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The article discusses the microalga Cyanophora paradoxa and its classification as a "Living Fossil." The microalga contains archaic plastids called "cyanelles" and has been studied for its structure and function. The article presents the original description of C. paradoxa and highlights recent findings regarding its genome and evolutionary history. It also discusses the structure of photosystem I in C. paradoxa and its significance in understanding the evolution of photosynthetic organisms. The article concludes that C. paradoxa exhibits both ancient and modern traits, making it a paradigmatic "Green Living Fossil." [Extracted from the article]

Hydra is known for its natural occurrence, anatomical simplicity, intricate physiology, regenerative capacity, and ease of maintenance and manipulation in laboratory environments. It has proven to be a valuable model organism in various disciplines. Its applications range from developmental biology, stem cell research, animal physiology to environmental toxicology including ecotoxicology. The sensitivity of Hydra to a variety of environmental stressors and chemical agents such as metals, nanomaterials, and toxic organic compounds provides valuable insights into physiological mechanisms affected by environmental stressors and pollution, and Hydra can be of great use in environmental monitoring. Furthermore, since green Hydra lives in a symbiotic relationship with unicellular photoautotrophic algae, it is a suitable model organism for symbiosis research. Recently, it has become a popular model in holobiont research. The adaptability and importance of Hydra also extends to aquatic science and aquatic ecology, particularly in the context of monitoring and water pollution. Since the 1980s, Hydra has been increasingly used in various fields of research and has established itself as an important versatile model organism in numerous scientific studies. Hydra also represents an outstanding model in the fields of education and STEM. Hydra continues to be an important model in the 21st century, contributing significantly to our understanding of the biology of water and advancing freshwater research, and possibly finding its way to regenerative medicine and tumor pathobiology research. [ABSTRACT FROM AUTHOR]

Kempnyia (Plecoptera: Perlidae) is an endemic genus of Brazilian stoneflies that has 36 valid species and is distributed primarily in the Atlantic Forest and the mountainous areas of Central Brazil, particularly in Goiás and Tocantins states. Despite being the Brazilian genus with the most DNA sequences available on GenBank, integrative studies on the genus began only recently, in 2014. In this context, herein we studied the morphology and molecular data of Kempnyia specimens deposited in the Aquatic Biology Laboratory (UNESP, Assis) and the Entomology Museum of the Federal University of Viçosa (UFVB, Viçosa) collections. For the integrative approach adopted, in addition to studying the specimens morphologically, we used sequences of the COI mitochondrial gene combined with the following species delimitation methods: Automatic Barcode Gap Discovery (ABGD), both primary (ABGDp) and recursive (ABGDr) partitions; Assemble Species by Automatic Partitioning (ASAP); Poisson Tree Processes (PTP) and the Bayesian implementation of the Poisson Tree Processes (bPTP). As a result, we provided 28 new COI sequences of 21 species and support the description of four new species, namely, K. guaranisp. nov., K. tupiniquimsp. nov., K. unasp. nov., and K. zwickiisp. nov., consequently increasing the known diversity of the genus to 40 species. We also discuss the morphological variations observed in other species of the genus and provide several new geographic records. Therefore, our study brings new insights into the values of intra- and interspecific molecular divergence within Kempnyia, serving as a basis for new studies. [ABSTRACT FROM AUTHOR]

Purpose. To create a general bibliographic list of English-language scientific publications devoted to the peculiarities of pikeperch (Sander lucioperca Linnaeus, 1758) reproduction in natural and artificial conditions using various technologies as well as to briefly highlight Englishlanguage professional sources, in which the main attention is paid to the specifics of pikeperch development in the first stages of ontogenesis -- starting from embryonic development and ending with the age-0+. Methodology. An interdisciplinary approach was used to create this thematic Englishlanguage bibliography. Its was based on the practical application of the principles of analytics and systematics. In turn, the limits of applicability of the latter were outlined by holistic and selective methods. The actual bibliographic core consists of sources that are found in the vast majority on the Internet, mostly with free access to the full texts. Findings. A thematic bibliography of 149 English-language sources is included. All of them are placed in alphabetical order by author or title and are drawn in accordance with the requirements of the State Standard of Ukraine (DSTU 8302:2015 "Information and documentation. Bibliographic reference. General provisions and rules of compilation" with amendments -- UKND code 01.140.40) and the most common international standard (APA style). The absolute majority of the mentioned sources were published in the last 25 years in wellknown international journals («Aquaculture International», "Aquaculture Report", "Aquatic Research", "Biologia", "Czech Journal of Animal Science", "Ecology of Freshwater Fish", "Fish Physiology and Biochemistry", "Journal of Applied Ichthyology", "Knowledge and Management of Aquatic Ecosystems", "North American Journal of Aquaculture", "Turkish Journal of Fisheries and Aquatic Sciences", etc.). Practical Value. The presented thematic English-language bibliography can be used in educational, research, organizational and other types of activities related to the reproduction and preservation of aquatic living biological resources in Ukraine and in other countries of the world. The sources given in it will deepen and supplement the knowledge of scientists and producers regarding the peculiarities of reproduction and ontogenesis of pikeperch at the stages from gastrula to the age-0+. [ABSTRACT FROM AUTHOR]

