Early Life Stages Research Articles

Identification and characterization of a novel strain of Decapod hepanhamaparvovirus in black tiger shrimp (Penaeus monodon) from Madagascar that does not cause histological lesions

Decapod hepanhamaparvovirus (DHPV) is a single-stranded DNA virus that primarily affects the early life stages of penaeid shrimp, potentially leading to significant losses in hatchery operations. In an interesting finding, we observed that a small portion Black tiger shrimp (Penaeus monodon) originating from Madagascar harbored DHPV even in the absence of any discernible clinical signs. Detailed histopathological analysis of P. monodon post-larvae individuals revealed an absence of distinctive histological lesions typically associated with DHPV infection. However, sensitive molecular techniques, including PCR and real-time PCR and reverse transcriptase quantitative PCR (RT-qPCR) confirmed the presence of viral DNA and DHPV encoded transcripts in these specimens. The complete genome sequence of this newfound viral isolate, spanning 6254 nucleotides, showed a 96.9% nucleotide sequence similarity to a previously documented DHPV strain also originating from Madagascar. Moreover, it exhibited a genetic resemblance of 80.7% to 88.2% when compared to DHPV strains from other geographical regions. These findings underscore the unique genomic and histological characteristics of this novel DHPV isolate. This knowledge proves to be of paramount significance for the screening of broodstock and post-larvae in captive breeding programs, as it aids in identifying the presence of DHPV. Furthermore, it paves the way for future investigations into unraveling the precise role of viral-encoded proteins in shaping the clinical and histological manifestations of DHPV infections.

Larval fish community in the Bay of Whales (eastern Ross sea): Species composition, relative abundance and spatial distribution

Early life stages of fish represent a key component in the food chain of the pelagic ecosystem of the Southern Ocean, connecting producer trophic levels to those of higher predators. Pelagic larvae and early juveniles of notothenioid fishes overwhelmingly dominate the ichthyoplankton community living on the continental shelf. Scientific research surveys targeting early life stages of fish in the pelagic realm have been mainly carried out in the western Ross Sea, whereas the eastern side can be considered unexplored. As source of high primary production, the presence and timing of formation of wide ice-free areas throughout the year in the Ross Sea play a fundamental role in structuring larval fish community. The Ross Ice Shelf Polynya (RISP) is a large coastal polynya, which is driven and maintained by local prevailing winds and oceanic currents. In the present study, we report the first data on species composition, relative abundance and spatial distribution of larval fish community found off the Bay of Whales in the eastern Ross Sea. As reported for other areas of the Ross Sea, the Antarctic silverfish Pleuragramma antarcticum was by far the most abundant species, followed by other nototheniids and channichthyids in smaller amounts. The huge abundance of P. antarcticum early larvae supports the hypothesis of a potential nursery area near the Bay of Whales. Present results strongly advocate for future investigations in these poorly known and remote areas.

Exposure to acifluorfen induces developmental toxicity in the early life stage of zebrafish

Acifluorfen, a selective herbicide from the diphenyl ether family, targets broad leaf weeds. Diphenyl ether inhibits chlorophyll production in green plants by inhibiting protoporphyrinogen oxidase (PPO), causing cellular damage. Despite its known impacts on plants, the influence of acifluorfen on zebrafish embryo development remains unclear. In this study, we explored the LC50 of acifluorfen in early-stage wild-type zebrafish, determining it to be 54.99 mg/L. Subsequent examinations revealed morphological changes in zebrafish, including reduced body length. Using the cmlc2:dsRED transgenic model, we observed heart dysfunction in acifluorfen-exposed zebrafish, marked by an enlarged heart area, edema, and decreased heart rate. In response to dose-dependent acifluorfen exposure, the inhibition of angiogenesis in the brain was observed in transgenic zebrafish models (fli1a:eGFP). Organ malformations, specifically in the liver and pancreas, were noted, in lfabp:dsRED;elastase:eGFP transgenic models, indicating reduced organ size in acifluorfen-exposed zebrafish. Furthermore, acifluorfen heightened the expression of apoptosis-related genes (casp8, casp9, and tp53) in zebrafish embryos. We then determined whether acifluorfen affected the viability of zebrafish liver (ZFL) cells based on its effects on liver development in vivo. The results indicated that the proliferation of ZFL cells decreased significantly in a dose-dependent manner. Additionally, acifluorfen-treated ZFL cells exhibited a slight increase in apoptotic cells stained with annexin V and propidium iodide. In summary, these findings establish a baseline concentration for acifluorfen's effects on aquatic ecosystems and non-target organisms.

