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Mucosal barriers are gatekeepers of health and exhibit homeostatic variation in relation to habitat and disease. Mucosal Mapping technology provides an in‐depth examination of the dynamic mucous cells (MCs) in fish mucosal barriers on tangential sections, about 90° from the view of traditional histology. The method was originally developed and standardized in academia prior to the establishment of QuantiDoc AS to apply mucosal mapping, now trademarked as Veribarr™ for the analysis of skin, gills and gastrointestinal tracts. Veribarr™ uses design‐based stereology for the selection and measurement of cell area (size) (μm2), the volumetric density of MCs in the epithelium (MCD, amount of the epithelia occupied by MCs, in %) and the calculated abundance of the MCs (barrier status or defence activity). MC production was mapped across the skin and gill epithelia in 12 species, discovering that gills consistently have two distinct groups of MCs, one on the lamellae where MCs are few and small and one on the filament where MCs are larger and more abundant. MCs were usually much larger in the skin than in the gills, with the latter requiring fewer and smaller cells for adequate respiration. The difference observed between MCs in gill lamella and gill filament is likely a result of functional demands. In addition, our findings also highlight a variation in the mucosal parameters between the species skin, which cannot be explained by the weight differences, and a potential link between MC distribution and species‐specific lifestyles in the gill lamella. This diversity necessitates the development of species and tissue site‐specific reference intervals for mucosal health evaluation. Mucosal bivariate reference intervals were developed for MC production, including size (trophy) and calculated defence activity (plasia) in the skin and gills of Atlantic salmon, to contrast new measurements against historical data patterns. The application of mucosal reference intervals demonstrates that stress from parasites and treatments can manifest as changes in mucosal architecture, as evidenced by MC hypertrophy and hyperplasia within the gill lamellae. These reference intervals also facilitate comparisons with wild Atlantic salmon, revealing a somewhat higher MC level in farmed salmon gill lamellae. These findings suggest that MC hyperplasia and hypertrophy in the gills are stress/environmental responses in aquaculture. They also advocate for developing specific mucosal bivariate homeostatic reference intervals in aquaculture to improve fish health and welfare across all farmed species. [ABSTRACT FROM AUTHOR]

The inclusion of microalgae in functional fish diets has a notable impact on the welfare, metabolism and physiology of the organism. The microbial communities associated with the fish are directly influenced by the host's diet, and further understanding the impact on mucosal microbiota is needed. This study aimed to analyze the microbiota associated with the skin and gills of Sparus aurata fed a diet containing 10% microalgae. Sequencing of the V3-V4 variable region of 16S rDNA molecules was employed to determine the composition of the microbial communities. The study employed bioinformatics tools to explore the taxonomic composition and interactions of the microbiota, emphasizing the integration of taxonomic analysis and abundance correlation networks as crucial for understanding microbial community dynamics and the impact of functional diets. The results indicated that there were not changes in the composition of the skin and gill microbiota. However, notable differences were observed in the bacterial interaction networks. The skin and gill networks exhibited distinct overall patterns influenced by their respective environments and functions. The gill network showed a highly connected and redundant structure, increasing its resilience, while the skin network showed a more fragmented structure, suggesting a potentially greater vulnerability to perturbations. Key taxa, such as Acinetobacter and Polaribacter, were identified as critical for maintaining the stability and functionality of these microbial ecosystems. Polaribacter could demonstrate potential protection against pathogens through negative interactions. These tentative studies open up an additional avenue to consider, such as the interactions among bacterial communities, as well as new proposals to corroborate these findings. These observations underline the importance of understanding the composition and interactions within bacterial groups to fully grasp the dynamics of microbial communities. [ABSTRACT FROM AUTHOR]

ABSTRACT Myxobolus Bütschli, 1882 is a highly important genus of fish myxozoans, consisting of many species that cause serious diseases in ornamental cyprinid fish species in different geographic areas by infecting a wide range of organs. This study describes a new Myxobolus species infecting the gill lamellae, gill rakers and skin epidermis of goldfish (Carassius auratus) from Mohammadshahr, Iran, based on detailed morphological, histological and molecular analysis. Mature spores were small and spherical in shape, consisting of two symmetrical shell valves in frontal view, measuring 10.3 (9.8–10.9) μm in length and 10.5 (10.3–11.2) μm in width. Two equal‐sized relatively pyriform polar capsules were 5.4 (3.9–6.0) μm long and 4.5 (3.7–5.2) μm wide. The polar tubules were coiled with 4–6 turns. A comparative analysis of the morphological and molecular data confirmed that this species is distinct from other identified myxosporeans. Plasmodia in the cutaneous tissue were found in the epidermis, causing extensive hyperplasia of Malpighian cells and mild inflammatory infiltration. In the gill tissue, plasmodia affected only one side of the lamellae, leading to hyperplasia of the lamellar epithelium, edema, and lymphoplasmacytic branchitis. A novel myxozoan species, Myxobolus branchioepidermis n. sp., has been proposed. The study provides a comprehensive analysis of the morphological, histological, and molecular characteristics of this parasite, which infects the gill lamellae and epidermal layer of the skin in oranda goldfish (C. auratus). The identification of this new species adds to the growing body of research on myxozoan parasites and highlights its potential impact on ornamental fish aquaculture. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are a worldwide contaminant of significant environmental concern due to their persistence, widespread distribution, and toxic potential. These plastic particles are taken up by invertebrates such as bivalves. Previous studies have indicated that MPs can serve as carriers for other contaminants, such as heavy metals, thereby increasing their bioavailability to organisms, with unpredictable ecological consequences. Therefore, the main aim of this study was to evaluate the effects of exposure to MPs, cadmium (Cd), and their mixtures (Mix) in the gills, digestive gland, and gonad of the Asian clam, Corbicula fluminea, assessing the oxidative stress responses, LDH activity, and neurotoxicity over 7, 14, 21, and 30 days. The results show that exposure to MPs and their mixtures with the lowest Cd concentration led to the activation of the first line of antioxidant defenses, especially SOD and CAT, in the gills, digestive gland, and gonads. An increase in GST activity was also observed in the gonads. However, the response of GST activity in the gills and digestive gland was opposite that observed in the gonads. Furthermore, LDH activity exhibited contrasting responses, increasing in the digestive gland and decreasing in the gills and gonads. Exposure to MPs induced AChE activity, which contradicts previous findings. The results provide novel insights into the biological responses occurring in different target organs and shed light on the effects of MPs and their mixtures on C. fluminea. [ABSTRACT FROM AUTHOR]

Concepts of capital have become increasingly vacuous. Attempts to appear au courant have led to conceptualisations that create more confusion than clarification. A critical question is how to redefine 'capital' to make it both consistent and concrete relevant to the challenges of the twenty-first century. Capital Redefined: A Commonist Value Theory for Liberating Life, authored by S.A.H. Hosseini and Barry Gills, seeks to address this challenge. Based on a careful reading, analysis of, and reflections on, their theory, it is argued that while to liberate life fully, subsequent works would need to develop evolutionary theories of the commons centred on land, the theory succeeds in developing a distinctive critique and redefinition of capital. [ABSTRACT FROM AUTHOR]

The proliferation of policy notwithstanding, climate emergency continues to unfold and the need for new ideas is urgent. In this short article, I contextualize the need for 'revolutions for life' and set out some of the key ideas from Hosseini and Gills' recent book Capital redefined. [ABSTRACT FROM AUTHOR]

