Early Life Stages Research Articles

Modulation of metabolic and immunoregulatory pathways in the gut transcriptome of Atlantic salmon (Salmo salar L.) after early nutritional programming during first feeding with plant-based diet.

Plant-based nutritional programming is the concept of exposing fish at very early life stages to a plant-based diet for a short duration to improve physiological responses when exposed to a similar plant-rich diet at a later developmental stage. The mechanisms of action underlying nutritional programming have not been fully deciphered, and the responses may be controlled at multiple levels. This 22-week study examines gut transcriptional changes after nutritional programming. Triplicate groups of Atlantic salmon were fed with a plant (V) vs. a marine-rich (M, control) diet for 2 weeks (stimulus phase) at the first exogenous feeding. Both stimulus fish groups (M and V fish) were then fed the M diet for 12 weeks (intermediate phase) and lastly fed the V diet (challenge phase) for 6 weeks, generating two dietary regimes (MMV and VMV) across phases. This study used a whole-transcriptome approach to analyse the effects of the V diet at the end of stimulus (short-term effects) and 22 weeks post-first feeding (long-term effects). After the stimulus, due to its developmental stage, the whole intestine was used, whereas, after the challenge, pyloric caeca and middle and distal intestines were examined. At the stimulus end, genes with increased expression in V fish enriched pathways including regulatory epigenetic responses and lipid metabolism, and genes involved in innate immune response were downregulated. In the middle intestine at the end of the challenge, expression levels of genes of lipid, carbohydrate, and energy metabolism were increased in V fish, while M fish revealed increased expression of genes associated with autoimmune and acute adaptive immune response. The distal intestine of V fish showed increased expression of genes associated with immune response and potential immune tolerance. Conversely, the distal intestine of M fish at challenge revealed upregulation of lipid and carbohydrate metabolic pathways, tissue degeneration, and apoptotic responses. The present study demonstrated nutritional programming-associated changes in the intestinal transcriptome, with altered expression of genes involved in both immune responses and different metabolic processes. While there were limited changes in growth between the groups, the results show that there were transcriptional differences, suggesting a programming response, although the mechanism of this response still requires to be fully elucidated.

Sublethal effects of early-life exposure to common and emerging contaminants in birds

The plight of wild birds is becoming critical due to exposure to environmental contaminants. Although laboratory studies have provided insights into the developmental effects of chemical exposures, less is known about the adverse effects of environmental chemicals in developing wild birds. Early life stages are critical windows during which long-term organization of physiological, behavioral, and neurological systems can occur. Thus, contaminant exposure at early life stages can directly influence survival and reproductive success, with consequences for population stability and resilience in wild species. This review synthesizes existing knowledge regarding both short- and long-term effects of early-life exposure to widespread contaminants in birds. We focus especially on wild birds and on contaminants of concern within the Gulf of Mexico as an example of a habitat under anthropogenic stress from exposure to a complex mixture of chemicals and changing land uses that exacerbate existing vulnerabilities of wildlife in this region. Chemical contaminants for discussion in this review are based on avian mortality records from the Wildlife Health Information Sharing Partnership (WHISPers) database and on additional review of the literature regarding avian contaminants of concern for the northern Gulf of Mexico, and include oil and associated polycyclic aromatic hydrocarbons, dioxin and dioxin-like compounds, flame retardants, pesticides, heavy metals, and plastics. We provide an overview of effects in bird species at both the pre-hatching and post-hatching early life stages, discuss differences in sensitivities by route of exposure, life stage, and life history, and provide recommendations for future research. We find that additional research is needed on altricial species, post-hatching early-life exposure, long-term effects, and on ecologically relevant contaminant concentrations and routes of exposure. Given the increasing frequency and intensity of anthropogenic stressors encountered by wild animals, understanding both lethal and sublethal impacts of contaminants on the health of individuals and populations will be critical to inform restoration, management, and mitigation efforts.

