Search Results (990)

This study explores the metabolic response and carbon budget of two cyclopoid copepod species, Diacyclops belgicus Kiefer, 1936 (a stygobitic, groundwater-adapted species) and Diacyclops crassicaudis crassicaudis (Sars G.O., 1863) (a stygophilic, predominantly surface-associated species). We measured oxygen consumption rates (OCRs), carbon requirements (CRs), ingestion (I) rates, and egestion (E) rates at 14 °C and 17 °C, representing current and predicted future conditions in the collection habitats of the two species. Diacyclops belgicus displayed OCRs (28.15 and 18.32 µL O₂/mg DW × h at 14 and 17 °C, respectively) and carbon budget (CR: 0.14 and 0.10 µg C/mg × d at 14 and 17 °C) lower than those of D. crassicaudis crassicaudis (OCR: 55.67 and 47.93 µL O₂/mg DW × h at 14 and 17 °C; CR: 0.3 and 0.27 µg C/mg × d at 14 and 17 °C). However, D. belgicus exhibited metabolic rates and carbon requirements comparable to those of other epigean species, challenging the assumption that low metabolic rates are universal among stygobitic species. Temperature variations did not significantly affect the metabolic responses and carbon requirements of the two species, suggesting that they may cope with moderate temperature increases. Full article

Metschnikowia bicuspidata is the specific pathogen for “milky disease” in the Chinese mitten crab (Eriocheir sinensis), accounting for huge losses to the industry. And yet, there is no precise study describing the pathogenesis of M. bicuspidata, largely hindering the development of novel control methods against its causing diseases. Here, we compared the transcriptomes of M. bicuspidata cells collected from a control group (cultured without E. sinensis hemocytes) and a treatment group (cultured with E. sinensis hemocytes), using RNA sequencing. Through comprehensively analyzing the differentially expressed genes (DEGs), both the most regulated ones and the ones involved in crucial enriched KEGG pathways, we found that certain processes might be required for M. bicuspidata’s survival under hemocyte stress. Key genes involved in oxidative phosphorylation, fatty acid metabolism, upper glycolysis, and gluconeogenesis were upregulated, and those for β-glucan unmasking, autophagy, and cell polarity were downregulated, in the treatment group. Our results suggest that M. bicuspidata colonizes and therefore establishes an infection in E. sinensis via enhancing aerobic respiration, glucose-6-phosphate accumulation, and cell-wall masking. In addition, we applied multiple means to evaluate a series of candidate reference genes and found that PMA1 in combination with ACT1 is the most suitable choice for accurate normalization in quantitative real-time PCR (qRT-PCR) assays. Thus, we used this combination as the reference and performed qRT-PCR verification of several DEGs. It is shown that the expression trends of these tested DEGs in qRT-PCR assays are the same as those in RNA-Seq assays. This study not only provides insights into strategies facilitating M. bicuspidata’s survival within E. sinensis, initially elucidating the pathogenesis of this yeast, but also recommends a useful molecular tool regarding qRT-PCR assays in this pathogen. Full article

In recent years, the invasive Atlantic blue crab (Callinectes sapidus) has increased its spread throughout the Mediterranean Sea, threatening native biodiversity and local economies. This study aimed to valorize C. sapidus sampled in Sicily by utilizing its exoskeleton as a source of chitosan, astaxanthin, and bio-phenolic compounds. These biomolecules were evaluated for their reducing, radical scavenging, and antitumor activity. The ferric ion reducing antioxidant power (FRAP) and the free radical scavenging activity against radical 2,2-Diphenyl-1-picrylhydrazyl (DPPH) were significantly higher for chitosan (3.16 ± 0.10 mg AAE/g and 8.1 ± 0.10 µmol TE/g). No significant differences were observed among the tested biomolecules in their activity in scavenging the radical 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). Both bio-phenolic compounds and astaxanthin exhibited dose-dependent cytotoxicity on CaCo-2 (IC₅₀ = 12.47 and 18 µg/mL) and HepG2 (IC₅₀ = 10.25 and 1.26 µg/mL) cell lines, while only bio-phenols showed no cytotoxic effect on differentiated CaCo-2 cells up to 20 µg/mL. These findings highlight the value of blue crab by-products in supporting a circular economy, offering a sustainable approach to managing this invasive species while providing bioactive compounds with promising medical and nutraceutical applications. Full article