While it is known that sea surface temperature (SST) variability in the subtropical northeastern Pacific (SNEP) can be forced by wintertime atmospheric variability, the region over which atmospheric variability plays the significant driving role remains to be elucidated. Based on observational data during 1900–2014 and a first-order autoregressive model, we show that SNEP SST variability is dominantly forced by wintertime atmospheric variability over the North Pacific, slightly north of the SNEP. Atmospheric variability south of the SNEP, however, does not play the dominant driving role because of atmospheric barotropic response that partially offsets baroclinic Gill response over the ocean surface. Further, by decomposing North Pacific atmospheric variability into tropical Pacific (TP)-forced and non-TP-forced components using a tropical Pacific pacemaker experiment, we find that the leading modes in the two components comparably contribute to forcing SNEP SST in the historical record. Further analyses show that their contribution is unstable on decadal timescales, with stronger forcing effect from TP-forced Aleutian Low (AL) variability before the 1930s and after the 1980s. Such non-stationary forcing effect is primarily attributed to the relative amplitude between TP-forced AL and non-TP-forced atmospheric variability, which would affect the predictability of SNEP SST variability. [ABSTRACT FROM AUTHOR]

Article PDF first page previewGraphGraphCloseBy Stephanie BurtReported by Author [Extracted from the article]

The Egyptian aquaculture sector is still struggling to establish L. vannamei culture. In an effort to stimulate shrimp production with minimal environmental impact and less water loss, biofloc technology (BFT) has been employed. Chronic mortality was recently observed in L. vannamei which was raised in the BFT system. Examining samples of moribund shrimp revealed sporadic melanization on the musculature and gills, suggesting the potential existence of black gill disease. The present work was carried out to isolate and identify potentially implicated fungus species based on mycological properties of interest. To isolate and serve as initial identification tools, wet mount preparations and colonial features, along with slide culture techniques, were used. PCR assays, gene sequencing, and phylogenetic analyses were used in the molecular identification process to clarify the confirmation of the fungal isolates that were acquired. The pathogenicity tests were designed to fulfil Koch's postulates in addition to clarifying the infectivity of isolated fungus. Moreover, histopathological examination was employed to notice tissues' alterations associated with experimentally infected shrimp. The results revealed the isolation of three fungal isolates, namely, BNS 1117, BNS 2117, and BNS 3117, that were confirmatively identified as Fusarium verticillioides, and their selected sequences were submitted to Genbank. Moreover, experimental infection using F. verticillioides selected isolate (BNS 31,117) at both high (5 × 105 CFU/mL, group A) and low (3 × 105 CFU/mL, group B) doses of its conidial suspensions experienced cumulative mortality of 72.2% and 21.1%, respectively. Besides, the selected isolate was re-isolated from the experimentally infected shrimp in a pure form, which satisfied Koch's postulates. Histopathological alterations demonstrated several degrees of either degenerative, oedema, or proliferative changes in the hepatopancreas, musculatures, and gills, respectively. This study sets a new record for F. verticillioides to be included in Fusarium species linked to shrimp mortality. [ABSTRACT FROM AUTHOR]

Research Summary: This study explores how traditional craft produces novelty, which appears to be at odds with its emphasis on continuation. While prior research has explored how tradition is rediscovered and revived from the past, traditional craft can produce intrinsic novelty potentially through its own repetitive acts. This study examines a Japanese cuisine Kaiseki, which is traditional but simultaneously innovative. The analysis of a well‐known chef's design processes reveals that the chef designs novel dishes by responding to what has been done before, making something better and differently and thereby going beyond the limit of the tradition; Kaiseki tradition is re‐enacted through such practices. A process philosophy of Gills Deleuze is engaged to explain our concept of "tradition as capacity" as well as "tradition as object." Managerial Summary: Tradition is now seen as important source of value. This study explains how craft can be both traditional and innovative. Typically, innovation has been explained by recombination with new technologies and restoration and reinterpretation to reinvigorate identity rooted in the past, this study sheds light on the intrinsic novelty within the practices of craft. This novelty is evident in traditional Japanese cuisine, called Kaiseki, which is traditional but also innovative because customers seek novel exquisite experience as they do in any Michelin Guide starred restaurants. Through the analysis of a chef's practices, we propose a new conceptualization of tradition as capacity. The creative force of this tradition as capacity is important for creating new opportunities and novel values. [ABSTRACT FROM AUTHOR]

Introduction: Anacanthorus silvoi n. sp. (Dactylogyridae, Anacanthorinae) is described from the gills of Hoplias aff. malabaricus (Bloch, 1794) from the Salgado River, Ceará state, Brazil. Materials and Methods: The monogeneans were affixed onto slides using Gray and Wess's medium for examination of their sclerotized structures. For analysis of internal organs, a single specimen was preserved in 5% formalin, stained with Gomori's trichrome, and mounted in Gray and Wess's medium. Results: Anacanthorus silvoi n. sp. is characterized by having a short broad tube MCO with a medial constriction (i.e., MCO with distal region wider than the proximal region, and flexed lateral flap in the distal region in A. cururutuiensis and a MCO with a small projection in the form of a hook in the distal region in A. siphonocommus). Conclusions: The present study corroborates previous studies that the absence of an accessory piece is a characteristic shared by all Anacanthorus members parasites of Erythrinidae. [ABSTRACT FROM AUTHOR]

Metazoans comprise multiple physical niches ("microenvironments"), each colonized by unique microbiomes that contribute to their hosts' evolutionary dynamics, influencing their health, physiology, and adaptation to changing environments. Most wildlife microbiome studies focus on higher metazoans and multiple host microenvironments, while studies of lower species often concentrate on a single microenvironment, sometimes pooling whole bodies or specimens. This is particularly evident in small-sized animals, such as freshwater meiofaunal invertebrates, thus impeding a holistic understanding of microbiome assembly across host microenvironments and its relation with host population genetics. Leveraging the anostracan fairy shrimp Branchinecta , which has easily discernible organs and expected high levels of intraspecific genetic divergence, we aimed to investigate the microbiome assembly processes and test the phylosymbiosis signal in two microenvironments (gill and intestine) across four host populations of Branchinecta gaini within Maritime Antarctica, using 16S rRNA metabarcoding. Our results showed that the gill and intestine harbor strikingly different microbiomes resulting from the B. gaini ecological filtering of the surrounding environment microbial community. Both microenvironments exhibit their respective core microbiomes, yet the gill's core microbiome is narrower and constitutes a smaller proportion of the overall bacterial community compared to that of the intestine. Within each host population (i.e. each sampling site), the microbiome assembles through distinct eco-evolutionary processes in both microenvironments, mostly stochastically (ecological drift) in the gill and deterministically (variable selection) in the intestine. Across different B. gaini populations, variable selection dominates in driving compositional divergence of both microenvironment microbiomes, although to a lesser extent in the gill. Lastly, our study reveals robust correlation between host intraspecific genetic structure and intestine microbiome composition, providing evidence of phylosymbiosis in anostracans. Contrastingly, phylosymbiosis was less pronounced in the gill microbiome. We discuss the potential differences in ecological filtering between each host microenvironment that may underlie the difference in the strength of phylosymbiosis. Our study highlights the relevance of considering host microenvironment and intraspecific levels in testing the phylosymbiosis hypothesis to better understand the intricate eco-evolutionary relationships between hosts and their microbiomes. [ABSTRACT FROM AUTHOR]

