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Abstract This study used berberine hydrochloride to treat the Asian paddle crab, Charybdis japonica infected with the Gram-negative bacterium Aeromonas hydrophila at concentrations of 0, 100, 200 and 300 mg/L. The effect of berberine hydrochloride on the survival rate and gut microbiota of C. japonica was investigated. Berberine hydrochloride improved the stability of the intestinal flora, with an increase in the abundance of probiotic species and a decrease in the abundance of both pathogenic bacteria after treatment with high concentrations of berberine hydrochloride. Berberine hydrochloride altered peroxidase activity (POD), malondialdehyde (MDA), and lipid peroxidation (LPO) in the intestinal tract compared to the control. Berberine hydrochloride could modulate the energy released from the enzyme activities of hexokinase (HK), phosphofructokinase (PFK), and pyruvate kinase (PK) in the intestinal tract of C. japonica infected with A. hydrophila. Zona occludens 1 (ZO-1), Zinc finger E-box binding homeobox 1 (ZEB1), occludin and signal transducer, and activator of transcription5b (STAT5b) expression were also increased, which improved intestinal barrier function. The results of this study provide new insights into the role of berberine hydrochloride in intestinal immune mechanisms and oxidative stress in crustaceans.

Global climate change has caused rapid temperature changes in marine environments. Understanding how marine organisms respond to temperature changes can help predict their richness of future biodiversity. In this study, we examined the gene expression levels and the difference in the pathways that are responsive to acute temperature stress in low- and high-latitude populations of the shore swimming crab, Charybdis japonica. The two populations of C. japonica were exposed to low- and high-temperature stresses (15°C and 28°C) and used for transcriptome sequencing. Genetic regulatory ability changes were compared to determine the diverse response of the two crab populations to temperature change. The gene expression levels and functional enrichment analysis showed that the low-latitude crab regulated more genes (938) that were mainly enriched in DNA replication and metabolic pathways, whereas the high-latitude crab regulated less genes (309) that were mainly enriched in genetic information processing at low-temperature stress. Furthermore, the low-latitude crab regulated less genes (33) that were mainly enriched in genetic information processing, whereas the high-latitude crab regulated more genes (280) that were mainly enriched in signal transduction and cellular process at high-temperature stress. These results implied that the low-latitude population was more resilient to high-temperature stress, while the high-latitude population was more resilient to low-temperature stress. This study enhances our understanding of how different geographic C. japonica populations respond to varying temperature environments in their living zone, which could be helpful for predicting future biodiversity trends of intertidal crustaceans under global climate change.

Although there is ample literature that explores what SoTL is and offers guidelines on how to do SoTL, we have not paid enough attention to the fundamental assumptions that underpin systematic scholarly inquiry itself, regardless of the context or the object of study. Instead, we seem to have a narrative that relates SoTL to the disciplines and/or educational research. In this paper, I challenge this narrative with the help of philosophy of science. Specifically, I argue that SoTL is at risk of being appropriated by disciplinary paradigms. This means we would do well to adjust how we conceptualize SoTL. To find a better way, I use Habermas' concept of "knowledge-constitutive interests" to argue that we should start by recognizing the fundamental interests at play when we do SoTL, regardless of disciplinary context. I connect Habermas' three interests (instrumental, interpretive, and emancipatory) to Hutchings' taxonomy of SoTL questions ("what works? what is?" and "what could be?") and to three basic paradigms of inquiry (normative, interpretive, and critical realist). These connections show how philosophy of science in the form of Habermas' critical theory can combine with existing conceptual literature on SoTL and established paradigms of inquiry that exist independently of the disciplines. I aim to show that we can use philosophy of science to conceptualize SoTL in a way that allows it to stand fully on its own merits, as its own form of inquiry, with disciplinary perspectives only influencing it in appropriate and useful ways.

