Knowledge mapping analysis of the global seaweed research using CiteSpace.

Seaweed research has gained substantial momentum in recent years, attracting the attention of researchers, academic institutions, industries, policymakers, and philanthropists to explore its potential applications and benefits. Despite the growing body of literature, there is a paucity of comprehensive scientometric analyses, highlighting the need for an in-depth investigation. In this study, we utilized CiteSpace to examine the global seaweed research landscape through the Web of Science Core Collection database, assessing publication trends, collaboration patterns, network structures, and co-citation analyses across 48,278 original works published since 1975. Our results demonstrate a diverse and active research community, with a multitude of authors and journals contributing to the advancement of seaweed science. Thematic co-citation cluster analysis identified three primary research areas: "Coral reef," "Solar radiation," and "Mycosporine-like amino acid," emphasizing the multidisciplinary nature of seaweed research. The increasing prominence of "Chemical composition" and "Antioxidant" keywords indicates a burgeoning interest in characterizing the nutritional value and health-promoting properties of seaweed. Timeline co-citation analysis unveils that recent research priorities have emerged around the themes of coral reefs, ocean acidification, and antioxidants, underlining the evolving focus and interdisciplinary approach of the field. Moreover, our analysis highlights the potential of seaweed as a functional food product, poised to contribute significantly to addressing global food security and sustainability challenges. This study underscores the importance of bibliometric analysis in elucidating the global seaweed research landscape and emphasizes the need for sustained knowledge exchange and collaboration to drive the field forward. By revealing key findings and emerging trends, our research offers valuable insights for academics and stakeholders, fostering a more profound understanding of seaweed's potential and informing future research endeavors in this promising domain.

Ecotoxicity of commonly used oilfield-based emulsifiers on Guinean Tilapia (Tilapia guineensis) using histopathology and behavioral alterations as protocol.

This study examined the histological aberrations in the gill and liver tissues and behavioural changes of Tilapia guineensis fingerlings exposed to lethal concentrations of used Oilfield-based emulsifiers for 96 h. Various concentrations of the surfactants were tested, ranging from 0.0 to 15.0 ml/L. The behaviour of the fish was observed throughout the experiment, and the results showed that increasing concentrations of the surfactants led to progressively abnormal behaviour, including hyperventilation and altered opercular beat frequency. These behavioural changes indicated respiratory distress and neurotoxic effects. Histological analysis revealed structural aberrations in the gill and liver tissues, with higher concentrations causing more severe damage, such as lesions, necrosis, inflammation, and cellular degeneration. This implies that surfactants released even at low concentrations are capable of inducing changes in the tissues of aquatic organisms. These findings highlight the toxic effects of the surfactants on fish health and provide biomarkers of toxicity. Future research should focus on understanding the specific mechanisms and long-term consequences of surfactant toxicity on fish genetic composition, populations, and ecosystems to implement effective conservation measures.

De novo transcriptional analysis of the response to starvation stress in the white ridgetail prawn, Exopalaemon carinicauda.

To study the mechanism of the biomolecular response in Exopalaemon carinicauda to starvation stress, we subjected muscle tissue RNA samples from four stress points, including 0 d(control group), 10 d, 20 d, and 30 d, to starvation stress on white ridgetail prawn with a body weight of 1.41 + 0.42 g, aquaculture water temperature of 23-25 °C, salinity of 26, dissolved oxygen ≥5 mg/L, and pH 8-8.5, Then performed de novo transcriptome assembly and gene expression analysis using BGISEQ-500 with a tag-based digital gene expression (DGE) system. By de novo assembling at the four times, we obtained 28,167, 21,115, 24,497, and 27,080 reads, respectively. The results showed that the stress at 10 d led to no significant difference in the expressed genes, while the stress at 20 d and 30 d showed a significant increase (or decrease) in the expression of 97 (276) and 143 (410) genes, respectively, which were involved in 8 different metabolic pathways. In addition, we detected 2647 unigene transcription factors. Eleven upregulated and sixteen downregulated genes from the different starvation stress groups were choose to verify the reliability of the transcriptome data, and the results showed that the expression trends of these genes were consistent with the results shown by the transcriptome. The analysis of the experimental data and our discussion of the response mechanism of white ridgetail prawn under starvation stress provides a foundation for further screening of the key genes of starvation stress and may help to elucidate their functions.