Background: Salmon aquaculture involves freshwater and seawater phases. Recently there has been an increase in multifactorial gill health challenges during the seawater phase which has led to an urgent need to understand the gill microbiome. There is a lack of understanding on what drives the composition of the gill microbiome, and the influence the freshwater stage has on its long-term composition. We characterise the gill microbiome from seven cohorts of Atlantic salmon raised in six different freshwater operational systems—recirculating aquaculture system (RAS), flowthrough (FT) and loch-based system, prior to and after transfer to seven seawater farms, over two different input seasons, S0 (2018) and S1 (2019). Results: Using the V1-V2 region of the 16S rRNA gene, we produced amplicon libraries absent of host contamination. We showed that hatchery system influenced the gill microbiome (PERMAOVA R2 = 0.226, p < 0.001). Loch and FT systems were more similar to each other than the three RAS systems, which clustered together. On transfer to sea, the gill microbiomes of all fish changed and became more similar irrespective of the initial hatchery system, seawater farm location or season of input. Even though the gill microbiome among seawater farm locations were different between locations (PERMAOVA R2 = 0.528, p < 0.001), a clustering of the gill microbiomes by hatchery system of origin was still observed 7–25 days after transfer (PERMAOVA R = 0.164, p < 0.001). Core microbiomes at genera level were observed among all fish in addition to freshwater only, and seawater only. At ASV level core microbiomes were observed among FT and loch freshwater systems only and among all seawater salmon. The gill microbiome and surrounding water at each hatchery had more shared ASVs than seawater farms. Conclusion: We showed hatchery system, loch, FT or RAS, significantly impacted the gill microbiome. On transfer to sea, the microbiomes changed and became more similar. After transfer, the individual sites to which the fish were transferred has a significant influence on microbiome composition, but interesting some clustering by hatchery system remained. Future gill disease mitigation methods that target enhancing the gill microbiome may be most effective in the freshwater stage, as there were more shared ASVs between water and gill at hatchery, compared to at sea. [ABSTRACT FROM AUTHOR]

Cichlidogyrus spp. are dactylogyridean ectoparasites of wild cichlids and cultured Nile tilapia that occur in several regions worldwide. They can be abundant in intensive Nile tilapia culture and cause mild to severe gill pathogenic effects that frequently are overlooked. From January to June 2018, a follow-up study was conducted on an intensive farm where 360 Nile tilapia were sampled and analyzed throughout a six-month culture cycle. During the survey, a population of monogeneans was observed to increase steadily over the course of the production cycle. To corroborate the status of these parasites, 13 additional farms were visited from January to April 2020, where a total of 130 Nile tilapia were examined. This secondary sampling aimed to identify and corroborate the dominant monogenean species and the infection dynamics, including the associated histopathological damages. Nine species of the genus Cichlidogyrus (Cichlidogyrus sp. C. bifurcatus, C. dossoui, C. halli, C. haplochromii, C. longicornis, C. sclerosus, C. thurstonae and C. tilapiae) were recovered from the gills and identified. Overall, Cichlidogyrus sclerosus was the most prevalent and abundant parasite. Also, significant differences were found in the monthly prevalence and intensity of C. sclerosus, especially in the fourth month of culture when the population peaked (Chi-square, p < .001; p < .001, respectively). Correlations were observed between temperature, nitrite, and C. sclerosus intensity. Four left gill arches of 130 Nile tilapia collected in the farms were removed and fixed at 10% formalin for histopathological examination. Histological alterations in gills tissues were graded by severity scores. Gills, at the site of monogenean attachments, showed mucus secretion, hyperplasia, hypertrophy, and lamellar fusion involving mucous cells, depending on the intensity of the damage. [ABSTRACT FROM AUTHOR]

Carbonate alkalinity (CA) is the major toxic factor that interferes with the survival and growth of shrimp in saline–alkaline water. Gills are the main entry organ for CA toxicity in shrimp. In this study, low-salinity cultured Litopenaeus vannamei were exposed to 5 mmol/L CA stress for 7 days and then recovered for 7 days to explore the physiological changes in the gills under CA stress and recovery conditions at multiple biological levels. The results showed that CA stress increased the activities of antioxidative biochemical indexes (T-AOC, T-SOD, and POD) and the relative expression levels of romo1, nrf2, and gpx genes, while it decreased the relative expression levels of the sod and hsp70 genes. In addition, CA stress also increased the relative expression levels of genes involved in endoplasmic reticulum (ER) stress (bip, ire1, and xbp1), immunity (alf, crus, pen-3 and propo), apoptosis (casp-3), detoxification metabolism (cyp450 and gst), and osmotic adjustment (ca, nka-α, nka-β, vatp, nhe, clc, aqp, tip4, and ccp). Although changes in some of the physiological indexes were reversed after the CA stress was relieved, they still could not effectively recover to the control level. These results reveal that CA stress has a negative impact on physiological homeostasis in the shrimp gills by inducing oxidation and ER stress and by interfering with immunity, apoptosis, detoxification, and osmotic adjustment. [ABSTRACT FROM AUTHOR]

Fish are exposed to various parasites such as monogeneans which are flatworms that preferentially affect the gills and skin of these hosts. This study represents the first investigation concerning the distribution of monogenean infracommunities of Enteromius guirali in Cameroon. A total of 100 fish were collected from Cesala River and preserved in 8% formalin solution. Parasite community consisted of Dactylogyrus mendehei and D. nyongensis. These monogenean species adopted an aggregated distribution. Their mean intensities and prevalence increased with host size. Both sides of E. guirali were similarly infested, and no preference for gill arches was recorded for each parasite species. Posterior hemibranch was always the most parasitized, showing the highest parasitic load. Median sector and distal filamentous zone were highly colonized by both monogenean species. This study contributes to understand that the large gill surface offered by great hosts, heterogeneity, bilateral symmetrically of the host’s gill system on one hand, and the morphology of haptoral parts and reproduction of parasites, on the other hand, are the main factors which determine the distribution of studied component community. [ABSTRACT FROM AUTHOR]

The feeding behaviour of fish is drastically influenced by food availability and dietary preferences. In omnivorous fish, chemoreception plays an important role in feeding and morphological adaptations may be observed in several regions of the body. However, it is not clearly known if the fish need to feel the taste before swallowing the food. The present study aims to describe the receptors for taste perception and their distribution at the level of the gill rackers, underlining their importance in the food sorting behaviour. Paired gills were harvested from Carpathian gudgeon fish Gobio carpathicus Vladykov, 1925 and immersed in 10% buffered formalin. The samples were processed according to the current paraffin embedding technique and stained with Goldner's trichrome method. The obtained results suggest that the Carpathian gudgeon presents, up to a point, the common gill morphology. However, on the pharyngeal face of the gills, more exactly on the gill rackers, are present several structures with an onion-like shape, disposed through the surface of the epithelium. Those elements consist of sensorial cells, sustained by sustentacular and basal cells, forming a taste bud. Due to their disposition on the inner surface of the gills, those structures may act like a sorter, enhancing the rackers sieve activity. In conclusion, the histological findings suggest that the Carpathian gudgeon, a common omnivorous fish, may use taste reception at the level of the gill rackers before swallowing the food. [ABSTRACT FROM AUTHOR]