Purpose. Analysis of obtained data and integration of previous hydroecological data and statistical information for the preparation of scientific and biological rationale and development of the regime for rational and environmentally sustainable fishery exploitation of the Khrystoforivske Reservoir. Methodology. Hydrochemical and hydrobiological methods of sampling, laboratory and statistical processing of the material were used in the water area of the Khrystoforivske reservoir of the Bokovenka river during comprehensive studies in the summer of 2022. We studied the hydrochemical parameters of the water body, species composition, quantitative parameters of the main groups of hydrobionts, including fish forage organisms (macrophytes, phytoplankton, zooplankton, zoobenthos), the biological productivity of the reservoir was measured based on the main groups of hydrobionts. To determine the state of the main groups of hydrobionts, two samples of phytoplankton, zooplankton and zoobenthos were collected. Macrophytes were studied, water samples were taken from different parts of the water body for hydrochemical analysis. The biomass of phytoplankton was calculated based on the biomass of standard volumes of algae, the biomass of zooplankton - by multiplying the quantity of organisms by their individual weights, zoobenthos - by weighing individual groups of hydrobionts on torsion scale and recalculating and summing up. The reservoir feeding capacity was assessed by the quantitative development of zooplankton according to known classifications. Findings. The main parameters of the chemical composition and properties of the water of the Khrystoforivske reservoir, which condition the bioproductivity and fish farming performance, were determined: pH, content of dissolved gases, organic substances, biochemical demand of O2, nutrients content, as well as general mineralization and hardness, concentration of the major ions. According to the hydrochemical classification, water is bicarbonate type II and is referred to fresh water. The degree of water saturation with easily-oxidizable organic matter has decreased over the past 15 years and is within standards for aquaculture. Considering all environmental and sanitary parameters, water of the Khrystoforivske reservoir is characterized by fair or average quality, it is eupolytrophic. The water characteristics indicate that the fishery exploitation at the reservoir during previous Special Commodity Fish Farming Regimes (SCFF) (1996-2021) has produced no adverse effects on the general ecological and sanitary condition of water. Aquatic phytocoenoses of the Khrystoforivske reservoir are represented by associations of submerged and aerial-aquatic plants, with a total area of 5.2 hectares. The total production of aquatic plants is 36.245 tons. The phytoplankton of the reservoir includes 51 species of algae (six groups). In terms of quantity, small-celled Cyanoprokaryota predominated (about 70%). Diatoms, green and euglenic algae dominated in biomass. In 2022, the average biomass of phytoplankton in the Khrystoforivske reservoir was up to 1.80 g/m³, the total annual production of phytoplankton reached 201.06 tons. In total, 16 species of organisms have been identified in the zooplankton of the reservoir: Rotatoria, Cladocera and Copepoda. The average abundance of zooplankton in the reservoir was 31,390 ind./m³, and its average biomass reached 0.41 g/m³. The value of primary production of zooplankton is 123.9 kg/ha, and the total stock in the reservoir is 7.687 tons. The fish food supply in terms of zooplankters in the Khrystoforivske reservoir are low. The reservoir itself, based on the group of zooplankton, can be referred to fishery class III (the lowest class). The bottom fauna is represented by 40 taxonomic groups of invertebrates. The Chironomidae and Oligochaeta assemblies are most developed in terms of density, but molluscs dominate in biomass. There is a general trend towards a decrease in the quantitative parameters of macrozoobenthos, in particular, Mysidacea. The average biomass of soft benthos (2.17 g/m²) and the average biomass of the entire zoobenthos (33.62 g/m²) indicate that the reservoir preserves its fishery potential due to macrozoobenthos. The primary production of zoobenthos of the Khrystoforivske reservoir is 130.2 kg/ha. The total stock of zoobenthos is up to 8.072 tons. The values of the fish food supply are quite high due to zoobenthos in the reservoir, the water body in terms of benthos biomass is referred to fishery class II (medium productive reservoirs). The obtained comprehensive data on the food supply of the Khrystoforivske reservoir indicate the availability of sufficient bioproduction potential for its continuous effective fish-farming on the basis of the special commodity fish farming regime. Originality. For the first time in the last 10 years, comprehensive data on the food supply of the Khrystoforivka reservoir, which is used in special commodity fish farming regime (SCFF), have been obtained and analysed. Practical value. The results obtained are of practical importance for the development of scientific and biological rationale for fish farming in the Khrystoforivske Reservoir. [ABSTRACT FROM AUTHOR]

Summary: Nitrosophilus labii HRV44T is a thermophilic chemolithoautotroph possessing clade II type nitrous oxide (N2O) reductase (NosZ) that has an outstanding activity in reducing N2O to dinitrogen gas. Here, we attempt to understand molecular responses of HRV44T to N2O. Time course transcriptome and proteomic mass spectrometry analyses under anaerobic conditions revealed that most of transcripts and peptides related to denitrification were constitutively detected, even in the absence of any nitrogen oxides as electron acceptors. Gene expressions involved in electron transport to NosZ were upregulated within 3 h in response to N2O, rather than upregulation of nos genes. Two genes encoding Crp/Fnr transcriptional regulators observed upstream of nap and nor gene clusters had significant negative correlations with nosZ expression. Statistical path analysis further inferred a significant causal relationship between the gene expression of nosZ and that of one Crp/Fnr regulators. Our findings contribute to understanding the transcriptional regulation in clade II type N2O-reducers.

Summary: Wetlands are hotspots for carbon and nutrient cycling. The important role of plant-microbe interactions in driving wetland biogeochemistry is widely acknowledged, prompting research into their molecular biological basis for a deeper understanding of these processes. We analyzed transcriptomic responses of soil microbes to root exudates in coastal wetland soils using 13CO2 pulse labeling. Metatranscriptomics revealed 388 upregulated and 11 downregulated genes in response to root exudates. The Wood-Ljungdahl pathway and dissimilatory sulfate reduction/oxidation were the most active microbial pathways independent of root influence, whereas pathways with the strongest upregulation in response to root influence were related to infection, stress response, and motility. We demonstrate shifts within the active community toward higher relative abundances of Betaproteobacteria, Campylobacterota, Kiritimatiellota, Lentisphaerota, and Verrucomicrobiota in response to exudates. Overall, this study improves our mechanistic understanding of wetland plant-soil microbe interactions by revealing the phylogenetic and transcriptional response of soil microorganisms to root influence and exudate input.