Seaweed and climate change: A mapping review.

Seaweed has garnered increasing interest due to its capacity to mitigate climate change by curbing carbon emissions from agriculture, as well as its potential to serve as a supplement or alternative for dietary, livestock feed, or fuel source production. Moreover, seaweed is regarded as one of the earliest plant forms to have evolved on Earth. Owing to the extensive body of literature available and the uncertainty surrounding the future trajectory of seaweed research under evolving climate conditions, this review scrutinizes the structure, dynamics, and progression of the literature pertaining to seaweed and climate change. This analysis is grounded in the Web of Science Core Collection database, augmented by CiteSpace software. Furthermore, we discuss the productivity and influence of individual researchers, research organizations, countries, and scientific journals. To date, there have been 8047 articles published globally (after a series of filters and exclusions), with a notable upswing in publication frequency since 2018. The USA, China, and Australia are among the leading countries contributing to this research area. Our findings reveal that current research on seaweed and climate change encompasses 13 distinct research clusters, including "marine heatwave", "temperate estuary", "ocean acidification", and "macroalgal bloom". The most frequently cited keywords are "climate change", "biomass", "community", and "photosynthesis". The seaweed species most commonly referenced in relation to climate change include Gracilaria sp., Sargassum sp., Ecklonia maxima, and Macrocystis pyrifera. These results provide valuable guidance for shaping the direction of specialized topics concerning marine biodiversity under shifting climate conditions. We propose that seaweed production may be compromised during prolonged episodes of reduced water availability, emphasizing the need to formulate strategies to guarantee its continued viability. This article offers fresh perspectives on the analysis of seaweed research in the context of impending climate change.

Catfishes: A global review of the literature.

This study aims to elucidate the evolution of catfish research publications over recent decades, identify emerging research clusters, examine keyword patterns, determine major contributors (including authors, organizations, and funding agencies), and analyze their collaborative networks and citation bursts on a global scale. The USA, Brazil, China, and India collectively contribute approximately 67% of the total catfish research publications, with a marked increase in prevalence since 2016. The most frequently occurring and dominant keywords are "channel catfish" and "responses," respectively. Intriguingly, our findings reveal 28 distinct article clusters, with prominent clusters including "yellow catfish," "channel catfish", "pectoral girdle," "African catfish", "Rio Sao Francisco basin," "Edwardsiella ictaluri," and "temperature mediated". Concurrently, keyword clustering generates seven main clusters: "new species", "growth performance", "heavy metal", "gonadotropin-releasing", "essential oil", and "olfactory receptor". This study further anticipates future research directions, offering fresh perspectives on the catfish literature landscape. To the best of our knowledge, this is the first article to conduct a comprehensive mapping review of catfish research publications worldwide.

Microbe, climate change and marine environment: Linking trends and research hotspots.

Microbes, or microorganisms, have been the foundation of the biosphere for over 3 billion years and have played an essential role in shaping our planet. The available knowledge on the topic of microbes associated with climate change has the potential to reshape upcoming research trends globally. As climate change impacts the ocean or marine ecosystem, the responses of these "unseen life" will heavily influence the achievement of a sustainable evolutionary environment. The present study aims to identify microbial-related research under changing climate within the marine environment through the mapping of visualized graphs of the available literature. We used scientometric methods to retrieve documents from the Web of Science platform in the Core Collection (WOSCC) database, analyzing a total of 2767 documents based on scientometric indicators. Our findings show that this research area is growing exponentially, with the most influential keywords being "microbial diversity," "bacteria," and "ocean acidification," and the most cited being "microorganism" and "diversity." The identification of influential clusters in the field of marine science provides insight into the hot spots and frontiers of research in this area. Prominent clusters include "coral microbiome," "hypoxic zone," "novel Thermoplasmatota clade," "marine dinoflagellate bloom," and "human health." Analyzing emerging trends and transformative changes in this field can inform the creation of special issues or research topics in selected journals, thus increasing visibility and engagement among the scientific community.

