Maternal care in crayfish has been extensively studied,but little is known of its response to environmental factors.We studied the duration of maternal care and its association with the juvenile development of marbled...Maternal care in crayfish has been extensively studied,but little is known of its response to environmental factors.We studied the duration of maternal care and its association with the juvenile development of marbled crayfish Procambarus virginalis in adverse environmental conditions.We exposed females with developmental stage 3 juveniles to environments of low water volume(LW)with food provided,low water volume with no feed(starvation)(LWS),and low water volume without feeding plus an intruder(red swamp crayfish male)(LWSI).A control group with standard water level/feed conditions was included for comparison.Groups were monitored for up to 90 days.The LWS group showed significantly prolonged maternal care(~65 days)as indicated by an extended attachment phase,delayed moulting of mothers(~53 days),and retarded juvenile development.In the LWSI group,conflict precluded extended maternal care.Low use of shelter and feeding was evident under all stress conditions.The results showed that crayfish females modify maternal care in accordance with conditions,providing a longer period of safety for offspring under adverse circumstances.It is possible that the expression of maternal pheromones can manipulate the developmental rate in juveniles,a topic for future research.展开更多
With the birth of Software-Defined Networking(SDN),integration of both SDN and traditional architectures becomes the development trend of computer networks.Network intrusion detection faces challenges in dealing with ...With the birth of Software-Defined Networking(SDN),integration of both SDN and traditional architectures becomes the development trend of computer networks.Network intrusion detection faces challenges in dealing with complex attacks in SDN environments,thus to address the network security issues from the viewpoint of Artificial Intelligence(AI),this paper introduces the Crayfish Optimization Algorithm(COA)to the field of intrusion detection for both SDN and traditional network architectures,and based on the characteristics of the original COA,an Improved Crayfish Optimization Algorithm(ICOA)is proposed by integrating strategies of elite reverse learning,Levy flight,crowding factor and parameter modification.The ICOA is then utilized for AI-integrated feature selection of intrusion detection for both SDN and traditional network architectures,to reduce the dimensionality of the data and improve the performance of network intrusion detection.Finally,the performance evaluation is performed by testing not only the NSL-KDD dataset and the UNSW-NB 15 dataset for traditional networks but also the InSDN dataset for SDN-based networks.Experimental results show that ICOA improves the accuracy by 0.532%and 2.928%respectively compared with GWO and COA in traditional networks.In SDN networks,the accuracy of ICOA is 0.25%and 0.3%higher than COA and PSO.These findings collectively indicate that AI-integrated feature selection based on the proposed ICOA can promote network intrusion detection for both SDN and traditional architectures.展开更多
A lot of water reservoirs offer good natural conditions for crayfish breeding. Today there are four crayfish species present in Latvia--the European species noble crayfish （Astacus astacus）, narrow-clawed crayfish ...A lot of water reservoirs offer good natural conditions for crayfish breeding. Today there are four crayfish species present in Latvia--the European species noble crayfish （Astacus astacus）, narrow-clawed crayfish （Astacus leptodactylus）, the North American signal crayfish （Pacifastacus leniusculus） and spiny-cheek crayfish （Orconectes limosus）. In general, crayfish were found in 258 localities--lakes （175）, rivers and streams （66）, reservoirs, ponds and gravel-pits （17）. A. astacus in Latvia is the dominant crayfish species distributed in all regions. Narrow-clawed crayfish was registered since 1960s. North American signal crayfish was introduced due to its resistance to diseases, but spiny-cheek crayfish arrived from Lithuania waters spontaneously. The main threat for crayfish population is crayfish plague, initiated by mucus Aphanomyces astaci. Astacus astacus was more susceptible species in comparison with Pacifastacus leniusculus and Orconectes limosus. Though the North American signal crayfish and spiny-cheek crayfish were not only resistant, they were the carriers of this disease. The physical habitat alterations, pollution and overfishing are significant during the first year breeding period. Crayfish might serve as bacteria carriers and can cause substantial fish diseases （such as aeromonosis, flavobacteriosis）.展开更多
Lotus root-redswamp crayfish integrated farming is a kind of ecologicalgrow mode on the basis of paddy field, which is an innovated mode for agricultural structure adjustment and special agriculture with high efficien...Lotus root-redswamp crayfish integrated farming is a kind of ecologicalgrow mode on the basis of paddy field, which is an innovated mode for agricultural structure adjustment and special agriculture with high efficiency. In order to regulate producing technology of this mode, the essay puts forward some technical require- ments, stressing on cultivar selection, field works, farming technology and product quality, which aims at providing technical support for agricultural production.展开更多
The rice-crayfish farming model has been rapidly developed and become an economically viable method to supply food in China in recent years.However,its environmental and economic sustainability has not been thoroughly...The rice-crayfish farming model has been rapidly developed and become an economically viable method to supply food in China in recent years.However,its environmental and economic sustainability has not been thoroughly investigated.This study uses a survey in 2016 and a field experiment in 2017 in Qianjiang,Hubei Province,China to assess the relative economics of concurrent rice-wheat(RW),rice-crayfish(RC),and crayfish monoculture(CM)models in waterlogged land areas.Thefield survey indicated that the RC model had a higher benefit-cost ratio(3.5:1)than the RW(2.0:1)and CM(3.1:1)models and the RC model protected farmers’enthusiasm for grain production facing unfavourable weather conditions.The field experiment aimed to explore nitrogen management strategies in RC fields.In the experiment,four levels of nitrogen concentration gradient-0 kg N ha^(-1)(0 N),75 kg N ha^(-1)(75 N),150 kg N ha^(-1)(150 N)and 225 kg N ha^(-1)(225 N),were set in a 2-year-old rice-crayfish(RC2)field,an 8-year-old rice-crayfish(RC8)field,and a RWfield as a control.Thefield experiment results suggested that the peak rice yield in RW,RC2,and RC8 occurred when 225 N,150 N and 75 N were used,respectively.In RC2 and RC8,however,residual feed-nitrogen that was not used by crayfish was utilized by rice plants.Thus,an optimal amount of nitrogen in RCfields was proposed to improve the nitrogen use efficiency and reduce environmental pollution by nitrogen fertilizer.Farmers use less nitrogen but have higher net income in RC than in RW and CM.It is necessary to sustainably develop integrated farming technologies(i.e.,properfield configurations for ricefields)to effectively sustain rice production.The results also showed that the RC farming model was a viable diversification option for rice farmers in waterlogged land.展开更多