A one-step biosynthetic pathway for the fabrication of La2O3–LaPO4 nanocomposites (NCs) was developed, employing Charybdis natator. The structure and phase changes of the NCs were confirmed, and their diverse applications were explored. The peaks at 206, 332, and 442 nm in UV-DRS studies confirmed the formation of La2O3–LaPO4 NCs. Fourier transform infrared spectral analysis revealed La–O stretching at 716 cm−1 and the presence of PO43−{\text{PO}}_{4}^{3-} bands at 532, 560, 578, and 618 cm−1. X-ray diffraction patterns showed a hexagonal phase of La2O3 with peaks at 2θ 11.04 and 28.57 and monoclinic LaPO4 phases at 2θ = 18.79 and 41.88. X-ray photoelectron spectroscopy data showed binding energy peaks at 836.04 and 852.77 eV, corresponding to 3d5/2 and 3d3/2 of the lanthanum. The average particle size from HR-TEM analysis was 28.95 nm after annealing at 800°C and SAED patterns confirmed their crystalline nature. The high affinity of the NCs towards ctDNA was established by a binding constant value of 2.08 (mg·mL−1)−1. Under UV exposure, 96% degradation efficiency for methyl orange within 120 min at pH 4 was displayed, with a rate constant of 2.72 × 10−2 min−1 affirming their photocatalytic potential. Their biocompatibility was assessed through MTT assay and luminescence characteristics were evaluated.

Crabs of the genus Charybdis are some of the world’s most aggressive and voracious marine invasive crustaceans. They are found in a wide variety of ecosystems in the Red Sea. Their near ubiquity in diverse marine habitats, however, makes them a possible resource for novel marine-derived bioactive products. To provide an important insight into the potential for C. natator as a beneficial product, its shell methanolic extract was chromatographically analyzed for identification of potential bioactive ingredients. Additionally, two different doses, i.e. a low and a high dose, of this extract were tested for their ability to protect against copper-induced oxidative stress and proinflammatory response in adult zebrafish Danio rerio. Gene expression levels of transcripts of proinflammatory mediators, i.e. nf-κβ and tnf-α; antioxidant enzymes, i.e. sod, cat, and gpx; and lipid-metabolizing enzymes, i.e., acox1 and fasn, were determined. The results showed that C. natator shell is rich in potential bioactive metabolites, including diverse unsaturated fatty acids, alkanes, flavonoids, and phenolic acids. Most antioxidant and proinflammatory transcripts in the protected groups were restored to levels that were lower than those in the CuSO4-stressed group. The low dose showed special success in inducing these effects. Also, the low-dose-protected group showed significantly elevated acox1 and decreased fasn, suggesting the capability of crab shell extract at a low dose to assist lipolysis and inhibit lipogenesis. The abundant presence of saturated fatty acids in the shell extract can be the reason for the inadequacy of the high dose to promote the antioxidant and anti-inflammatory activities. These results suggest that there is a potential to develop therapeutic industrial uses for C. natator shell, instead of considering it as a discard. Its wealth of bioactive metabolites may contribute to the market for natural products to combat inflammatory and oxidative stress, the origin of many diseases in the modern world.

To investigate the effects of predation by the paddle crab Charybdis japonica on the culture and survival of scallops (Mizuhopecten yessoensis) during bottom culture, we investigated the behavioral characteristics of three sizes (small, medium, and large) of scallops in response to exposure to crabs. We found that scallops escaped from crab predation by continuous shell closure or movement. Shell closure force increased with scallop size, and scallops of the same size that were stimulated by the presence of crabs closed their shell more frequently than control scallops. We also measured the activities of superoxide dismutase, catalase, arginine kinase, and octopine dehydrogenase in the gill, adductor muscle, and mantle of scallops before and after exposure to predation. Tissues that showed significant differences between control and test specimens were selected for deep sequencing of the transcriptome to identify and validate the key genes that were sensitive to predation. We found that when M. yessoensis is stimulated by the presence of predators, its behavioral characteristics and related physiological and ecological indexes undergo significant changes. The results are relevant for developing specifications for M. yessoensis seedling casting during bottom culture.