Crayfish Research: A Global Scientometric Analysis Using CiteSpace.

A scientometric analysis was conducted to investigate the trends and development of crayfish research in terms of literature published, author, affiliation, and countries' collaborative networks, as well as the co-citation dataset (e.g., author, article, and keywords). The study analyzed 12,039 bibliographic datasets from the Web of Science, using CiteSpace as a tool for the co-citation analysis. The study revealed extraordinary increases in publication trends, with a total of 21,329 authors involved in approximately 80% of countries around the world (163/195) having conducted crayfish research. Unsurprisingly, countries such as the USA and China, followed by European countries, were among the top countries that have published crayfish-related studies. The findings also indicated that "invasive crayfish" was the world's top keyword for crayfish research. Crayfish species are important for both environmental sustainability (invasiveness and species composition) and social wellbeing (aquaculture), which provides directions for research, philanthropic, academic, government, and non-government organizations regarding how to invest limited resources into policies, programs, and research towards the future management of this species. Our study concluded that strategic collaboration among authors, institutions, and countries would be vital to tackle the issue of invasive crayfish species around the world.

The Evolution of Coral Reef under Changing Climate: A Scientometric Review.

In this scientometric review, we employ the Web of Science Core Collection to assess current publications and research trends regarding coral reefs in relation to climate change. Thirty-seven keywords for climate change and seven keywords for coral reefs were used in the analysis of 7743 articles on coral reefs and climate change. The field entered an accelerated uptrend phase in 2016, and it is anticipated that this phase will last for the next 5 to 10 years of research publication and citation. The United States and Australia have produced the greatest number of publications in this field. A cluster (i.e., focused issue) analysis showed that coral bleaching dominated the literature from 2000 to 2010, ocean acidification from 2010 to 2020, and sea-level rise, as well as the central Red Sea (Africa/Asia), in 2021. Three different types of keywords appear in the analysis based on which are the (i) most recent (2021), (ii) most influential (highly cited), and (iii) mostly used (frequently used keywords in the article) in the field. The Great Barrier Reef, which is found in the waters of Australia, is thought to be the subject of current coral reef and climate change research. Interestingly, climate-induced temperature changes in "ocean warming" and "sea surface temperature" are the most recent significant and dominant keywords in the coral reef and climate change area.

Cholinesterase activity as a potential biomarker for neurotoxicity induced by pesticides in vivo exposed Oreochromis niloticus (Nile tilapia): assessment tool for organophosphates and synthetic pyrethroids.

Organophosphates (OPs) and synthetic pyrethroids (SPs) are the most popular broad spectrum pesticides, used in agriculture as they have a strong pesticidal activity while also being biodegradable in the environment. The present study aimed to demonstrate the effects of these pesticides on the Acetylcholinesterase (AChE) activity in brain, gills and body muscles of Oreochromis niloticus - an important enzyme for the assessment and biomonitoring pollution caused by neurotoxins in the environment. The fish were exposed for 24 and 48 h to the LC0 concentrations of the malathion (1.425 mg/L), the chlorpyrifos (0.125 mg/L) and the λ-cyhalothrin (0.0039 mg/L), respectively. The activity of the AChE was significantly increased (p < 0.05) at 24 h and decreased at 48 h (except for the chlorpyrifos-treated brain and gills while tissues had shown no activity at 48 h's exposure) in all pesticides-treated tissues. The maximum increase in the activity and inhibition in the AChE activity were recorded as +92% and -52% in the chlorpyrifos and the lambda-cyhalothrin exposed brain tissues, respectively. Thus, the alterations in the AChE activities indicated that the applied pesticides are highly neurotoxic to fish and the enzyme (AChE) could be used as a useful biomarker for estimation of water pollution.