Summary: Global warming significantly impacts amphibian populations globally, and modeling helps understand these effects. Here, we used MaxEnt and MigClim models to predict the impact of climate change on habitat suitability for Hoplobatrachus chinensis. Our results indicate that temperature is a key factor affecting H. chinensis distribution. Increasing temperatures positively correlated with habitat suitability, with suitable habitat expanding northward by 2060 while maintaining suitability in the southern parts of the range. We found a 25.18% overlap between the current potential suitable habitat of H. chinensis and agricultural wetlands. Our model indicated that H. chinensis might be able to track shifts in suitable habitats under climate change given a 15 km dispersal ability per generation. Climate change will likely expand suitable habitat for H. chinensis. Our predictions offer important guidance for the conservation of the species, especially for the integrated role of natural and agricultural wetlands such as rice paddies.

Summary: Although diverse microorganisms can remove ammonium and nitrate simultaneously, their metabolic mechanisms are not well understood. Paracoccus denitrificans R-1 showed the maximal NH4+ removal rate 9.94 mg L−1·h−1 and 2.91 mg L−1·h−1 under aerobic and anaerobic conditions, respectively. Analysis of the nitrogen balance calculation and isotope tracing experiment indicated that NH4+ was consumed through assimilation. The maximal NO3− removal rate of strain R-1 was 18.05 and 19.76 mg L−1·h−1 under aerobic and anaerobic conditions, respectively. The stoichiometric consumption ratio of acetate to nitrate was 0.902 and NO3− was reduced to N2 for strain R-1 through 15NO3− isotopic tracing experiment, which indicated a respiratory process coupled with the oxidation of electron donors. Genomic analysis showed that strain R-1 contained genes for ammonium assimilation and denitrification, which effectively promoted each other. These findings provide insights into microbial nitrogen transformation and facilitate the simultaneous removal of NH4+ and NO3− in a single reactor.

The article features an interview with Jocelyn Runnebaum, a marine scientist at The Nature Conservancy, discussing her career path and experiences. Runnebaum emphasizes the importance of economics in higher education and offers advice to new graduates seeking jobs. She highlights her work in marine science, offshore wind, and aquaculture, as well as her involvement in advisory bodies. The article also provides resources for job seekers in the fisheries field and emphasizes the value of soft skills in the job market. [Extracted from the article]

The biophysics of water, has been debated over more than a century. Although its importance is still underestimated, significant breakthroughs occurred in recent years. The influence of protein condensation on water availability control was documented, new findings on water-transport proteins emerged, and the way water molecules rearrange to minimize free energy at interfaces was deciphered, influencing membrane thermodynamics. The state of knowledge continued to progress in the field of deep-sea marine biology, highlighting unknown effects of high hydrostatic pressure and/or temperature on interactions between proteins and ligands in extreme environments, and membrane structure adaptations. The role of osmolytes in protein stability control under stress is also discussed here in relation to fish egg hydration/buoyancy. The complexity of water movements within the cell is updated, all these findings leading to a better view of their impact on many cellular processes. The way water flow and osmotic gradients generated by ion transport work together to produce the driving force behind cell migration is also relevant to both marine biology and cancer research. Additional common points concern water dynamic changes during the neoplastic transformation of cells and tissues, or embryo development. This could improve imaging techniques, early cancer diagnosis, and understanding of the molecular and physiological basis of buoyancy for many marine species. [ABSTRACT FROM AUTHOR]

Queen triggerfish Balistes vetula is an important reef-associated species for commercial fisheries in the U.S. Caribbean. It exhibits a relatively unique reproductive strategy as a nesting benthic spawner, investing substantial energy in territorial defense, building and maintaining nests, and caring for fertilized eggs during the reproductive season. Prior to this study, no comprehensive life history information existed in the literature for queen triggerfish. This study provides the first comprehensive documentation of age, growth, size/age at sexual maturity, reproductive seasonality, and reproductive output for a Balistes species in the Caribbean. From 2013 to 2023, we collected 2190 fish samples from fisheries-dependent and -independent sources from the waters of Puerto Rico and the U.S. Virgin Islands. Fish ranged from 67 to 477 mm fork length (FL). We documented that queen triggerfish is sexually dimorphic with males attaining larger mean sizes-at-age compared to females and the species is characterized by a moderately young age at median sexual maturity (A50 = 3.3 y). The maximum age for our U.S. Caribbean samples was 23 y based on increment counts from otoliths. Spawning season encompassed the months of December to August in the region, and female spawning frequency ranged from an estimated 2 to 84 times per year; female spawning frequency increased with increasing size and age of fish. We documented that commercial fishers in the U.S. Caribbean mainly target "plate-size" individuals, defined in our study as 235–405 mm FL, which appears to act as a self-imposed slot size range limit and results in the fishery not removing individuals in the smallest and largest size groups at high rates. The percentage of immature fish from fisheries-dependent sources was close to 0 (0.8%). Commercial fishing for queen triggerfish in the region currently appears to be sustainable, but monitoring of the population should continue. [ABSTRACT FROM AUTHOR]

This article examines the potential impact of climate change on the distribution of the Redbelly Tilapia in Iraq. The study finds that northern Iraq is the most suitable habitat for the species and emphasizes the need for proactive measures to prevent its establishment in these regions. The research provides actionable insights for conservation efforts and informs policy decisions to preserve native ecosystems. The article also highlights the importance of collaborative efforts among neighboring countries to address the challenges of invasive species spread. Additionally, the study suggests the need to balance conservation and aquacultural benefits when selecting suitable habitats for aquacultural facilities. [Extracted from the article]

This document is an essay that explores the artistic practice of Agnes Questionmark, a multimedia artist who uses performance to examine themes of organic posthumanism, environmental issues, feminist and queer theories, and the possible evolution of human beings in response to climate change. The essay focuses on three sets of performances by Questionmark, where her body is immersed in natural ecosystems, artificial spatial devices, and pools, respectively. Through these performances, Questionmark blurs the boundaries between the human body, nature, and queer theory, challenging normative models and exploring the transformative potential of the body and its relationship with water. The text discusses the artwork and performances of Agnes Questionmark, focusing on two specific pieces: Sirenomelia and TRANSGENESIS. Sirenomelia explores the concept of anomaly through the fusion of human and fish characteristics, challenging traditional notions of gender and celebrating bodily deformities. TRANSGENESIS imagines a new form of evolutionism, where humans hybridize with animals to create a new species, questioning the taxonomic order and emphasizing interconnectedness with other beings. The performances aim to provoke thought and open minds, encouraging a reevaluation of societal norms and relationships with nature. The text discusses the performance art of Agnes Questionmark, specifically focusing on her performance titled "Sirenomelia." The performance explores the concept of gender transition and challenges traditional notions of identity and sexuality. Questionmark draws inspiration from the octopus, a creature that exhibits queer characteristics, to highlight the fluid [Extracted from the article]

