Search Results (118)

The giant freshwater prawn (Macrobrachium rosenbergii, GFP) is a highly valuable crustacean species in global aquaculture. However, a social hierarchy exists among the distinct male morphotypes, specifically blue-clawed males (BC), orange-clawed males (OC), and small males (SMs). In this study, to identify the specific metabolites among BC, OC, and SM, hemolymph samples were collected for the untargeted liquid chromatography–mass spectrometry metabolomics (LC–MS). A total of 172, 546, and 578 significantly different metabolites (SDMs) were identified in OC vs. BC, SM vs. BC, and SM vs. OC, respectively. Notably, creatine and glutamate in BC males likely enhance their aggressive behavior through improved energy metabolism. In the SM group, the up-regulation of prostaglandin E3, testosterone, and arachidonic acid may lead to premature gonadal maturation and enhance immunity. Serotonin, Glu-Pro, and pentanoylcarnitine detected in OC males reflect their physiological need for rapid growth and adaptation to social behaviors. In the SM group, the up-regulation of prostaglandin E3, arachidonic acid, and testosterone may promote premature gonadal maturation and enhance immunodominance. These findings will enhance the understanding of the physiological basis of social hierarchy formation in male GFPs from a metabolomics perspective. Full article

Macrobrachium rosenbergii, commonly known as giant freshwater prawns (GFPs), is an economically and nutritionally important decapod crustacean species in China. Understanding the genetic diversity of selective breeding populations is crucial in breeding plans for selecting genetically diverse broodstocks and maintaining genetic diversity. The genetic structure of six breeding populations (Hefu (HF), Nantaihu No.2 (NTH), Jiaxin (JX), Shufeng (SF), Taiwan (TW), and Guangxi (GX)) of GFP in China was examined using 16 newly developed microsatellite loci and the mitochondrial control region (D-loop). The microsatellite data revealed that all 16 loci have high diversity, with all values of polymorphism information content (PIC) more than 0.5. The average expected heterozygosity (He, 0.89) and the number of alleles (Na, 18.25) of SF were the highest, followed by He (0.89) and Na (14.75) of the JX, and GX has the lowest He (0.83) and Na (11.31). The average PIC value for the six stocks ranged from 0.80 to 0.87. Pairwise comparisons revealed that Fst ranged from 0.03541 to 0.09637 and was significant (p < 0.05) between most populations, indicating from low to moderate genetic differentiation among the six populations. The D-loop analysis identified 114 variable sites and 29 haplotypes, with an average haplotype diversity (Hd) and nucleotide diversity (π) of 0.640 and 0.01247, respectively. Genetic differentiation among the six populations based on the D-loop was from moderate to high, with Fst values of 0.05603–0.80788, and all p < 0.05. This study demonstrates that selective breeding stocks of M. rosenbergii in China show moderate to high genetic diversity and have the potential for further selective breeding, providing a theoretical basis for conserving and utilizing M. rosenbergii genetic resources. Full article

Biological invasions are one of the main causes of biodiversity loss globally, affecting the quality of ecosystem services, the economy, and public health. Research on the presence, distribution, impacts, and introduction pathways of invasive alien species is essential for understanding and tackling the invasion process. Continental, coastal, and marine aquatic ecosystems of the Yucatan Peninsula concentrate a high number of native species; however, the states that are in the region (Campeche, Yucatan, and Quintana Roo) also have the largest loss of natural capital at the national level. The presence of aquatic invasive species has contributed to this downward trend, mainly in protected areas. For this research, an analysis of the national biodiversity information system, the global biodiversity information facility, and the specialized scientific literature was carried out to determine the presence of aquatic invasive species within the protected areas of the Yucatan Peninsula and adjacent marine zone. The results indicated that there are 22 documented aquatic invasive species in 25 protected areas, which were classified into the following taxonomic groups: marine macroalgae (3 species), plants (2), inland and marine fish (11), crustaceans (2), mollusks (2), and hydrozoans (2). A total of 15 of these species had a very high invasiveness score, 6 had a high score, and 1 had a medium score. This research will be useful in strengthening regional public policy and guiding decision makers on the management of aquatic invasive species, mainly for those that are seriously affecting aquatic ecosystems, such as Pterygoplichthys disjunctivus and P. pardalis in freshwater protected areas and Pterois volitans in marine protected areas. Efficient management strategies will be a key element in the protection of biodiversity and ecosystem services, and for sustainable regional development. Full article