The coagulation property of hemolymph is one of the characteristic indicators of the immune function of crustaceans. This article focuses on the abnormal phenomenon of wild Charybdis japonica, where the hemolymph cannot coagulate in the Qinhuangdao Sea area. The pathogens were isolated and purified, and three dominant strains, N1, N2, and Q1, were obtained. These strains were identified as Vibrio natriegens, V. fortis, and Metschnikowia bicuspidata through morphological observation, physiological and biochemical experiments, and 16S rDNA or ITS sequence analysis. Subsequently, drug sensitivity and probiotic antagonism analyses were performed. Considering the potential for cross-species transmission of crustacean pathogens, the isolated pathogens may bring potential hazards to Portunus trituberculus, an important aquaculture economic species in China. Therefore, artificial infection and histopathological analysis were conducted on P. trituberculatus. The results of drug sensitivity and antagonism assays revealed that stain V. natriegens exhibited susceptibilities towards antibiotics such as streptomycin and norfloxacin, but 10 probiotics had no antagonistic effect on it; strain V. fortis exhibited susceptibilities to antibiotics such as tetracycline and chloramphenicol, moreover, strain V. fortis showed inhibitory effects on Bacillus velezensis and B. amyloliquefaciens. Strain M. bicuspidata exhibited drug susceptibility towards polymyxin B and showed inhibitory effects on B. toyonensis, B. velezensis, and B. amyloliquefaciens. The results of artificial infection tests using V. natriegens, V. fortis, and M. bicuspidata in P. trituberculatus showed cumulative mortality rates of 100%, 75%, and 35%, respectively, after 120 hours of infection. The hemolymph of the deceased P. trituberculatus following injection with strain V. natriegens or V. fortis exhibited a light blue and did not coagulate normally. Conversely, the hemolymph of the deceased crabs following injection with strain M. bicuspidata appeared milky white and normal coagulation. Histopathology examination demonstrated that strains V. natriegens, V. fortis, and M. bicuspidata can all induce lesions in several tissues. This study is the first to isolate V. natriegens and V. fortis from crustaceans, and the infection tests on the P. trituberculatus can replicate the symptoms, such as hemolymph noncoagulation. Based on these findings, it is speculated that the pathogens capable of casing hemolymph noncoagulation syndrome in P. trituberculatus may originate from wild C. japonica. The drug resistance and probiotic antagonism test results can provide a theoretical basis for precise medication and offer insights into the development and application of probiotic preparations targeting the three pathogens. [ABSTRACT FROM AUTHOR]

Background/Objectives: The swimming crab Charybdis feriata is an important commercial fishery species and a major economic contributor to the southeast coastal fishing communities in China. Under the scenario of resource decline and shortage in the market over recent years, it has become more urgent and necessary to explore the fine-scale population genetic characteristics of C. feriata. Methods: In this study, the genotyping-by-sequencing (GBS) method was used to estimate the genome-wide genetic variation in and population differentiation pattern of C. feriata collected from four geographical locations (Zhoushan, Quanzhou, Yangjiang, and Qinzhou) along the southeast coast of China. Results: A total of 18,815 high-quality single-nucleotide polymorphisms (SNPs) were identified and the results revealed the existence of high genetic diversity and low genetic divergence among the populations of C. feriata. Floating eggs and larvae transported by alongshore currents during the reproductive season might enhance the interpopulation genetic exchange. Principal component analysis (PCA) and a phylogenetic tree showed a high genetic connectivity of C. feriata across the southeast coast of China, but C. feriata distributed in the Zhoushan Archipelago might possess some genetic distinctiveness and diversification. Conclusions: The results supplemented basic genetic information of C. feriata at the genome level and also provided specific knowledge that could lead to the improved spatial management of fishery resources. [ABSTRACT FROM AUTHOR]