Early life stage exposure to fenbuconazole causes multigenerational cardiac developmental defects in zebrafish and potential reasons

Early life stage exposure to fenbuconazole causes multigenerational cardiac developmental defects in zebrafish and potential reasons

Embryotoxicity Induced by Triclopyr in Zebrafish (Danio rerio) Early Life Stage.

Triclopyr, an auxin-like herbicide that is widely employed for managing weeds in food crops and pastures, has been identified in various environmental settings, particularly aquatic ecosystems. Limited understanding of the environmental fate of this herbicide, its potential repercussions for both the environment and human health, and its insufficient monitoring in diverse environmental compartments has caused it to be recognized as an emerging contaminant of concern. In this study, we have investigated how triclopyr affects zebrafish, considering a new alternative methodology. We focused on the endpoints of developmental toxicity, neurotoxicity, and behavior of zebrafish embryos and larvae. We determined that triclopyr has a 96 h median lethal concentration of 87.46 mg/L (341.01 µM). When we exposed zebrafish embryos to sublethal triclopyr concentrations (0.5, 1, 5, 10, and 50 μM) for up to 144 h, we found that 50 µM triclopyr delayed zebrafish egg hatchability. Yolk sac malabsorption was significant at 0.5, 1, 5, and 10 µM triclopyr. In zebrafish larvae, uninflated swim bladder was significant only at 50 µM triclopyr. Furthermore, zebrafish larvae had altered swimming activity after exposure to 10 µM triclopyr for 144 h. In summary, these comprehensive results indicate that even low triclopyr concentrations can elicit adverse effects during early zebrafish development.

Validating Measurement of Health Literacy among Adolescents Questionnaire (MOHLAA-Q) for Malaysian Version (MyMOHLAA-Q)

It has been determined that health literacy (HL) plays a significant factor in health and becomes an essential element in health promotion. Most HL instruments are designed for adults, whereas only a few are developed for adolescents. Thus, utilizing the existing validated instruments to assess HL is essential for success in promoting HL from the early stages of life. The Measurement of Health Literacy Among Adolescents Questionnaire (MOHLAA-Q) was developed in Germany to assess self-reported general health literacy among adolescents. This study aims to validate health literacy using MOHLAA-Q, thus establishing it as the Malaysian version of MOHLAA-Q (MyMOHLAA-Q). Face validity and content validity were done on 29 items of MOHLAA-Q. MOHLAA-Q is divided into 4 sections − A) Information about Health, B) Communication about Health, C) Attitudes towards Health and 4) Knowledge about Topic Related to Health. During the pilot testing, MOHLAA-Q administration took ∼15 minutes of 229 respondents from rural and urban areas. The internal consistency coefficients (Cronbach’s) for scales A−C ranged from 0.61 to 0.81. The final validated questionnaire is validated for 13 to 17-year-old Malay and English-speaking adolescents. The MyMOHLAA-Q experience allowed researchers to validate a measurement tool that can be used to assess health literacy among Malaysian adolescents.

Narrowed gene functions and enhanced transposon activity are associated with high tolerance to ocean acidification in a juvenile subarctic crustacean

