants to aquatic systems. [ABSTRACT FROM AUTHOR]

The red swamp crayfish Procambarus clarkii (Girard, 1852) has been responsible for negative impacts on native benthic fauna and flora in invaded freshwater ecosystems around the world, including Japan. We need to clarify the reproductive biology in the invaded habitats as basic information to effectively control the introduced populations, but the reproductive biology of P. clarkii in Japan (especially in western Japan) has not been well studied. We conducted monthly samplings of P. clarkii from November 2015 to November 2016 in a pond (which does not freeze, even in winter) in Okayama, western Japan, both by using shrimp cage traps and by hand nets to examine aspects of the reproduction, including a form alternation (i.e. Form I and II). We also reared spawning females in the laboratory and calculated the accumulated water temperature during the period to Stage-3 juveniles after spawning. The total number of individuals caught throughout the study period was 6,319 (2,601 males and 2,777 females, with eight of unknown sex and 933 juveniles). The males were all Form I with a breeding status from September to November 2016. We first found ovigerous females in July 2016 and females carrying hatchlings in October 2016, even in January 2016. The form alternation in males was confirmed not only in the cheliped length, but in the hook length. In laboratory observations, approximately 52 days with approximately 1,222 °C degree-days of the accumulated water temperature were necessary to Stage-3 juveniles after spawning. Our results indicate that P. clarkii can reproduce within approximately five months of hatching. [ABSTRACT FROM AUTHOR]

Silvofishery is a system that combines mangrove and fishery to protect mangrove ecosystems and restore their functions, one of which is as a habitat for macrozoobenthos. Investigate the mollusks and mangrove density. Mollusk sampling was carried out on sub-plots measuring 1 x 1 m² in the mangrove vegetation transect, and mangrove density was measured by counting the number of trees directly on all of the mangrove species at two silvofishery ponds. A total of 16 species of mollusks were found at the observation site, consisting of gastropods and bivalves. The density of mollusks in July was 20 ind/m2 in pond I, while it recorded 9 ind/m2 in pond II. In October, after pond II rehabilitation, the density was inversely proportional to July, and the highest density was found in pond I at 10 ind/m2, while pond II measured 9 ind/m2. After rehabilitation, the index value H' decreased in pond I and pond II from 2.82 and 2.98 to 2.52 and 2.68, respectively. The mangrove density was 887 ind/ha in pond I and 686 ind/ ha in pond II. The substrate in both ponds was clay. Nitrate concentration values in the substrate in both ponds ranged from 0.27% to 0.29%, phosphate recorded a percentage of 0.07--0.09%, and C-organic ranged from 3.00% to 5.72%. The water's physicochemical parameters and the type and content of the substrate were still suitable for mollusk life. [ABSTRACT FROM AUTHOR]

The Messinian Salinity Crisis is considered as one of the most influential Cenozoic events that impacted negatively on the benthic fauna of the Mediterranean area. Changing environmental conditions, including a sharp reduction of water exchange between the Mediterranean Sea and the Atlantic Ocean, altered the geographical ranges of many organisms, including sponges (Porifera). Here, we report a unique assemblage of isolated sponge spicules from the upper Miocene of southwestern Spain. The newly recognized sponge fauna was inhabiting the Guadalquivir Basin--the corridor between the Mediterranean and the Atlantic Ocean at that time. It represents a taxonomically rich sponge community that consisted of members of "soft" and "lithistid" demosponges and hexactinellids. Demosponges are represented by at least thirty-four taxa, while hexactinellids are significantly rarer; only six taxa have been identified. From among eighteen taxa recognized to the species level, at least eight seem to be inhabiting this area to these days; six are recorded from adjacent areas, such as the Western Mediterranean, South European Atlantic Shelf, and the Azores, and three are present in the Red Sea and/or the Northern Atlantic. Intriguingly, some taxa seem to have their closest relatives in distant areas, such as the Indo-Pacific and Japanese waters which suggests that the range of some once widely-distributed populations shrunk after the isolation of the Mediterranean and the Messinian Salinity Crisis, surviving to the present day only in refugia. [ABSTRACT FROM AUTHOR]

Chitin is the most abundant natural polymer in the oceans, where it is primarily recycled by chitin-degrading microorganisms. Endozoicomonadaceae (Oceanospirillales) bacteria are prominent symbionts of sessile marine animals, particularly corals, and presumably contribute to nutrient cycling in their hosts. To reveal the chitinolytic potential of this iconic, animal-dwelling bacterial family, we examined 42 publicly available genomes of cultured and uncultured Endozoicomonadaceae strains for the presence of chitinase-encoding genes. Thirty-two of 42 Endozoicomonadaceae genomes harbored endo-chitinase- (EC 3.2.1.14), 25 had exo-chitinase- (EC 3.2.1.52) and 23 polysaccharide deacetylase-encoding genes. Chitinases were present in cultured and uncultured Endozoicomonadaceae lineages associated with diverse marine animals, including the three formally described genera Endozoicomonas, Paraendozoicomonas and Kistimonas, the new genus Candidatus Gorgonimonas, and other, yet unclassified, groups of the family. Most endo-chitinases belonged to the glycoside hydrolase family GH18 but five GH19 endo-chitinases were also present. Many endo-chitinases harbored an active site and a signal peptide domain, indicating the enzymes are likely functional and exported to the extracellular environment where endo-chitinases usually act. Phylogenetic analysis revealed clade-specific diversification of endo-chitinases across the family. The presence of multiple, distinct endo-chitinases on the genomes of several Endozoicomonadaceae species hints at functional variation to secure effective chitin processing in diverse micro-niches and changing environmental conditions. We demonstrate that endo-chitinases and other genes involved in chitin degradation are widespread in the Endozoicomonadaceae family and posit that these symbionts play important roles in chitin turnover in filter- and suspension-feeding animals and in benthic, marine ecosystems at large. [ABSTRACT FROM AUTHOR]