Adsorption and Kinetics Studies of Cr (VI) by Graphene Oxide and Reduced Graphene Oxide-Zinc Oxide Nanocomposite.

In this work, graphene oxide (GO) and its reduced graphene oxide-zinc oxide nanocomposite (rGO-ZnO) was used for the removal of Cr (VI) from aqueous medium. By employing a variety of characterization techniques, morphological and structural properties of the adsorbents were determined. The adsorption study was done by varying concentration, temperature, pH, time, and amount of adsorbent. The results obtained confirmed that rGO-ZnO is a more economical and promising adsorbent for removing Cr (VI) as compared to GO. Kinetic study was also performed, which suggested that sorption of Cr (VI) follows the pseudo-first-order model. For equilibrium study, non-linear Langmuir was found a better fitted model than its linearized form. The maximum adsorption capacity calculated for GO and rGO-ZnO nanocomposite were 19.49 mg/g and 25.45 mg/g, respectively. Endothermic and spontaneous nature of adsorption was detected with positive values of ΔS (change in entropy), which reflects the structural changes happening at the liquid/solid interface.

Trends and New Developments in Artemia Research.

An increasing number of scientists since 1970 has examined Artemia as an important species in aquaculture-related fields. However, a global scientometric review of Artemia literature is still lacking, which is the objective of this research. Using a CiteSpace analysis, the distribution of core authors and institutions, highly cited keywords and papers, author and journal contributions, and hot topics in the literature, as well as a co-citation analysis, particularly regarding authors, journals, documents, and clusters, were determined. Hence, 8741 relevant publications were generated from the Web of Science Core Collection database. The results revealed that the most significant contributions in Artemia research primarily originated from the USA, Brazil, Spain, India, China, and Belgium. Moreover, Artemia research focused mainly on top keywords such as brine shrimp and antimicrobial activity. Emerging trends related to Artemia research were Atlantic halibut, elongation factor, Artemia salina, lean protein, inert diet, alpha-crystallin protein, and Artemia embryo. At the same time, the study generated a vast total of 45 co-citation clusters. The present study provides the existing body of knowledge on Artemia research by sharing a visual knowledge map. This study offers a valuable perspective and profound understanding for researchers, farmers, and consortia interested in promoting Artemia as a sustainable live food in the global aquaculture industry.

Dietary Guduchi (Tinospora cordifolia) enhanced the growth performance, antioxidative capacity, immune response and ameliorated stress-related markers induced by hypoxia stress in Nile tilapia (Oreochromis niloticus).

Nile tilapia can tolerate a wide range of farming conditions; however, fluctuations in the environmental conditions may impair their health status. The incorporation of medicinal herbs in aquafeed is suggested to overcome stressful conditions. In this study, dietary Guduchi (Tinospora cordifolia) was evaluated on the growth performance, antioxidative capacity, immune response, and resistance of Nile tilapia against hypoxia stress. Fish fed five diets incorporated with Guduchi at 0, 2, 4, 6, and 8 g/kg for 56 days then exposed with hypoxia stress for 72 h. The growth performance, feed intake, and feed efficiency ratio were significantly (P < 0.05) increased by including Guduchi in tilapia diets regardless of the inclusion level. Similarly, the lipase and protease activities were markedly (P < 0.05) increased in tilapia fed dietary Guduchi. The activities of lysozyme and bactericidal activities in serum and mucus, nitro-blue tetrazolium (NBT), and alternative complement activity (ACH50) were markedly (P < 0.05) enhanced in tilapia treated with Guduchi supplements regardless of the dose. Additionally, the activities of liver and intestinal superoxide dismutase, catalase, and glutathione peroxidase were markedly enhanced (P < 0.05) by including Guduchi in tilapia diets compared with the control. Before and after hypoxia stress, tilapia-fed dietary Guduchi had lower glucose and cortisol levels than fish-fed Guduchi-free diets (P < 0.05). In all groups, glucose and cortisol levels were markedly higher after hypoxia compared before hypoxia stress (P < 0.05). In conclusion, dietary Guduchi can be included at 5.17-5.49 g/kg to enhance the growth performance, digestive enzyme activity, immune and antioxidative responses, and the resistance of Nile tilapia against hypoxia stress.