Ocean acidification (OA) threatens marine crustaceans, particularly those at high latitudes where conditions are rapidly changing. Red king crab (RKC) support important fisheries in Alaskan waters. RKC early life stages are sensitive to OA when exposure occurs as embryos and juveniles. However, in a supporting study, RKC were surprisingly tolerant of varying OA conditions (pH 7.5, 7.8, & 8.0) when reared long-term from larval hatching to the first crab stage (C1). Here, we examined gene expression in the C1 juveniles to characterize transcriptional activity of these OA-tolerant crabs. Expression of nearly half of all genes (44%) correlated with OA treatment, suggesting a strong molecular response to OA, contrary to the phenotypic results. Downregulated functions were numerous in response to OA, and included reduced energy production, biosynthesis, immune function, and notably lipid and carbohydrate metabolic processes, which suggest a shift in metabolic strategy to protein catabolism, possibly to reduce CO2 production and facilitate acid/base regulation. Only a handful of functions were enriched in OA-induced genes, which were related to transcription regulation, control of growth and cell death, and signaling activity. Transposon activity was high in OA-reared crab, many of which were upregulated at consistent levels, suggesting that transposon mobilization may be a component of the RKC OA-response system. Genetic composition did not differ among OA treatments indicating that transcriptional differences in OA-reared crab were more likely attributed to phenotypic plasticity than selective mortality. Our results suggest that OA-reared RKC have a narrowed, possibly optimized, set of gene functions that enables OA-tolerance through the early juvenile stage. OA-exposure from hatch may benefit RKC and related species by “hardening” them against OA through physiological reprogramming. Future studies should test OA-hardened crabs in additional challenges, as metabolic and immune limitations may ultimately make them more vulnerable to infection or secondary stressors.

Plasticity of circadian and circatidal rhythms in activity and transcriptomic dynamics in a freshwater snail

Organisms have diverse biological clocks synchronised with environmental cycles depending on their habitats. Anticipation of tidal changes has driven the evolution of circatidal rhythms in some marine species. In the freshwater snail, Semisulcospira reiniana, individuals in nontidal areas exhibit circadian rhythms, whereas those in tidal areas exhibit both circadian and circatidal rhythms. We investigated whether the circatidal rhythms are genetically determined or induced by environmental cycles. The exposure to a simulated tidal cycle did not change the intensity of circatidal rhythm in individuals in the nontidal population. However, snails in the tidal population showed different activity rhythms depending on the presence or absence of the exposure. Transcriptome analysis revealed that genes with circatidal oscillation increased due to entrainment to the tidal cycle in both populations and dominant rhythmicity was consistent with the environmental cycle. These results suggest plasticity in the endogenous rhythm in the gene expression in both populations. Note that circatidal oscillating genes were more abundant in the tidal population than in the nontidal population, suggesting that a greater number of genes are associated with circatidal clocks in the tidal population compared to the nontidal population. This increase of circatidal clock–controlled genes in the tidal population could be caused by genetic changes in the biological clock or the experience of tidal cycle in the early life stage. Our findings suggest that the plasticity of biological rhythms may have contributed to the adaptation to the tidal environment in S. reiniana.

Religion, personality traits and the nature of entrepreneurial activities: insights from Scottish Muslim entrepreneurs

PurposePrevious studies have shown how the nature of businesses and the strategies pursued by their owners are affected by the personality traits of their owners. These personality traits can be formed in the early stages of life due to experiences and the surrounding context, where religion is a particularly important aspect of this context. This study aims to explore how religion affects entrepreneurial activities through the personality traits created.Design/methodology/approachThis study uses interviews with 43 Muslim entrepreneurs in Scotland to examine the role played by religion. This ensures that the national institutional context is kept consistent but also allows an in-depth examination of relationships, which are likely to be interlinked and recursive.FindingsThe traits created influence the nature of the entrepreneurial activities undertaken with the potential to harm and support the entrepreneurial endeavours. It is the combination of personality traits that are formed which have the greatest effect. As such, it is found that Muslim entrepreneurs display less openness and creativity associated with new ideas, but this does not reflect risk aversion rather hard work in itself is valued, and patience combined with an external locus of control mean entrepreneurial behaviours are not altered to boost poorly performing business activities.Originality/valueFor Muslim entrepreneurs in Scotland, their traits explain why growth may not be a foremost consideration of these entrepreneurs rather they may value hard work and meeting the ideals of formal and informal institutions associated with religion. For those seeking to support minority groups through the promotion of entrepreneurship, either they must seek to overcome these ingrained traits or alter support to complement the different objectives held by Muslim entrepreneurs.

Investigating the relationship between microbial network features of giant kelp "seedbank" cultures and subsequent farm performance.