The use of towed underwater unmanned vehicles equipped with photo, video, and sonar systems has proven its effectiveness in studying the seafloor surface in integrated research of the World Ocean. This class of devices solves a wide range of tasks, including biological studies of benthic fauna and surveys of underwater technogenic objects. The towed vehicle "Videomodule" was developed at the Shirshov Institute of Oceanology, Russian Academy of Sciences, and has been successfully employed for such surveys for several years. The paper discusses the technical features and application issues of working with the "Videomodule." [ABSTRACT FROM AUTHOR]

Feeding features of juvenile muksun Coregonus muksun (Pallas, 1814) when growing in cages installed on the channel of the Lower Ob are considered. It was found that, along with artificial food, juveniles feed on zoobenthos and zooplankton organisms that enter cages during drifting, and consumption was noted from the first to the last days of rearing. The bulk of the food bolus was artificial food, 88.3–94.3%; aquatic invertebrates accounted for 1.3–5.7% of the weight of the food bolus where Chironomid larvae dominated. There were no statistically significant differences in the intake of invertebrates by young muksun before and after feeding (p = 0.442) at average values of 0.005 and 0.006 g, respectively. The ability of the transition of juveniles from artificial to natural food base at all stages of development was noted, which is an indicator of successful adaptation to environmental conditions during cage rearing in the channels of the Ob River. [ABSTRACT FROM AUTHOR]

To understand the health status of aquatic ecosystem in Lake Erhai, the community structure of benthic animals was investigated based on 27 samples from 11 typical monitoring sections in March, June, September and December 2021, and the benthic index of biotic integrity (B-IBI) assessment system was also established. The results showed that Lake Erhai contains 56 genera and species of benthic animals, which refers to 4 phyla, 6 classes, 28 families and 54 genera. The assessment system of B-IBI for Lake Erhai consists mainly of the total number of classification units, proportion of chironomid individuals, and BMWP index, which obtained by range test, discriminatory power and Pearson correlation screen. The health status of aquatic ecosystem in Lake Erhai can divide into five grades according to ratio scoring method, i.e., >2.61, 2.10~2.61, 1.82~2.10, 1.42~1.82 and <1.42, representing health, sub-health, fair, poor and very poor health status, respectively. Based on above method and standard, the health of aquatic ecosystem for Lake Erhai in 2021 is fair status. Specifically, five, six, five, nine and two sampling sites were in health, sub-health, fair, poor and very poor health status, accounting for 18.5%, 22.2%, 18.5%, 33.3% and 7.4% of the total sites, respectively. [ABSTRACT FROM AUTHOR]

In freshwater systems, contributions of chemosynthetic products by sulfur‐oxidizing bacteria in sediments as nutritional resources in benthic food webs remain unclear, even though chemosynthetic products might be an important nutritional resource for benthic food webs in deep‐sea hydrothermal vents and shallow marine systems. To study geochemical aspects of this trophic pathway, we sampled sediment cores and benthic animals at two sites (90 and 50 m water depths) in the largest freshwater (mesotrophic) lake in Japan: Lake Biwa. Stable carbon, nitrogen, and sulfur isotopes of the sediments and animals were measured to elucidate the sulfur nutritional resources for the benthic food web precisely by calculating the contributions of the incorporation of sulfide‐derived sulfur to the biomass and of the biogeochemical sulfur cycle supporting the sulfur nutritional resource. The recovered sediment cores showed increases in 34S‐depleted sulfide at 5 cm sediment depth and showed low sulfide concentration with high δ34S in deeper layers, suggesting an association of microbial activities with sulfate reduction and sulfide oxidation in the sediments. The sulfur‐oxidizing bacteria may contribute to benthic animal biomass. Calculations based on the biomass, sulfur content, and contribution to sulfide‐derived sulfur of each animal comprising the benthic food web revealed that 58%–67% of the total biomass sulfur in the benthic food web of Lake Biwa is occupied by sulfide‐derived sulfur. Such a large contribution implies that the chemosynthetic products of sulfur‐oxidizing bacteria are important nutritional resources supporting benthic food webs in the lake ecosystems, at least in terms of sulfur. The results present a new trophic pathway for sulfur that has been overlooked in lake ecosystems with low‐sulfate concentrations. [ABSTRACT FROM AUTHOR]

