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International Journal of Environmental... Mar 2023Rice-aquatic animal integrated systems can alleviate food and environmental insecurity. Understanding how this practice is adopted by farmers is significant for...
Rice-aquatic animal integrated systems can alleviate food and environmental insecurity. Understanding how this practice is adopted by farmers is significant for promoting the development of the agricultural industry. Given the information inadequacy and information frictions in agricultural society in China, farmers are susceptible to the behaviors of their neighbors through social interaction. This paper defines neighboring groups that are both spatially and socially connected to identify whether neighbors influence farmers' adoption of rice-crayfish integrated systems using a sample in the lower and middle reaches of the Yangtze River in China. The findings reveal that for every one-unit increase in neighbors' adoption behavior, the probability of farmers' adoption increases by 0.367 units. Therefore, our results may have great value for policymakers seeking to take advantage of the neighborhood effect to complement formal extension systems and promote the developments of China's ecological agriculture.
Topics: Animals; Humans; Oryza; Astacoidea; Farmers; Rivers; Agriculture; Seafood; China
PubMed: 36901408
DOI: 10.3390/ijerph20054399 -
Ecotoxicology and Environmental Safety Apr 2023Ammonia, as one of the primary water pollutants in aquaculture, has been shown to induce a wide range of ecotoxicological effects on aquatic animals. In order to...
Ammonia, as one of the primary water pollutants in aquaculture, has been shown to induce a wide range of ecotoxicological effects on aquatic animals. In order to investigate the antioxidant and innate immune responses in crustaceans disrupted by ammonia, red swamp crayfish (Procambarus clarkii) were exposed to 0, 15, 30, and 50 mg/L total ammonia nitrogen for 30 d, the alterations of antioxidant responses as well as innate immunity were studied. The results showed that the severity of hepatopancreatic injury were aggravated by the increasing ammonia levels, which were mainly characterized by tubule lumen dilatation and vacuolization. The swollen mitochondria and disappeared mitochondria ridges suggested that oxidative stress induced by ammonia targets the mitochondria. Concurrently, enhanced MDA levels, and decreased GSH levels as well as the decreased transcription and activity of antioxidant enzymes, including SOD, CAT, and GPx were noticed, which suggested that high concentrations of ammonia exposure induce oxidative stress in P. clarkii. Furthermore, a significant decrease of the hemolymph ACP, AKP, and PO along with the significant downregulation of immune-related genes (ppo, hsp70, hsp90, alf1, ctl) jointly indicated that ammonia stress inhibited the innate immune function. Our findings demonstrated that sub-chronic ammonia stress induced hepatopancreatic injury and exert suppressive effects on the antioxidant capacity as well as innate immunity of P. clarkii. Our results provide a fundamental basis for the deleterious effects of ammonia stress on aquatic crustaceans.
Topics: Animals; Antioxidants; Astacoidea; Ammonia; Oxidative Stress; Immunity, Innate
PubMed: 36871356
DOI: 10.1016/j.ecoenv.2023.114724 -
Scientific Reports Mar 2023Using stable carbon and nitrogen isotope analysis (δC and δN) to assess trophic interactions in freshwater ecosystems is a well established method, providing insight...
Using stable carbon and nitrogen isotope analysis (δC and δN) to assess trophic interactions in freshwater ecosystems is a well established method, providing insight into ecosystem functioning. However, the spatial and temporal variability of isotope values, driven by environmental fluctuation is poorly understood and can complicate interpretations. We investigated how the temporal variation of stable isotopes in consumers (fish, crayfish and macrozoobenthos) of a canyon-shaped oligotrophic reservoir is associated with environmental factors such as water temperature, transparency, flooded area, and water quality measures. Consumers and their putative food sources were sampled and analyzed for carbon and nitrogen stable isotopes annually, and environmental parameters were measured monthly from 2014 to 2016. Results revealed significant differences in δC and δN values in each consumer among studied years. Over the years, fish and crayfish expressed differences in δC between 3 and 5‰, whereas in zoobenthos differences were 12‰. Variability in δN was similar across all consumers (2-4‰). Moreover, results suggest that the flooded area of the reservoir was a major driver of δC stable isotope values variation in consumers, while variation in δN was not linked to any of the studied environmental factors. Bayesian mixing models further showed significant changes in the origin of detritivorous zoobenthos carbon sources (reversal shift from terrestrial detritus to algae origin) between years with low water level to years with the standard water level. Other species showed only slight differences in food source utilization among years. Our study highlights the importance of environmental factors as sources of variation in consumer's stable isotope values which should be considered especially when studied ecosystem strongly fluctuate in some environmental factor.