The synergistic effects of plant polysaccharide and Pediococcus acidilactici as a synbiotic additive on growth, antioxidant status, immune response, and resistance of Nile tilapia (Oreochromis niloticus) against Aeromonas hydrophila.

This study evaluated the growth performance, immune responses, and disease resistance of Nile tilapia upon pistachio hulls derived polysaccharide (PHDP) and Pediococcus acidilactici (PA) separately or as synbiotic. Fish received four types of diets: T1, control; T2, PHDP (0.1%); T3, PA (0.2%); T4, PHDP (0.1%) +PA (0.2%) for 56 days. The results showed that final weight and weight gain were markedly higher in fish fed T4 diet than that given T1 and T2 diets (P ≤ 0.05). In addition, a significantly greater specific growth rate was obtained by the T4 diet compared to the control. Fish survival was significantly improved in all supplemented diets compared to the control. On the other hand, the activities of lipase, protease, and amylase showed significant increases in the T4 group compared with other feeding groups. The total leucocytes and lymphocytes proportion significantly elevated in T3 and T4 than remaining groups (P ≤ 0.05). Further, fish fed T3 diet presented significantly higher serum total protein, total immunoglobulin, lysozyme activity (LYZ), alternative complement activity (ACH50), and alkaline phosphatase activity compared to fish fed T1 and T2 diets, while the mentioned indices were found significantly highest in T4 group than others. Fish received T3 and T4 diets had higher skin mucus LYZ and ACH50 than those fed T1 and T2 diets (P ≤ 0.05). The malondialdehyde levels were significantly declined in T3 and T4 when compared to the control. Fish fed T3 and T4 diets demonstrated significantly enhanced superoxide dismutase, catalase, and glutathione peroxidase activities compared to the control. The intestinal propionic acid significantly increased by T2 and T4 diets, while the highest levels of acetic acid detected in fish given T4 diet. The expression levels of tumor necrosis factor α (TNF-α), interleukin 1ß (IL-1ß), and interleukin 10 (IL-10) were significantly affected by T3 and T4 supplements. The efficacy of T4 diet against Aeromonas hydrophila infection was documented by a significantly lower mortality rate. In conclusion, the combination of PHDP and PA presented promising results as a synbiotic feed additive for Nile tilapia.

A Review of the Nursery Culture of Mud Crabs, Genus Scylla: Current Progress and Future Directions.

The nursery stages of mud crab, genus Scylla, proceed from the megalopa stage to crablet instar stages. We review the definition and several of the key stages in mud crab nursery activities. The practice of the direct stocking of megalopa into ponds is not recommended due to their sensitivity. Instead, nursery rearing is needed to grow-out mud crabs of a larger size before pond stocking. Individual nursery rearing results in a higher survival rate at the expense of growth and a more complicated maintenance process compared with communal rearing. The nursery of mud crabs can be done both indoors or outdoors with adequate shelter and feed required to obtain a good survival percentage and growth performance. Artemia nauplii are still irreplaceable as nursery feed, particularly at the megalopa stage, while the survival rate may be improved if live feed is combined with artificial feed such as microbound diet formulations. Water quality parameters, identical to those proposed in tiger shrimp cultures, can be implemented in mud crab rearing. The transportation of crablets between different locations can be done with or without water. The provision of monosex seeds from mud crab hatcheries is expected to become commonplace, increasing seed price and thus improving the income of farmers. Numerous aspects of a mud crab nursery including nutrition; feeding strategies; understanding their behaviour, i.e., cannibalism; control of environmental factors and practical rearing techniques still need further improvement.

Thermal Tolerance and Physiological Changes in Mud Crab, Scylla paramamosain Crablet at Different Water Temperatures.