Grazing by zooplankton can regulate bloom-forming cyanobacteria but can also transfer toxin-producing cells, as well as toxic metabolites, to the food web. While laboratory investigations have provided extensive knowledge on zooplankton and toxic cyanobacteria interactions, information on zooplankton feeding on toxin-producing cyanobacteria in natural water bodies remains scarce. In this study, we quantified Microcystis-specific mcyE synthase genes from the gut contents of various cladoceran and copepod taxa to assess the in situ crustacean community and taxon-specific ingestion of potentially toxic Microcystis in Lake Peipsi, a large eutrophic lake in Estonia, Northern Europe. Microcystis cells with mcyE genes were found in all crustaceans examined. However, some species, such as the cyclopoid copepod Mesocyclops leuckarti, were more efficient in ingesting potentially toxic Microcystis than other co-occurring cladocerans (Daphnia spp., Bosmina spp., Chydorus sphaericus) and copepods (Eudiaptomus gracilis). The amount of toxigenic Microcystis cells grazed by crustacean population changed temporarily, and copepods were the predominant consumers of toxigenic Microcystis during several months of the 5-month study period. Crustacean ingestion of toxigenic Microcystis was not related to Microcystis biomass or mcyE gene copy numbers in the environment but was instead related to the abundance of major crustacean grazers. Our findings emphasize the close interaction between crustacean zooplankton and toxigenic Microcystis, indicating that some species may play a more significant role in linking toxic cells within the food web than others. Full article

Crustaceans are delicious and highly nutritional food. However, crustaceans are one of the main food allergens, causing severe public health issues. Thus, it is important to increase the knowledge on crustacean allergens and protect the health of sensitized individuals. This review systematically summarizes the basic information on major crustacean allergens’ characteristics, structures, and function. It also summarizes the latest evaluation and detection methods of crustacean allergens. In addition, various processing techniques to alleviate crustacean’s allergenicity are discussed and compared. A host of multiplex approaches as innovative research is attractive to decrease crustacean allergenicity. In addition, the strategies to address the risk of crustacean allergens are also reviewed and discussed in detail. This review provides updates and new findings on crustacean allergens, which helps better understand crustacean allergy and provide novel strategies for its prevention and management. Full article

(1) Background: Global climate change is intensifying, and the vigorous development and utilization of saline–alkali land is of great significance. As an important economic aquatic species in the context of saline–alkali aquaculture, it is highly significant to explore the regulatory mechanisms of Eriocheir sinensis under alkaline conditions. In particular, the brain (cerebral ganglion for crustaceans) serves as a vital regulatory organ in response to environmental stress; (2) Methods: In this study, a comparative transcriptome approach was employed to investigate the key regulatory genes and molecular regulatory mechanisms in the cerebral ganglion of E. sinensis under alkaline stress. (3) Results: The results demonstrated that the cerebral ganglion of E. sinensis exhibited a positive response to acute alkaline stress. Pathways associated with signal transduction and substance transportation, such as “phagosome” and “regulation of actin cytoskeleton”, along with regulatory genes involved in antioxidation, were upregulated synergistically to maintain homeostasis under alkaline stress. Furthermore, it was discovered for the first time that bursicon plays a positive regulatory role in the adaptation of E. sinensis to alkalinity. (4) Conclusions: The present study elucidates the molecular regulatory pattern of the cerebral ganglion in E. sinensis under acute alkaline stress as well as revealing a novel role of bursicon in facilitating adaptation to alkalinity in E. sinensis, providing valuable theoretical insights into the molecular regulatory mechanisms underlying the responses of cerebral ganglia to saline–alkali environments. These findings also offer a theoretical reference for promoting the sustainable development of the E. sinensis breeding industry under saline–alkali conditions. Full article