Topics: Animals; Bayes Theorem; Ecosystem; Astacoidea; Carbon; Nitrogen Isotopes; Seafood
PubMed: 36871020
DOI: 10.1038/s41598-023-30849-9 -
PeerJ 2023Primary burrowing crayfishes face high extinction risk, but are challenging to study, manage, and conserve due to their difficult-to-sample habitat (, terrestrial...
Primary burrowing crayfishes face high extinction risk, but are challenging to study, manage, and conserve due to their difficult-to-sample habitat (, terrestrial burrows) and low population densities. We apply here a variety of methods to characterize the distribution, habitat associations, and conservation status of the Boston Mountains Crayfish (Reimer, 1966), an endemic burrowing crayfish found only in the Ozark Mountains of Arkansas, United States. We used species distribution modeling (SDM) on historic occurrence records to characterize the distribution and macro-scale habitat associations of this species. We then ground-truthed SDM predictions with conventional sampling, modeled fine-scale habitat associations with generalized linear models (GLM), and lastly developed and tested an environmental DNA (eDNA) assay for this species in comparison to conventional sampling. This represents, to our knowledge, the first successful eDNA assay for a terrestrial burrowing crayfish. Our MaxEnt-derived SDM found a strong effect of average annual precipitation on the historic distribution of , which occurred most frequently at locations with moderately high average annual precipitation (140-150 cm/yr) within our study region. was difficult to detect by conventional sampling in 2019 and 2020, found at only 9 of 51 sites (17.6%) sampled by searching for and manually excavating crayfish burrows. Surprisingly, habitat suitability predicted from our MaxEnt models was not associated with contemporary occurrences per GLMs. Instead, presence was negatively associated with both sandy soils and the presence of other burrowing crayfish species. Poor SDM performance in this instance was likely caused by the omission of high resolution fine-scale habitat data (, soils) and biotic interactions from MaxEnt models. Finally, our eDNA assay detected from six of 25 sites (24.0%) sampled in 2020, out-performing conventional surveys by burrow excavation for this species. Given the difficulty of studying primary burrowing crayfishes and their high conservation need, we propose that eDNA may become an increasingly important monitoring tool for and similar species.
Topics: Animals; Astacoidea; Ecosystem; Soil; Sand; North America
PubMed: 36846445
DOI: 10.7717/peerj.14748 -
International Journal of Molecular... Feb 2023The Australian red claw crayfish , an emerging species within the freshwater aquaculture trade, is not only an ideal species for commercial production due to its high...
The Australian red claw crayfish , an emerging species within the freshwater aquaculture trade, is not only an ideal species for commercial production due to its high fecundity, fast growth, and physiological robustness but also notoriously invasive. Investigating the reproductive axis of this species has been of great interest to farmers, geneticists, and conservationists alike for many decades; however, aside from the characterisation of the key masculinising insulin-like androgenic gland hormone (IAG) produced by the male-specific androgenic gland (AG), little remains known about this system and the downstream signalling cascade involved. This investigation used RNA interference to silence in adult intersex (), known to be functionally male but genotypically female, successfully inducing sexual redifferentiation in all individuals. To investigate the downstream effects of knockdown, a comprehensive transcriptomic library was constructed, comprised of three tissues within the male reproductive axis. Several factors known to be involved in the IAG signal transduction pathway, including a receptor, binding factor, and additional insulin-like peptide, were found to not be differentially expressed in response to silencing, suggesting that the phenotypic changes observed may have occurred through post-transcriptional modifications. Many downstream factors displayed differential expression on a transcriptomic level, most notably related to stress, cell repair, apoptosis, and cell proliferation. These results suggest that IAG is required for sperm maturation, with necrosis of arrested tissue occurring in its absence. These results and the construction of a transcriptomic library for this species will inform future research involving reproductive pathways as well as biotechnological developments in this commercially and ecologically significant species.
Topics: Humans; Animals; Male; Female; Astacoidea; Transcriptome; Semen; Australia; Insulin
PubMed: 36834703
DOI: 10.3390/ijms24043292 -
Genes Feb 2023(Eschscholtz, 1823) (Decapoda:Astacidea:Astacidae) constitutes an ecologically and economically highly important species. In the present study, the mitochondrial genome...