The present work is aimed at investigating the effects of seasonal changes and habitat conditions on reproductive state and gonadal development of two macrobenthic fauna. Echinometra mathaei and Tridacna squamosa were collected seasonally (summer and winter) in July 2019 and January 2020 from three sites along the Red Sea coast, Egypt: Hamraween, Sedy Malek, and Porto Ghalb. Sexual differences and gonadal maturation in the two species were determined by performing biopsies of their gonads followed by morphologic analyses. Hematoxylin and eosin–stained gonadal sections were examined and analyzed. In E. mathaei, reproductive behavior was more active in the summer than in the winter; in T. squamosa, reproductive behavior was active almost all the year, especially during the winter. The reproductive activity and gonadal maturation of both species were affected by environmental factors. The results indicated that temperature is a vital factor affecting the reproductive activity of both species. This study concluded that temperature fluctuations may pose significant challenges to coastal marine ecosystems. [ABSTRACT FROM AUTHOR]

Copyright of Natura Sloveniae: Revija za Terensko Biologijo / Journal of Field Biology is the property of Natura Sloveniae and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Profound environmental changes, such as drastic sea-ice decline, leave large-scale ecological footprints on the distribution and composition of marine biotas in the Arctic. Currently, the impact of such stressors is not sufficiently understood due to the lack of pan-Arctic data that allow for estimating ecological baselines, as well as modelling current and forecast potential changes in benthic biodiversity and ecosystem functioning. Here, we introduce a PAN-Arctic data collection of benthic BIOtas (PANABIO), and discuss its timeliness, potential, and details of its further development. The data collection contains records of benthic fauna at genus-level or species-level identified in field samples obtained by means of grabs, towed gear, or seabed imaging. Currently, it includes records of 2,968 species or genera, ranging from presence to counts, densities or biomass, grouped per sample. The data represent the pan-Arctic realm, covering all major marine areas, i.e., the central Arctic Ocean, Chukchi Sea, East Siberian Sea, Laptev Sea, Kara Sea, Barents Sea (incl. White Sea), Svalbard waters, Greenland Sea, Norwegian Sea, Canadian Archipelago, Beaufort Sea, and Bering Sea. All data are point-referenced sampling locations. Currently, 124,040 records from 10,645 samples taken at 10,631 stations between 1800 and 2014 are included, but these numbers will increase with more data becoming available. The data collection is available in a PostgreSQL-based data warehouse that can be accessed and queried through an open-access frontend web service at https://critterbase.awi.de/panabio. A snap shot of the current data collection (of 26 June 2023) is also available from the data publisher PANGAEA. [ABSTRACT FROM AUTHOR]

Carijoa riisei is an invasive octocoral whose dispersal in the tropics has increased considerably in recent years. This study evaluated the changes in the benthic fauna assemblages associated with C. riisei growing on rocks from a sea port and on the metal of a submerged shipwreck in the bays of Manzanillo, Colima, in the Mexican Central Pacific. Quarterly samples were collected between April 2021 and January 2022, with the presence or absence of C. riisei. The effect of C. riisei on the benthic fauna according to the type of substrate was evaluated with PERMANOVA models. The presence of C. riisei was found to affect taxonomic diversity. In the absence of the octocoral, 209 species were recorded, whereas in its presence, 190 were found. The decline of taxa occurred at the level of families, genera, and species. The interaction of the presence/absence of C. riisei and substrate generated significant changes in the Shannon (1D) and Simpson (2D) diversity indexes. However, the presence of C. riisei coincided with higher abundances of Ophiothela mirabilis, Ericthonius brasiliensis, and Pseudobranchiomma schizogenica. In conclusion, the snowflake coral favors the dominance of some species and reduces the biological diversity of several taxa, mainly mollusks, polychaetes, sipunculids, and anthozoans, generating significant changes in the structure of benthic communities. This study highlights the need to evaluate species composition in areas where the octocoral grows, to determine whether its presence has an ecological impact and whether control measures are required. [ABSTRACT FROM AUTHOR]

Many sessile and tube-dwelling polychaetes can act as ecosystem engineers, influencing the physical–chemical and biological characteristics of their habitats, increasing structural complexity. Thus, they are considered structuring species. In summer of 2021, in southern Sicily (Ionian Sea), benthic assemblages dominated by Ampharetidae Amage adspersa were discovered via an ROV survey at a depth range between 166 and 236 m on muddy horizontal seafloor. Large aggregations of this species (up to 297.2 tubes m−2), whose tubes are formed from Posidonia oceanica debris, occurred alternately with tube-free areas. The area was characterized by the sporadic presence of vulnerable sea pens Funiculina quadrangularis (up to 0.08 col. m−2) and Virgularia mirabilis (up to 0.16 col. m−2), and it was possible to detect signs of trawling as well the presence of marine litter (up to 24.0 items 100 m−2). The habitat description, distribution, and density of the tubes of A. adspersa were assessed via imaging analysis. In addition, morphological diagnostic analyses were carried out on some sampled specimens and on their tubes. The acquired data shed new light on how polychaetes can exploit the dead tissues of P. oceanica, contributing to highlight interactions between benthic fauna and seagrass detritus in the marine environment and their ecological role in enhancing the spatial heterogeneity of soft areas of the Mediterranean seafloor. [ABSTRACT FROM AUTHOR]