This study presents the first comprehensive data on a vermetid formation along the Apulian coast of the Adriatic Sea, representing one of the northernmost records in the Mediterranean. Surveys along the Brindisi coastline employed visual inspection to map the bioconstruction’s distribution and extension. Detailed data on the bioconstruction inner and the outer edge length, thickness, width, slope and topographic complexity were collected at three selected sites. Moreover, photographic replicates were used to assess shell aperture density and diameters of Dendropoma sp. Associated fauna was studied using two quantitative sampling squares in each transect. The results showed that the vermetid bioconstruction consisted of a thin, encrusted monolayer (thickness < 1.5 cm) that extended for 3.273 linear kilometers, covering 17.23% of the investigated area; it had an average width of 0.5 m, with a mean density of Dendropoma sp. at 2.52 ind/cm². The associated fauna was composed of 47 taxa dominated by crustaceans, mollusks and annelids. Species richness was correlated with the bioconstruction’s thickness and complexity. These findings underline the ecological importance of vermetid bioconstructions as biodiversity hotspots. The lack of massive mortality events along the Apulian coast, in contrast to other Mediterranean vermetid bioconstructions, underscores the necessity for targeted conservation measures. Full article

Seafood is a crucial source of nutrients, with global consumption steadily increasing. Among seafood-related allergies, shellfish are a significant cause of food allergy and anaphylaxis worldwide, affecting approximately 0.5–2.5% of the general population. While the majority of existing research has focused on crustaceans, allergic reactions to mollusks, including their clinical characteristics, remain poorly understood. In the Canary Islands, limpets (a type of marine gastropod) are widely consumed as part of the traditional cuisine. Despite isolated reports of limpet allergy, no large-scale studies or comprehensive clinical analyses have been published on this topic. A cohort of patients sensitized to limpets was analyzed: 66 patients were monosensitized to limpets (Group A), while 64 patients demonstrated additional sensitization to other shellfish (Group B). Limpet ingestion was associated with delayed and severe symptoms, including anaphylaxis and severe asthma. Notably, only 11.5% of patients in Group A tested positive for shellfish allergens using ALEX testing compared to 67.9% in Group B. The identification of protein bands in the 25–40 and 50–200 kDa molecular weight ranges in monosensitized patients provides a novel finding that differentiates this study from prior research. Our study represents the largest reported series of patients with documented limpet allergy to date. Full article

Eriocheir sinensis is an important and popular crustacean species in China, producing huge economic benefits. Large individuals of E. sinensis are preferred due to market demand. The long-term goal of our research group is to produce a new variety of E. sinensis with better growth performance and stronger abilities to resist environmental changes through mass selection. The present study aimed to evaluate the progress of the genetic breeding of E. sinensis by analyzing the genetic diversity and genetic distance between the basic breeding population (pooled population of Suqian and Yixing, G0) and generation 1 (G1) using whole-genome sequencing (WGS). The growth traits, including body weight, shell length, shell width, and third appendage length, in the G1 generation increased by 8.3%, 7.9%, 9.6%, and 9.3%, respectively, compared with those of the G0 generation, indicating that the G1 generation showed better growth performance. A total of 372,448,393 high-quality single nucleotide polymorphisms (SNPs) were detected in 40 E. sinensis individuals, with an average of 9,331,209.83 SNPs. The fixation index values were 0.007 between the Yixing and Suqian populations and 0.015 between the G0 generation and G1 generation, indicating a close genetic background between these groups, especially when considered in combination with the phylogenetic tree and principal component analysis. All of these data suggest that genetic information was stably inherited by the G1 generation, with no introduction of foreign genetic information during the genetic breeding process. In addition, the genetic diversity analysis revealed that the G0 and G1 generations showed a high level of genetic diversity and a relatively stable genetic structure. The present study evaluated the recent progress of the genetic improvement of E. sinensis by our research group, providing valuable evidence for further genetic improvement in this species. Future studies will be performed to select growth-related SNPs and genes through genome-wide association studies. Full article