This study aimed to investigate the mechanism underlying the synergistic antimicrobial effect of ferulic acid (FA) and ε-polylysine hydrochloride (PL) on Shewanella putrefaciens (S. putrefaciens) and their application on crayfish (Procambarus clarkii). The treatment with FA and PL exhibited a strong synergistic inhibitory effect against S. putrefaciens. The combination of 1/4 Minimum Inhibitory Concentration (MIC) FA and 1/4 MIC PL was the most effective, damaging the cell structure and inhibiting the growth of S. putrefaciens. Plasma-activated water (PAW) can induce microbial inactivation through physical action. In addition, treatments with FA, PL, PAW, PAW-FA, PAW-PL, and PAW + PL-FA substantially decreased total viable counts (TVCs), total volatile base nitrogen (TVB-N), the thiobarbituric acid value (TBA), and the juice loss rate of crayfish, with FA-PL showing the best effect. This study confirmed the antimicrobial efficacy of PL, FA, and PAW, indicating their potential as effective preservatives for controlling spoilage in freshwater crustaceans. Full article

Starting with the Remane diagram, various conceptual models have been proposed to show how species richness varies along a salinity gradient. However, as relatively few estuaries experience extreme hypersalinity, quantitative data are lacking to evaluate the model. We used data for 1891 samples of benthic macroinvertebrates from 12 estuaries in southwestern Australia (salinity 0–122 ppt) to determine the salinities in which 257 taxa were recorded. The pattern of richness differed from the conceptual models, with relatively few species (≤20%) recorded in freshwater and oligohaline salinities. Richness peaked at 35 ppt (seawater, 44%) before declining precipitously, with 21% and 10% of taxa recorded in hyperhaline salinities of 40 and 48 ppt, respectively. Taxa were recorded across the full salinity range, and several holohaline annelids, crustaceans, and insects were identified. Descriptive statistics and the frequency distribution of each taxon along the salinity gradient are provided. These identify stenohaline taxa and those with different extents of euryhalinity and how the occurrence of these taxa changes with salinity. The results help predict how benthic macroinvertebrate species and assemblages in estuaries in southwestern Australia and other Mediterranean climatic regions may shift due to climate change, particularly increased incidences and magnitude of hypersalinity. Full article

Sesquiterpenoid hormones are widely present in arthropods and play crucial roles in growth, molting and reproduction. Methyl farnesoate (MF) functions similarly to juvenile hormone (JH) in crustaceans, playing a broad regulatory role in their growth and development. However, compared to insects, systematic studies on the mechanisms of sesquiterpenoid hormones in crustaceans are still lacking. Neocaridina denticulata, a small freshwater shrimp known for its fast growth, high reproductive capacity and ease of maintenance, is an ideal model organism for crustacean research. To investigate the effects of MF on the growth and development of juvenile N. denticulata, MF feeding experiments were conducted and the changes at the phenotypic and molecular levels were examined. In this experiment, the basal diet was used as a control, with 40 μg/kg, 4 μg/kg and 0.4 μg/kg of MF added to the feed. The MF-enriched diets were fed to juvenile N. denticulata and the growth in body length was measured every 10 days. After 40 days of feeding experiment, the activities of amylase (AMS), lipase (LPS), trypsin (Try), superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GSH-PX) were assessed, and transcriptome analysis was performed. We found that MF showed an initial inhibitory effect on body length (day 30), but by day 40, the low-concentration group exhibited significantly enhanced growth compared to the control, indicating a dose- and time-dependent effect. Activities of AMS, LPS, Try and SOD generally decreased, whereas MDA levels and GSH-PX activity increased after 40 days of MF exposure. Moreover, transcriptomic analysis revealed that MF regulated various biological processes including growth, metabolism and immune responses. High concentration group appeared to restrict growth via modulation of exoskeleton-related and cellular stress genes. Medium concentration group enhanced growth by optimizing metabolic and signaling pathways. Low concentration group preferentially up-regulated genes related to muscle function, potentially supporting locomotion and competitive ability. This study provides new insights into the regulatory mechanism of sesquiterpenoid hormones in crustaceans and their potential applications in aquaculture in the future. Full article