(Eschscholtz, 1823) (Decapoda:Astacidea:Astacidae) constitutes an ecologically and economically highly important species. In the present study, the mitochondrial genome of the freshwater crayfish from Greece is analyzed for the first time, using 15 newly designed primer pairs based on available sequences of closely related species. The analyzed coding part of the mitochondrial genome of consists of 15,050 base pairs including 13 protein-coding genes (PCGs), 2 ribosomal RNA gene (rRNAs), and 22 transfer RNA genes (tRNAs). These newly designed primers may be particularly useful in future studies for analyzing different mitochondrial DNA segments. Based on the entire mitochondrial genome sequence, compared to other haplotypes from related species belonging in the same family (Astacidae) available in the GenBank database, a phylogenetic tree was constructed depicting the phylogenetic relationships of . Based on the results, the genetic distance between and is smaller than the genetic distance between and , despite the fact that the latter two are classified within the same genus, questioning the phylogenetic position of as a different genus than . In addition, the sample from Greece seems genetically distant compared with a conspecific haplotype available in the GenBank database, possibly implying a genetic distinction of from Greece.
Topics: Animals; Astacoidea; Greece; Lakes; Genome, Mitochondrial; Phylogeny; Decapoda
PubMed: 36833421
DOI: 10.3390/genes14020494 -
Environmental Science and Pollution... Apr 2023Although pesticides are often discharged into surface waters in pulses as opposed to a sustained release, the effect of episodic pollution events on freshwater crayfish...
Although pesticides are often discharged into surface waters in pulses as opposed to a sustained release, the effect of episodic pollution events on freshwater crayfish is largely unknown. We monitored change in heart rate and distance moved to assess the response of signal crayfish Pacifastacus leniusculus to short-term exposure to environmentally relevant concentrations of metazachlor (MTZ), terbuthylazine (TER), and thiacloprid (TCL). Crayfish exposed to 20 µg/L of MTZ exhibited a significant increase in mean heart rate and distance moved. Increased heart rate was detected at 118 ± 74 s post-exposure to MTZ. There were no significant differences in mean heart rate and distance moved in crayfish exposed to 6 µg/L of TCL and 4 µg/L of TER. A significant correlation between heart rate and distance moved was found in all exposed groups. These results suggest that pulse exposure to MTZ impact crayfish physiology and behavior during short-term period. With pulse exposure to TCL and TER, crayfish not exhibiting a locomotor response may continue to be exposed to lower, but potentially harmful, levels of pollutants. Evidence of the impacts of pesticide pulse at environmentally relevant concentrations on crayfish is scarce. Further study is required to determine the ecological effects of such events on freshwater crayfish.
Topics: Animals; Pesticides; Astacoidea; Heart Rate; Water Pollutants, Chemical
PubMed: 36820980
DOI: 10.1007/s11356-023-25908-7 -
Gaceta Sanitaria 2023To find out whether the leptospirosis incidence rate among red swamp crayfish collectors in the harvesting season is higher than in the general population, and to...
OBJECTIVE
To find out whether the leptospirosis incidence rate among red swamp crayfish collectors in the harvesting season is higher than in the general population, and to identify risk factors and assess the direct and indirect health costs associated with leptospirosis seroconversion.
METHOD
This study was carried out between 1 July 2017 and 31 March 2018 in the municipality of Isla Mayor (Seville, Spain). It took the form of a prospective cohort study (exposed population: swamp crayfish collectors; non-exposed population: general population). The population was invited to take part in a prevalence study to be conducted using the ELISA qualitative technique, and informed consent was obtained from those who agreed. Negative serology cases were then included in the cohort study. Both cohorts were monitored clinically and symptomatic cases were serology tested. A second serum sample was taken from the swamp crayfish collectors at the end of the monitoring period to detect asymptomatic cases. Serovars were confirmed by microscopic agglutination testing. A bivariate descriptive analysis was carried out and cumulative incidence and relative risk were calculated, with positive serology being taken as the dependent variable.