Modulation of gut microbiota composition and predicted metabolic capacity after nutritional programming with a plant-rich diet in Atlantic salmon (Salmo salar): insights across developmental stages

To promote sustainable aquaculture, the formulation of Atlantic salmon (Salmo salar) feeds has changed in recent decades, focusing on replacing standard marine-based ingredients with plant-based alternatives, increasingly demonstrating successful outcomes in terms of fish performance. However, little is known about how these plant-based diets may impact the gut microbiota at first feeding and onwards. Nutritional programming (NP) is one strategy applied for exposing fish to a plant-based (V) diet at an early stage in life to promote full utilisation of plant-based ingredients and prevent potential adverse impacts of exposure to a plant-rich diet later in life. We investigated the impact of NP on gut microbiota by introducing fish to plant ingredients (V fish) during first feeding for a brief period of two weeks (stimulus phase) and compared those to fish fed a marine-based diet (M fish). Results demonstrated that V fish not only maintained growth performance at 16 (intermediate phase) and 22 (challenge phase) weeks post first feeding (wpff) when compared to M fish but also modulated gut microbiota. PERMANOVA general effects revealed gut microbiota dissimilarity by fish group (V vs. M fish) and phases (stimulus vs. intermediate vs. challenge). However, no interaction effect of both groups and phases was demonstrated, suggesting a sustained impact of V diet (nutritional history) on fish across time points/phases. Moreover, the V diet exerted a significant cumulative modulatory effect on the Atlantic salmon gut microbiota at 16 wpff that was not demonstrated at two wpff, although both fish groups were fed the M diet at 16 wpff. The nutritional history/dietary regime is the main NP influencing factor, whereas environmental and host factors significantly impacted microbiota composition in M fish. Microbial metabolic reactions of amino acid metabolism were higher in M fish when compared to V fish at two wpff suggesting microbiota played a role in digesting the essential amino acids of M feed. The excessive mucin O-degradation revealed in V fish at two wpff was mitigated in later life stages after NP, suggesting physiological adaptability and tolerance to V diet. Future studies are required to explore more fully how the microbiota functionally contributes to the NP.

Habitat distinctness doesn't influence on the abundance and relative growth of the juveniles Atherinella brasiliensis (Quoy & Gaimard, 1824) in a subtropical estuarine ecosystem

Shallow coastal habitats with and without vegetation may perform nursery function from distinct way for many species, raising questions about the role of vegetation on structuring nursery ground. Unfortunately, degradation and inappropriate human use of these areas associated with the lack of ecological data about fish populations can limit appropriate strategies to protect both species and habitats. In this paper we examine the nursery value of different estuarine habitats by comparing the abundance and relative growth of juveniles Atherinella brasiliensis. Fish were sampled once a month from November 2018 to October 2019 in five habitats: no vegetation close to the ocean, no vegetation close to the river, no vegetation and distant from other sampling points (control), mangrove and saltmarsh. Juveniles are present and abundant in all habitats and specimens had similar relative growth in the salt marsh, mangrove habitats and non vegetated habitats. The results indicate that estuarine habitats offers suitable conditions to A. brasiliensis in early stages of life, indicating that these sites have nursery value for juveniles of this species. Conservation and/or preservation of estuarine shallows habitats along the coast is important for A. brasiliensis and probably for other species, and the identification of priority areas could help to provide subsidies to management policies on conservation of coastal marine environments.

Lipids as biomarkers to assess the nutritional and physiological status of two diadromous fish (Anguilla anguilla and Chelon auratus) at early life stages in a temperate macrotidal estuary.

Estuaries are considered as key habitats for the early life stages of fish. However, in the face of massive destruction of many estuarine intertidal areas, management and conservation measures are needed. Fish condition indicators may be used as a proxy of habitat quality and provide valuable information for management of coastal areas. In this study, the larvae of golden mullet (Chelon auratus) and European glass eels (Anguilla anguilla) were sampled in three sites of the Gironde Estuary. Different lipid classes and fatty acids were quantified: phospholipids (globally, phosphatidylethanolamine and phosphatidylcholine), triglycerides, omega-3 (particularly docosahexaenoic and eicosapentaenoic acids), omega-6 and C18:1. These biomarkers provide information on the nutritional status of the larvae as well as on prey availability and larvae diet between sites. One site significantly differed from the others as it seemed to offer abundant and better-quality prey. The very high levels of omega-3 contained in mullet larvae suggested that this site provided a high amount of diatoms. However, the mullet larvae that colonized this site also showed physiological stress that could be explained by exposure to pollutants through their prey. This work constitutes an essential baseline for developing biomarkers to assess the quality of habitats in a global change context.