To explore the impacts of acute ammonia nitrogen (NH3-N) stress on gill structure and the antioxidant ability of red and white muscles in juvenile yellowfin tuna (Thunnus albacares), this study used natural seawater as a control, establishing two experimental NH3-N groups at 5 and 10 mg/L. Gills and red and white muscle were taken at 6, 24, and 36 h for the determination of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GHS-PX) levels, and to observe gill structure. The results indicated that, with increasing time, the MDA concentration and CAT activity in the gills of the 5 mg/L group showed a trend of first increasing and then decreasing, while SOD activity exhibited a downward trend. In the 10 mg/L group, MDA concentration showed an increasing trend, while SOD, CAT, and GSH-PX activities demonstrated a trend of first increasing and then decreasing. In the 5 mg/L group, the MDA concentration and GSH-PX activity in the red muscle showed an increasing trend. In the 10 mg/L group, MDA concentration and SOD and CAT activities exhibited a downward trend. In the 5 mg/L group, the MDA concentration and SOD activity in the white muscle showed a downward trend, while CAT activity exhibited an increasing trend. In the 10 mg/L group, MDA concentration and CAT activity demonstrated a trend of first increasing and then decreasing, while SOD activity showed a downward trend. Ammonia nitrogen can lead to necrosis and shedding of gill epithelial cells, cell vacuolation, edema, as well as proliferation, hypertrophy, and fusion of secondary lamellae. This study demonstrates that NH3-N can alter gill structure and reduce the antioxidant ability of gills and red–white muscle. The findings provide scientific data that can support the aquaculture and recirculating aquaculture systems of juvenile tuna. [ABSTRACT FROM AUTHOR]

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Background: Strains XG04 and XGT2 of Lentinus edodes (Berk.) Singer demonstrate a high degree of genomic similarity, with XGT2 representing a systematic selection of XG04 and exhibiting enhanced phenotypic traits. Methods: An investigation into the differences between these strains was conducted using untargeted metabolomics to identify potential causal factors. Five exogenous inducers were assessed for their relationship with the observed phenotypes, and their impacts on fruiting body characteristics were analyzed. Results: Notably, the exogenous inducer rolipram, at a concentration of 0.4%, was found to increase cAMP expression levels in L. edodes primordia, which subsequently affected gill development, leading to the formation of gill-free fruiting bodies. Morphological differences between the two strains were evident; XG04 exhibited a spherical morphology with absent gills, rendering it commercially unviable, whereas XGT2 displayed a thicker cap and a more robust stipe, maintaining its characteristic umbrella shape. Conclusions: As the concentration of rolipram increased, both cap retraction and gill reduction in XGT2 occurred in a dose-dependent manner. The endogenous cAMP levels in the fruiting bodies were measured before and after rolipram treatment, revealing that the cap retraction and gill reduction in XGT2 progressed in a dose-dependent manner alongside increasing cAMP expression levels. Furthermore, a positive correlation was observed between cAMP levels and rolipram concentration. This study provides a foundation for improving the quality and productivity of mushroom cultivation by manipulating fruiting body characteristics through external stimuli. [ABSTRACT FROM AUTHOR]

The feeding behaviour of fish is drastically influenced by food availability and dietary preferences. In omnivorous fish, chemoreception plays an important role in feeding and morphological adaptations may be observed in several regions of the body. However, it is not clearly known if the fish need to feel the taste before swallowing the food. The present study aims to describe the receptors for taste perception and their distribution at the level of the gill rackers, underlining their importance in the food sorting behaviour. Paired gills were harvested from Carpathian gudgeon fish Gobio carpathicus Vladykov, 1925 and immersed in 10% buffered formalin. The samples were processed according to the current paraffin embedding technique and stained with Goldner’s trichrome method. The obtained results suggest that the Carpathian gudgeon presents, up to a point, the common gill morphology. However, on the pharyngeal face of the gills, more exactly on the gill rackers, are present several structures with an onion-like shape, disposed through the surface of the epithelium. Those elements consist of sensorial cells, sustained by sustentacular and basal cells, forming a taste bud. Due to their disposition on the inner surface of the gills, those structures may act like a sorter, enhancing the rackers sieve activity. In conclusion, the histological findings suggest that the Carpathian gudgeon, a common omnivorous fish, may use taste reception at the level of the gill rackers before swallowing the food.

Abstract Microplastics are emerging pollutants of global concern, and their presence in the aquatic environment poses a serious risk for aquatic biota. While many studies have been conducted on the presence of microplastics in marine habitats, little research has been done in freshwater African reservoirs on microplastic pollution and their impacts on fish within the subtropical regions. To bridge this gap, the current study investigated microplastic abundances and distribution in freshwater fish within Nandoni reservoir, South Africa, across two seasons (i.e., hot–wet, cool–dry). Fish were randomly sampled using seine and gill nets from seven sites within the reservoir. In the laboratory, fish were then sorted according to taxa before dissecting them to remove the gills and the gastrointestinal tract (GIT). The organs were digested using hot hydrochloric acid and hydrogen peroxide, and the microplastics were classified according to their colours and shapes. Among the 94 fishes (i.e., 8 species) examined, microplastics were detected in 86.6% of the eight species caught. Microplastics were dominant in the gills and GIT during the cool–dry and hot–wet seasons, respectively. High microplastic abundances were found in the gills of Micropterus salmoides and the GIT of Coptodon rendalli, where fibres and the transparent colour were the most dominant. The results further showed high microplastic abundances in benthopelagic feeders highlighting that habitat influences fish consumption of microplastics whether directly or indirectly. Significant differences were observed in the feeding zone and season for all microplastic types. Microplastic sources in the reservoirs could be due to anthropogenic activities such as illegal dumping, fishing, and agriculture. Thus, there is a need for further investigation into the relation of fish weight, fish sex and body in relation to microplastic pollution. The highlighted ecological factors should be taken into consideration for future research and management actions aimed at mitigating and protecting the negative impacts of microplastic pollution on environmental and human health.

Microplastics are emerging pollutants of global concern, and their presence in the aquatic environment poses a serious risk for aquatic biota. While many studies have been conducted on the presence of microplastics in marine habitats, little research has been done in freshwater African reservoirs on microplastic pollution and their impacts on fish within the subtropical regions. To bridge this gap, the current study investigated microplastic abundances and distribution in freshwater fish within Nandoni reservoir, South Africa, across two seasons (i.e., hot–wet, cool–dry). Fish were randomly sampled using seine and gill nets from seven sites within the reservoir. In the laboratory, fish were then sorted according to taxa before dissecting them to remove the gills and the gastrointestinal tract (GIT). The organs were digested using hot hydrochloric acid and hydrogen peroxide, and the microplastics were classified according to their colours and shapes. Among the 94 fishes (i.e., 8 species) examined, microplastics were detected in 86.6% of the eight species caught. Microplastics were dominant in the gills and GIT during the cool–dry and hot–wet seasons, respectively. High microplastic abundances were found in the gills of Micropterus salmoides and the GIT of Coptodon rendalli, where fibres and the transparent colour were the most dominant. The results further showed high microplastic abundances in benthopelagic feeders highlighting that habitat influences fish consumption of microplastics whether directly or indirectly. Significant differences were observed in the feeding zone and season for all microplastic types. Microplastic sources in the reservoirs could be due to anthropogenic activities such as illegal dumping, fishing, and agriculture. Thus, there is a need for further investigation into the relation of fish weight, fish sex and body in relation to microplastic pollution. The highlighted ecological factors should be taken into consideration for future research and management actions aimed at mitigating and protecting the negative impacts of microplastic pollution on environmental and human health. [ABSTRACT FROM AUTHOR]