Microbial inoculants can increase the yield of cultivated crops and are successful in independent trials; however, efficacy drops in large-scale applications due to insufficient consideration of microbial community dynamics. The structure of microbiomes, in addition to the impact of individual taxa, is an important factor to consider when designing growth-promoting inoculants. Here, we investigate the microbial network and community assembly patterns of Macrocystis pyrifera gametophyte germplasm cultures (collectively referred to as a "seedbank") used to cultivate an offshore farm in Santa Barbara, California, and identify network features associated with increased biomass of mature sporophytes. We found that [1] several network features, such as clustering coefficient and edge ratios, significantly vary with biomass outcomes; [2] gametophytes that become low- or high-biomass sporophytes have different hub taxa; and [3] microbial community assembly of gametophyte germplasm cultures is niche-driven. Overall, this study describes microbial community dynamics in M. pyrifera germplasm cultures and ultimately supports the development of early life stage inoculants that can be used on seaweed cultivars to increase biomass yield.

Improving the Synergy between Informal and Formal Education in Education Management in Nigeria

The interplay between informal and formal education in our society cannot be undermined as both play prominent roles in producing a complete person that is generally accepted in the society that can adequately contribute meaningful to the society and nations economic development. At the early life stage of a child, he starts to learn the ideals, customs, norms and values of his community and society through the support of his parents and other elders around him, that is why some academic scholars have agreed that education is the of transmission of values, cultures, norms and associated societal knowledge of certain group of people from generation to generation. Naturally, societies present to its people some inherent cultures, norms, values that need to be sustained through individual involvement in adherence and obedience to these societal demands, by doing so they internalize it and become well accepted as loyal citizens of the society. This process continues from childhood till adulthood when the child begins to take charge of certain aspects of his life. All these knowledge transmission, acquisition and transfer processes are done anywhere within the child’s environment and also not planned or structured, rather through daily life activities and involvement. This approach to education was applied when the communities and its societies where yet not developed but primitive. However, as society became sophisticated and complex, the need to institutionalize knowledge transmission process was eminent as to meet with the contemporary societal demands and life generally. To this extent, schools began to be built, knowledge transmission became planned and curriculums development became obvious, learning became structured, teachers are trained in different field of endeavors to prepare the individuals in their various localities to meet with challenges of both developing and developed world and also contribute meaningfully to the society and nation at large. Hence the managers of this knowledge process are required to be conscious of the needs of the society and nation as to foster effective and efficient teaching and learning processes that take cognizance of all these societal needs, putting them in perspectives for effective knowledge transmission and delivery in schools. Hence this paper was necessitated to focus on the synergy between informal and formal education in education management. In pursuance of this, the importance of formal, informal education and educational management will be considered, ways of improving the synergy between formal and informal education will also be discussed herein.

Multilevel assessment of carbamazepine effects: An integrative approach using zebrafish early-life stages

Carbamazepine (CBZ) is the most commonly used drug in epilepsy treatment, and its metabolites are commonly detected among persistent pharmaceuticals in the aquatic environment. This study aimed to investigate CBZ effects on early-life-stage zebrafish (Danio rerio) (from 2 to 168 hpf) by employing of an integrative approach linking endpoints from molecular to individual level: (i) development; (ii) locomotor activity; (iii) biochemical markers (lactate dehydrogenase, glutathione-S-transferase, acetylcholinesterase and catalase) and (iv) transcriptome analysis using microarray. A 168 h - LC50 of 73.4 mg L−1 and a 72 h - EC50 of 66.8 mg L−1 for hatching were calculated while developmental effects (oedemas and tail deformities) were observed at CBZ concentrations above 37.3 mg L−1. At the biochemical level, AChE activity proved to be the most sensitive parameter, as evidenced by its decrease across all concentrations tested (∼25% maximum reduction, LOEC (lowest observed effect concentration) < 0.6 μg L−1). Locomotor behaviour seemed to be depressed by CBZ although this effect was only evident at the highest concentration tested (50 mg L−1). Molecular analysis revealed a dose-dependent effect of CBZ on gene expression. Although only 25 genes were deregulated in organisms exposed to CBZ when compared to controls, both 0.6 and 2812 μg L−1 treatments impaired gene expression related to development (e.g. crygmxl1, org, klf2a, otos, stx16 and tob2) and the nervous system (e.g. Rtn3, Gdf10, Rtn3), while activated genes were associated with behavioural response (e.g. prlbr and taar). Altogether, our results indicate that environmentally relevant CBZ concentrations might affect biochemical and genetic traits of fish. Thus, the environmental risk of CBZ cannot be neglected, especially in a realistic scenario of constant input of domestic effluents into aquatic systems.