Characterization of Adverse Outcomes from Legacy-Contaminated Groundwater Exposure to Early Life Stages of Fathead Minnow.

Complex mixtures of chemicals present in groundwater at legacy-contaminated industrial sites can pose significant risks to adjacent surface waters. The combination of short-term molecular and chronic apical effect assessments is a promising approach to characterize the potential hazard of such complex mixtures. The objectives of this study were to: (1) assess the apical effects (survival, growth, development, and liver histopathology) after chronic exposure of early life stages (ELSs) of fathead minnows (FHM; Pimephales promelas) to contaminated groundwater from a legacy-contaminated pesticide manufacturing and packaging plant, and (2) identify possible molecular mechanisms responsible for these effects by comparing results to mechanistic outcomes previously determined by a short-term reduced transcriptome assay (EcoToxChips). This study revealed a significant increase in mortality and prevalence of spinal curvatures, as well as a significant reduction in the length of FHMs exposed to the groundwater mixtures in a concentration-dependent manner. There was an increasing trend in the prevalence of edema in FHMs, though not significantly different from controls. Additionally, no histopathological effects were observed in the liver of FHMs exposed to the groundwater mixtures. Short-term molecular outcomes determined in a parallel study were found to be informative of chronic apical outcomes, including cardiotoxicity, spinal deformities, and liver toxicity. Overall, the results observed in this study demonstrated that short-term transcriptomics analyses could support the hazard assessment of complex contaminated sites.

Turbidity effects on prey consumption and survival of larval European smelt (Osmerus eperlanus)

The anadromous European smelt (Osmerus eperlanus) plays a key role in food webs of many riverine ecosystems in Europe. However, population sizes in several German rivers (e.g. Elbe or Weser rivers) have diminished drastically over the past decade. Turbidity has been considered one of the stressors affecting the successful recruitment of European smelt, as their early life stages may be particularly sensitive to changes in the abiotic environment. In this study, we investigated whether prey consumption and survival of European smelt larvae would be negatively affected by an acute exposure to elevated turbidity. We reared the larvae in the laboratory and exposed them in four separate trials (18 to 26 days post hatch, 9.5 ± 0.8 mm standard length, mean ± SD) to six turbidity levels (0–500 NTU, nephelometric turbidity units). We found that prey uptake increased at low turbidity levels and decreased at high turbidity levels, with an optimum between 100 and 200 NTU. Survival started to decrease at turbidity levels above 300 NTU. In addition, we conducted a systematic literature analysis in which we found that prey consumption of larval and juvenile fishes had been tested across a wide range of turbidity levels, mostly using pelagic (e.g. planktonic) prey items, with more studies focusing on perciform fishes and juvenile rather than larval life stages. Our empirical findings contribute to establishing thresholds for optimal larval European smelt performance under increased turbidity and provide valuable information for developing mechanistic models that assess potential consequences for European smelt recruitment dynamics.

Rheumatic diseases in the elderly: Challenges and management

Abstract The elderly demographic is seeing a gradual rise as a proportion of the overall global population, whilst also experiencing high rates of musculoskeletal issues, requiring specialized care. The management of rheumatic diseases in the elderly presents unique challenges due to the complex interplay among physiological changes, cognitive decline, and altered immune responses. Such conditions can be categorized into those progressing from earlier life stages (such as rheumatoid arthritis, systemic lupus erythematosus, spondyloarthritis, and gout) and those predominantly emerging in old age (such as polymyalgia rheumatica, giant cell arteritis, osteoarthritis, crystal arthropathies, and osteoporosis), each with distinct characteristics and management needs. These diseases often present atypically with nonspecific symptoms and altered serological markers, complicating diagnosis and management due to increased toxicity risks and comorbidities. Comprehensive, multidisciplinary care that includes cardiovascular health monitoring, bone density maintenance, gastrointestinal tolerance management, infection prevention, and mental health support are essential to improve outcomes and quality of life for elderly patients with rheumatic diseases.