BACKGROUND: The study aimed to explore the clinical presentations, laboratory findings, treatments and prognosis of patients with Haff disease after eating crayfi sh. METHODS: Sixteen patients with Haff disease after ...BACKGROUND: The study aimed to explore the clinical presentations, laboratory findings, treatments and prognosis of patients with Haff disease after eating crayfi sh. METHODS: Sixteen patients with Haff disease after eating crayfish were admitted to the Emergency Department of Beijing Chao-yang Hospital between June 2013 and August 2017. Clinical data was retrospectively analyzed. RESULTS: Alcohol consumption and exercise were found to be most commonly associated with the onset of rhabdomyolysis after consuming crayfi sh. Most patients were young adults and the symptoms mostly occurred within 24 hours of consumption of crayfi sh. Clinical symptoms included myalgia (100%), fatigue (87.5%), nausea (43.8%), dizziness (62.5%), chest distress (37.5%) and fever (18.8%). Also found after laboratory testing was elevations in the levels of creatine kinase (11,376±5,535 U/L), myoglobin (350±158 ng/mL), lactate dehydrogenase (6,539±3,180 U/L), alanine transaminase (174±71 U/L) and aspartate aminase (348±100 U/L). The incidence of renal dysfunction was low (6.25%), and all 16 patients had a good prognosis. CONCLUSION: Patients with Haff disease exhibited typical symptoms after consuming crayfish, and laboratory findings gave highly accurate diagnostic results. The development of rhabdomyolysis was considered to be associated with alcohol consumption and exercise, but further studies are needed to demonstrate its relationship with crayfi sh consumption. Compared with other causes of rhabdomyolysis, rhabdomyolysis after crayfi sh consumption has fewer complications and better prognosis.展开更多
Crayfish shell is an abundant natural waste and is also a potential biosorbent for pollutants,especially,heavy metals.In this study,the safety of the use of crayfish shell as a biosorbent was first assessed by release...Crayfish shell is an abundant natural waste and is also a potential biosorbent for pollutants,especially,heavy metals.In this study,the safety of the use of crayfish shell as a biosorbent was first assessed by release experiments involving primary heavy metal ions,such as Cu^(2+),Zn^(2+),and Cr^(3+),in aqueous solution under different environmental conditions.The release concentrations of heavy metals were dependent on pH,ionic strength,and humic acid;and the maximum release concentrations of heavy metals were still lower than the national standard.Specifically,Cu^(2+) and Pb^(2+) removal by crayfish shell in synthetic wastewater was investigated.The removal process involved biosorption,precipitation,and complexation,and the results indicate that crayfish shell is an excellent biosorbent for Cu^(2+) and Pb^(2+) removal.The precipitation step is particularly dependent on Ca species,pH,and temperature.The maximum removal capacities of Pb^(2+) and Cu^(2+) were 676.20 and 119.98 mg/g,respectively.The related precipitates and the generated complex products include Cu_(2)CO_(3)(OH)_(2),Ca_(2)CuO_(3),CuCO_(3),Pb_(2)CO_(3)(OH)_(2),CaPb_(3)O_(4),and PbCO_(3).展开更多
The neutralizing activities of eight monoclonal antibodies （MAbs） against white spot syndrome virus （WSSV） （2D2, 2B2,1D2, 1D5, 1C2, 4A1, 6A4 and 6B4） were analyzed by in vivo experiments. Gills from WSSV-infecte...The neutralizing activities of eight monoclonal antibodies （MAbs） against white spot syndrome virus （WSSV） （2D2, 2B2,1D2, 1D5, 1C2, 4A1, 6A4 and 6B4） were analyzed by in vivo experiments. Gills from WSSV-infected shrimp were homogenized and ten-fold serially diluted by PBS, and then incubated with MAbs （hybridoma culture supernatant）, respectively. The mixture of WSSV and MAbs were injected into crayfish （Procambarus clarkii）. After challenge, the death rates of crayfish were counted to determine the neutralizing activities of MAbs. At the same time, the mixture of myeloma culture supernatant and WSSV or PBS was served as positive or negative control, respectively. The results showed that, at each virus dilution, the mean time to death of the crayfish injected with MAb-treated virus was significantly longer than that in the positive control, though they all showed 100% mortality within 25 d, and meanwhile, few crayfish died in the negative control. Among the eight MAbs, 2D2, 2B2, 1D2 and 1D5, especially the former two, delayed the mortality significantly, and 1 C2, 4A1 and 6A4 delayed the mortality as well but not so efficiently, while MAb 6IM was efficient only when the virus concentration increased. The results indicated that the anti-WSSV MAbs can neutralize WSSV in different virus dilutions.展开更多
It is a common issue in the processing industry of crayfish that flavored crayfish stored at room temperature is perishable.In order to establish an effective putrid prediction mechanism,high-throughput sequencing and...It is a common issue in the processing industry of crayfish that flavored crayfish stored at room temperature is perishable.In order to establish an effective putrid prediction mechanism,high-throughput sequencing and solid phase microextraction gas chromatography-mass spectrometry(SPME-GCMS)were used to analyse the microbial community structure and volatile flavor compounds of normal and putrid crayfish.The results showed that Aeromonas(57%),Macrococcus(7.7%),Vibrio sp.(6.6%),Acinetobacter(5%),Citrobacter(4.9%)and Enterobacter(1.49%)were the main bacterial genus in the refrigerated fresh crayfish(HNA).And Staphylococcus(17.04%),Aeromonas(4.46%),Xanthomonas(4.16%),Streptococcus(4.62%)and Enterococcus(2.77%)were the main bacterial genus in the marinated and refrigerated crayfish(HND).With the spoilage of samples(HNE and HNC),the diversity of bacteria decreased,and the specific spoilage bacteria grew rapidly,mainly Enterococcus,Bacillus,Lactobacillus,Leuconostoc,Weissella.Meanwhile,the volatile compounds in non-spoilage sample(HNA and HND)were mainly alkane compounds,aldehydes compound and esters compounds;and the volatile compounds in spoilage samples were mainly alcohols,acids,benzene compounds,terpenoids,N-containing compounds,S-containing compounds and ethers.This indicated that the contents and types of volatile compounds changed with the sample spoilage and deterioration.Correlation analysis results showed that Enterococcus,Lactobacillus and Bacillus were significantly positively correlated with alcohols,acids,benzene,terpenoids,N-containing compounds,S-containing compounds and ether compounds,while Aeromonas,Megasphaera,Acinetobacter,Citrobacter and Vibrio were significantly positively correlated with alkane compounds and esters compounds,and Leuconostoc were significantly positively correlated with alcohol compounds.These results can provide a theoretical guidance for the storage of cooked flavor crayfish at room temperature.展开更多