Air-breathing fish risk losing aerially sourced oxygen to ambient hypoxic water since oxygenated blood from the air-breathing organ returns through the heart to the branchial basket before distribution. This loss is thought to help drive the evolutionary reduction in gill size with the advent of air-breathing. In many teleost fish, gill size is known to be highly plastic by modulation of their anatomic diffusion factor (ADF) with inter-lamellar cell mass (ILCM). In the anoxia-tolerant crucian carp, ILCM recedes with hypoxia but regrows in anoxia. The air-breathing teleost Chitala ornata has been shown to increase gill ADF from normoxic to mildly hypoxic water by reducing ILCM. Here, we test the hypothesis that ADF is modulated to minimize oxygen loss in severe aquatic hypoxia by measuring ADF, gas-exchange, and by using computed tomography scans to reveal possible trans-branchial shunt vessels. Contrary to our hypothesis, ADF does not modulate to prevent oxygen loss and despite no evident trans-branchial shunting, C. ornata loses only 3% of its aerially sourced O2 while still excreting 79% of its CO2 production to the severely hypoxic water. We propose this is achieved by ventilatory control and by compensating the minor oxygen loss by extra aerial O2 uptake. [ABSTRACT FROM AUTHOR]

The capture of a rare, critically endangered adult angular rough shark, Oxynotus centrina (Linnaeus, 1758), with abnormal coloration is reported in this paper. The shark exhibited a partial reduction in pigmentation, resulting in an overall pale appearance with white‐greyish patches. Since the retinal pigmentation appeared normal, the shark was considered leucistic. This represents the first documented case of leucism in this species and the first colour disorder reported in the family Oxynotidae Gill, 1912. Despite the atypical appearance, the physical health of the shark seemed unaffected, supporting the notion that pigment disorders in deep‐sea sharks do not inherently impair survival and growth. Full morphometric characteristics are presented and compared with those of a normal individual of the same sex caught in the same area, showing no differences. [ABSTRACT FROM AUTHOR]

Microplastics have emerged as a significant global environmental concern in the recent decade. The aim of this study was to elucidate microplastic contamination of commercial fish species in a natural lagoon environment. Microplastic contamination was examined in the gastrointestinal tracts and gills of 157 commercial fish from 18 species with varying feeding habits in a vital and sensitive lagoon ecosystem, which connects to the Indian ocean. Microplastics were extracted using digestion, followed by stereomicroscopic inspection using Nile Red stain, and identified via μ-FTIR analysis. Over half of studied fishes ingested microplastics (54.14%). Filaments (50%) and blue items (43%) were the most commonly ingested. Of all the fish species, Eubleekeria splendens had the highest average concentration of microplastics in GIT (1.41 ± 2.52 items/g w.w. tissues), although no statistically significant difference in amount of ingested microplastics (items/g w.w. tissues) was observed among species. The highest concentrations of inhaled microplastics were recorded in Sillago vincenti (1.38 ± 1.30 items/g w.w. tissues). The majority of the extracted microplastics (33%) belonged in the size class 500–1500 μm with rayon, polyethylene terephthalate, and polypropylene as the primary polymers. This study found no correlation between microplastic ingestion and fish species and feeding habits, but a positive correlation with fish size was observed. These findings reveal widespread microplastic contamination in edible fish, posing potential risks to commercially important species due to increasing pollution in lagoon ecosystems. [ABSTRACT FROM AUTHOR]

The document titled "Author Index" from the Clinical Teacher journal provides an extensive list of authors and their corresponding page numbers. The index includes a diverse range of contributors from various cultural backgrounds, showcasing a wide array of perspectives and expertise in the field. This resource can be valuable for library patrons conducting research on specific topics by providing a comprehensive list of authors and their associated works. [Extracted from the article]

The toxic effect and differences of Cr(VI) on superoxide dismutase (SOD) activity, MDA, and metallothionein (MT) content in the hepatopancreas and gill of Portunus trituberculatus were investigated during Cr(VI) enrichment (15 days) and release experiments (15 days). Results showed that the 1.50 and 0.30 mg/L test groups significantly exhibited higher SOD, MDA, and MT content in the hepatopancreas and gill compared with the control group after 15 days of enrichment (p < 0.05). After 15 days of Cr release, the SOD, MDA, and MT content in the hepatopancreas and gill of both test groups recovered to the normal level of the control group (p > 0.05). The gill of P. trituberculatus achieved the highest SOD activity, MDA, and MT content earlier than the hepatopancreas, but the highest values were lower. The gill showed a shorter recovery time than the hepatopancreas. We concluded that the gill of P. trituberculatus exhibited a more rapid response to, and recovery from, Cr(VI) exposure compared to the hepatopancreas, making it a more sensitive tissue for assessing Cr(VI) toxicity, though both tissues showed a capacity for recovery after the removal of the contaminant. [ABSTRACT FROM AUTHOR]

Sardines and anchovies are the most important small pelagic species throughout the Mediterranean, caught mainly by purse-seiners. Their rapid bacterial degradation after capture and storage limits their commercial use and shelf life. Gills are the most vulnerable tissue in fish, harboring bacterial communities which have not been previously investigated in these species. This study examined cultivable bacteria from gills of harvested sardines and anchovies, tanks in which they are stored aboard, and fishing nets on four occasions (twice for both warm and cold seasons). A total of 471 bacteria were isolated, belonging to 74 genera and 163 species by MALDI-TOF MS identification. A number of genera and species identified from fish and surfaces occurred only in the warm or cold season, but a fraction occurred in both seasons. Sardine gills harbored most of the isolated bacteria (254), belonging to 53 genera and 111 species, as opposed to anchovy with 120 strains, belonging to 30 genera and 64 species. A diverse cultivable bacterial community consisting of 17 species was isolated exclusively from the polyethylene surfaces of nets and tanks. This finding is significant regarding their potential migrations between planktonic and sessile lifestyles. Possible contamination and cross-contamination are likely to increase with the rise in ambient and seawater temperature during the hauling and sorting of fish in the tanks. The food safety risks stem from pathogens and fish spoilage bacteria on both the fish and the surfaces of fishing nets and storage tanks. [ABSTRACT FROM AUTHOR]

The mechanism(s) of sodium, chloride and pH regulation in teleost fishes has been the subject of intense interest for researchers over the past 100 years. The primary organ responsible for ionoregulatory homeostasis is the gill, and more specifically, gill ionocytes. Building on the theoretical and experimental research of the past, recent advances in molecular and cellular techniques in the past two decades have allowed for substantial advances in our understanding of mechanisms involved. With an increased diversity of teleost species and environmental conditions being investigated, it has become apparent that there are multiple strategies and mechanisms employed to achieve ion and acid-base homeostasis. This review will cover the historical developments in our understanding of the teleost fish gill, highlight some of the recent advances and conflicting information in our understanding of ionocyte function, and serve to identify areas that require further investigation to improve our understanding of complex cellular and molecular machineries involved in iono- and acid-base regulation. [ABSTRACT FROM AUTHOR]

The complex relationships between the structure and function of fish gills have been of interest to comparative physiologists for many years. Morphological plasticity of the gill provides a dynamic mechanism to reversibly alter its structure in response to changes in the conditions experienced by the fish. The best known example of gill remodelling is the growth or retraction of cell masses between the lamellae, a rapid process that alters the lamellar surface area that is exposed to the water (i.e. the functional lamellar surface area). Decreases in environmental O2 availability and/or increases in metabolic O2 demand stimulate uncovering of the lamellae, presumably to increase the capacity for O2 uptake. This review addresses four questions about gill remodelling: (1) what types of reversible morphological changes occur; (2) how do these changes affect physiological function from the gill to the whole animal; (3) what factors regulate reversible gill plasticity; and (4) is remodelling phylogenetically widespread among fishes? We address these questions by surveying the current state of knowledge of gill remodelling in fishes, with a focus on identifying gaps in our understanding that future research should consider. [ABSTRACT FROM AUTHOR]