Laminar Architecture and Morphometry of Developing Human Fetal Cerebellum

Abstract Background: One of the organs in the human fetus that starts to differentiate extremely early and keeps doing so throughout the postnatal period is the cerebellum. The goal of this study was to create a nomogram using the chronological events that were occurring and the relationship with progressing gestational age. Granule cells and Purkinje cells play a crucial role in the normal development of the cerebellum. Any disruption at the cellular level can lead to abnormal migration of these cells, potentially resulting in hypoplasia of the cerebellar vermis. Methodology: Tissue specimens from 60 human fetuses were studied for histological changes after being grouped into four from 13th week to 32nd week. Fetuses with any neurological deficit were excluded from the study. Different layers were identified, and the thickness of each layer was noted. Results: The first two groups had three layers, but the composition was different in both. The marginal and mantle layers in the second group disappeared completely. The third group showed presence of five layers, with addition of lamina dissecans, appearing for a transient period. The fourth group had four layers. The thickness of external granular layer and internal granular layer (IGL) increased throughout, except that the IGL made an appearance from the second group only. Lamina dissecans appeared, causing a significant shift between 23 and 27 weeks. The fetus has a four-layered structure near term, with an external granular layer persisting throughout the early postnatal stage of life. Progression of pregnancy was positively connected with the molecular and Purkinje cell layer (PCL) thickness. Conclusion: Progression of pregnancy was positively connected with the molecular and PCL thickness. Age determination and neuropsychiatric disorders of the developing fetus may benefit from such a link.

Ferrocenedicarboxylate modified Bi-MOF for water decontamination via different advanced oxidation processes: Multifunction, mechanisms and biotoxicity test

Peroxymonosulfate (PMS), peroxydisulfate (PDS) and hydrogen peroxide (H2O2)-based advanced oxidation processes are extensively applied for aqueous pollutants degradation. However, few cases reported the comparison the PMS, PDS and H2O2 activation performances of a heterogeneous catalyst. In this work, 1,1′-ferrocenedicarboxylate (Fc) modified Bi-BDC (Bi-BDC-Fcx) with unique electronic structure and strong oxidation ability was synthesized and applied for degrading bisphenols (BPs) via photocatalytic PMS, PDS, and H2O2 activation, respectively. The optimum Bi-BDC-Fc0.1 exhibited the best photocatalytic PMS, PDS and H2O2 activation performance to degrade various organic pollutants, including BPs, in which the bisphenol A degradation efficiencies followed the order of Bi-BDC-Fc0.1/UVL/PMS, Bi-BDC-Fc0.1/UVL/PDS and Bi-BDC-Fc0.1/UVL/H2O2. The reaction mechanisms of photocatalytic PMS, PDS and H2O2 activation over Bi-BDC-Fc0.1 were comprehensively clarified by experimental results along with DFT calculations. Also, the toxicity and ecotoxicological impact of the pristine BPs and their intermediates were evaluated by the phytotoxicity experiments and zebrafish early-life stage toxicity test. This work presented a comprehensive investigation of degradation performance and the ecotoxicology assessment of Bi-BDC-Fcx/UVL/PMS, Bi-BDC-Fcx/UVL/PDS, and Bi-BDC-Fcx/UVL/H2O2 systems, providing valuable insights to design and utilize the newly developed catalysts for water purification.

Habitat selection and spatial behaviour of vulnerable juvenile lemon sharks: Implications for conservation

Nearshore environments represent important habitat for many marine vertebrates during their early-life stages. Globally, these coastal sites are impacted by human activities that have the potential to negatively impact biodiversity in ways we do not yet fully appreciate. To improve our understanding of the relevance of mangrove removal in tropical elasmobranch nursery grounds, we studied the globally Vulnerable lemon shark (Negaprion brevirostris) in a mangrove-fringed lagoon in Bimini, The Bahamas, following a decade of coastal development and habitat disruption. We used two years of acoustic telemetry detections and generalised linear mixed models (GLMMs) to evaluate the link between juvenile shark spatial behaviour and six features of their physical environment. AIC-adjusted model-averaged predictions of habitat selection demonstrated that distance from the central mangrove forest was the most important feature for sharks. After updating model averaging to account for overall preference for proximity to the central forest, we found that medium density seagrass was secondarily preferred over all other habitat types (bare sand, sargassum, urban and rocky outcrops, and deep water) within the core use area (probability of use ≥ 50 %). Locally, our results support including this core area in future marine protected area considerations. More broadly, in the face of rapid global population declines of many elasmobranchs and wide-spread habitat fragmentation in coastal marine nurseries, we identified widely applicable habitat features underpinning an area of high ecological significance for a threatened shark during a vulnerable life stage and outlined a habitat selection framework suitable for using marine vertebrate movement data as ecological indicators for future applied conservation.