Species belonging to the crustacean infraorder Astacoidea represent taxa of particular interest from a conservation point of view, such as the threatened European crayfish (i.e., Austropotamobius pallipes), and at the same time include invasive taxa having highly negative impacts where they are introduced. Among the latter, some freshwater-dwelling species seem to show some abilities to tolerate high salinity levels, such as Procambarus clarkii Girard, 1852. By using metadata and field observation, this review will investigate whether the alien P. clarkii can threaten coastal waters. Specifically, we will shed light on P. clarkii’s (1) invasiveness, (2) its dispersal pattern, (3) its tolerance to salinity, and (4) its ecological plasticity as an invasive species in relation to estuaries. This new habitat colonization is also possible as P. clarkii has been observed to survive up to 20 ppt of water salinity and a maximum of 30–35 ppt with its lifetime drastically reduced. As a result, P. clarkii colonizes different ecosystems globally, reaching estuarine and coastal ecosystems due to active and passive transport by human and animal vectors. Due to recent discoveries of alien crayfish in estuarine and coastal waters, monitoring activities have become mandatory to preserve coastal habitats and all the aquatic resources (e.g., limicolous birds, endemic fish, fishery and aquaculture activities) inhabiting therein. Full article

Micro- and nanoplastic pollutants are among the major environmental challenges, and are exacerbated by the continuous degradation of growing amounts of plastic debris in the aquatic environment. The purpose of this study was to investigate the morphology of micro/nanoplastics (M/NPs) formed from polyethylene terephthalate (PET) by mechanical degradation in an aquatic environment, which mimics the processes in the natural environment well, and to determine the impact of these particles on model aquatic organisms. To this end, M/NPs were obtained by ball milling in an aqueous medium and the effect of milling length on particle size and shape was investigated. The particles obtained in an environment simulating natural conditions were irregularly shaped, and those of nanometric size tended to form aggregates of various shapes. The ingestion and toxicity of PET M/NPs to freshwater zooplankton were then assessed. Daphnia magna and Thamnocephalus platyurus were used in a series of acute ecotoxicity tests, by exposure to M/NP dispersions at environmentally realistic concentrations (0.01–1.0 mg/L), as well as at very high concentrations (100–1000 mg/L). A significant uptake of PET particles by both types of invertebrates was observed, and the M/NPs were mainly concentrated in the digestive tracts of the crustaceans. However, they did not cause acute toxicity to the tested organisms or a reduction in their swimming activity, even at concentrations as high as 1000 mg/L. Full article

Bacteriophages, or phages, which are viruses with specifically restricted tropism for bacteria, have regained interest in the last few decades as alternative therapeutic agents against antibiotic-resistant pathogenic bacteria in animals and humans worldwide. In this context, bacteriophage therapy has been developed to treat bacterial infections of cultured fish, shellfish, and crustaceans. Nowadays, aquaculture is the only feasible solution to meet the continuously growing global demand for high-quality seafood. As such, it is crucial to focus on controlling the spread of pathogenic bacteria, as they have a significant economic impact on aquaculture systems. Overall, the documented research supports the application of bacteriophage therapy in aquaculture, but also underlies the need for additional studies, as it is still mostly in the scientific stage. This review aims to highlight and critically examine recent advancements in the application of bacteriophages to treat the most common bacterial infectious diseases in both freshwater and saltwater aquaculture species, providing topical perspectives and innovative advances. Full article