This study was carried out to determine the physiological changes (survival, growth, molting cycle, sex differentiation, and gill condition) of mud crab, Scylla paramamosain crablet at different water temperatures of 24, 28 and 32 °C, and ambient temperature of 27 to 30 °C. Thermoregulatory behavior, represented by preferred temperature (29.83 ± SD 2.47 °C), critical thermal minimum (17.33 ± SD 0.58 °C), critical thermal maximum (40 ± SD 0.00 °C), and thermal tolerance interval (22.67 ± SD 0.58 °C), were checked for Crablet 1 stage only (with ambient temperature as acclimation temperature).Both low (24 °C) and high (32 °C) temperatures were associated with lower growth performance, and survival rate (p < 0.05), in comparison with both 28 °C and ambient temperature treatments.Male ratio at low temperaturetreatment (24 °C) was higher (80.09 ± SD 18.86%) than for other treatments (p < 0.05), observed as 44.81 ± D 10.50%, 41.94 ± SD 19.44%, and 76.30 ± SD 5.13% for 28 °C, 32 °C and ambient temperature treatments, respectively. However, there was no significant difference observed between 24 °C, 28 °C, and ambient temperature treatments. Anatomical alterations of gill lamellae of S. paramamosain crablet for both 32 °C, and 24 °C treatments, appeared thinner and paler than at both 28 °C, and ambient temperature treatments. Based on this study, temperature of 28 to 30 °C was recommended as the optimal temperature for the long-term nursery phase of S. paramamosain.

Improving Survival of Juvenile Scalloped Spiny Lobster (Panulirus homarus) and Crucifix Crab (Charybdis feriatus) Using Shelter and Live Prey.

Cannibalism is a major problem in lobster and crab aquaculture. Reducing the aggressive characteristics of lobsters and crabs can improve survival during the culturing process. In this study, juvenile scalloped spiny lobsters (Panulirus homarus) and crucifix crabs (Charybdis feriatus) were both cultured under different shelter and live prey conditions. Groups with shelter (seaweed and cotton filter) showed a better survival rate than the control group (no shelter; p < 0.05) for both Pa. homarus and Char. feriatus. Co-culturing with live prey (Litopenaeus vannamei) significantly benefited the juveniles of Pa. homarus and visibly increased the survival of juvenile Char. feriatus. Although providing shelter is currently the main method for reducing agonistic behavior, it must be continually altered as the lobsters and crabs grow. Live prey can grow and attract lobsters and crabs to hunt them, and live prey can be supplemented at any time. They can also be used as an additional source of income during the harvest season.

Amino acid compounds released by the giant freshwater prawn Macrobrachium rosenbergii during ecdysis: a factor attracting cannibalistic behaviour?

Ecdysis is a common phenomenon that happens throughout the life phase of the giant freshwater prawn Macrobrachium rosenbergii. It is vital to better understand the correlation between cannibalism and biochemical compound that exists during the moulting process. The objective of the present study was to determine the amino acid profile released by M. rosenbergii during the ecdysis process that promotes cannibalism. To accomplish this, changes in amino acid levels (total amino acid (TAA) and free amino acid (FAA)) of tissue muscle, exoskeleton, and sample water of culture medium from the moulting (E-stage) and non-moulting (C-stage) prawns were analysed using high-performance liquid chromatography (HPLC). Comparison study revealed that among the TAA compounds, proline and sarcosine of tissues from moulting prawn were found at the highest levels. The level of FAA from water that contains moulting prawns (E-stage) was dominated by tryptophan and proline. Significant values obtained in the present study suggested that these amino acid compounds act as a chemical cue to promote cannibalism in M. rosenbergii during ecdysis. The knowledge of compositions and compounds that were released during the moulting process should be helpful for better understanding of the mechanism and chemical cues that play roles on triggering cannibalism, and also for future dietary manipulation to improve feeding efficiencies and feeding management, which indirectly impacts productivity and profitability.