Summary: The phytoplankton Phaeocystis globosa plays an important role in sulfur cycling and climate control, and can develop harmful algal blooms (HABs). Here we report a chromosome-scale reference genome assembly of P. globosa, which enable in-depth analysis of molecular underpinnings of important ecological characteristics. Comparative genomic analyses detected two-rounds of genome duplications that may have fueled evolutionary innovations. The genome duplication may have resulted in the formation of dual HiDP and LoDP dimethylsulphoniopropionate (DMSP) biosynthesis pathways in P. globosa. Selective gene family expansions may have strengthened biological pathways critical for colonial formation that is often associated with the development of algal blooms. The copy numbers of rhodopsin genes are variable in different strains, suggesting that rhodopsin genes may play a role in strain-specific adaptation to ecological factors. The successful reconstruction of the P. globosa genome sets up an excellent platform that facilitates in-depth research on bloom development and DMSP metabolism.

Summary: Oyster reefs are hotspots of denitrification mediated removal of dissolved nitrogen (N), however, information on their denitrifier microbiota is scarce. Furthermore, in oyster aquaculture, triploids are often preferred over diploids, yet again, microbiome differences between oyster ploidies are unknown. To address these knowledge gaps, farmed diploid and triploid oysters were collected over an annual growth cycle and analyzed using shotgun metagenomics and quantitative microbial elemental cycling (QMEC) techniques. Regardless of ploidy, Psychrobacter genus was abundant, with positive correlations found for genes of central metabolism, DNA metabolism, and carbohydrate metabolism. MAGs (metagenome-assembled genomes) yielded multiple Psychrobacter genomes harboring norB, narH, narI, and nirK denitrification genes, indicating their functional relevance within the eastern oysters. QMEC analysis indicated the predominance of carbon (C) and nitrogen (N) cycling genes, with no discernable patterns between ploidies. Among the N-cycling genes, the nosZII clade was overrepresented, suggesting its role in the eastern oyster’s N removal processes.

Summary: Alpine lakes play pivotal roles in plateau hydrological processes but are highly sensitive to climate change, yet we lack comprehensive knowledge of their multitrophic biodiversity patterns. Here, we compared the biodiversity characteristics of diverse taxonomic groups across water depths and in surface sediments from a freshwater lake and a hypersaline lake on the northwestern Tibetan Plateau. Using multi-marker environmental DNA metabarcoding, we detected 134 cyanobacteria, 443 diatom, 1,519 invertebrate, and 28 vertebrate taxa. Each group had a substantially different community composition in the two lakes, and differences were also found between water and sediments within each lake. Cooccurrence network analysis revealed higher network complexity, lower modularity, and fewer negative cohesions in the hypersaline lake, suggesting that high salinity may destabilize ecological networks. Our results provide the first holistic view of Tibetan lake biodiversity under contrasting salinity levels and reveal structural differences in the ecological networks that may impact ecosystem resilience.

Factors influencing the distribution and variations of abundance of phytoplankton of dams are yet to be accounted for in Southwest Nigeria. Therefore, the objective of this paper was to evaluate the seasonal distribution and variations of abundance of phytoplankton community in Ikere Gorge Dam, Oyo State, Southwest Nigeria using standard techniques. Data obtained show that a total of 494 microalgal taxa belonging to eight divisions were recorded. Zygnematophyceae comprised 360 taxa (64%), Bacillarophyceae 22 taxa (14%), Chlorophyceae 66 taxa (13%), Cyanophyceae 20 taxa (4%), Dinophyceae 8 taxa (1%), Trebouxiophyceae 13 taxa (2%), Ulvophyceae 3 taxa (0.02%), Xanthophyceae 2 taxa (0.01%). The observations and results confirm hypotheses that phytoplankton abundance varies more between season (wet and dry) than spatially in Ikere gorge dam. No single taxon or a combination of two or three taxa accounted for more than 80% of the phytoplankton abundance. Canonical correspondence analysis revealed DO, TDS, nitrate-nitrogen and water transparency as the major water quality variables driving variation in the composition of plankton communities in the dam. This study showed seasonality is the major factor influencing the diversity and abundance of phytoplankton community through changes in concentrations of DO, nitrates, and phosphate. Ikere Gorge dam showed a strong seasonal variation in physicochemical water quality variables owing to the size of the dam that is not well-mixed, and with long water residence times. This study contributes to understanding the water quality, determinant factors, and drivers of biological communities in dams of tropical regions that are being influenced by anthropogenic activities. [ABSTRACT FROM AUTHOR]

Summary: Gametogenesis drives the maturation of germ cell precursors into functional gametes, facilitated by interactions with the niche environment. However, the molecular mechanisms, especially in invertebrates, remain incompletely understood. In this study, the gonadal microenvironment and gametogenic processes in the Pacific oyster, a model for diffuse gonadal organization and periodic gametogenesis, are investigated. We combine single-nucleus RNA-seq and bulk RNA-seq to analyze gonadal microenvironments in oysters. Twenty-three male and nineteen female gonadal cell clusters are identified, revealing four male and three female germ cell types, alongside follicular cells in females and Sertoli/Leydig cells in males. The NOTCH and BMP (bone morphogenetic protein) signaling pathways play a significant role in the male germline niche, suggesting similarities with mammalian germ cell microenvironment. This study offers valuable insights into germ cell developmental transitions and microenvironmental characteristics.