Perfluoroctane sulfonate (PFOS) is an emerging pollutant widely existing in aquatic environments that has attracted many scholars’ attention. Cherax quadricarinatus (C. quadricarinatus) are crustaceans that live in freshwater environments. This study aimed to investigate the long-term toxic exposure effect of PFOS on C. quadricarinatus. Three PFOS environment concentrations (1 ng/L, 100 ng/L, and 10 μg/L) were set for 28 days of exposure to C. quadricarinatus. The results indicated that PFOS was detected in the serum, muscle, and hepatopancreas of the C. quadricarinatus, and the order of accumulation levels was as follows: hepatopancreas > serum > muscle. Furthermore, transcriptomics showed that the function of differentially expressed genes (DEGs) in PFOS exposure groups was related to biological processes, metabolism, organic system, and immune response. The Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that DEGs were significantly enriched in the lysosome signaling pathway, retinol binding, fructose and mannose metabolism, and glutathione metabolism, etc., and the lysosome signaling pathway was the most significant, which indicated that lysosome signaling pathway is the key pathway for the toxic effects of PFOS on C. quadricarinatus. Full article

Concerns over pharmaceutical contaminants are increasing due to their high biological activity and ubiquity, with wastewater being the main source. Ibuprofen is extensively used worldwide and commonly detected in freshwaters due to its low degradability during wastewater treatment. Daphnia magna is the most-used model taxon for toxicity testing of ibuprofen, but this crustacean is known to be less sensitive to some contaminants than several freshwater insect groups. Our study assessed the toxicity of ibuprofen (nominal concentration range 2.0–2147.5 µg/L) to a native New Zealand mayfly, Deleatidium spp., in a 7-day static renewal experiment, with the neonicotinoid imidacloprid (1.4 µg/L) as a reference toxicant. Test concentrations of ibuprofen included three field-realistic and four higher concentrations that might occur in severely polluted streams. Mayfly responses indicated some negative trends (decreased survival and moulting propensity, increased impairment and immobility), but all patterns were non-significant. The imidacloprid control also had no significant impacts but tended to increase mayfly impairment. Overall, Deleatidium nymphs were largely unaffected by the entire range of experimental ibuprofen concentrations, suggesting that ibuprofen may be a relatively benign stressor for these organisms, although longer-term exposure experiments are needed to confirm if they demonstrate susceptibility to chronic exposure. Full article

Chitin synthase is an essential enzyme of the chitin synthesis pathway during molting. In this study, we identified and characterized a chitin synthase (EsCHS) gene in the Chinese mitten crab, Eriocheir sinensis. The spatio-temporal expression and functional role of EsCHS were investigated. The open reading frame of EsCHS was 4725 bp long and encoded 1574 amino acid residues that contained the typical domain structure of the glycosyltransferase family 2. Phylogenetic analysis revealed that EsCHS belongs to the group I chitin synthase family. The expression of EsCHS was found in regenerative limbs, the cuticle and the intestines. During the molting cycle, EsCHS began to increase in the pre-molt stage and reached a significant peak in the post-molt stage. The knockdown of EsCHS resulted in the significant downregulation of chitin biosynthesis pathway genes, including TRE, HK, G6PI, PAGM and UAP. Moreover, the long-term RNAi of EsCHS resulted in thinning procuticles, abnormal molting and high mortality, suggesting that EsCHS is indispensable for the formation of chitin in the cuticle during molting. In conclusion, EsCHS is involved in the chitin biosynthesis pathway and plays an important role in molting in E. sinensis. These findings highlight the potential of incorporating EsCHS into selective breeding programs to optimize molting regulation and improve growth performance in crustacean aquaculture. Full article