External coloration in animals depends on the interaction of several different factors including the genetics and epigenetics processes that underlie the color expression,the mechanisms of color perception,and the gen...External coloration in animals depends on the interaction of several different factors including the genetics and epigenetics processes that underlie the color expression,the mechanisms of color perception,and the general mechanisms controlling color evolution and function.Among all,camouflages from predators and conspicuousness are of particular interest because pose animal to choose between opposite adjustment in coloration.The external coloration of crustaceans is mainly due to the accumulation of carotenoids in the exoskeleton and the epidermal layer,and the trade-off between camouflage and communication had led to a variety of responses,involving signal partitioning,spectral sensibility,changing coloration,or signaling behavior.Here,we used digital images to explore intrapopulation variability of the external coloration of Pacifastacus leniusculus among body regions within an individual and between sexes.We found that 1)ventral coloration of claws are more saturated and brilliant than upper parts,2)males express a more saturated and brightness coloration than females,especially on the lower portion of claws,3)color intensity and brightness increases with size differently in different body regions,and 4)brightness is more variable in males than in females.All the above patterns support the hypothesis that color in this species could be the result of a compromise between camouflage from predators and conspicuousness for communication.The results of this study suggest that carotenoid might have something to do with intraspecific communication and perform more complex functions than that of a simple pigment.展开更多
Clonal organisms are particularly useful to investigate the contribution of epigenetics to phenotypic plasticity,because confounding effects of genetic variation are negligible.In the last decade,the apomictic parthen...Clonal organisms are particularly useful to investigate the contribution of epigenetics to phenotypic plasticity,because confounding effects of genetic variation are negligible.In the last decade,the apomictic parthenogenetic marbled crayfish,Procambarus virginalis,has been developed as a model to investigate the relationships between phenotypic plasticity and genetic and epigenetic diversity in detail.This crayfish originated about 30 years ago by autotriploidy from a single slough crayfish Procambarus fallax.As the result of human releases and active spreading,marbled crayfish has established numerous populations in very diverse habitats in 22 countries from the tropics to cold temperate regions.Studies in the laboratory and field revealed considerable plasticity in coloration,spination,morphometric parameters,growth,food preference,population structure,trophic position,and niche width.Illumina and PacBio whole-genome sequencing of marbled crayfish from representatives of 19 populations in Europe and Madagascar demonstrated extremely low genetic diversity within and among populations,indicating that the observed phenotypic diversity and ability to live in strikingly different environments are not due to adaptation by selection on genetic variation.In contrast,considerable differences were found between populations in the DNA methylation patterns of hundreds of genes,suggesting that the environmentally induced phenotypic plasticity is mediated by epigenetic mechanisms and corresponding changes in gene expression.Specific DNA methylation fingerprints persisted in local populations over successive years indicating the existence of epigenetic ecotypes,but there is presently no information as to whether these epigenetic signatures are transgenerationally inherited or established anew in each generation and whether the recorded phenotypic plasticity is adaptive or nonadaptive.展开更多
Masa is a cereal based snack made from rice, maize or millet. It is popularly consumed in the northern regions of Nigeria. The objective of this work was to assess the nutritional and sensory properties of the rice-Ma...Masa is a cereal based snack made from rice, maize or millet. It is popularly consumed in the northern regions of Nigeria. The objective of this work was to assess the nutritional and sensory properties of the rice-Masa, enriched with soybean and crayfish. The enriched rice-Masa produced were labelled sample A (100% rice), sample B (rice: soybean blend (80:20), sample C (rice: crayfish blend (80:20) and sample D (rice: soybean: crayfish (80:10:10). The proximate and mineral composition was evaluated according to standard methods. Anti-nutrient content was also determined. Sensory evaluation was carried out to assess the acceptability of the enriched rice-Masa. The chemical analysis showed that protein, fibre, iron, zinc and vitamin A and beta carotene contents were highest in sample D with values 8.35 (±0.08) g/100g, 1.08 (±0.02) g/100g, 2.82 (±0.03) mg/100g, 4.20 (±0.03) mg/100g, 602.3 (±1.28) μg/100g and 420.2 (±0.98) μg/100g respectively, while calcium was highest in sample C with a value of 27.34 (±0.06) mg/100g. Moisture and ash contents increased from 47.4 (±0.50) g/100g to 50.9 (±0.80) g/100g and 0.40 (±0.01) g/100g to 1.15 (±0.01) g/100g respectively, while carbohydrate and energy contents decreased from 28.1 (±0.03) g/100g to 21.9 (±0.04) g/100g and 308.42 kcal/100g to 285.64 kcal/100g respectively. The sensory evaluation showed that with regards to taste, aroma, texture and overall acceptability, the sample enriched with soybean was more preferred to that enriched with crayfish, or a combination of both. Enrichment of Masa could contribute to improvement of nutritional status if promoted as a nutritious, healthy indigenous snack not only where Masa is already widely consumed, but also in other parts of Nigeria where it has not found wide acceptance.展开更多
This paper describes a wheeled underwater robot developed for locating chemical sources autonomously under stagnant flow conditions. In still water, the released chemical stays in the immediate vicinity of the source ...This paper describes a wheeled underwater robot developed for locating chemical sources autonomously under stagnant flow conditions. In still water, the released chemical stays in the immediate vicinity of the source location. The search for chemical sources under such conditions is extremely laborious since the presence of a chemical source cannot be detected from a distant place. The chemical sensors on the robot show no response unless a chemical substance released from the source arrives at the sensors. Crayfish in search of food are known to actively generate water currents by waving their small appendages with a fan-like shape. It is considered that the generated water currents help their olfactory search. The smell of food is carried to their olfactory organs from the surroundings by the generated flow, and then is perceived. The robot presented in this paper employs arms mimicking the maxillipeds of a crayfish to generate water currents and to draw chemicals to its sensors. By waving the arms vertically, a three-dimensional flow field is generated and water samples are drawn from a wide angular range. The direction of a chemical source can be determined by comparing the responses of four laterally aligned electrochemical sensors. Experimental results show that the flow field generated by the maxilliped arms is more effective in collecting chemical samples onto the sensors than that generated by a pump. The robot equipped with the maxilliped arms can detect the presence of a chemical source even if the source is placed off the trajectory of the robot.展开更多