Chronic exposure to environmental concentrations of benzo[a]pyrene causes multifaceted toxic effects of developmental compromise, redox imbalance, and modulated transcriptional profiles in the early life stages of marine medaka (Oryzias melastigma)

Polycyclic aromatic hydrocarbons (PAHs) accumulate and integrate into aquatic environments, raising concerns about the well-being and safety of aquatic ecosystems. Benzo[a]pyrene (BaP), a persistent PAH commonly detected in the environment, has been extensively studied. However, the broader multifaceted toxicity potential of BaP on the early life stages of marine fish during chronic exposure to environmentally relevant concentrations needs further exploration. To fill these knowledge gaps, this study assessed the in vivo biotoxicity of BaP (1, 4, and 8 μg/L) in marine medaka (Oryzias melastigma) during early development over a 30-day exposure period. The investigation included morphological, biochemical, and molecular-level analyses to capture the broader potential of BaP toxicity. Morphological analyses showed that exposure to BaP resulted in skeletal curvatures, heart anomalies, growth retardation, elevated mortality, delayed and reduced hatching rates. Biochemical analyses revealed that BaP exposure not only created oxidative stress but also disrupted the activities of antioxidant enzymes. This disturbance in redox balance was further explored by molecular level investigation. The transcriptional profiles revealed impaired oxidative phosphorylation (OXPHOS) and tricarboxylic acid (TCA) cycle pathways, which potentially inhibited the oxidative respiratory chain in fish following exposure to BaP, and reduced the production of adenosine triphosphate (ATP) and succinate dehydrogenase (SDH). Furthermore, this investigation indicated a potential connection to apoptosis, as demonstrated by fluorescence microscopy and histological analyses, and supported by an increase in the expression levels of related genes via real-time quantitative PCR. This study enhances our understanding of the molecular-level impacts of BaP's multifaceted toxicity in the early life stages of marine medaka, and the associated risks.

Life-history stage influences immune investment and oxidative stress in response to environmental heterogeneity in Antarctic fur seals

Immune defenses are crucial for survival but costly to develop and maintain. Increased immune investment is therefore hypothesized to trade-off with other life-history traits. Here, we examined innate and adaptive immune responses to environmental heterogeneity in wild Antarctic fur seals. In a fully crossed, repeated measures design, we sampled 100 pups and their mothers from colonies of contrasting density during seasons of contrasting food availability. Biometric and cortisol data as well as blood for the analysis of 13 immune and oxidative status markers were collected at two key life-history stages. We show that immune responses of pups are more responsive than adults to variation in food availability, but not population density, and are modulated by cortisol and condition. Immune investment is associated with different oxidative status markers in pups and mothers. Our results suggest that early life stages show greater sensitivity to extrinsic and intrinsic effectors, and that immunity may be a strong target for natural selection even in low-pathogen environments such as Antarctica.

A new Alien Fish from the Southern Black Sea (Sinop, Türkiye): Sebastes schlegelii Hilgendorf, 1880 (Scorpaeniformes, Sebastidae)

Sebastes schlegelii Hilgendorf, 1880 is an Indo-Pacific species with a widespread distribution in the coastal waters of the Far Eastern region. This study represents the first documentation of S. schlegelii off Sinop coast from the Southern Black Sea. The four specimens collected on 28 May 2023 and 18 June 2023 from rocky habitat at a depth of about 6 meters off Sinop coast had a total length range of 226 to 237 mm and weights ranging from 197.57 to 254.98 g. The spread of this species to the southern Black Sea coast is attributed to the transportation of early life stage individuals from the northern coast of the Black Sea to the southern coast via the cyclonic Rim Current.