The substitution of fishmeal with high-level soybean meal in the diet of crustaceans usually induces lipid accumulation and oxidative stress in the hepatopancreas. Therefore, it is essential to alleviate these adverse effects. In the present study, SBPs were used to alleviate the negative effects of a fishmeal decrease on the growth performance, lipid metabolism, antioxidant capacity, and gut microbiota of oriental river prawn (Macrobrachium nipponense) in an 8-week feeding trial. Three isonitrogenic and isolipidic diets were prepared as follows: R (reference diet with 32% fishmeal), CT (control diet with 22% fishmeal), and SBP (22% fishmeal with 1.25 g/kg soybean bioactive peptides). The prawns (initial biomass per tank 17 g) were randomly divided into three groups with four replicates. The results showed that the low-fishmeal diet induced the following: (1) the inhibition of growth performance and survival of prawns; (2) an increase in triglyceride content in the hepatopancreas and hemolymph and downregulation of carnitine palmitoyl transferase 1 (cpt1) gene expression; (3) a reduction in antioxidant enzymes’ activities and their genes expression levels and an increase malondialdehyde (MDA) content; and (4) an increase in the abundance of the conditional pathogen Pseudomonas in the gut. SBPs supplementation in the CT diet effectively alleviated most of the above adverse effects. SBPs enhanced inducible nitric oxide synthase (iNOS) activity to synthesize nitric oxide (NO) by activating the imd-relish pathway. Most importantly, SBPs increased the potential probiotic Rikenellaceae_RC9_gut_group abundance and decreased the abundance of the conditional pathogen Pseudomonas in the gut. In conclusion, SBPs supplementation can improve low-fishmeal-diet-induced growth inhibition by regulating the gut microbiota composition to ameliorate lipid deposition and oxidative stress and strengthen immune status in oriental river prawn. Full article

Invertebrate tropomyosins belong to the key food allergens. Several peptides likely to be released during proteolysis can be found in many sequences of proteins from this family. The aim of the present study was to evaluate the possibility of identifying tropomyosins with known and unknown amino acid sequences in unheated, boiled and fried seafoods. The workflow included in silico proteolysis simulation of tropomyosin sequences and analysis of the distribution of resulting peptides among proteins. The experiment entailed the proteolysis of unheated, boiled and fried products, containing crustaceans or mollusks, and the identification of resulting peptides using LC-MS/MS. Finally, taxonomic lineages of identified peptides were determined. Predicted peptides were identified in unheated samples. The boiling of seafoods resulted in an increase in the length of peptides containing predicted sequences. Some peptides from the boiled samples contained entire linear epitopes. The prediction of tropomyosin cleavage sites failed in the case of fried products. Peptides from the unheated and boiled samples were attributed to crustacean, arthropod or molluscan tropomyosins. In turn, peptides from the fried samples possessed inconclusive taxonomic lineages. Our results show that bioinformatics analysis (especially using Unipept program) may be a viable tool supporting LC-MS/MS experiments aimed at the detection of allergens. Full article

Farnesyl pyrophosphate synthase (FPPS) is a key enzyme in the terpenoid biosynthesis pathway, responsible for converting isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) into farnesyl pyrophosphate (FPP). In crustaceans, FPPS plays an important role in various physiological processes, particularly in synthesizing the crustacean-specific hormone methyl farnesoate (MF). This study analyzed the evolutionary differences in the physicochemical properties, subcellular localization, gene structure, and motif composition of FPPS in Neocaridina denticulata sinensis (named NdFPPS) compared to other species. The significant evolutionary divergence of FPPS was observed in crustaceans, likely linked to its role in MF synthesis. After the RNA interference (RNAi)-mediated knockdown of NdFPPS, transcriptomic analysis of gills revealed the significant enrichment of differentially expressed genes (DEGs) in pathways related to metabolism and immunity. Gene set enrichment analysis (GSEA) showed that most of these immune-related pathways were significantly suppressed, suggesting that NdFPPS may indirectly regulate the immune response by modulating metabolic levels. During the early stages of Vibrio parahaemolyticus infection, the expression of NdFPPS in the gills was significantly downregulated and subsequently returned to its original levels. Overall, our results provide new perspectives on the role of FPPS in immune regulation and enrich the functional information of FPPS. Full article