Monitoring heart rate (HR) and ventilatory rate (VR) during defined sensory stimuli and during aggressive and submissive social interactions has provided additional information of a crayfish's physiological state ...Monitoring heart rate (HR) and ventilatory rate (VR) during defined sensory stimuli and during aggressive and submissive social interactions has provided additional information of a crayfish's physiological state which is not achieved by behavioral observations. In this study, the HR and VR of crayfish were monitored before, during and after the act of copulation in both heterosexual partners. The female crayfish abruptly reduces HR and VR during copulation but the male maintains HR and VR. After separation from copulation the female HR and VR are elevated, potentially paying back the O2 debt. The tight relationship with HR and VR in direction of change indicates a potential neural coupling. These physiological changes in cardiac and respiratory systems suggest an autonomic-like regulation of HR and VR. How these neuronal functions are driven and regulated remains to be determined. Olfactory cues from the female to the male during copulation may be reduced by the reduction in VR in the female. These studies offer experimental paradigms for future neuronal and pharmacological investigations into autonomic regulation of HR and VR as well as the neural circuitry involved.展开更多
Microbial fermented feed possesses a natural fermentation flavor and exhibits good palatability.It is not only easily digestible and absorbable by livestock but also non-toxic.Additionally,it has the capacity to inhib...Microbial fermented feed possesses a natural fermentation flavor and exhibits good palatability.It is not only easily digestible and absorbable by livestock but also non-toxic.Additionally,it has the capacity to inhibit the proliferation of pathogenic bacteria,facilitate the growth and development of animals,and enhance their immune response,disease resistance,and overall production performance.This paper summarizes the selection of common feed materials and microbial strains used in fermented feed,as well as their effects on the growth performance,muscle quality,antioxidant capacity,and immune function of crayfish.The aim of this study is to provide a reference for the further popularization and application ofmicrobialfermented feed in crayfishaquaculture.展开更多
Intense pressure from both onshore and offshore oil exploration and exploitation activities, together with the accompanying urbanization and industrialization has resulted in massive contamination of land and water re...Intense pressure from both onshore and offshore oil exploration and exploitation activities, together with the accompanying urbanization and industrialization has resulted in massive contamination of land and water resources in Niger Delta, Nigeria. Whereas crayfish is very sensitive to contaminant in the aquatic environment and constitute an important part of human diet, its quality and safety from environmental pollutant is of serious health concern. Evaluation of dietary intake, potential carcinogenic and non-carcinogenic risk of lead, cadmium, mercury and arsenic exposure via consumption of dried crayfish purchased from major markets in Calabar, Nigeria was carried out between June and August 2021. Thirty-six composite samples of dried crayfish purchased from 180 vendors were used for the study. Heavy metals concentrations were determined using Atomic Absorption Spectrophotometer (Model AA-6800, Japan) after wet digestion. Metals concentrations (Mg/kg) were of the ranges 0.02 - 0.24, 0.14 - 0.86, 0.32 - 0.72, 0.04 - 0.19 for Pb, Cd, Hg and As respectively. The mean content of cadmium and mercury exceeded FAO/ WHO and Commission of European Communities maximum levels for crustaceans. Average Estimated Daily Intake for each of the metals was found to be above the recommended daily intake level except for arsenic. The average estimated daily intake values for Cd and Hg were also above the tolerable upper intake level. Average Target Hazard Quotient of all the metals and Hazard Index of all the markets were below 1.00. The Incremental Lifetime Cancer Risk of the metals was greater than the standard tolerable regulatory risk (10<sup>-4</sup>) for carcinogens. Consumption of crayfish purchased from major markets in Calabar could pose a range of carcinogenic and non-carcinogenic human health risks.展开更多
Taking Hubei Province as an example,starting with the present situation and existing problems of grain production,this paper expounds the great significance of"crayfish-rice continuous cropping"model in impr...Taking Hubei Province as an example,starting with the present situation and existing problems of grain production,this paper expounds the great significance of"crayfish-rice continuous cropping"model in improving grain quality,and analyzes the beneficial influence of"crayfish-rice continuous cropping"on grain production and the difficulties it faces.This paper also puts forward some measures and suggestions for the further popularization of"crayfish-rice continuous cropping"in order to maintain food security.展开更多
This study investigated the exposure levels of PFASs in crayfish sourced from Hubei Province,assessed the health and safety risks associated with consuming crayfish,and explored the bioaccumulation of PFASs in sedimen...This study investigated the exposure levels of PFASs in crayfish sourced from Hubei Province,assessed the health and safety risks associated with consuming crayfish,and explored the bioaccumulation of PFASs in sediment affecting crayfish.The results showed that 10 types of PFASs were detected in all crayfish samples,with a detection rate of 100%,and the concentration range of ΣPFASs was 0.902.67μg/kg ww,with perfluorooctanoic acid(PFOA)and perfluorododecanoic acid(PFDoDA)being the most abundant compounds.In sediment samples,8 types of PFASs were detected with a 100%detection rate,and perfluorobutyric acid(PFBA)and perfluorooctanesulfonic acid(PFOS)were found to be the most abundant.The hazard index(HI)for PFASs in crayfish was significantly larger than 1,and Monte Carlo simulation results indicated that exposure to PFASs through consumption of the edible portions of crayfish may pose a significant risk to human health.Spearman correlation analysis revealed a significant correlation(p<0.01)between the concentrations of perfluorononanoic acid(PFNA),perfluorobutanesulfonic acid(PFBS),and PFOS in crayfish and their corresponding compounds in sediments.Additionally,the biological-sediment accumulation factor(BSAF)values for PFOA and PFNA exceeded 10,indicating a certain potential for bioaccumulation.展开更多
In this article the name of the Handling editor was incorrectly given as Jian-Kui Liu,and should have been Timothy James.In addition,there were 24 Accession numbers in the last column of Table 1 and four in the first ...In this article the name of the Handling editor was incorrectly given as Jian-Kui Liu,and should have been Timothy James.In addition,there were 24 Accession numbers in the last column of Table 1 and four in the first paragraph of the second subsection in the Results that incorrectly included two erroneous,extra digits'69';otherwise 23 of the 24 and three of the four of these were correct.展开更多
基金financially supported by the Grant Agency of the University of South Bohemia No.GAJU 027/2022/Z and 065/2022/Zmade using facilities of the large research infrastructure supported by the Ministry of Education,Youth and Sports of the Czech Republic project CENAKVA(LM2023038).