Summary: Coral conservation requires a mechanistic understanding of how environmental stresses disrupt biomineralization, but progress has been slow, primarily because corals are not easily amenable to laboratory research. Here, we highlight how the starlet sea anemone, Nematostella vectensis, can serve as a model to interrogate the cellular mechanisms of coral biomineralization. We have developed transgenic constructs using biomineralizing genes that can be injected into Nematostella zygotes and designed such that translated proteins may be purified for physicochemical characterization. Using fluorescent tags, we confirm the ectopic expression of the coral biomineralizing protein, SpCARP1, in Nematostella. We demonstrate via calcein staining that SpCARP1 concentrates calcium ions in Nematostella, likely initiating the formation of mineral precursors, consistent with its suspected role in corals. These results lay a fundamental groundwork for establishing Nematostella as an in vivo system to explore the evolutionary and cellular mechanisms of coral biomineralization, improve coral conservation efforts, and even develop novel biomaterials.

Factors influencing the distribution and variations of abundance of phytoplankton of dams are yet to be accounted for in Southwest Nigeria. Therefore, the objective of this paper was to evaluate the seasonal distribution and variations of abundance of phytoplankton community in Ikere Gorge Dam, Oyo State, Southwest Nigeria using standard techniques. Data obtained show that a total of 494 microalgal taxa belonging to eight divisions were recorded. Zygnematophyceae comprised 360 taxa (64%), Bacillarophyceae 22 taxa (14%), Chlorophyceae 66 taxa (13%), Cyanophyceae 20 taxa (4%), Dinophyceae 8 taxa (1%), Trebouxiophyceae 13 taxa (2%), Ulvophyceae 3 taxa (0.02%), Xanthophyceae 2 taxa (0.01%). The observations and results confirm hypotheses that phytoplankton abundance varies more between season (wet and dry) than spatially in Ikere gorge dam. No single taxon or a combination of two or three taxa accounted for more than 80% of the phytoplankton abundance. Canonical correspondence analysis revealed DO, TDS, nitrate-nitrogen and water transparency as the major water quality variables driving variation in the composition of plankton communities in the dam. This study showed seasonality is the major factor influencing the diversity and abundance of phytoplankton community through changes in concentrations of DO, nitrates, and phosphate. Ikere Gorge dam showed a strong seasonal variation in physico-chemical water quality variables owing to the size of the dam that is not well-mixed, and with long water residence times. This study contributes to understanding the water quality, determinant factors, and drivers of biological communities in dams of tropical regions that are being influenced by anthropogenic activities.

Summary: The intricate coexistence of Symbiodiniacean algae with a diverse range of marine invertebrates underpins the flourishing biodiversity observed within coral reef ecosystems. However, the breakdown of Symbiodiniaceae–host symbiosis endangers these ecosystems, necessitating urgent study of the symbiotic mechanisms. The symbiosis between nudibranchs and Symbiodiniaceae has been identified as an efficacious model for examining these mechanisms, yet a comprehensive understanding of their histological structures and cellular processes remains elusive. A meticulous histological exploration of the nudibranch Pteraeolidia semperi, employing optical, fluorescence, and electron microscopy, has revealed fine tubules extending to the body surface, with associated epithelial cells having been shown to adeptly encapsulate Symbiodiniaceae intracellularly. By tracing the stages of the “bleaching” in nudibranchs, it was inferred that algal cells, translocated via the digestive gland, are directly phagocytosed and expelled by these epithelial cells. Collectively, these insights contribute substantially to the scholarly discourse on critical marine symbiotic associations.

This paper introduces a real-time water quality dataset of five ponds for fish farming obtained through an IoT framework for monitoring the aquatic environmental conditions. It utilizes sensors and an Arduino microcontroller to collect data on pH, temperature, and turbidity in pond water in Jamalpur District, Bangladesh. The data is stored in an IoT cloud platform named ThingSpeak and analyzed using 10 machine learning algorithms. The dataset consists of 4 columns and 40,280 rows, where pH, temperature, turbidity, and fish are recorded. Fish represents the target variable, while the others serve as independent variables. Within the dataset, there are 11 distinct fish categories including sing, silver carp, Katla, prawn, karpio, shrimp, rui, pangas, tilapia, magur, and koi. Results showed that only three ponds are suitable for fish farming among five ponds and the Random Forest algorithm performs the best. The study also includes details of the IoT system's hardware. This dataset will be useful for researchers and fish farmers to predict fish survival.

In the European Union, assessments of the quality of the aquatic environment based on aquatic invertebrates are mandatory. Biological methods are supplemented with hydromorphological assessments of watercourses. There are many studies analysing the relationships between aquatic invertebrates and the hydromorphological assessment of the environment by the River Habitat Survey (RHS) method, but thus far, there has been no detailed study including water mites (Acari, Hydrachnidia) and the application of this method. In the present study, the following research hypothesis was put forth: a hydromorphological characterization of habitats is a significant element explaining the nature of water mite communities, and the RHS method can be used to predict the characteristics of Hydrachnidia populations in a river. The research was carried out in a small lowland river, the River Krąpiel (north-western Poland). Six locations were selected as representative of some state of habitat modification for the assessment of the hydromorphological conditions of the river and the collection of biological samples. The following conclusions can be drawn from the research: (1) the biology and ecology of water mites make them suitable as bioindicators of the environment, including hydromorphological modifications, and (2) the hydromorphological characteristics of habitats explain the nature of water mite communities in the river at the level of general population parameters (number of specimens and species), while at the species level, general regularities in water mite fauna distribution in river ecosystems, the continuity of the river ecosystem, and characteristics at a smaller spatial scale (habitat scale) better explain water mite community structure than the hydromorphological indices determined for a given site or section of the river. [ABSTRACT FROM AUTHOR]