Biodiversity patterns provide insights into the conservation value of ecosystems and also aid in an understanding of some research priorities. This research paper presents an exhaustive inventory of crustaceans and fish species from the Yucatan Peninsula’s epicontinental, underground, and anchialine aquatic systems. Using records spanning from 1936 to 2024, this study analyzed over 2600 entries across 670 aquatic systems, including cenotes, flooded cave lakes, springs, and wetlands. A total of 329 species were recorded, comprising 117 fish and 212 crustacean species. The richness and endemism of these species were assessed through a completeness analysis, utilizing non-parametric models (Chao 2, Jackknife 1, Bootstrap) to estimate potential species richness. Notably, the region exhibits high endemism, especially among crustaceans, with up to 50 species and 2 endemic families being unique to the Yucatan Peninsula. This study underscores the importance of the eastern YP for crustaceans and the central YP for fish, highlighting areas critical for conservation. These findings emphasize the need for further exploration, as the diversity of aquatic species remains incompletely understood. This comprehensive synthesis aims to inform future conservation strategies, environmental management, and regional planning efforts, particularly highlighting the vulnerability of these unique aquatic systems to environmental degradation. Full article

The most economically important trait of the Procambarus clarkii is meat quality. Protein deposition is essential in muscle growth and nutritional quality formation. The effects and potential mechanisms of feed protein sources on crustaceans’ muscle protein deposition have not been elucidated. This study established an all-animal protein source (AP) and an all-plant protein source group (PP), with a feeding period of 8 weeks (four replicates per group, 45 individuals per replicate). The results demonstrated that muscle protein deposition, muscle fiber diameter, and hardness were significantly higher in the PP group (p < 0.05). The transcript levels of genes involved in protein synthesis were notably upregulated, while those of protein hydrolysis and negative regulators of myogenesis notably downregulated in PP group (p < 0.05). Furthermore, protein sources shaped differential intestinal microbiota composition and microbial metabolites profiles, as evidenced by a significant decrease in g_Bacteroides (p = 0.030), and a significant increase in taurochenodeoxycholic acid (TCDCA) in PP group (p = 0.027). A significant correlation was further established by Pearson correlation analysis between the g_Bacteroides, TCDCA, and genes involved in the MSTN-mediated protein deposition pathway (p < 0.05). In vitro anaerobic fermentation confirmed the ability of the two groups of intestinal flora to metabolically produce differential TCDCA (p = 0.038). Our results demonstrated that the ‘Bacteroides-TCDCA-MSTN’ axis may mediate the effects of different protein sources on muscle development and protein deposition in P. clarkii, which was anticipated to represent a novel target for the muscle quality modulation in crustaceans. Full article

Efficient extraction of bioactive compounds from red lobster by-products is crucial for maximizing their nutritional and economic value. This study compared high-hydrostatic pressure extraction (HHPE), ultrasound-assisted extraction (UAE), and conventional extraction (CE), assessing the yield and bioaccessibility of carotenoids (astaxanthin, β-carotene, lycopene), antioxidants (DPPH, FRAP assays), and minerals (sodium, magnesium, potassium, calcium). HHPE and UAE significantly enhanced carotenoid extraction (p < 0.05), with UAE yielding the highest astaxanthin (3.61 mg/100 g FW) and HHPE producing the most β-carotene (0.64 mg/100 g FW). HHPE also significantly increased antioxidant capacity (38.04% increase over CE, p < 0.05). Despite reduced bioaccessibility after in vitro digestion, HHPE and UAE represent sustainable methods for recovering valuable bioactive compounds, improving the nutritional profile of red lobster by-products. Full article