文摘Maternal care in crayfish has been extensively studied,but little is known of its response to environmental factors.We studied the duration of maternal care and its association with the juvenile development of marbled crayfish Procambarus virginalis in adverse environmental conditions.We exposed females with developmental stage 3 juveniles to environments of low water volume(LW)with food provided,low water volume with no feed(starvation)(LWS),and low water volume without feeding plus an intruder(red swamp crayfish male)(LWSI).A control group with standard water level/feed conditions was included for comparison.Groups were monitored for up to 90 days.The LWS group showed significantly prolonged maternal care(~65 days)as indicated by an extended attachment phase,delayed moulting of mothers(~53 days),and retarded juvenile development.In the LWSI group,conflict precluded extended maternal care.Low use of shelter and feeding was evident under all stress conditions.The results showed that crayfish females modify maternal care in accordance with conditions,providing a longer period of safety for offspring under adverse circumstances.It is possible that the expression of maternal pheromones can manipulate the developmental rate in juveniles,a topic for future research.
基金supported by the National Natural Science Foundation of China under Grant 61602162the Hubei Provincial Science and Technology Plan Project under Grant 2023BCB041.
文摘With the birth of Software-Defined Networking(SDN),integration of both SDN and traditional architectures becomes the development trend of computer networks.Network intrusion detection faces challenges in dealing with complex attacks in SDN environments,thus to address the network security issues from the viewpoint of Artificial Intelligence(AI),this paper introduces the Crayfish Optimization Algorithm(COA)to the field of intrusion detection for both SDN and traditional network architectures,and based on the characteristics of the original COA,an Improved Crayfish Optimization Algorithm(ICOA)is proposed by integrating strategies of elite reverse learning,Levy flight,crowding factor and parameter modification.The ICOA is then utilized for AI-integrated feature selection of intrusion detection for both SDN and traditional network architectures,to reduce the dimensionality of the data and improve the performance of network intrusion detection.Finally,the performance evaluation is performed by testing not only the NSL-KDD dataset and the UNSW-NB 15 dataset for traditional networks but also the InSDN dataset for SDN-based networks.Experimental results show that ICOA improves the accuracy by 0.532%and 2.928%respectively compared with GWO and COA in traditional networks.In SDN networks,the accuracy of ICOA is 0.25%and 0.3%higher than COA and PSO.These findings collectively indicate that AI-integrated feature selection based on the proposed ICOA can promote network intrusion detection for both SDN and traditional architectures.
文摘A lot of water reservoirs offer good natural conditions for crayfish breeding. Today there are four crayfish species present in Latvia--the European species noble crayfish （Astacus astacus）, narrow-clawed crayfish （Astacus leptodactylus）, the North American signal crayfish （Pacifastacus leniusculus） and spiny-cheek crayfish （Orconectes limosus）. In general, crayfish were found in 258 localities--lakes （175）, rivers and streams （66）, reservoirs, ponds and gravel-pits （17）. A. astacus in Latvia is the dominant crayfish species distributed in all regions. Narrow-clawed crayfish was registered since 1960s. North American signal crayfish was introduced due to its resistance to diseases, but spiny-cheek crayfish arrived from Lithuania waters spontaneously. The main threat for crayfish population is crayfish plague, initiated by mucus Aphanomyces astaci. Astacus astacus was more susceptible species in comparison with Pacifastacus leniusculus and Orconectes limosus. Though the North American signal crayfish and spiny-cheek crayfish were not only resistant, they were the carriers of this disease. The physical habitat alterations, pollution and overfishing are significant during the first year breeding period. Crayfish might serve as bacteria carriers and can cause substantial fish diseases （such as aeromonosis, flavobacteriosis）.
基金Supported by the Key Agricultural Supporting Program of Jiangsu Province(BE2014360)~~
文摘Lotus root-redswamp crayfish integrated farming is a kind of ecologicalgrow mode on the basis of paddy field, which is an innovated mode for agricultural structure adjustment and special agriculture with high efficiency. In order to regulate producing technology of this mode, the essay puts forward some technical require- ments, stressing on cultivar selection, field works, farming technology and product quality, which aims at providing technical support for agricultural production.