In the Asian paddle crab (Charybdis japonica) gillnet fishery in the Yellow Sea, China, the minimum mesh size (MMS) regulation has been of a major importance due to high bycatch rates of undersized crabs. In this study, we evaluated how gillnet mesh size can affect the capture probability of C. japonica and capture patterns in this fishery by comparing the performance of gillnets with four different mesh sizes (60, 70, 80, and 90 mm). Our results showed that changes in gillnet mesh size significantly affect the capture probability of different sizes of crabs. Specifically, increased mesh size decreased the capture probability of undersized crabs and their fraction in the catches decreased from 64 % to 24 % when mesh size was increased from 60 mm to 90 mm. In contrast, gillnets with larger mesh sizes significantly improved the capture probability of legal-sized crabs. Moreover, no significant differences were observed for the species catch composition between gillnets of different mesh sizes. Based on these results, we recommend 90 mm as the MMS in gillnets to improve sustainability in C. japonica fishery.

In May 2020, a bottom-trawl survey in the southern Bohai Sea collected the portunid crab Charybdis bimaculata, a species formerly found in the northern Yellow Sea. In subsequent surveys, C. bimaculata was found to be abundant and likely to occupy habitats and niches of native species. To study the suitability of habitat in the southern Bohai Sea for this crab, nine trawl surveys were conducted between 2020 and 2022 to monitor its dispersal. Using Biomod2 software and combining species occurrence and environmental data, a distribution model for C. bimaculata in the southern Bohai Sea is developed. We analyze relationships between this and other crustacean species by comparing niche widths and their overlap. A random forest model outperforms eight others, and has the highest evaluation indices among single algorithm species-distribution models. The evaluation index of an ensemble model is significantly higher than those of single algorithm models, indicating its greater accuracy and robustness. We report suitable habitat for C. bimaculata to occur mainly in central and northeastern Laizhou Bay, and for this habitat suitability to shift over years from the middle to northeastern waters. Niche width showed a negative trend from 2020 to 2022, and is greater in May than August for each year. Niche overlaps between C. bimaculata and other major crustaceans in the southern Bohai Sea exist. We consider that increased sea surface temperature caused by climate change enabled invasion of C. bimaculata from northern Yellow Sea waters into the southern Bohai Sea, where it can overwinter and complete its life cycle. These results provide a scientific basis upon which monitoring of C. bimaculata in the Bohai Sea can be strengthened to better cope with its invasion and any negative impact on local biodiversity.

To investigate the effects of predation by the paddle crab Charybdis japonica on the culture and survival of scallops (Mizuhopecten yessoensis) during bottom culture, we investigated the behavioral characteristics of three sizes (small, medium, and large) of scallops in response to exposure to crabs. We found that scallops escaped from crab predation by continuous shell closure or movement. Shell closure force increased with scallop size, and scallops of the same size that were stimulated by the presence of crabs closed their shell more frequently than control scallops. We also measured the activities of superoxide dismutase, catalase, arginine kinase, and octopine dehydrogenase in the gill, adductor muscle, and mantle of scallops before and after exposure to predation. Tissues that showed significant differences between control and test specimens were selected for deep sequencing of the transcriptome to identify and validate the key genes that were sensitive to predation. We found that when M. yessoensis is stimulated by the presence of predators, its behavioral characteristics and related physiological and ecological indexes undergo significant changes. The results are relevant for developing specifications for M. yessoensis seedling casting during bottom culture. [ABSTRACT FROM AUTHOR]