The interaction between freshwater biota and microplastics (MPs) has recently been described, mostly focusing on indoor experiments using fish, crustaceans, and chironomids. Among aquatic invertebrates, although having an important ecological role, aquatic butterfly larvae have not yet been investigated concerning plastics. We examined the interaction between aquatic larvae of the moth Cataclysta lemnata (Linnaeus, 1758) and MPs. We verified if (i) larvae could use MPs to build their protective cases, (ii) they could chew PVC, and (iii) there were effects on the pupae emergence to adult moths after larvae exposure to PVC. By performing two indoor experiments, (i) we exposed larvae to different MPs polymers, aquatic plant Lemna minuta, and a mix of MPs with L. minuta, and (ii) exposed larvae to a PVC layer. For the first time, we observed that C. lemnata larvae use MPs to build their cases and chewed the PVC layer. About half of the larvae (48.0%) pupated of which 43.7% emerged as adults. Our findings suggest that MPs are used by C. lemnata larvae, potentially affecting their life cycle. Future studies should explore whether MPs are transported by adult moths, linking aquatic and terrestrial ecosystems. Full article

The Yucatan Peninsula (YP) presents heterogeneous environments in a karstic landscape that has been formed from permeable sedimentary rocks dating from the Cretaceous period. Its aquifers now face significant pressure from tourism, agriculture, soil use changes and population growth. Aquifer delimitation typically relies on environmental and socioeconomic criteria, overlooking the subterranean fauna. Stygobiotic crustaceans are highly diverse in the YP’s subterranean karstic systems, expressing adaptations to extreme environments while often also displaying the primitive morphology of evolutionary relics. With distributions restricted to specific environments, they are potential markers of water reserves. A literature review recovered records of 75 species of crustaceans from 132 subterranean systems in the YP, together with geomorphological, hydrological, hydrogeochemical and historical precipitation data. Fourteen UPGMA clusters were informative for mapping species composition, whereby the “Ring of Cenotes”, “Caribbean Cave” and “Cozumel Island” regions were delineated as consolidated aquifers. These aquifers are distinguished by abiotic factors as well: freshwater species dominate the Ring of Cenotes, while marine-affinity species characterize the Caribbean Cave and Cozumel Island aquifers. Stygobiotic crustaceans, being linked to geologically ancient water reserves and having a restricted distribution, offer a complementary tool for aquifer delimitation. Their presence suggests long-term and stable water availability. The use of these unique organisms for integrative aquifer delimitation can provide a way to improve the monitoring networks of regional aquifers. Full article

This study evaluates, for the first time, the reducing capacity, radical scavenger activity, and in vitro antitumor and anti-inflammatory effects of chitosan, astaxanthin, and bio-phenols extracted from the exoskeleton of Sicilian Procambarus clarkii, the most widespread species of invasive crayfish in the Mediterranean region. Among the extracted compounds, astaxanthin exhibited the highest antioxidant activity in all assays. Chitosan and polyphenols demonstrated reducing and radical scavenging activity; chitosan showed significant ferric ion reducing capacity in the FRAP test, while bio-phenolic compounds displayed notable radical scavenging activity in the DPPH and ABTS assays. Both astaxanthin and polyphenols showed dose-dependent cytotoxicity on two different cancer cell lines, with IC50 values of 1.45 µg/mL (phenolic extract) and 4.28 µg/mL (astaxanthin extract) for HepG2 cells and 2.45 µg/mL (phenolic extract) and 4.57 µg/mL (astaxanthin extract) for CaCo-2 cells. The bio-phenolic extract also showed potential anti-inflammatory effects in vitro by inhibiting nitric oxide production in inflamed RAW 264.7 macrophages, reducing the treated/control NO ratio to 77% and 74% at concentrations of 1.25 and 1.5 μg/mL, respectively. These results suggest that P. clarkii exoskeletons could be a valuable source of bioactive molecules for biomedical, pharmaceutical, and nutraceutical application while contributing to the sustainable management of this invasive species. Full article