基金funded by the National Key Research and Development Program of China(2017YFD0301400)the Fundamental Research Funds for the Central Universities,China(266620202KPY014)。
文摘The rice-crayfish farming model has been rapidly developed and become an economically viable method to supply food in China in recent years.However,its environmental and economic sustainability has not been thoroughly investigated.This study uses a survey in 2016 and a field experiment in 2017 in Qianjiang,Hubei Province,China to assess the relative economics of concurrent rice-wheat(RW),rice-crayfish(RC),and crayfish monoculture(CM)models in waterlogged land areas.Thefield survey indicated that the RC model had a higher benefit-cost ratio(3.5:1)than the RW(2.0:1)and CM(3.1:1)models and the RC model protected farmers’enthusiasm for grain production facing unfavourable weather conditions.The field experiment aimed to explore nitrogen management strategies in RC fields.In the experiment,four levels of nitrogen concentration gradient-0 kg N ha^(-1)(0 N),75 kg N ha^(-1)(75 N),150 kg N ha^(-1)(150 N)and 225 kg N ha^(-1)(225 N),were set in a 2-year-old rice-crayfish(RC2)field,an 8-year-old rice-crayfish(RC8)field,and a RWfield as a control.Thefield experiment results suggested that the peak rice yield in RW,RC2,and RC8 occurred when 225 N,150 N and 75 N were used,respectively.In RC2 and RC8,however,residual feed-nitrogen that was not used by crayfish was utilized by rice plants.Thus,an optimal amount of nitrogen in RCfields was proposed to improve the nitrogen use efficiency and reduce environmental pollution by nitrogen fertilizer.Farmers use less nitrogen but have higher net income in RC than in RW and CM.It is necessary to sustainably develop integrated farming technologies(i.e.,properfield configurations for ricefields)to effectively sustain rice production.The results also showed that the RC farming model was a viable diversification option for rice farmers in waterlogged land.
基金supported by the Beijing Natural Science Foundation(7182055)Beijing Municipal Administration of Hospitals Incubating Program(Px2016022)
文摘BACKGROUND: The study aimed to explore the clinical presentations, laboratory findings, treatments and prognosis of patients with Haff disease after eating crayfi sh. METHODS: Sixteen patients with Haff disease after eating crayfish were admitted to the Emergency Department of Beijing Chao-yang Hospital between June 2013 and August 2017. Clinical data was retrospectively analyzed. RESULTS: Alcohol consumption and exercise were found to be most commonly associated with the onset of rhabdomyolysis after consuming crayfi sh. Most patients were young adults and the symptoms mostly occurred within 24 hours of consumption of crayfi sh. Clinical symptoms included myalgia (100%), fatigue (87.5%), nausea (43.8%), dizziness (62.5%), chest distress (37.5%) and fever (18.8%). Also found after laboratory testing was elevations in the levels of creatine kinase (11,376±5,535 U/L), myoglobin (350±158 ng/mL), lactate dehydrogenase (6,539±3,180 U/L), alanine transaminase (174±71 U/L) and aspartate aminase (348±100 U/L). The incidence of renal dysfunction was low (6.25%), and all 16 patients had a good prognosis. CONCLUSION: Patients with Haff disease exhibited typical symptoms after consuming crayfish, and laboratory findings gave highly accurate diagnostic results. The development of rhabdomyolysis was considered to be associated with alcohol consumption and exercise, but further studies are needed to demonstrate its relationship with crayfi sh consumption. Compared with other causes of rhabdomyolysis, rhabdomyolysis after crayfi sh consumption has fewer complications and better prognosis.
基金supported by the Key Special Program on the S&T for the Pollution Control and Treatment of Water Bodies(No.2017ZX07603-003)。
文摘Crayfish shell is an abundant natural waste and is also a potential biosorbent for pollutants,especially,heavy metals.In this study,the safety of the use of crayfish shell as a biosorbent was first assessed by release experiments involving primary heavy metal ions,such as Cu^(2+),Zn^(2+),and Cr^(3+),in aqueous solution under different environmental conditions.The release concentrations of heavy metals were dependent on pH,ionic strength,and humic acid;and the maximum release concentrations of heavy metals were still lower than the national standard.Specifically,Cu^(2+) and Pb^(2+) removal by crayfish shell in synthetic wastewater was investigated.The removal process involved biosorption,precipitation,and complexation,and the results indicate that crayfish shell is an excellent biosorbent for Cu^(2+) and Pb^(2+) removal.The precipitation step is particularly dependent on Ca species,pH,and temperature.The maximum removal capacities of Pb^(2+) and Cu^(2+) were 676.20 and 119.98 mg/g,respectively.The related precipitates and the generated complex products include Cu_(2)CO_(3)(OH)_(2),Ca_(2)CuO_(3),CuCO_(3),Pb_(2)CO_(3)(OH)_(2),CaPb_(3)O_(4),and PbCO_(3).
基金The National Basic Research Program of China under contract No 2006CB101806the National"863"Project of China under con-tract No 2006AA100312
文摘The neutralizing activities of eight monoclonal antibodies （MAbs） against white spot syndrome virus （WSSV） （2D2, 2B2,1D2, 1D5, 1C2, 4A1, 6A4 and 6B4） were analyzed by in vivo experiments. Gills from WSSV-infected shrimp were homogenized and ten-fold serially diluted by PBS, and then incubated with MAbs （hybridoma culture supernatant）, respectively. The mixture of WSSV and MAbs were injected into crayfish （Procambarus clarkii）. After challenge, the death rates of crayfish were counted to determine the neutralizing activities of MAbs. At the same time, the mixture of myeloma culture supernatant and WSSV or PBS was served as positive or negative control, respectively. The results showed that, at each virus dilution, the mean time to death of the crayfish injected with MAb-treated virus was significantly longer than that in the positive control, though they all showed 100% mortality within 25 d, and meanwhile, few crayfish died in the negative control. Among the eight MAbs, 2D2, 2B2, 1D2 and 1D5, especially the former two, delayed the mortality significantly, and 1 C2, 4A1 and 6A4 delayed the mortality as well but not so efficiently, while MAb 6IM was efficient only when the virus concentration increased. The results indicated that the anti-WSSV MAbs can neutralize WSSV in different virus dilutions.