Environmental pollution and degradation caused by the processing and refining of crude oil has been on the increase since its discovery in the Niger Delta region of Nigeria. Its negative impacts are unquantifiable though its refined products are of immense benefits to the nation and the world at large. An assessment of the performance of Pistia stratiotes as affected by the water soluble fraction of Universal Energy Akwa Ibom crude oil was carried out in Abraka, Delta State, Nigeria in 2023. The five levels of WSF (0, 10, 25, 50, 75 and 100%) were used. Pistia stratiotes thalli were obtained from below the Bridge along River Ethiope and exposed to the different treatments. The results showed a significant reduction (p≤0.05) in all the plant parameters measured (leaf area, plant number, fresh weights, dry weight biomass, relative growth rate and survival percentage) in plants grown in the WSF media when compared to their counterparts exposed to the control plots. Against the normal healthy plants observed in the control, signs of dieback, yellowness of leaves, suppress growth and deaths were observed in plants subjected to the water soluble fraction of the crude oil and the effects were WSF dose dependent. There was gradual reduction in the shoot biomass of the plant with increasing level of WSF. There is a gradual increase in the root biomass although there was a total root growth. The study has established that the performance of Pistia stratiotes was significantly affected by the presence of water soluble fraction of crude oil. The study has great implication on water biology and food security. Continuous environmental monitoring and remediation exercises should be conducted in oil producing communities by the government. [ABSTRACT FROM AUTHOR]

Increasingly, scientists and non-scientists, especially employees of government agencies, tend to use weak or equivocal language when making statements related to science policy and governmental regulation. We use recent publications to provide examples of vague language versus examples of strong language when authors write about regulating anthropogenic pressures on natural resources. Lifeless language is common in agency reports, policy documents, and even scientific papers published by academics. Such language limits success in regulating anthropogenic pressures on natural resources. This challenge must be recognized and countered as a driver of the condition of water and associated resources. We also list sources of vague wording, provide global examples of how ambiguous language and political influences have contributed to water resource degradation, discuss the recent history of science censorship, and offer possible solutions for more direct scientific discourse. We found that: (1) equivocal language was especially common in concluding statements and not only by government employees; (2) authors discussed confusing language concerns in an agency publication; and (3) agency employees sometimes used active, strong language. Key drivers of weak language include: (1) holding on to old paradigms and resisting new knowledge; (2) scientific uncertainty; (3) institutional manuscript review policies; (4) employment and funding insecurity; and (5) avoiding the appearance of advocacy. Examples associated with euphemistic language included climate change, flow and physical habitat alteration, dams, agriculture, mining, forestry, and fisheries, as well as resistance towards monitoring, assessing, and reporting ecological conditions. Suggestions for mitigating equivocal language involve employment protections and greater focus on scientific ethics. We conclude that natural resource scientists should resist calls to employ imprecise language. Instead, they should be strong advocates for prescriptive and protective natural resource actions--based on their science--to halt and reverse the systemic degradation of those resources. [ABSTRACT FROM AUTHOR]

The article deals with the relationship between morphometry and hydrobiological regime. The Shurtan reservoir located in the southern part of the Republic of Uzbekistan is chosen as the Object of the study. Studying the problem of reservoir overgrowth and its connection with morphometry, especially in reservoirs with depth up to 2 metres, and the influence of sunlight penetration, requires application of various research methods. The water level mark in the reservoir during the period of field studies was ∇ 420.325 m, the reservoir water volume was 7.5 million m3 and the water surface area was 7.10 km2. On the basis of application of modern technologies of geoinformation system for assessment of hydrological and hydrobiological processes on the reservoir, an electronic map of the Shurtan reservoir basin was made. The results of the study using GIS technologies showed that the coastal zones of the reservoir bowl are covered with algae (reeds), their area is growing every year. If its area in 2007 was-0.386km2, in 2014 it reached an area of 0.677km2. In 2018, work was done to clear the coastal zones of vegetation, but by 2023 everything is covered with plants again. [ABSTRACT FROM AUTHOR]

In the present study, we report on the Eurasian Ruffe (Gymnocephalus cernuus) in the Mandra Lake at City of Burgas. This is the only water basin in southeastern Bulgaria that is known to be inhabited by the species. The Eurasian Ruffe was detected in Mandra Lake for the first time in 1998; since then, there has been no information concerning the local population. We captured two adult G. cernuus in the winter of 2020 and propose these specimens represent a permanent viable population. In this study, we report the first specimens registered by professional biologists, thus confirming the data acquired by sports fishermen over the years. [ABSTRACT FROM AUTHOR]

Summary: Marine group II (MGII) is the most abundant planktonic heterotrophic archaea in the ocean. The evolutionary history of MGII archaea is elusive. In this study, 13 new MGII metagenome-assembled genomes were recovered from surface to the hadal zone in Challenger Deep of the Mariana Trench; four of them from the deep ocean represent a novel group. The optimal growth temperature (OGT) of the common ancestor of MGII has been estimated to be at about 60°C and OGTs of MGIIc, MGIIb, and MGIIa at 47°C–50ºC, 37°C–44ºC, and 30°C–37ºC, respectively, suggesting the adaptation of these species to different temperatures during evolution. The estimated OGT range of MGIIc was supported by experimental measurements of cloned β-galactosidase that showed optimal enzyme activity around 50°C. These results indicate that MGIIc may have originated from a common ancestor that lived in warm or even hot marine environment, such as hydrothermal vents.

Summary: Antibiotic resistance genes (ARGs) are emerging as environmental pollutants that can persist and disseminate in aquatic environments. Lakes, as important sources of freshwater, also serve as potential natural reservoirs of ARGs. In this study, we analyzed the distribution and potential risks of resistance genes in five typical freshwater lakes on the Yunnan-Guizhou Plateau. Our findings revealed that multidrug and MLS ARGs dominated in the studied lakes. Notably, while Lugu Lake exhibited higher abundance of ARGs, mobile genetic elements (MGEs), and metal resistance genes (MRGs), a greater resistome risk was observed in the eutrophic Xingyun Lake. The dissemination processes of ARGs and MRGs are primarily driven by microbial communities and the horizontal gene transfer via MGEs. Limnohabitans, Flavobacterium, and Acinetobacter were identified as key players in the dissemination of ARGs. Our study highlights the persistence of ARGs and provides valuable baseline data and risk assessment of ARGs in plateau freshwater lakes.