Las especies invasoras representan una amenaza para la mayoría de los ecosistemas en el mundo, sin embargo, los organismos que son capaces de establecerse en áreas diferentes a su zona de origen cuentan con estrategias de historia de vida que les permiten ser exitosas en la colonización. En Colombia se ha reportado un número elevado de especies invasoras, entre las que se encuentra la jaiba espinosa Charybdis hellerii, originaria del Indo-Pacífico, pero llegada a nuestras costas desde el mar Mediterráneo presuntamente en embarcaciones de comercio. Actualmente este cangrejo se ha reportado desde la zona de la alta Guajira hasta el Golfo de Morrosquillo, lo que evidencia su éxito al ser capaz de soportar las diversas condiciones del Caribe colombiano.En el presente estudio se evaluó la variabilidad fenotípica mediante morfometría geométrica, comparando y analizando el caparazón de ejemplares recolectados en diferentes localidades del nororiente y la parte central de la costa Caribe colombiana (La Guajira, Ciénaga Grande de Santa Marta, Santa Marta, Córdoba, Sucre). Con el estudio de esta estructura no se pudo observar dimorfismo sexual, pero sí se estableció (ANOVA; p

The Scylla and Charybdis in this discussion of teacher evaluation are standardized achievement test data on the one hand, and classroom observational systems on the other. These are the two most common methods used to judge teachers' competency. Both have serious flaws: the former primarily with validity, the latter primarily with reliability. At most these evaluation strategies provide teachers' and their supervisors information about which to converse. But these two methods have such serious flaws that they should never be used as the primary grounds for rewarding, punishing, or firing teachers. When both methods of evaluation are used to judge teacher competency, the correlation between achievement tests and observational data is quite low. When two methods claiming to assess the same construct do not correlate well, either one or both methods are failing to assess the intended construct. There are two alternatives for navigating between Scylla and Charybdis: "Duties Based Teacher Evaluation" and "Performance Measures." These methods have much to recommend them, though like all methods of personnel evaluation, reliability and validity issues remain problematic.

The brachyuran crab Charybdis hellerii is originally from the Pacific; nevertheless, the species has been introduced to tropical waters globally. Its initial sighting in the Western Atlantic was documented in 1990 based on specimens collected in Cuba in 1987. In this paper, we present findings of C. hellerii from two localities in eastern Cuba: Santiago de Cuba and Taco bays. Up to this point, the species has solely been documented in estuaries in Cuba, and it likely exists throughout the entire archipelago. Given its feeding behaviour and extensive distribution, encompassing areas within the National Park Alejandro de Humboldt, this species can be key in the formulation of conservation plans for Cuban marine ecosystems.

Abstract Berberine hydrochloride is the main effective component of Coptis spp. used in Chinese herbal medicine and its underlying molecular mechanisms, responsible for inducing effects in crustacean species, are not fully understood. In this study, the molecular response of the crab Charybdis japonica to berberine hydrochloride exposure was studied using transcriptome sequencing. The survival rate, gene expression and activities of several immune enzymes were measured after berberine hydrochloride treatments, with or without injection of the pathogenic bacterium Aeromonas hydrophila. A total of 962 differentially expressed genes (464 up-regulated and 498 down-regulated) were observed during exposure to 100 mg/L of berberine hydrochloride and in the control group after 48 h. Enrichment analysis revealed that these genes are involved in metabolism, cellular processes, signal transduction and immune functions, indicating that exposure to berberine hydrochloride activated the immune complement system. This bioactive compound simultaneously activated fibrinogen beta (FGB), fibrinogen alpha (FGA), alpha-2-macroglobulin (A2M), kininogen (KNG), fibrinogen gamma chain (FGB), alpha-2-HS-glycoprotein (AHSG), caspase-8 (CASP8), cathepsin L (CTSL), adenylate cyclase 3 (Adcy3) and MMP1. Its action could significantly increase the survival rate of the crabs injected with A. hydrophila and promote the activity of LZM, Caspas8, FGA, ACP and AKP in the hepatopancreas. When A. hydrophila was added, the neutralization of 300 mg/L berberine hydrochloride maximized the activities of Caspas8, LZM, ACP and AKP. Our results provide a new understanding of the potential effects of berberine hydrochloride on the immune system mechanisms in crustaceans.