文摘It is a common issue in the processing industry of crayfish that flavored crayfish stored at room temperature is perishable.In order to establish an effective putrid prediction mechanism,high-throughput sequencing and solid phase microextraction gas chromatography-mass spectrometry(SPME-GCMS)were used to analyse the microbial community structure and volatile flavor compounds of normal and putrid crayfish.The results showed that Aeromonas(57%),Macrococcus(7.7%),Vibrio sp.(6.6%),Acinetobacter(5%),Citrobacter(4.9%)and Enterobacter(1.49%)were the main bacterial genus in the refrigerated fresh crayfish(HNA).And Staphylococcus(17.04%),Aeromonas(4.46%),Xanthomonas(4.16%),Streptococcus(4.62%)and Enterococcus(2.77%)were the main bacterial genus in the marinated and refrigerated crayfish(HND).With the spoilage of samples(HNE and HNC),the diversity of bacteria decreased,and the specific spoilage bacteria grew rapidly,mainly Enterococcus,Bacillus,Lactobacillus,Leuconostoc,Weissella.Meanwhile,the volatile compounds in non-spoilage sample(HNA and HND)were mainly alkane compounds,aldehydes compound and esters compounds;and the volatile compounds in spoilage samples were mainly alcohols,acids,benzene compounds,terpenoids,N-containing compounds,S-containing compounds and ethers.This indicated that the contents and types of volatile compounds changed with the sample spoilage and deterioration.Correlation analysis results showed that Enterococcus,Lactobacillus and Bacillus were significantly positively correlated with alcohols,acids,benzene,terpenoids,N-containing compounds,S-containing compounds and ether compounds,while Aeromonas,Megasphaera,Acinetobacter,Citrobacter and Vibrio were significantly positively correlated with alkane compounds and esters compounds,and Leuconostoc were significantly positively correlated with alcohol compounds.These results can provide a theoretical guidance for the storage of cooked flavor crayfish at room temperature.
文摘External coloration in animals depends on the interaction of several different factors including the genetics and epigenetics processes that underlie the color expression,the mechanisms of color perception,and the general mechanisms controlling color evolution and function.Among all,camouflages from predators and conspicuousness are of particular interest because pose animal to choose between opposite adjustment in coloration.The external coloration of crustaceans is mainly due to the accumulation of carotenoids in the exoskeleton and the epidermal layer,and the trade-off between camouflage and communication had led to a variety of responses,involving signal partitioning,spectral sensibility,changing coloration,or signaling behavior.Here,we used digital images to explore intrapopulation variability of the external coloration of Pacifastacus leniusculus among body regions within an individual and between sexes.We found that 1)ventral coloration of claws are more saturated and brilliant than upper parts,2)males express a more saturated and brightness coloration than females,especially on the lower portion of claws,3)color intensity and brightness increases with size differently in different body regions,and 4)brightness is more variable in males than in females.All the above patterns support the hypothesis that color in this species could be the result of a compromise between camouflage from predators and conspicuousness for communication.The results of this study suggest that carotenoid might have something to do with intraspecific communication and perform more complex functions than that of a simple pigment.
文摘Clonal organisms are particularly useful to investigate the contribution of epigenetics to phenotypic plasticity,because confounding effects of genetic variation are negligible.In the last decade,the apomictic parthenogenetic marbled crayfish,Procambarus virginalis,has been developed as a model to investigate the relationships between phenotypic plasticity and genetic and epigenetic diversity in detail.This crayfish originated about 30 years ago by autotriploidy from a single slough crayfish Procambarus fallax.As the result of human releases and active spreading,marbled crayfish has established numerous populations in very diverse habitats in 22 countries from the tropics to cold temperate regions.Studies in the laboratory and field revealed considerable plasticity in coloration,spination,morphometric parameters,growth,food preference,population structure,trophic position,and niche width.Illumina and PacBio whole-genome sequencing of marbled crayfish from representatives of 19 populations in Europe and Madagascar demonstrated extremely low genetic diversity within and among populations,indicating that the observed phenotypic diversity and ability to live in strikingly different environments are not due to adaptation by selection on genetic variation.In contrast,considerable differences were found between populations in the DNA methylation patterns of hundreds of genes,suggesting that the environmentally induced phenotypic plasticity is mediated by epigenetic mechanisms and corresponding changes in gene expression.Specific DNA methylation fingerprints persisted in local populations over successive years indicating the existence of epigenetic ecotypes,but there is presently no information as to whether these epigenetic signatures are transgenerationally inherited or established anew in each generation and whether the recorded phenotypic plasticity is adaptive or nonadaptive.
文摘Masa is a cereal based snack made from rice, maize or millet. It is popularly consumed in the northern regions of Nigeria. The objective of this work was to assess the nutritional and sensory properties of the rice-Masa, enriched with soybean and crayfish. The enriched rice-Masa produced were labelled sample A (100% rice), sample B (rice: soybean blend (80:20), sample C (rice: crayfish blend (80:20) and sample D (rice: soybean: crayfish (80:10:10). The proximate and mineral composition was evaluated according to standard methods. Anti-nutrient content was also determined. Sensory evaluation was carried out to assess the acceptability of the enriched rice-Masa. The chemical analysis showed that protein, fibre, iron, zinc and vitamin A and beta carotene contents were highest in sample D with values 8.35 (±0.08) g/100g, 1.08 (±0.02) g/100g, 2.82 (±0.03) mg/100g, 4.20 (±0.03) mg/100g, 602.3 (±1.28) μg/100g and 420.2 (±0.98) μg/100g respectively, while calcium was highest in sample C with a value of 27.34 (±0.06) mg/100g. Moisture and ash contents increased from 47.4 (±0.50) g/100g to 50.9 (±0.80) g/100g and 0.40 (±0.01) g/100g to 1.15 (±0.01) g/100g respectively, while carbohydrate and energy contents decreased from 28.1 (±0.03) g/100g to 21.9 (±0.04) g/100g and 308.42 kcal/100g to 285.64 kcal/100g respectively. The sensory evaluation showed that with regards to taste, aroma, texture and overall acceptability, the sample enriched with soybean was more preferred to that enriched with crayfish, or a combination of both. Enrichment of Masa could contribute to improvement of nutritional status if promoted as a nutritious, healthy indigenous snack not only where Masa is already widely consumed, but also in other parts of Nigeria where it has not found wide acceptance.