In this review, we explore the inconsistencies in the data and gaps in our knowledge that exist in what is currently known regarding gill chemosensors which drive the cardiorespiratory reflexes in fish. Although putative serotonergic neuroepithelial cells (NEC) dominate the literature, it is clear that other neurotransmitters are involved (adrenaline, noradrenaline, acetylcholine, purines, and dopamine). And although we assume that these agents act on neurons synapsing with the NECs or in the afferent or efferent limbs of the paths between chemosensors and central integration sites, this process remains elusive and may explain current discrepancies or species differences in the literature. To date it has been impossible to link the distribution of NECs to species sensitivity to different stimuli or fish lifestyles and while the gills have been shown to be the primary sensing site for respiratory gases, the location (gills, oro-branchial cavity or elsewhere) and orientation (external/water or internal/blood sensing) of the NECs are highly variable between species of water and air breathing fish. Much of what has been described so far comes from studies of hypoxic responses in fish, however, changes in CO2, ammonia and lactate have all been shown to elicit cardio-respiratory responses and all have been suggested to arise from stimulation of gill NECs. Our view of the role of NECs is broadening as we begin to understand the polymodal nature of these cells. We begin by presenting the fundamental picture of gill chemosensing that has developed, followed by some key unanswered questions about gill chemosensing in general. [ABSTRACT FROM AUTHOR]

The fish gill is a multifunctional organ that is important in multiple physiological processes such as gas transfer, ionoregulation, and chemoreception. This characteristic organ of fishes has received much attention, yet an often-overlooked point is that larval fishes in most cases do not have a fully developed gill, and thus larval gills do not function identically as adult gills. In addition, large changes associated with gas exchange and ionoregulation happen in gills during the larval phase, leading to the oxygen and ionoregulatory hypotheses examining the environmental constraint that resulted in the evolution of gills. This review thus focuses exclusively on the larval fish gill of teleosts, summarizing the development of teleost larval fish gills and its function in gas transfer, ionoregulation, and chemoreception, and comparing and contrasting it to adult gills where applicable, while providing some insight into the oxygen vs ionoregulatory hypotheses debate. [ABSTRACT FROM AUTHOR]

Gill function in gas exchange and ion regulation has played key roles in the evolution of fishes. In this review, we summarize data from the fields of palaeontology, developmental biology and comparative physiology for when and how the gills first acquired these functions. Data from across disciplines strongly supports a stem vertebrate origin for gas exchange structures and function at the gills with the emergence of larger, more active fishes. However, the recent discovery of putative ionocytes in extant cephalochordates and hemichordates suggests that ion regulation at gills might have originated much earlier than gas exchange, perhaps in the ciliated pharyngeal arches in the last common ancestor of deuterostomes. We hypothesize that the ancestral form of ion regulation served a filter-feeding function in the ciliated pharyngeal arches, and was later coopted in vertebrates to regulate extracellular ion and acid–base balance. We propose that future research should explore ionocyte homology and function across extant deuterostomes to test this hypothesis and others in order to determine the ancestral origins of ion regulation in fish gills. [ABSTRACT FROM AUTHOR]

Meristic characters are often used to differentiate between closely related forms, morphs, and species of fishes, and lend insight into ecology and post‐glacial recolonization in taxa with complicated or contentious phylogenies, including the genus Salvelinus. Previous studies of meristics in Salvelinus have focused mostly on individual populations. We collated data from 456 populations/systems across the North American and Russian Arctic and sub‐Arctic, and found that counts of pyloric caeca and gill rakers differed consistently between fish visually and/or genetically identified as Arctic char and Dolly Varden across their distributional ranges. [ABSTRACT FROM AUTHOR]

The present experiment was performed to reveal the mechanisms of toxic effects of ammonia nitrogen on Chinese hook snout carp (Opsariichthys bidens) based on the levels of antioxidant enzyme activities and the expression of 70‐kDa heat shock protein gene (HSP70) and tumor necrosis factor‐α (TNF‐α) after 96 h of acute toxic ammonia exposure to investigate its adaptability. The result showed that activities of antioxidant enzymes and lipid peroxidation in the intestine, liver, brain, and gills showed a general trend of increasing and then decreasing when exposed to ammonia nitrogen. The intestinal tissue structure was damaged to varying degrees, the expression of the HSP70 in the brain and gills increased at 0–12 h, and the expression of the TNF‐α in brain tissues decreased at 0–12 h. The expression of TNF‐α in the liver was continuously upregulated in the late stages of stress, and it did not decrease until the stress was released. The above results indicate that high concentrations of ammonia nitrogen caused varying degrees of damage to the neurological, respiratory, and metabolic‐related organs of the O. bidens. [ABSTRACT FROM AUTHOR]

The question of what the ancient life cycle of tetrapods was like forms a key component in understanding the origin of land vertebrates. The existence of distinct larval forms, as exemplified by many lissamphibians, and their transformation into adults is an important aspect in this field. The temnospondyls, the largest clade of Palaeozoic–Mesozoic non‐amniote tetrapods, covered a wide ecomorphological range from fully aquatic to terrestrial taxa. In various species, rich ontogenetic data have accumulated over the past 130 years, permitting the study of early phases of temnospondyl development. In temnospondyls, eight ontogenetic phases have been identified in which the skeleton formed. In branchiosaurids and the eryopiform Sclerocephalus, large parts of the ossification sequence are now known. Most taxa in which small specimens are preserved had aquatic larvae with external gills that superficially resemble larval salamanders. In the edopoids, dvinosaurs, and eryopiforms, the larvae developed slowly, with incompletely ossified axial and appendicular skeletons, but possessed a fast‐developing dermal skull with strong teeth. Irrespective of adult terrestriality or a fully aquatic life, there was no drastic transformation during later ontogeny, but a slow and steady acquisition of adult features. In dissorophoids, the limbs developed at a much faster pace, whereas skull formation was slowed down, especially in the amphibamiforms, and culminating in the neotenic Branchiosauridae. In the zatracheid Acanthostomatops, slow but profound transformation led to a fully terrestrial adult. The basal dissorophoid Stegops retained rapid development of dermal skull bones and established a fully dentigerous, strongly ossified palate early. In Micromelerpeton, formation of the last skull bones was slightly delayed and metamorphosis remained a long and steady phase of morphological transformations. In amphibamiforms, metamorphosis became more drastic, with an increasing number of events packed into a short phase of ontogeny. This is exemplified by Apateon, Platyrhinops, and Amphibamus in which this condensation was maximised. We distinguish three different types of metamorphosis (morphological, ecological and drastic) that evolved cumulatively in early tetrapods and within temnospondyls. [ABSTRACT FROM AUTHOR]