Lakeshore areas of conservation interest: Characteristics of nursery areas of the threatened lake‐dwelling grayling, Thymallus thymallus

AbstractResearch‐based knowledge is essential for effective conservation and restoration of threatened aquatic species and habitats. Here, our aim was to gather this knowledge on the lake‐dwelling grayling (Thymallus thymallus), typically a riverine fish. Such atypical populations are particularly vulnerable to anthropogenic impacts, including fishing pressure, climate change, eutrophication and waterway construction, some of which affect especially the early life stages. However, there is little information available to guide management and conservation of grayling in lakes. Accordingly, we assessed characteristics of the nursery areas in the threatened grayling population of Lake Puruvesi (eastern Finland). In particular, we used beach seines in two consecutive years to sample lakeshore sites (including islands) that were a priori presumed suitable for grayling. We assessed the occurrence of grayling fry (larvae and post‐larvae &lt;40 mm in length) regarding depth, year, the site's exposure (fetch), bottom shear stress, substrate coarseness and shoreline's north–south orientation. Overall, we found grayling fry in low numbers at every fourth site, with the sites’ exposure and dominant substrate coarseness being most relevant variables. In particular, more exposed sites (i.e. with higher fetch values) and fine‐grained substrates dominated by sand or gravel had more grayling fry. Average depth, bottom shear stress or shoreline orientation along the north–south axis did not have a significant effect. Together, the results suggest that the most important nursery areas for lake‐dwelling grayling are lakeshore zones that are barren and exposed. Hence, the sites share characteristics with those used for reproduction by the more common riverine grayling. We hope that these findings will facilitate lake‐dwelling grayling's management and conservation efforts.

Baculovirus Vector-Based Varicella-Zoster Virus Vaccine as a Promising Alternative with Enhanced Safety and Therapeutic Functions.

Varicella-zoster virus (VZV) poses lifelong risks, causing varicella and herpes zoster (HZ, shingles). Currently, varicella and HZ vaccines are predominantly live attenuated vaccines or adjuvanted subunit vaccines utilizing VZV glycoprotein E (gE). Here, we propose our vaccine candidates involving a comparative analysis between recombinant baculoviral vector vaccines (AcHERV) and a live attenuated vaccine strain, vOka. AcHERV vaccine candidates were categorized into groups encoding gE only, VZV glycoprotein B (gB) only, or both gE and gB (gE-gB) as AcHERV-gE, AcHERV-gB, and AcHERV-gE-gB, respectively. Humoral immune responses were evaluated by analyzing total IgG, IgG1, IgG2a, and neutralizing antibodies. Cell-mediated immunity (CMI) responses were evaluated by enzyme-linked immunospot (ELISPOT) assay and Th1/Th2/Th17 cytokine profiling. In the mouse model, AcHERV-gE-gB elicited similar or higher total IgG, IgG2a, and neutralizing antibody levels than vOka and showed robust VZV-specific CMI responses. From the perspective of antigens encoded in vaccines and their relationship with CMI response, both AcHERV-gB and AcHERV-gE-gB demonstrated results equal to or superior to AcHERV-gE, encoding only gE. Taken together, these results suggest that AcHERV-gE-gB can be a novel candidate for alleviating risks of live attenuated vaccine-induced latency and effectively preventing varicella during early stages of life while providing strong CMI for effective resistance against HZ and therapeutic potential in later stages of life.