К вопросу о педагогическом сопровождении формирования основ нравственной культуры дошкольника

The realities of the modern educational landscape are in constant interaction with complex challenges in the moral upbringing of preschool children, demanding a profound understanding of sociocultural and psychological aspects. Amid rapid technological advancements, changes in family structures, and cultural contexts, moral education and moral culture have become crucial aspects ensuring the holistic development of a child's personality. Educators are tasked with developing and implementing effective pedagogical support strategies that foster the formation of ethical values, social responsibility, and behavioral culture in children.Analyzing pedagogical strategies and methods in the realm of moral education for preschoolers allows the identification of optimal approaches that promote the development of their ethical values, responsibility, and social competence. These findings serve as the foundation for practical recommendations and methodological approaches aimed at enhancing the process of moral education in preschool institutions, encompassing innovative teaching methods, playful techniques, and pedagogical strategies that instill children with values and ethical skills. These methodologies, in our view, involve parental support and the engagement of the family institution, ensuring harmonious collaboration between educational institutions and parents in the moral development of preschoolers, instilling in them the necessary level of moral culture.The study of pedagogical support for the moral culture of preschoolers not only highlights the importance of shaping moral values in the early stages of life but also underscores the pivotal role of pedagogical strategies in this process. The development and implementation of innovative methodological approaches tailored to each child's individual needs represent an integral component in ensuring stable and harmonious moral development in educational settings. These research findings form the basis for further advancements in the field of education and upbringing, contributing to the establishment of ethical foundations for future generations.

A Comparative Study on Al0.6Ti0.4N Coatings Deposited by Cathodic Arc and HiPIMS in End Milling of Stainless Steel 316L

The machining of austenitic stainless steel alloys is usually characterized by high levels of adhesion and built-up edge; therefore, improving tribological conditions is fundamental to obtaining higher tool life and better surface finish. In this work, three different Al0.6Ti0.4N coatings are compared, two deposited by Cathodic Arc Evaporation (CAE) and one with High-Power Impulse Magnetron Sputtering (HiPIMS). The effects of the micromechanical properties and the microstructure of the coatings were then studied and related to the machining performance. Both arc-deposited coatings (CAE 1 and 2) exhibited similar average tool life, 127 min and 128 min, respectively. Whereas the HiPIMS lasted for only 21.2 min, the HiPIMS-coated tool had a much shorter tool life (more than six times lower than both CAE coatings) due to the intense adhesion that occurred in the early stages of the tool life. This higher adhesion ultimately caused built-up edge and chipping of the tool. This was confirmed by the cutting forces and more deformation on the shear band and undersurface of the chips, which are related to higher levels of friction. The higher adhesion could be attributed to the columnar structure of the HiPIMS and the (111) main texture, which presents a higher surface energy when compared to the dominant (200) from both arc depositions. Studies focused on tribology are necessary to further understand this relationship. In terms of micromechanical properties, tools with the highest plasticity index performed better (CAE 2 = 0.544, CAE 1 = 0.532, and HiPIMS = 0.459). For interrupted cutting machining where adhesion is the main wear mechanism, a reserve of plasticity is beneficial to dissipate the energy generated during friction, even if this was related to lower hardness levels (CAE 2 = 26.6 GPa, CAE 1 = 29.9 GPa, and HiPIMS = 33.6 GPa), as the main wear mechanism was adhesive and not abrasive.

Marine heatwaves alter the nursery function of coastal habitats for juvenile Gulf of Alaska Pacific cod

Marine Heatwaves (MHWs) can directly influence survival of marine fishes, particularly for early life stages, including age-0 juveniles during their residence in coastal nursery habitats. However, the ability of nurseries to support high fish densities, optimize foraging and growth, and protect against predators may be altered during MHWs. Gulf of Alaska Pacific cod (Gadus macrocephalus) larval, juvenile, and adult abundances declined dramatically following MHW events in 2014–2016 and 2019. To evaluate coastal nursery function during MHWs, we compared diet composition, recent growth, size, condition, and abundance of age-0 juveniles throughout their first summer before, during, and between MHWs. Diet shifted to larger prey during MHWs, particularly mysids, but diet did not appear to influence growth. We observed faster growth rates during MHWs, yet even when accounting for growth, we could not explain the higher body sizes observed in August during MHWs. Together with lower abundance and the near absence of small fish in the nursery by August during MHWs, these patterns highlight potential for size-selection and a reduced ability of nursery habitats to buffer against environmental variability during MHWs, with only a small number of large “super survivors” persisting through the summer.

Transcriptome analysis of East Asian common octopus, Octopus sinensis, paralarvae.