Macrobenthic traits, for example feeding mode, life history, morphology, are increasingly used for determining responses of macrobenthic fauna to environmental change and influences on ecosystem functioning. Yet, trait information is scarce or non-existent in several parts of the world, such as New Zealand. This deficit makes collecting trait data a difficult and time-consuming task, limiting its potential use in trait-based assessments. Here, we present the New Zealand Trait Database (NZTD) for marine benthic invertebrates, the first comprehensive assessment of macrobenthic traits in New Zealand. The NZTD provides trait information for more than 700 macrobenthic taxa, categorised by 18 traits and 77 trait modalities. The NZTD includes five freely downloadable datasets, (1) the macrobenthic trait dataset, with outcomes from a fuzzy coding procedure, (2) the trait source information, (3) the references by taxa, (4) the full references list, and (5) the full taxa list used in the NZTD. Establishing the NZTD closes the trait knowledge gap in New Zealand and facilitates future research applying trait-based approaches to New Zealand's coastal macrofauna. [ABSTRACT FROM AUTHOR]

The zoobenthos represents one of the most diverse and exclusive groups of the rocky intertidal zone, characterized by the permanent presence of many taxa and families. The objective of this work is to characterize the zoobenthos associated with the macroalga Colpomenia sinuosa in the rocky coast of Barbasquillo beach, identify the organisms present down to the lowest taxon, determine the abundance, diversity and relate the zoobenthos present with the abiotic factors (temperature, pH and salinity) of the area. The study area was monitored twice a month, with an interval of 15 days, from may to october 2022. A 5 x 10 m band transect was used, located in the meso littoral zone of Barbasquillo beach. The salinity, pH and temperature of the seawater in the study area varied during the monitoring months, presenting values of 30.82 ± 2.52 UPS; 7.45 ± 0.19 NBS and 24.34 ± 0.49°C respectively. The zoobenthic community associated with C. sinuosa was 2450 individuals, represented by 12 species, 21 genera, 17 families and 9 classes, belonging to 5 phyla. Mollusks were the most abundant group with 76.98%, followed by arthropods (19.55%), annelids (3.10%), echinoderms (0.29%) and chordates (0.08%), the most abundant species being Columbella rusticoides. In the study area there is a medium diversity and high dominance. In general, no clear relationships were observed between the environmental parameters considered in this work and the changes in the zoobenthic communities recorded. [ABSTRACT FROM AUTHOR]

Deep-sea benthic fauna is vital for a well-functioning marine ecosystem but is increasingly under threat from a changing environment. To monitor and conserve this fauna, an understanding of their large-scale spatial and bathymetric distribution and their environmental drivers is necessary. In this study, we conduct a multivariate analysis on abundance benthic fauna data collected at the phylum and multitaxon levels using an epibenthic sledge (EBS) across the Atlantic, and identify the environmental factors that affect such data. Our findings show a decrease in abundance with depth in most of the Atlantic but find relatively heterogeneous abundances with depth within the Southern Ocean. Principal component analyses indicate differences in environmental conditions south of the Antarctic Polar Front (~52° S), outlining contrasts in the quantities of macronutrients and physical factors. Despite this, community composition seemed markedly similar throughout the Atlantic with the Antarctic Circumpolar Current seemingly not affecting benthic community composition for higher taxonomic levels. Those differences that did occur were largely caused by benthic chlorophyll, benthic iron, and surface silicate through a Bio-ENV. Overall, we argue that further large-scale spatial and bathymetric distribution studies are important amid environmental changes that are driving shifts in benthic community abundance and composition. [ABSTRACT FROM AUTHOR]

Pollution associated with marine debris is of global ecological concern, as it threatens wildlife and local economies. Submerged marine debris alters local benthic species composition and community characteristics. The study site of Jaguri, Jeju Island, where a variety of submerged marine debris was found, was used to investigate the impact of submerged marine debris on the macrobenthic fauna of sandy and rocky substrates. The dominant macrobenthos taxon differed by sediment type; the polychaete Armandia lanceolata was dominant in sandy bottom environments and the mollusk Leiosolenus lischkei was dominant in rocky bottom environments. The presence of marine debris was associated with differences in biomass in both the soft and rocky areas. The site without debris had higher biomass in the soft area, and the site with nets had a higher density of benthic animals within the site with debris. In the rocky area. the site with debris had a higher biomass. Macrobenthos were affected by the type of deposited marine debris and the type of sediment substrate. This study provides a basis for future studies on the impact of debris on marine ecosystems and identified the benthos species affected by marine debris. [ABSTRACT FROM AUTHOR]

In recent decades, monitoring of benthic fauna in Albanian rivers is an important environmental component at a time when their flow and watershed area have been greatly modified by anthropogenic influences. Given the importance of these organisms in aquatic bio-ecological studies defined in the EU (European Union) directive, this study completes the taxonomic panorama of studies in the main rivers of our country. This research was conducted in a period from 2007 to 2019 aimed to give an overall assessment of the EPT group (Ephemeroptera-Plecoptera-Trichoptera) of benthic macro-invertebrates distributed in the seven rivers of Albania, namely: Drin, Mat, Shkumbin, Osum, Devoll, Drinos and the Shushica-Vlora River. The collection of the benthic macro invertebrates was realized by using the Kick-net sampling methodology (rectangular net, 500 micron mesh). A total of 33 stations with different ecological and geophysical typologies have been selected in all rivers. Using the Kick-net sampling a total of 8154 specimens' representatives of 28 families were collected. Caddisflies, or Trichoptera order, were dominant both in number of species (8 species) and in abundance (74.3% of all individuals). Meanwhile Mayflies (Ephemeroptera) and Stoneflies (Plecoptera) contributed much less to species richness and abundance. The presence of 20 EPT families of macro-invertebrates in the the Shushica River study testifies the highest degree of biodiversity. The river with the lowest diversity of EPT species represents (8 families) is the Drini River. Representatives of 28 insect families collected with Kick-net were: Ephemerellidae, Baetidae, Heptagenidae, Caenidae, Oligoneuridae, Potamanthidae, Ephemeridae, Isonychidae, Leptophlebiidae, Siphlonuridae, Leuctridae, Perlodidae, Perlidae, Chloroperlidae, Nemuridae, Capniidae, Brachycentridae, Hydropsychidae, Hydroptilidae, Glossosomatidae, Philopotamidae, Rhyacophilidae, Beraeidae, Leptoceridae, Polycentropidae, Helicopsychidae, Sericostomatidae, and Goeridae. We can conclude that taxonomic panorama of the main rivers of our country is represented by small differences of taxon diversity between the rivers in the northern, middle and southern part of our country. The changes are not only due to the typological conditions of the rivers but also due to the influence of the anthropogenic factor mainly in the urban area. [ABSTRACT FROM AUTHOR]