An examination of Homo naledi early juveniles recovered from the Rising Star cave system, South Africa

Background Six Homo naledi early juveniles were recovered from U.W. 101 (Dinaledi Chamber), U.W. 102 (Lesedi Chamber), and U.W. 110 in the Rising Star cave system. Aim This paper develops the information for the H. naledi early juvenile life stage, as defined by a combination of deciduous and permanent dentition, and the eruption of the first permanent molar. Subjects and methods The growing number of young individuals recovered from the Rising Star cave system allows us to gain a better understanding of their variation, or lack thereof, and provides a basis to estimate broad ranges for age at death of the individuals. The individuals are identified and described through craniodental remains and spatial associations. Results and conclusion Our results show that the teeth are remarkably consistent across the localities in their metric and non-metric traits, and our analyses refine previous estimations on dental eruptions with the first permanent molar erupting first in the sequence among permanent teeth.

Too Hot to Handle: Effects of Water Temperature on the Early Life Stages of Gongolaria barbata (Fucales)

Gongolaria barbata plays a crucial role as a habitat-forming Fucales species in the Mediterranean Sea, thriving in shallow, sheltered coastal regions, where it exhibits optimal growth in a temperature range of 10 to 25 °C. In the northern Adriatic Sea, a semi-enclosed part of the Mediterranean, there has been a remarkable increase in seawater temperatures in recent decades, often exceeding 28 °C in summer. These high temperatures pose a significant threat to the vulnerable early life stages of G. barbata. This study delves into the effects of four temperatures (15, 18, 24, and 28 °C) on the growth of G. barbata over its first 16 days, closely monitoring mortality, deformities, and overall survival. Our experiments reveal that higher temperatures can result in deformities and increased mortality of germlings. Notably, a temperature of 28 °C resulted in the death of all germlings within the first week, whereas those exposed to 24 °C survived until the second week, albeit with significant deformities prior to death. In contrast, germlings cultivated at 15 and 18 °C exhibited normal development with minimal deformities. These results highlight the susceptibility of the early life stages of G. barbata to temperature-induced stress and provide valuable insights into the potential consequences of rising seawater temperatures in the Mediterranean.

Association Between Self-Reported Opioid Use and Behavioral/Social Health Characteristics—Arizona, 2020

Abstract Background Arizona observed a sharp increase in opioid overdose deaths between 2017 and 2021. Our objective was to better understand the relationship between behavioral/ social characteristics and self-reported opioid misuse among Arizona adults. Methods A cross-sectional study design was done using data from the Arizona 2020 Behavioral Risk Factor Surveillance System (BRFSS) (N = 10,291). Confidence intervals and p-values were found using chi-square for respondents with and without a self-reported opioid misuse. Logistic regression models were developed for the association between adverse childhood experiences (ACEs), mental health, and risk-taking behaviors (RTBs) and opioid misuse. Results Respondents who reported 2–3 ACEs (ORadjusted: 4.7; 95% CI: [2.8, 7.9]) and who reported 4 or more ACEs (ORadjusted: 8.3; 95% CI: [5.0, 13.6]); respondents who reported poor mental health (ORadjusted: 3.3; 95% CI: [2.1, 5.2]); and respondents who reported two or more RTBs (ORadjusted: 3.9; 95% CI: [2.5, 6.1]) had higher odds of self-reported opioid misuse compared to those without self-reported opioid misuse. Discussion Opioid misuse was found to be associated with poor mental and physical health, increased RTBs, and history of at least two ACEs among Arizona adults in this study. These findings stress the importance of opportunities for targeted prevention in both Arizona adults and youth, including screening for ACEs and RTBs, in early stages of life.

Contribution of the serotonergic system to developmental brain abnormalities in autism spectrum disorder.

This review highlights a key role of the serotonergic system in brain development and in distortions of normal brain development in early stages of fetal life resulting in cascades of abnormalities, including defects of neurogenesis, neuronal migration, neuronal growth, differentiation, and arborization, as well as defective neuronal circuit formation in the cortex, subcortical structures, brainstem, and cerebellum of autistic subjects. In autism, defects in regulation of neuronal growth are the most frequent and ubiquitous developmental changes associated with impaired neuron differentiation, smaller size, distorted shape, loss of spatial orientation, and distortion of cortex organization. Common developmental defects of the brain in autism include multiregional focal dysplastic changes contributing to local neuronal circuit distortion, epileptogenic activity, and epilepsy. There is a discrepancy between more than 500 reports demonstrating the contribution of the serotonergic system to autism's behavioral anomalies, highlighted by lack of studies of autistic subjects' brainstem raphe nuclei, the center of brain serotonergic innervation, and of the contribution of the serotonergic system to the diagnostic features of autism spectrum disorder (ASD). Discovery of severe fetal brainstem auditory system neuronal deficits and other anomalies leading to a spectrum of hearing deficits contributing to a cascade of behavioral alterations, including deficits of social and verbal communication in individuals with autism, is another argument to intensify postmortem studies of the type and topography of, and the severity of developmental defects in raphe nuclei and their contribution to abnormal brain development and to the broad spectrum of functional deficits and comorbid conditions in ASD.