RESULTS
A total of 278 people were included in the study, of whom 92 made up the swamp crayfish collectors cohort and 186 the general population cohort. Women made up 46.8% of the sample, but only 29.3% of the collectors cohort. The mean age was 45.1 (±16.4) years. Nine cases of seroconversion were detected: eight among swamp crayfish collectors and one in the general population. Overall cumulative incidence was therefore 3.2%: 8.7% in the exposed group and 0.5% in the non-exposed group. Relative risk was 16.2% (95% confidence interval: 2.1-127.4). The total cost of medical assistance and illness-related losses associated with leptospirosis was 1568€/case.
CONCLUSIONS
Leptospirosis in Isla Mayor is strongly associated with red swamp crayfish collecting. It's incidence here is much higher than that reported in studies published in other countries.
Topics: Animals; Humans; Female; Middle Aged; Male; Spain; Cohort Studies; Prospective Studies; Wetlands; Leptospirosis; Astacoidea
PubMed: 36804781
DOI: 10.1016/j.gaceta.2023.102288 -
International Journal of Environmental... Jan 2023Rice-duck and rice-crayfish co-culture patterns can increase soil productivity and sustainability and reduce the use of chemical pesticides and fertilizers, thereby...
Initial Studies on the Effect of the Rice-Duck-Crayfish Ecological Co-Culture System on Physical, Chemical, and Microbiological Properties of Soils: A Field Case Study in Chaohu Lake Basin, Southeast China.
Rice-duck and rice-crayfish co-culture patterns can increase soil productivity and sustainability and reduce the use of chemical pesticides and fertilizers, thereby reducing the resulting negative environmental impacts. However, most studies have focused on the rice-duck and rice-crayfish binary patterns and have ignored integrated systems (three or more), which may have unexpected synergistic effects. To test these effects, a paddy field experiment was carried out in the Chaohu Lake Basin, Hefei city, Southeast China. Four groups, including a rice-duck-crayfish ecological co-culture system (RDC), idle field (CK), single-season rice planting system (SSR), and double-season rice planting system (DSR), were established in this study. The results showed that the RDC improved the soil physical properties, fertility, humus content, and enzyme activity. In the RDC system, the soil total nitrogen content ranged from 8.54% to 28.37% higher than other systems in the 0-10 cm soil layer. Similar increases were found for soil total phosphorus (8.22-30.53%), available nitrogen (6.93-22.72%), organic matter (18.24-41.54%), urease activity (16.67-71.51%), and acid phosphatase activity (23.41-66.20%). Relative to the SSR treatment, the RDC treatment reduced the total losses of nitrogen and phosphorus runoff by 24.30% and 10.29%, respectively. The RDC also did not cause any harm to the soil in terms of heavy metal pollution. Furthermore, the RDC improved the yield and quality of rice, farmer incomes, and eco-environmental profits. In general, the RDC can serve as a valuable method for the management of agricultural nonpoint-source pollution in the Chaohu Lake area and the revitalization of the countryside.
Topics: Animals; Soil; Ducks; Astacoidea; Coculture Techniques; Oryza; Agriculture; Phosphorus; China; Fertilizers; Nitrogen
PubMed: 36767373
DOI: 10.3390/ijerph20032006 -
Frontiers in Immunology 2023In invertebrates, hemocytes are the key factors in innate immunity. However, the types of invertebrate immune hemocytes are unclassified due to the limitation of...
In invertebrates, hemocytes are the key factors in innate immunity. However, the types of invertebrate immune hemocytes are unclassified due to the limitation of morphological classification. To determine the immune hemocytes of crustaceans, the heterogeneity of hemocytes of shrimp and crayfish , two representative crustacean species, were characterized in this study. The results of single-cell RNA sequencing indicated that shrimp and crayfish contained 11 and 12 types of hemocytes, respectively. Each of different types of hemocytes specifically expressed the potential marker genes. Based on the responses of shrimp and crayfish to the infection of white spot syndrome virus (WSSV) and the challenge of lipopolysaccharide (LPS), four types of immune hemocytes of crustaceans were classified, including semi-granular hemocytes involved in antimicrobial peptide production, granular hemocytes responsible for the production of antimicrobial peptides, hemocytes related to cell proliferation and hemocytes in immunity-activated state. Therefore, our study provided the first classification of crustacean hemocytes as well as of immune hemocytes of crustaceans at the single-cell resolution, which would be helpful to understand the innate immunity of invertebrates.
Topics: Animals; Hemocytes; Immunity, Innate; Astacoidea; White spot syndrome virus 1; Penaeidae
PubMed: 36761772
DOI: 10.3389/fimmu.2023.1121528