The genes involved in cephalopod development and their association with hatching and survival during early life stages have been extensively studied. However, few studies have investigated the paralarvae transcriptome of the East Asian common octopus (Octopus sinen sis). This study aimed to identify the genes related to embryonic development and hatching in O. sinensis using RNA sequencing (RNA-seq) and verify the genes most relevant to different embryonic stages. RNA samples from hatched and 25days post-hatching (dph) O. sinensis paralarvae were used to construct cDNA libraries. Clean reads from individual samples were aligned to the reference O. sinensis database to identify the differentially expressed genes (DEGs) between the 0- and 25-dph paralarvae libraries. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to supplement the RNA-seq data for embryogenic developmental stages. A total of 12,597 transcripts were annotated and 5,468 DEGs were identified between the 0- and 25-dph O. sinensis paralarvae, including 2,715 upregulated and 2,753 downregulated transcripts in the 25-dph paralarvae. Several key DEGs were related to transmembrane transport, lipid biosynthesis, monooxygenase activity, lipid transport, neuropeptide signaling, transcription regulation, and protein-cysteine S-palmitoyltransferase activity during the post-hatching development of O. sinensis paralarvae. RT-qPCR analysis further revealed that SLC5A3A, ABCC12, and NPC1 transcripts in 20 and/or 30days post-fertilization (dpf) embryos were significantly higher (p < 0.05) than those in 10-dpf embryos. Transcriptome profiles provide molecular targets to understand the embryonic development, hatching, and survival of O. sinensis paralarvae, and enhance octopus production.

Sediment source and dose influence the larval performance of the threatened coral Orbicella faveolata.

The effects of turbidity and sedimentation stress on early life stages of corals are poorly understood, particularly in Atlantic species. Dredging operations, beach nourishment, and other coastal construction activities can increase sedimentation and turbidity in nearby coral reef habitats and have the potential to negatively affect coral larval development and metamorphosis, reducing sexual reproduction success. In this study, we investigated the performance of larvae of the threatened Caribbean coral species Orbicella faveolata exposed to suspended sediments collected from a reef site in southeast Florida recently impacted by dredging (Port of Miami), and compared it to the performance of larvae exposed to sediments collected from the offshore, natal reef of the parent colonies. In a laboratory experiment, we tested whether low and high doses of each of these sediment types affected the survival, settlement, and respiration of coral larvae compared to a no-sediment control treatment. In addition, we analyzed the sediments used in the experiments with 16S rRNA gene amplicon sequencing to assess differences in the microbial communities present in the Port versus Reef sediments, and their potential impact on coral performance. Overall, only O. faveolata larvae exposed to the high-dose Port sediment treatment had significantly lower survival rates compared to the control treatment, suggesting an initial tolerance to elevated suspended sediments. However, significantly lower settlement rates were observed in both Port treatments (low- and high-dose) compared to the control treatment one week after exposure, suggesting strong latent effects. Sediments collected near the Port also contained different microbial communities than Reef sediments, and higher relative abundances of the bacteria Desulfobacterales, which has been associated with coral disease. We hypothesize that differences in microbial communities between the two sediments may be a contributing factor in explaining the observed differences in larval performance. Together, these results suggest that the settlement success and survival of O. faveolata larvae are more readily compromised by encountering port inlet sediments compared to reef sediments, with potentially important consequences for the recruitment success of this species in affected areas.

Case Study: Growth Performance and Business Analysis of Brown-Marbled Grouper (Epinephelus fuscoguttatus) in Nursery and Grow-Out Cultivation

Grouper fish, particularly the brown-marbled grouper (Epinephelus fuscoguttatus), are among the most economically significant marine species widely farmed and exported. This study aimed to analyze the growth performance and business analysis of the production of brown-marbled grouper, both in nursery and grow-out segments. The research was conducted using a case study method at a governmental production and research center located in Lampung Province, Indonesia. Primary data were collected through field observations, while secondary data were obtained from interviews with farm personnel. The study revealed that the nursery phase faced significant challenges, with larval survival rates as low as 4.2%. In contrast, survival rates improved considerably in larger fish, demonstrating better resilience as they grow (reaching 92-93%). From a business perspective, the grow-out activity was found to be more profitable due to lower investment costs. However, it requires a longer period to raise the fish to market size. Both nursery and grow-out operations proved to be profitable, with respective R/C ratios of 1.6-2.0. Overall, while grouper farming is economically viable, it requires careful management to overcome the high mortality in the early life stages and to optimize the investment cost-effectiveness of the nursery phase.