Anthropogenic activities alter the rivers' hydromorphological characteristics, affecting the ecosystems. River continuum interruption is identified as a principal cause of longitudinal quality variation. Macroinvertebrates, the most common biological quality indicator, are usually coupled with hydromorphological alteration assessment protocols. Environmental DNA (eDNA) metabarcoding is a recent advance in biomonitoring, complementing classical assessment, responding to time and cost-efficiency limitations. This study assesses the hydromorphological effects of two barriers (sluice and rock ramp) in a large Mediterranean modified river on the structure of macroinvertebrate assemblages using the classical method, coupled with eDNA metabarcoding while it further correlates them with the alteration of the riparian zone. Samplings were conducted at three stations for each barrier, one upstream and two downstream, during high and low flow periods. A range of statistical tests were performed for the assemblages' comparison, the diversity indices and the investigation of spatial and temporal patterns. The findings include differences among communities' composition for the two approaches with a moderate overlap between eDNA and classical taxonomy. The ramp had lower influence on biota in comparison to the sluice. Regarding the spatial pattern, no significant differences were revealed for both methods, but it could be attributed to the barriers' operation extent. As for a temporal pattern, there was a difference between the two methods and, while no separation was noted among the sites as a sum, site-specific differences were found. If some problems concerning the taxonomic assignment of ASVs, the sampling methodology and the primers selection are surpassed, eDNA proves a valuable tool. [ABSTRACT FROM AUTHOR]

The macro-invertebrate is an important part of the aquatic food web of urban rivers, and it is of great significance in understanding its ecological suitability for the stability of river ecosystems. Previous studies, such as those that have conducted suitability index and canonical correspondence analyses (CCAs), have widely used a macro-invertebrate suitability analysis; however, these studies can only confirm a few coupling relationships between the environment and macro-invertebrates. In our study, one-way ANOVA, HCA, PCA and GAM models were used to explain the differences in the spatial and temporal distribution of environmental factors, as well as to reduce data redundancy. A response curve of the critical environmental factors and macro-invertebrates was constructed, and the nonlinear relationship between these factors and benthic animals was quantified to analyze the ecological threshold of the macro-invertebrates. The study area was the Majiagou River, Harbin, China. The results show that COD had significant seasonal differences due to complex hydrological conditions, and most of the water quality factors had spatial differences. The GAM model explained 60% of the Margalef diversity index (MDI) variance. The relationship between chlorophyll-a and MDI was unimodal, and MDI and NH4+-N essentially showed a negative correlation; when the total nitrogen (TN) value reached 5.8 mg/L, MDI reached its peak. When MDI was higher than the mean value, the chlorophyll-a range was 18.1 μg/L~83 μg/L. The NH4+-N was less than 1.8 mg/L, and TN was 1.8~6.8 mg/L. This study provides a reference for the comprehensive management of urban river ecosystems. [ABSTRACT FROM AUTHOR]

• The Aptian-Albian benthic foraminifera of the Central Taurides are documented. • Stratigraphic ranges of the Aptian–Albian benthic foraminifera are discussed. • The new species " Palaeocornuloculina " taurica is described from the Aptian–Albian. The Lower Cretaceous carbonate successions of the Tauride Carbonate Platform(s) (TCP) are characterized by mostly restricted inner platform facies. The record of these stages is limited owing to frequent exposure of the platform to subaerial and supratidal settings during the Early Cretaceous. This study focuses on the Lower Cretaceous (Aptian–Albian) successions outcropping at two localities in the Geyik Dağı and Anamas Dağ areas, Central Taurides. These successions exhibit a peritidal shallowing upward trend evidenced by the dominance of mud-rich microfacies, lamination, fenestrae, oncoids, and changes in fossil content (benthic foraminifera, dasycladalean algae, rudists, etc.). The stratigraphic subdivisions of the studied successions utilize index taxa in the benthic foraminiferal assemblages which are documented and illustrated. Assemblage I (lower Aptian) is mainly characterized by Voloshinoides murgensis and Debarina hahounerensis ; Assemblage II (upper Aptian) by Mesorbitolina parva, Carseyella tunesiana and " Arenobulimina " geyikensis ; and Assemblage III (Albian) by Mesorbitolina gr. texana , Protochrysalidina elongata and Pseudonummoloculina heimi. Ranges and stratigraphic significance of some species through the Lower Cretaceous are discussed. Due to less favorable environmental conditions, the strata in the Anamas Dağ area have a low-diversity benthic foraminifera fauna and sparse macrofossils. In contrast, the strata in the Geyik Dağı area host rich and diverse larger benthic foraminifera as well as rudist bivalves and gastropods. A new species, " Palaeocornuloculina " taurica belonging to the family Ophthalmidiidae is described from these foraminifera-rich upper Aptian–Albian strata in the Geyik Dağı area. [ABSTRACT FROM AUTHOR]