Air bubble curtain improves the welfare of captive rainbow trout fry and fingerlings

Fish welfare is becoming a priority for the fish farming industry. The search for practical, easy-to-implement methods to promote farmed fish welfare is therefore essential. Environmental enrichment aims to improve the psychological and physiological needs of a captive animal by increasing the complexity of its environment. During previous studies, we observed that fish seemed to be positively affected by short diffusions of air bubbles. In this study, we evaluated the effects of an innovative enrichment strategy consisting of introducing into the tank at the earliest stages of life, a pipe generating a curtain of air bubbles. Using rainbow trout (Oncorhynchus mykiss) as a captive fish model, we compared the short- (∼7 weeks) and long-term (∼21 weeks) effects of this bubble curtain diffused for one hour four times a day (Bubble condition) to a standard condition without bubbles (Control) on fish growth, aggressive and abnormal behaviors, as well as on fish motivation to access a bubble curtain, their emotional responses and their learning abilities. We found that bubble diffusion decreased aggressive and abnormal behaviors during diffusions in both the short-term and the long-term experiments. In the long-term experiment, this decrease was also observed during feedings and neutral periods when no bubble was diffused. Bubbles were found to be attractive for young Control fish (bubble-naive fish) subjected to a motivation test in the short-term experiment. When subjected to the emotional reactivity test, Bubble fish seemed less fearful, exhibiting a lower maximum velocity than Control fish in the long-term experiment only. However, the other behavioral parameters measured during this test, appetite and plasma cortisol levels were similar between treatments, irrespective of the experimental period. The latency to consume the reward observed in the spatial learning test in the long-term experiment was decreased in Bubble fish compared with Control fish, showing enhanced learning abilities in fish that experienced bubbles for 21 weeks. Growth parameters and fin erosion index did not differ between treatments. We conclude that repeated bubble diffusions act as an environmental enrichment for fish, combining physical, occupational, and sensory enrichment via the tactile stimulations provided by the air bubbles. This type of enrichment had a positive impact on the behavior of farmed rainbow trout in the long term, and would make it possible to integrate the notion of “positive welfare” into fish farms, while guaranteeing easy technical maintenance.

Placental biomarkers of fetal-originated diseases

Fetal-originated diseases refer to birth defects of offspring and multiple chronic diseases in adulthood caused by abnormal embryonic development. However, due to the vulnerability of the fetus/ neonate and technical limitations, it is very difficult to carry out effective development assessment and early warning of long-term diseases in the early stages of life. It is known that the placenta is the unique link between the mother and the fetus, and its role in the occurrence and progression of fetal-originated diseases cannot be ignored. Studies have found that a variety of adverse environmental factors (such as nanoparticle exposure) cannot pass through the placental barrier, but can lead to fetal dysplasia and multi-organ development programming changes by affecting placental development, and ultimately mediate the occurrence of fetal-originated diseases. Meanwhile, some environmental factors that can pass through the placental barrier can cause placenta-fetal co-exposure, resulting in similar signaling pathways and epigenetic changes. The placenta originates from the fetus and the mother, and its development is accompanied by changes in indicators that can be objectively and quantitatively detected. These factors can be used as a biomarker to assess maternal exposure, and placental function, and to predict the developmental status and long-term disease susceptibility of offspring. To date, researchers have discovered a variety of potential placental biomarkers, and show promising application prospects. This paper reviews the recent research on placenta-related mechanisms leading to fetal-originated diseases and placental biomarkers, to provide the theoretical and experimental basis for early warning, prevention, and treatment of fetal-originated diseases.