The experiment was conducted to investigate the effects of acute stress with different nitrite concentrations on immunity and gill Na+/K+-ATPase activity of Litopenaeus vannamei. Litopenaeus vannamei with average weight of (1.68±0.23) g were selected. The nitrite concentrations were set as 0 (Control group),0.4, 0.8, 1.6, 3.2 mg/L respectively. The acute stress test lasted for 96 h. Hepatopancreas immune function and gill Na+/K+-ATPase activity were measured at 0, 12, 24, 48, 72, 96 h, respectively. The result showed that the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), acid phosphatase (ACP), alkaline phosphatase (AKP), and lactate dehydrogenase (LDH) in the liver pancreas of Litopenopenus vannamei in stress groups showed an overall trend of increasing first and then decreasing with the extension of stress time. In the 3.2 mg/L group, the activities of SOD, CAT, GSH-Px, and ACP in the liver pancreas of Litopenopenus vannamei all dropped to the level of the control group after 96 hours of stress. The activity of LDH dropped to the level of the control group after 24 hours of stress and then continued to decrease significantly below the level of the control group (P<0.05). Except for the 0.4 mg/L group, where the content of malondialdehyde (MDA) in the hiver pancreas of Litopenopenus vannamei dropped to the level of the control group after 96 hours of stress, the MDA content in all other groups was significantly higher than that of the control group during the 96 hours of stress (P<0.05). Within 96 hours of stress, the activity of Na+/K+-ATPase in the gills of Litopenopenus vannamei in the 0.4 mg/L group continued to rise; the activity of Na+/K+-ATPase in the gills of Litopenopenus vannamei in the 0.8 to 3.2 mg/L groups showed a trend of initial activation followed by inhibition with the extension of stress time, and in the 3.2 mg/L group, it dropped to the level of the control group after 96 hours of stress. The study shows that the immune function and gill Na+/K+-ATPase activity of Litopenaeus vannamei were significantly affected under acute nitrite stress of 0.4 to 3.2 mg/L. When the salinity is (24.0±1.0) parts per thousand, it is necessary to control the nitrite content within 0.4 mg/L during the healthy aquaculture process of the Litopenaeus vannamei. [ABSTRACT FROM AUTHOR]

The widespread use of pesticides in veterinary medicine, agriculture, public health, and aquatic environments has increasingly threatened aquatic life in recent years. This study aimed to evaluate the acute toxicity, behavioral changes, and histological alterations caused by pymetrozine (PY) in the Nile tilapia (Oreochromis niloticus). The 96-hour LC50 value for PY was found to be 0.28g/ L, indicating the concentration at which half of the test population succumbed within 96 hours. Behavioral changes such as hyperexcitation, irregular swimming, dark coloration, loss of balance, and lethargy were observed and varied with the concentration of PY. The study also demonstrated that the mortality rate, clinical lesions, behavioral changes, and histological alterations in the gills, liver, and kidneys were all influenced by both the dosage of PY and the duration of exposure, highlighting the toxicological impact of PY on the Nile tilapia. [ABSTRACT FROM AUTHOR]

Salinity significantly affects shellfish metabolism and growth. In this study, we evaluated the characterization of metabolomic differences in the juvenile black-shelled pearl oyster, Pinctada fucata martensii, under 15‰ (LSG), 25‰ (CG), and 35‰ (HSG) salinity conditions. Non-targeted metabolomics analyses revealed that salinity stress altered the metabolism of pearl oyster. A total of 229 significant differential metabolites (SDMs) were identified between LSG and CG via an in-house MS2 database, 241 SDMs were identified between LSG and HSG, and 50 SDMs were identified between CG and HSG. The pathway analysis showed that 21 metabolic pathways were found between LSG and CG, such as arginine and proline metabolism, glycerophospholipid metabolism, and pentose and glucuronide interconversion. A total of 23 metabolic pathways were obtained between LSG and HSG, such as aspartate, alanine, and glutamate metabolism. Only aminoacyl-tRNA biosynthesis, cysteine and methionine metabolism, and biotin metabolism were enriched between CG and HSG. A further integrated analysis suggested that amino acid metabolism might participate in osmoregulation and energy metabolism to respond to salinity stress in P. f. martensii, and the metabolic pathways differed under varying salinity stress conditions. In addition, low salinity stress might promote apoptosis in pearl oysters. Altogether, these results clarify the salinity tolerance mechanism of pearl oysters. [ABSTRACT FROM AUTHOR]

In order to explore the effects of NaHCO3 stress on antioxidant enzymes and tissue structure of gill and hepatopancreas of grass carp, three NaHCO3 concentration groups (10, 20, 30 mmol/L) were used to stress grass carp with NaHCO3, and the antioxidant enzymes (SOD, CAT) activity and histopathological observation of gill and hepatopancreas were carried out. The results showed that under NaHCO3 stress, the activities of SOD and CAT in gill and CAT in hepatopancreas of grass carp increased first and then decreased within 72 h, and only the activity of SOD in hepatopancreas increased within 72 h. In each experimental group, the activities of antioxidant enzymes in the two tissues were significantly different from those in the blank group. Compared with the blank group, in the gill tissue of grass carp in the experimental group, the gill filaments were seriously folded and wrinkled, the PVC of the flat epithelial cells was seriously exfoliated, and the MRC of the mitochondria-enriched cells was swollen; in the hepatopancreas, the swelling of the pancreatic cells, the increase of the intercellular space, the deviation of the hepatocyte nucleus and the decrease of the vacuolization were observed. Studies have shown that NaHCO3 stress can affect the antioxidant level of grass carp and cause tissue damage to the gills and hepatopancreas of grass carp, and the degree of damage increases with the increase of concentration. This study could provide reference for the breeding and application of grass carp in saline-alkali waters. [ABSTRACT FROM AUTHOR]

About 60% of marine vessels' power is consumed to overcome friction resistance between the hull and water. Air lubrication can effectively reduce this resistance and lower fuel consumption, and consequently emissions. This study aims to analyze the use of a gas-injected liquid lubrication system (GILLS) to reduce friction resistance in a real-world scenario. A 3D computational fluid dynamics model is adopted to analyse how a full-scale ship (the Sea Transport Solutions Designed Catamaran ROPAX ferry) with a length of 44.9 m and a width of 16.5 m is affected by its speed and draught. The computational model is based on a volume of fluid model using the k-ꞷ shear stress transport turbulence model. Results show that at a 1.5 m draught and 20 knots cruising speed, injecting 0.05 kg/s of compressed air into each GILLS unit reduces friction resistance by 10.45%. A hybrid model of natural air suction and force-compressed air shows a friction resistance reduction of 10.41%, which is a promising solution with less required external power. The proposed technique offers improved fuel efficiency and can help to meet environmental regulations without engine modifications. [ABSTRACT FROM AUTHOR]

So far, species of the genus Isonychia Eaton, 1871 have been reported to have transparent or partially pigmented wings, particularly their hindwings. A new species, I. fuscimarginata sp. n., recently collected from southern China, shows a different case. Both its forewings and hindwings have striking reddish brown to chocolate margins and stripes. Besides that, the entirely dark brown forelegs, shortened but apically widened male penises, and the colour and spine patterns of nymphal gills are useful characters for identification. This new species enriches the colour pattern of the genus Isonychia and the family Isonychiidae. [ABSTRACT FROM AUTHOR]

This document is an author index for the journal Andrology, providing a list of authors and the page numbers where their work can be found in the journal. The index includes authors from diverse backgrounds and countries. It is a valuable resource for library patrons conducting research on topics related to reproductive health, genetics, and endocrinology, offering a wide range of perspectives. [Extracted from the article]

Purpose: Studies on monogeneans parasitizing representatives of Siluriformes in Africa remain scarce and fragmentary. In order to contribute to fill this gap, we screened Heterobranchus longifilis from the Lindi River in the Democratic Republic of the Congo. Methods: Heterobranchus longifilis was purchased from fishermen in DR Congo, province of Tshopo, in Kisangani town, the Lindi River. The monogeneans were individually isolated from the gill and transferred directly onto a slide in a drop of Hoyer's medium. Results: Quadriacanthus lindiensis n. sp. is morphologically similar to Quadriacanthus longifilisi. However, it is distinguished from the latter by its non-sclerotized vagina, its dorsal cunei shape and the size of its bars. Conclusion: Only Q. lindiensis n. sp. was found on the gills of the single individual of H. longifilis screened. In the future, a representative sampling should enable us to verify if Q. lindiensis n. sp. co-occurs with other species known to parasitize H. longifilis. [ABSTRACT FROM AUTHOR]