A lithofacies and bionomic study of the Artinskian–Kungurian boundary deposits of the Cisuralian Series of the Permian System in the Yuryuzan–Ai Depression was carried out with reference to the Mechetlino section (Southern Urals). This section was a candidate for GSSP of the lower boundary of the Kungurian Stage. Eight lithological facies rock types, or lithofacies, were recognized in terrigenous–carbonate deposits. On the basis of their combinations, the section was divided into packages composed of carbonate–terrigenous flysch rocks, detrital carbonate deposits initiated by storms, and blocky submarine slump deposits. Six ecological assemblages of small foraminifers, reflecting depositional environments in benthic fauna source areas, were identified. The mechanisms of mixing and transport of plant remains along with benthic, planktonic, and nektonic fauna remains are indicated. A model of formation of the Lower Permian sedimentary assemblages in the Yuryuzan–Ai Depression of the Ural foredeep, reflecting the bionomic specificity of the assemblages of biogenic remains in the boundary interval of the Artinskian and Kungurian stages, is proposed. [ABSTRACT FROM AUTHOR]

The Jurassic rocks of Gebel Maghara, northern Sinai, Egypt, contain a well-preserved and highly diverse macrobenthic fauna, dominated by bivalves. This fauna, particularly bivalves and gastropods, have received little attention in the last 100 years. In an attempt to provide a sound database on the marine bivalve diversity of Egypt during the Jurassic period, a first faunal group, the protobranch bivalves, is reviewed in detail. Sixteen taxa (three of them new), belonging to two orders, five families, and nine genera are systematically described and compared to closely related Jurassic taxa from various locations, particularly in Europe and India. New species are Nuculoma douvillei n. sp., N. sinaiensis n. sp., and Palaeoneilo aegyptiaca n. sp. In addition, Palaeonucula cuneiformis (J. de C. Sowerby), P. muensteri (Goldfuss), Dacryomya diana (d'Orbigny), D. lacryma (J. de. C. Sowerby), and Praesaccella juriana Cox are identified from Jurassic strata of Egypt for the first time. The younger records of the genus Palaeoneilo have not been accepted by some researchers, since almost all exhibit only limited features. The genus occurs with certainty in the Middle Jurassic (Bajocian‒Bathonian) rocks of Egypt, based on well-preserved external and internal characters. Similarly, Dacryomya and Ryderia from Bathonian‒Kimmeridgian rocks of Egypt are younger than previously recorded from other parts of the world. The identified genera have wide geographic ranges and have been reported from different faunal provinces, which suggests that latitudinal climate differences did not influence their distribution pattern to a great extent. UUID: https://zoobank.org/7f3a9185-d690-4563-bdc0-df1c8d42ec0d [ABSTRACT FROM AUTHOR]

Cold-water corals form an important part of temperate benthic ecosystems by increasing three-dimensionality and providing an important ecological substrate for other benthic fauna. However, the fragile three-dimensional structure and life-history characteristics of cold-water corals can leave populations vulnerable to anthropogenic disturbance. Meanwhile, the ability of temperate octocorals, particularly shallow-water species, to respond to adjustments in their environment linked to climate change has not been studied. This study reports the first genome assembly of the pink sea fan (Eunicella verrucosa), a temperate shallow-water octocoral species. We produced an assembly of 467 Mb, comprising 4,277 contigs and an N50 of 250,417 bp. In total, 213 Mb (45.96% of the genome) comprised repetitive sequences. Annotation of the genome using RNA-seq data derived from polyp tissue and gorgonin skeleton resulted in 36,099 protein-coding genes after 90% similarity clustering, capturing 92.2% of the complete Benchmarking Universal Single-Copy Orthologs (BUSCO) ortholog benchmark genes. Functional annotation of the proteome using orthology inference identified 25,419 annotated genes. This genome adds to the very few genomic resources currently available in the octocoral community and represents a key step in allowing scientists to investigate the genomic and transcriptomic responses of octocorals to climate change. [ABSTRACT FROM AUTHOR]