The presence of pharmaceuticals in the aquatic environment presents a challenge to modern science. The most significant impact this can induce is the emergence of antibiotic resistance, which can lead to a global health emergency. It is important to note that the impact of pharmaceuticals in the aquatic environment is not limited to antibiotic resistance. Pharmaceuticals can also affect the behaviour and reproductive systems of aquatic organisms, with cascading effects on entire ecosystems. Numerous studies have reported the emergence of pharmaceuticals due to the uncontrolled disposal of polluted domestic, agricultural, and industrial wastewater in water bodies. This work discusses the potential of pharmaceuticals that on one hand are highly important for mankind, yet their non-judicious usage and disposal induce equally intriguing and problematic conditions to the health of aquatic systems. Pathways through which pharmaceutics can make their way into water bodies are discussed. Furthermore, the risk imposed by pharmaceuticals on aquatic life is also elaborated. The possible and pragmatic remediation methods through which pharmaceutical products can be treated are also discussed. Emphasis is placed on the potential of phytoremediation and advanced oxidative process, and the factors affecting the efficacy of these remediation methods are discussed. [ABSTRACT FROM AUTHOR]

The data obtained by the authors confirm that I Unionicola i mites are narrow host specialists that are associated with either one or a few closely related freshwater mussel species belonging to one or two sister genera. They discovered 39 taxa that belonged to the genus I Mallomonas i (37 taxa) and the genus I Synura i (2 taxa). Some articles on the communities of aquatic ecosystems included a broad spectrum of taxonomic groups. Twenty-one studies on the diversity of aquatic organisms inhabiting water ecosystems in Europe, Asia, Africa, North America, and Oceania were collected for the current Special Issue. [Extracted from the article]

In 2018, the hardscape construction of NCOS (North Campus Open Space), a restored wetland on the Northern border of COPR (Coal Oil Point Reserve), was completed, thus approximately doubling the overall size of the wetland and offering the rather unique opportunity of being able to compare the two side-by-side.  Basic water quality and aquatic invertebrate monitoring of both sites were undertaken to better understand the dynamics of how a newly constructed wetland developed into an established wetland.The surprising result of this first year of monitoring is that COPR and NCOS were more or less equivalent in species richness and abundance, with the Shannon-Wiener Index giving a slight nod to NCOS for more diversity and Evenness in the data.Four taxa are the most significant contributors to the total taxa observed – Copepods, Ostracods, Cladocera, and Corixidae.  Additionally, we found Chironomids, Ceratopogonidae, Ephydridae, and Nematodes in significant abundance.Sampling protocols were evaluated indicating that sampling in algae gives more than an order-of-magnitude greater abundance and diversity than in sampling in open water and that the Filtered Beaker method gives more precise species density information than the Sweep-Net method; when sampling at shallower depths where the Sweep-Net is not fully submerged.Additionally, the effect on other aquatic invertebrates of the use of VectoBac for mosquito abatement was looked at – indicating a minimum, if any, affect.

The aim of this review paper is to identify the production trends of shrimp and rice farming systems and associated hydrobiological parameters such as salinity in the coastal districts of Bangladesh. An intensive literature review has been conducted to explore salt stress-driven land use change, crop production, and changing ecosystem hydrobiology to adapt climate change impact from 2012–2022. The results indicate that a gradual extension of salt-driven land use and land cover (LULC) change has stressed agricultural production to a greater extent from 1973 to 2022 due to the high level of salinity. The unplanned expansion of shrimp culture is creating adverse consequences for the coastal ecosystem. Some suggestions have been proposed by analysing the mechanisms of crops' response to salt stress, including several physiological, biochemical, and molecular bases to mitigate the adverse effects of salinity on agricultural production. Alternatively, prawn, shrimp, and crab have similar or slightly higher economic outputs, except for the crop-based agricultural system, which is highly affected by salinity rise. However, due to low input costs, low maintenance, and less environmental impact, farmers are shifting towards crab fattening and thus changing the hydrobiology of coastal land use and land cover. [ABSTRACT FROM AUTHOR]

Summary: Trade restrictions for endangered elasmobranch species exist to disincentivise their exploitation and curb their declines. However, trade monitoring is challenging due to product variety and the complexity of import/export routes. We investigate the use of a portable, universal, DNA-based tool which would greatly facilitate in-situ monitoring. We collected shark and ray samples across the Island of Java, Indonesia, and selected 28 commonly encountered species (including 22 CITES-listed species) to test a recently developed real-time PCR single-assay originally developed for screening bony fish. In the absence of a bespoke elasmobranch identification online platform in the original FASTFISH-ID model, we employed a deep learning algorithm to recognize species based on DNA melt-curve signatures. By combining visual and machine-learning assignment methods, we distinguished 25/28 species, 20 of which were CITES-listed. With further refinement, this method can improve monitoring of the elasmobranch trade worldwide, without a lab or species-specific assays.

Summary: Marine biofouling causes huge economic losses to the marine industry every year. Albofungin is a potential antifoulant showing strong anti-macrofouling activities against larval settlement of major fouling organisms. In the present study, directed RNA-seq and proteomic analyses were used to investigate changes in the transcriptome and proteome of a major fouling barnacle Amphibalanus amphitrite cyprids in response to albofungin treatment. Results showed that albofungin treatment remarkably upregulated the metabolism of xenobiotics by the cytochrome P450 pathway to discharge the compound and downregulated energy metabolic processes. Intriguingly, immunostaining and whole-mount in situ hybridization (WISH) revealed the spatial expression patterns of selected differentially expressed genes (glutathione S-transferase [GST], nitric oxide synthase [NOS], and calmodulin [CaM]) distributed in the thorax and antennule of A. amphitrite. Our study provides new insights into the mechanism of albofungin in interrupting the larval settlement of A. amphitrite and suggests its potential application as an antifouling agent in marine environments.