Introduction: The present study describes three new dactylogyrid species infecting the gill filaments of cichlid fishes (Cichliformes: Cichlidae) from the Amazon basin, Peru: Sciadicleithrum amazoniensis n. sp. on Biotodoma cupido (Heckel, 1840), and Sciadicleithrum feliciajaramae n. sp. and Sciadicleithrum souzatecci n. sp. on Bujurquina peregrinabunda Kullander, 1986. Materials and methods: Some monogeneans were stained with Gomori's trichrome and mounted in Canada Balsam to determine internal soft structures. Others were cleared in Hoyer's medium for the study of sclerotized structures. Drawings were made using a drawing tube and a microprojector. Results: Sciadicleithrum amazoniensis n. sp. is characterized by the presence of a male copulatory organ (MCO) with a coil of approximately 2 counterclockwise rings, an accessory piece articulated to base of the MCO with an expanded proximal end and a bifurcated distal end, and a sinistral vaginal aperture. Sciadicleithrum feliciajaramae n. sp. can be differentiated from all its congeners by its J-shaped MCO with about half a counterclockwise loop and a rod-shaped accessory piece articulated to the base of the MCO, with the distal end bent. Sciadicleithrum souzatecci n. sp. differs from all other members of Sciadicleithrum by having an elongated MCO with about a clockwise loop and a funnel-shaped base. Additionally, Sciadicleithrum souzatecci n. sp. is characterized by its weakly sclerotized, C-shaped accessory piece with a robust middle process. Conclusions: Present findings are added to the other 26 species previously known in Sciadicleithrum.This is the first data on the parasites of B. peregrinabunda. [ABSTRACT FROM AUTHOR]

Introduction: Net biofouling has a significant impact for the global salmon industry in the seawater grow-out stage in terms of its management. Current mitigation strategies occur primarily through the regular removal of biofouling using in situ cleaning. While in situ net cleaning is effective there is uncertainty as to whether the equipment or dispersed material has an impact upon the fish in the cages. Through direct contact with the environment, the significant surface area of the gill including its microbiome is directly exposed to the acute environmental changes generated by net cleaning. This study aimed to provide a detailed understanding of the impact of in situ net cleaning on Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) gill health. Methods: Three field trials were conducted on commercial fish farms in western Norway. Fouling organisms on net pens and flushed particles during in situ cleaning were identified and screened for major fish pathogens. Hydrographic profile measurements were performed to measure the impact on water quality. Gill samples were examined for histopathological changes, immune gene expression, and the prevalence of major pathogens. 16S rRNA amplicon sequencing was employed to explore the impact of net cleaning on gill microbiome. Results and discussion: Data obtained from these trials identified a diversity of fouling species including hydroids, algae, skeleton shrimps, and filter feeders on net pens, a direct impact on measured water quality indicators, a moderate change in gill inflammatory and antigen presentation activity at the level of mRNA, and a large significant change in gillmicrobiome. Observed changes in gill microbial community involved a decrease in bacterial richness coupled to an increase in identified bacterial genera related to negative health consequences. Parallel analyses for pathogens load in biofouling organisms and flushed particles highlighted the presence of several fish bacteria and parasites. However, minor changes were detected in salmon gill pathogen diversity and loading. Our results suggest that biofouling organisms may actas transient reservoirs for somefishpathogensbutnotvirusesandthatgillmicrobial dysbiosis could be related to the host stress response during and post net cleaning. [ABSTRACT FROM AUTHOR]

In recent years, organizations aiming to empower women and girls to participate in STEM have proliferated. While the issue of gender inequality in STEM is well documented, little is known about the feminist appeals these organizations make to girls. This study analyses the websites of five Australian ‘women in tech’ organizations to understand how they frame and respond to the problem of gender inequality, and what feminist sentiments they reflect. Combining a postfeminist sensibility (Gill, 2007) with Myers et al. (2019) concept of STEMinism, we propose a ‘STEMinist sensibility’ to interpret the ways in which gender issues and subjects are represented on STEM initiative websites. We identify four themes characterizing a STEMinist sensibility: 1) acknowledging the problem and promoting solutions to gender inequality, 2) a focus on tech girls as problem solvers, 3) cultivating community and connection for success, and 4) playing with girlification. We show how websites acknowledge the structural impediments women and girls face, yet simultaneously represent girls as both problematic and as problem-solvers in a way that renders them individually responsible for resolving the problems arising from gender inequality in their fields. These findings have implications for organizations promoting STEM initiatives to women and girls. [ABSTRACT FROM AUTHOR]

【Objective】 Trachidermus fasciatus is a nation’s second-class protected species, belonging to a migratory fish with eurysalinity. The study aims to explore a suitable desalination pattern for T. fasciatus before the proliferation and release of the fish. 【Method】The microstructural changes of the gills of juvenile T. fasciatus under acute freshwater stress, different desalination speeds (the salinity was reduced by 5 concentrations each time, and reduced every 12, 24, 48 h, recorded as A, B, C groups) and different desalination amplitudes (the salinity was reduced once every 24 h, and 2, 3 and 5 salinity concentrations were reduced each time, recorded as D, E and B groups) were investigated by tissue sectioning techniques. 【Result】The results showed that, when the juvenile T. fasciatus at salinity of 25 was directly put into freshwater for acute freshwater stress, the morphology of gill tissue structure was normal at 1 h; at 12 h, the gill filaments showed a slight epidermal detachment; at 24 h, the hemocytes appeared to be absorbed and swollen; at 3 d, the number of gill filaments and gill lamellae with vacuoles increased significantly; at 7 d, the gill filaments and gill lamellae showed the most serious epidermal detachment, and the length of gill lamellae was increased while the width was decreased, with bent ends, cytolysis and irregular shape. Vacuoles appeared at the base of the branchial lamella and their positions also increased. The number of blood cells decreased and the number of mitochondria-rich cells increased. At salinity of 25, the gill tissues of group A-C did not change significantly. When salinity was reduced to 15, the structural breakage of gill filaments was more obvious in group A than that in groups B and C; when salinity reached freshwater, the gill tissue structure of group A was severely broken, the length of gill lamellae was increased but the width was reduced, the structure was incomplete, the number of mitochondria-rich cells was increased, and the number of hemocytes was reduced compared with that at salinity of 15; the structures of gill filaments and gill lamellae of group A were significantly different than those of groups B and C, with the degree of incompleteness being more serious, and the difference between groups B and C was not obvious. The differences between groups B and C were not obvious, and the gill tissue structure was broken to a similar extent. When the initial salinity was 25 under freshwater acclimation for 1 h, the differences in gill tissue structure were not obvious among group D, group E and group B; at 12 h, the number of vacuoles in gill tissues of the three groups increased; at 24 h, the number of vacuoles in the gills of group B and group D was more than that of group E; at 3 d, the gill tissues of group B had more detachments compared with the other two groups; at 7 d, the number of mitochondria-rich cells and blood cells was more than that of groups B and D. The degree of incompleteness of gill tissue structure was more serious in group B than that in groups D and E.【Conclusion】With the increase of freshwater acclimation time, T. fasciatus improves its osmotic capacity by increasing the length of gill lamellae and controlling the number of hemocytes and mitochondria-rich cells to reduce the harm of stress on gills. In addition, lowering the desalination rate and amplitude will help T. fasciatus to better adapt to the salinity change, and it is recommended to choose the desalination pattern with the salinity decreasing by 2 per day to reduce the damage of freshwater acclimation on the gill tissues and structures of T. fasciatus. [ABSTRACT FROM AUTHOR]