Copyright of South China Fisheries Science is the property of South China Fisheries Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the deep-sea, the interaction between benthic fauna and substrate mainly occurs through bioturbational processes which can be preserved as traces (i.e., lebensspuren). Lebensspuren are common features of deep seafloor landscapes and usually more abundant than the organism that produce them (i.e., tracemakers), rendering them promising proxies to infer biodiversity. The density and diversity relationships between lebensspuren and benthic fauna are to the present day unclear and contradicting hypotheses have been proposed suggesting negative, positive, or even null correlations. To test these hypotheses, in this study lebensspuren, tracemakers (specific epibenthic fauna that produce these traces), degrading fauna (benthic fauna that can erase lebensspuren), and fauna in general were characterized taxonomically at eight deep-sea stations in the Kuril Kamchatka Trench area. No general correlation (over-all study area) could be observed between diversities of lebensspuren, tracemakers, degrading fauna and fauna. However, a diversity correlation was observed between specific stations, showing both negative and positive correlations depending on: 1) the number of unknown tracemakers (especially significant for dwelling lebensspuren); and 2) the lebensspuren with multiple origins; and 3) tracemakers that can produce different lebensspuren. Lebensspuren and faunal density were not correlated. However, lebensspuren density was either positively or negatively correlated with tracemaker densities, depending on the lebensspuren morphotypes. A positive correlation was observed for resting lebensspuren (e.g., ophiuroid impressions, Actinaria circular impressions), while negative correlations were observed for locomotion-feeding lebensspuren (e.g., echinoid trails). In conclusion, lebensspuren diversity may be a good proxy for tracemaker biodiversity when the lebensspuren-tracemaker tandem can be reliable characterized; and lebensspuren-density correlations vary depending the specific lebensspuren residence time, tracemaker density and associated behaviour (rate of movement), but on a global scale abiotic and other biotic factors may also play an important role. [ABSTRACT FROM AUTHOR]

The knowledge of aquatic biodiversity in lentic ecosystems is scarce in many regions of the world. Therefore, it was considered important to accomplish preliminary assessments of benthic fauna associated with low depths in three sampling subaquatic fringes between 0 and 10 m on a rocky shore along the northeast area of Coatepeque Lake, El Salvador. The most abundant families were Thiaridae (Gastropoda), Hyalellidae (Malacostraca, Amphipoda), and Coenagrionidae (Insecta, Odonata) from the edge to a depth of 2,5 m. A reduced species richness and abundance were found in fine sediments (10 m) in comparison to shallower strata, as well as a lot of empty shells of the Thiaridae family and cephalic capsules of chironomid larvae (Insecta, Diptera). [ABSTRACT FROM AUTHOR]

Benthic foraminiferal turnover during the Palaeocene–Eocene Thermal Maximum (PETM) has been extensively studied but numerous questions remained unresolved, question such as why some foraminiferal species went into extinction at a particular location but survive in another or why some species survive in extremely low oxygen environment. Because foraminiferal community interaction with the environment is driven by biological traits instead of taxonomic composition, this study has adopted trait-based approach to provide insight into the life strategies of foraminifera that enables them to survive in extreme environmental conditions. The result from this study shows that traits such as test composition, perforation, ornamentation and living habits play an important role in the ecological functioning and adaptability of foraminifera in the environment. The faunal assemblage in the studied site is dominantly cosmopolitan taxa suggesting the environment was perturbed during the PETM. Foraminiferal composition is characterised by faunal turnover indicated in extensive mortalities and extinction of both planktonic and benthic fauna. The ordination (non-metric dimensional scaling) of faunal composition also indicated ecological disturbance. The planktonic community was relatively stable before and after PETM but experienced a high level of ecological perturbation during the carbon isotopic excursion (CIE). The benthic community showed higher evidence of perturbation as the fauna assemblage ordination indicated that ecological stress started before the PETM with the disarray of samples in the ordination diagram. Only the recovery interval experienced some level of ecological stability. The environmental disturbance noticed in the fauna composition reflected on the trait. Benthic foraminiferal traits indicated instability throughout the studied section. The evidence of environmental disturbance in the benthic community suggests that the source of the light carbon that caused the PETM may have originated beneath sea floor in the Atlantic Ocean. [ABSTRACT FROM AUTHOR]

The outer membrane protein (OMP) is a kind of biofilm matrix component that widely exists in Gram-negative bacteria. However, the mechanism of OMP involved in the settlement of molluscs is still unclear. In this study, the mussel Mytilus coruscus was selected as a model to explore the function of ompR, a two-component system response regulator, on Pseudoalteromonas marina biofilm-forming capacity and the mussel settlement. The motility of the ΔompR strain was increased, the biofilm-forming capacity was decreased, and the inducing activity of the ΔompR biofilms in plantigrades decreased significantly (p < 0.05). The extracellular α-polysaccharide and β-polysaccharide of the ΔompR strain decreased by 57.27% and 62.63%, respectively. The inactivation of the ompR gene decreased the ompW gene expression and had no impact on envZ expression or c-di-GMP levels. Adding recombinant OmpW protein caused the recovery of biofilm-inducing activities, accompanied by the upregulation of exopolysaccharides. The findings deepen the understanding of the regulatory mechanism of bacterial two-component systems and the settlement of benthic animals. [ABSTRACT FROM AUTHOR]

Corals are a dominant benthic fauna that occur across a vast range of depths from just below the ocean's surface to the abyssopelagic zone. However, little is known about the evolutionary mechanisms that enable them to inhabit such a wide range of environments. The mitochondrial (mt) genome, which is involved in energetic pathways, may be subject to selection pressures at greater depths to meet the metabolic demands of that environment. Here, we use a phylogenomic framework combined with codon-based models to evaluate whether mt protein-coding genes (PCGs) associated with cellular energy functions are under positive selection across depth in three groups of corals: Octocorallia, Scleractinia, and Antipatharia. The results demonstrated that mt PCGs of deep- and shallow-water species of all three groups were primarily under strong purifying selection (0.0474 < ω < 0.3123), with the exception of positive selection in atp6 (ω = 1.3263) of deep-sea antipatharians. We also found evidence for positive selection at fifteen sites across cox1, mtMutS, and nad1 in deep-sea octocorals and nad3 of deep-sea antipatharians. These results contribute to our limited understanding of mt adaptations as a function of depth and provide insight into the molecular response of corals to the extreme deep-sea environment. [ABSTRACT FROM AUTHOR]