文摘This paper describes a wheeled underwater robot developed for locating chemical sources autonomously under stagnant flow conditions. In still water, the released chemical stays in the immediate vicinity of the source location. The search for chemical sources under such conditions is extremely laborious since the presence of a chemical source cannot be detected from a distant place. The chemical sensors on the robot show no response unless a chemical substance released from the source arrives at the sensors. Crayfish in search of food are known to actively generate water currents by waving their small appendages with a fan-like shape. It is considered that the generated water currents help their olfactory search. The smell of food is carried to their olfactory organs from the surroundings by the generated flow, and then is perceived. The robot presented in this paper employs arms mimicking the maxillipeds of a crayfish to generate water currents and to draw chemicals to its sensors. By waving the arms vertically, a three-dimensional flow field is generated and water samples are drawn from a wide angular range. The direction of a chemical source can be determined by comparing the responses of four laterally aligned electrochemical sensors. Experimental results show that the flow field generated by the maxilliped arms is more effective in collecting chemical samples onto the sensors than that generated by a pump. The robot equipped with the maxilliped arms can detect the presence of a chemical source even if the source is placed off the trajectory of the robot.
文摘Monitoring heart rate (HR) and ventilatory rate (VR) during defined sensory stimuli and during aggressive and submissive social interactions has provided additional information of a crayfish's physiological state which is not achieved by behavioral observations. In this study, the HR and VR of crayfish were monitored before, during and after the act of copulation in both heterosexual partners. The female crayfish abruptly reduces HR and VR during copulation but the male maintains HR and VR. After separation from copulation the female HR and VR are elevated, potentially paying back the O2 debt. The tight relationship with HR and VR in direction of change indicates a potential neural coupling. These physiological changes in cardiac and respiratory systems suggest an autonomic-like regulation of HR and VR. How these neuronal functions are driven and regulated remains to be determined. Olfactory cues from the female to the male during copulation may be reduced by the reduction in VR in the female. These studies offer experimental paradigms for future neuronal and pharmacological investigations into autonomic regulation of HR and VR as well as the neural circuitry involved.
文摘Microbial fermented feed possesses a natural fermentation flavor and exhibits good palatability.It is not only easily digestible and absorbable by livestock but also non-toxic.Additionally,it has the capacity to inhibit the proliferation of pathogenic bacteria,facilitate the growth and development of animals,and enhance their immune response,disease resistance,and overall production performance.This paper summarizes the selection of common feed materials and microbial strains used in fermented feed,as well as their effects on the growth performance,muscle quality,antioxidant capacity,and immune function of crayfish.The aim of this study is to provide a reference for the further popularization and application ofmicrobialfermented feed in crayfishaquaculture.
文摘Intense pressure from both onshore and offshore oil exploration and exploitation activities, together with the accompanying urbanization and industrialization has resulted in massive contamination of land and water resources in Niger Delta, Nigeria. Whereas crayfish is very sensitive to contaminant in the aquatic environment and constitute an important part of human diet, its quality and safety from environmental pollutant is of serious health concern. Evaluation of dietary intake, potential carcinogenic and non-carcinogenic risk of lead, cadmium, mercury and arsenic exposure via consumption of dried crayfish purchased from major markets in Calabar, Nigeria was carried out between June and August 2021. Thirty-six composite samples of dried crayfish purchased from 180 vendors were used for the study. Heavy metals concentrations were determined using Atomic Absorption Spectrophotometer (Model AA-6800, Japan) after wet digestion. Metals concentrations (Mg/kg) were of the ranges 0.02 - 0.24, 0.14 - 0.86, 0.32 - 0.72, 0.04 - 0.19 for Pb, Cd, Hg and As respectively. The mean content of cadmium and mercury exceeded FAO/ WHO and Commission of European Communities maximum levels for crustaceans. Average Estimated Daily Intake for each of the metals was found to be above the recommended daily intake level except for arsenic. The average estimated daily intake values for Cd and Hg were also above the tolerable upper intake level. Average Target Hazard Quotient of all the metals and Hazard Index of all the markets were below 1.00. The Incremental Lifetime Cancer Risk of the metals was greater than the standard tolerable regulatory risk (10<sup>-4</sup>) for carcinogens. Consumption of crayfish purchased from major markets in Calabar could pose a range of carcinogenic and non-carcinogenic human health risks.
文摘Taking Hubei Province as an example,starting with the present situation and existing problems of grain production,this paper expounds the great significance of"crayfish-rice continuous cropping"model in improving grain quality,and analyzes the beneficial influence of"crayfish-rice continuous cropping"on grain production and the difficulties it faces.This paper also puts forward some measures and suggestions for the further popularization of"crayfish-rice continuous cropping"in order to maintain food security.
基金supported by The National Key Research and Development Program of China(2022YFF1102500).
文摘This study investigated the exposure levels of PFASs in crayfish sourced from Hubei Province,assessed the health and safety risks associated with consuming crayfish,and explored the bioaccumulation of PFASs in sediment affecting crayfish.The results showed that 10 types of PFASs were detected in all crayfish samples,with a detection rate of 100%,and the concentration range of ΣPFASs was 0.902.67μg/kg ww,with perfluorooctanoic acid(PFOA)and perfluorododecanoic acid(PFDoDA)being the most abundant compounds.In sediment samples,8 types of PFASs were detected with a 100%detection rate,and perfluorobutyric acid(PFBA)and perfluorooctanesulfonic acid(PFOS)were found to be the most abundant.The hazard index(HI)for PFASs in crayfish was significantly larger than 1,and Monte Carlo simulation results indicated that exposure to PFASs through consumption of the edible portions of crayfish may pose a significant risk to human health.Spearman correlation analysis revealed a significant correlation(p<0.01)between the concentrations of perfluorononanoic acid(PFNA),perfluorobutanesulfonic acid(PFBS),and PFOS in crayfish and their corresponding compounds in sediments.Additionally,the biological-sediment accumulation factor(BSAF)values for PFOA and PFNA exceeded 10,indicating a certain potential for bioaccumulation.
文摘In this article the name of the Handling editor was incorrectly given as Jian-Kui Liu,and should have been Timothy James.In addition,there were 24 Accession numbers in the last column of Table 1 and four in the first paragraph of the second subsection in the Results that incorrectly included two erroneous,extra digits'69';otherwise 23 of the 24 and three of the four of these were correct.