Summary: Mesophotic reefs have been proposed as climate change refugia but are not synonymous ecosystems with shallow reefs and remain exposed to anthropogenic impacts. Planulae from the reef-building coral Stylophora pistillata, Gulf of Aqaba, from 5- and 45-m depth were tested ex situ for capacity to settle, grow, and acclimate to reciprocal light conditions. Skeletons were scanned by phase contrast-enhanced micro-CT to study morphology. Deep planulae had reduced volume, smaller diameter on settlement, and greater algal symbiont density. Light conditions did not have significant impact on settlement or mortality rates. Photosynthetic acclimation of algal symbionts was evident within 21–35 days after settlement but growth rate and polyp development were slower for individuals translocated away from their parental origin compared to controls. Though our data reveal rapid symbiont acclimation, reduced growth rates and limited capacity for skeletal modification likely limit the potential for mesophotic larvae to settle on shallow reefs.

This document is an editorial published in Frontiers in Physiology titled "Sensory systems of aquatic animals." The editorial discusses the importance of sensory systems in aquatic animals for their survival and adaptation to different environments. It highlights four articles included in the special issue that examine the auditory, olfactory, and visual systems of various aquatic species, as well as the biology of TRP channels. The articles provide new insights into the sensory biology of aquatic animals and have implications for understanding their biology and managing anthropogenic impacts on their habitats. [Extracted from the article]

Employing history of science methods, including analyses of the scientific literature, archival documents, and interviews with scientists, this paper presents a history of lampreys in neurobiology from the 1830s to the present. We emphasize the lamprey’s roles in helping to elucidate spinal cord regeneration mechanisms. Two attributes have long perpetuated studies of lampreys in neurobiology. First, they possess large neurons, including multiple classes of stereotypically located, ‘identified’ giant neurons in the brain, which project their large axons into the spinal cord. These giant neurons and their axonal fibers have facilitated electrophysiological recordings and imaging across biological scales, ranging from molecular to circuit-level analyses of nervous system structures and functions and including their roles in behavioral output. Second, lampreys have long been considered amongst the most basal extant vertebrates on the planet, so they have facilitated comparative studies pointing to conserved and derived characteristics of vertebrate nervous systems. These features attracted neurologists and zoologists to studies of lampreys between the 1830s and 1930s. But, the same two attributes also facilitated the rise of the lamprey in neural regeneration research after 1959, when biologists first wrote about the spontaneous, robust regeneration of some identified CNS axons in larvae after spinal cord injuries, coupled with recovery of normal swimming. Not only did large neurons promote fresh insights in the field, enabling studies incorporating multiple scales with existing and new technologies. But investigators also were able to attach a broad scope of relevance to their studies, interpreting them as suggesting conserved features of successful, and sometimes even unsuccessful, CNS regeneration. Lamprey research demonstrated that functional recovery takes place without the reformation of the original neuronal connections, for instance, by way of imperfect axonal regrowth and compensatory plasticity. Moreover, research performed in the lamprey model revealed that factors intrinsic to neurons are integral in promoting or hindering regeneration. As this work has helped illuminate why basal vertebrates accomplish CNS regeneration so well, whereas mammals do it so poorly, this history presents a case study in how biological and medical value have been, and could continue to be, gleaned from a non-traditional model organism for which molecular tools have been developed only relatively recently.

Research on the algicidal and bactericidal properties of a copper-containing glassy phosphate composition (CGPC) is reported. It was established that the presence of CGPC in aqueous solutions inhibits the reproduction of bacteria and microflora of water [water biology] because a protective phosphate film, forming both on the surface of heating elements and on the surface of the microflora of the water, does not lose its continuity, because the readily soluble sodium components of the composition undergo partial hydrolysis, and prevents the access of oxygen to the microflora of water and water-containing solutions, whereas copper cations effect inhibition of the vital activity of biological pollutants. CGPC can be recommended for water treatment for any purpose associated with water use. [ABSTRACT FROM AUTHOR]

A correction to the article "Opah (Lampris megalopsis) Genome Sheds Light on the Evolution of Aquatic Endothermy" that was published in a 2022 issue is presented.

Although they are among the most abundant snakes on Earth, and are heavily exploited for their skins and meat, Asian bockadams (or "dog-faced water snakes", Cerberus schneiderii) have attracted relatively little study across their wide geographic range. Based on dissection of 3,382 snakes brought to processing facilities in and around the city of Cirebon in West Java, Indonesia, we document facets of the biology of these mangrove-dwelling aquatic homalopsids. Females attain larger body sizes than do males, and are heavier-bodied (due in part to greater fat reserves) but have shorter tails relative to snout-vent length. Males showed testicular enlargement late in the year (August-November) but both reproductive and non-reproductive females were found year-round. Litters were large (3 to 45 offspring), especially in larger females. The commercial harvest falls mainly on adult snakes of both sexes, with seasonal variation in sex ratios. Life-history traits such as early maturation and frequent production of large litters render this species resilient to commercial harvesting. Future research should explore reasons for strong variation among facilities in the sex ratios of snakes, potentially identifying ways to focus the harvest on the sex (males) whose numbers are less critical for population viability. [ABSTRACT FROM AUTHOR]

Tropical and sub-tropical streams harbor great biodiversity and are responsible for crucial ecosystem services. Intending to contribute to the understanding of how anthropogenic stressors and pressures alter functional or taxonomic diversity in biotic assemblages or processes in these systems, Water Biology and Security published eight papers. The research originated from Cameroon (Central Africa), southeastern Brazil, eastern Amazonia, and eastern China, representing eight river basins: Huai, Sui and Yishusi from east Asia; S~ao Francisco, Doce, Jequitinhonha, and Amazon from South America; and Congo from Africa. The last two are the most biodiverse on the planet. The studied biomes included tropical rainforest and savanna, neotropical savanna and rainforest, neotropical savanna mountains, and subtropical monsoon forest. The response variables included fish assemblages (3 papers), entire macroinvertebrate assemblages or sub-groups (4 papers), and stream physical habitat structure (1 paper). [ABSTRACT FROM AUTHOR]