A rapidly warming Arctic Ocean and associated sea‐ice decline is resulting in changing sea‐ice protist communities, affecting productivity of under‐ice, pelagic, and benthic fauna. Quantifying such effects is hampered by a lack of biomarkers suitable for tracing specific basal resources (primary producers and microorganisms) through food webs. We investigate the potential of δ13C values of essential amino acids (EAAs) (δ13CEAA values) to estimate the proportional use of diverse basal resources by organisms from the under‐ice (Apherusa glacialis), pelagic (Calanus hyperboreus) and benthic habitats (sponges, sea cucumber), and the cryo‐pelagic fish Boreogadus saida. Two approaches were used: baseline δ13CEAA values, that is, the basal resource specific δ13CEAA values, and δ13CEAA fingerprints, or mean‐centred baseline δ13CEAA values. Substantial use of sub‐ice algae Melosira arctica by all studied organisms suggests that its role within Arctic food webs is greater than previously recognized. In addition, δ13CEAA fingerprints from algae‐associated bacteria were clearly traced to the sponges, with an individually variable kelp use by sea cucumbers. Although mean‐centred δ13CEAA values in A. glacialis, C. hyperboreus, and B. saida tissues were aligned with microalgae resources, they were not fully represented by the filtered pelagic‐ and sea‐ice particulate organic matter constituting the spring diatom‐dominated algal community. Under‐ice and pelagic microalgae use could only be differentiated with baseline δ13CEAA values as similar microalgae clades occur in both habitats. We suggest that δ13CEAA fingerprints combined with microalgae baseline δ13CEAA values are an insightful tool to assess the effect of ongoing changes in Arctic basal resources on their use by organisms. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In coastal environments, strong feedback can exist between benthic fauna and sediment dynamics. Benthic populations can modify sediment dynamics through biofiltration and bioturbation, while hydro- and sediment dynamics directly determine local environmental conditions for benthic organisms. However, these complex feedbacks are difficult to study in situ. Here, we carried out mesocosm experiments to characterize the effects of a benthic species (the gastropod Crepidula fornicata) on mud dynamics under hydrodynamic conditions representative of their natural habitat. Different experimental tests related to the inclusion (or not) of dead or live crepidula reveal that biofiltration can increase particle settling up to 40%. Flocculation, which is strengthened by organic matter enrichment in shell beds, also substantially increases particle settling. Thus, both processes enhance sedimentation above live crepidula habitats. Furthermore, these experiments highlight serious technical, physical and biological challenges that have to be tackled for properly investigating bio-physical interactions. [ABSTRACT FROM AUTHOR]

The Wakagawa estuary tidal flat was heavily polluted by industrial wastewater in the past. Since then, organic pollution has decreased due to inflow regulations, etc., and it is now an important wetland with rich biota. However, it is expected that metallic elements remain in the tidal flat and affect benthic organisms. Therefore, some benthic animals, mainly sediment feeders, which are expected to be strongly affected by the sediment, were collected in 2016. Then the concentrations of some metallic elements in their bodies were measured. In this paper, copper, zinc, iron, and manganese concentrations in the soft bodies of six benthic gastropod species are reported. It was suggested that soil zinc concentration was not uniform and some areas were high in this tidal flat, especially in places where water flow is obstructed topographically and mud tends to accumulate. Some degree of partial accumulation in the sediment within this tidal flat was suggested for copper, iron and manganese. Exclusive or partial detritus feeders showed higher metal concentrations than microalgae feeders. Among gastropods, three species of genus Batillaria (B. attramentaria, B. multiformis and B. zonalis) for copper; Batillaria multiformis, B. zonalis and Pirenella nipponica for zinc; Batillaria zonalis and Pirenella nipponica for iron and manganese, are considered useful as an indicator species. [ABSTRACT FROM AUTHOR]

Despite the importance of outer membrane vesicles (OMVs) in benthic animal settlement, the underlying molecular mechanism remains elusive. Here, the impact of OMVs and OMVs synthesis-related tolB gene in Mytilus coruscus plantigrade settlement was tested. The OMVs were extracted from Pseudoalteromonas marina through density gradient centrifugation, and a tolB knockout strain, achieved by homologous recombination, was utilized for the investigation. Our results demonstrated that OMVs could significantly enhance M. coruscus plantigrades settlement. Deleting the tolB resulted in downregulation of c-di-GMP, accompanied by a reduction of OMV production, a decline in bacterial motility and increasing biofilm-forming ability. Enzyme treatment resulted in a 61.11% reduction in OMV-inducing activity and a 94.87% reduction in LPS content. Thus, OMVs regulate mussel settlement via LPS, and c-di-GMP is responsible for the OMV-inducing capacity. These findings provide new insights into the interactions between bacteria and mussels. [ABSTRACT FROM AUTHOR]