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The Journal of Animal Ecology Dec 2019The role of biotic interactions in shaping the distribution and abundance of species should be particularly pronounced in symbionts. Indeed, symbionts have a dual niche...
The role of biotic interactions in shaping the distribution and abundance of species should be particularly pronounced in symbionts. Indeed, symbionts have a dual niche composed of traits of their individual hosts and the abiotic environment external to the host, and often combine active dispersal at finer scales with host-mediated dispersal at broader scales. The biotic complexity in the determinants of species distribution and abundance should be even more pronounced for hyper symbionts (symbionts of other symbionts). We use a chain of symbiosis to explore the relative influence of nested biotic interactions and the abiotic environment on occupancy and abundance of a hypersymbiont. Our empirical system is the epibiont ciliate Lagenophrys discoidea, which attaches to an ostracod that is itself ectosymbiotic on crayfish (the basal host). We applied multimodel selection and variance partitioning for GLMM to assess the relative importance of (a) traits of symbiotic hosts (ostracod sex and abundance), (b) traits of basal hosts (crayfish body weight, abundance and intermoult stage), (c) the abiotic environment (water chemistry and climate) and (d) geospatial autocorrelation patterns (capturing potential effects of crayfish dispersal among localities). Our models explained about half of the variation in prevalence and abundance of the hypersymbiont. Variation in prevalence was partly explained, in decreasing order of importance (18%-4%) by shared effects of symbiotic host traits and the abiotic environment, pure fixed effects of symbiotic hosts, abiotic environment and geospatial patterns (traits of basal hosts were not relevant). Hypersymbiont abundance was most strongly explained by random effects of host traits (mainly the symbiotic host), in addition to weaker fixed effects (mostly abiotic environment). Our results highlight the major role of the interplay between abundance of symbiotic hosts and water physico-chemistry in regulating populations of a hypersymbiotic ciliate, which is likely critical for dispersal dynamics, availability of attachment resources and suitability of on-host living conditions for the ciliate. We also found moderate signal of regulation by the basal host, for which we propose three mechanisms: (a) modulation of microhabitat suitability (crayfish-created water currents); (b) concentration of symbiotic hosts within crayfish; and (c) dispersal mediated by crayfish.
Topics: Animals; Astacoidea; Symbiosis
PubMed: 31408529
DOI: 10.1111/1365-2656.13091 -
Scientific Reports Nov 2022Diverse communities of groundwater-dwelling organisms (i.e., stygobionts) are important for human wellbeing; however, we lack an understanding of the factors driving...
Diverse communities of groundwater-dwelling organisms (i.e., stygobionts) are important for human wellbeing; however, we lack an understanding of the factors driving their distributions, making it difficult to protect many at-risk species. Therefore, our study objective was to determine the landscape factors related to the occurrence of cavefishes and cave crayfishes in the Ozark Highlands ecoregion, USA. We sampled cavefishes and cave crayfishes at 61 sampling units using both visual and environmental DNA surveys. We then modeled occurrence probability in relation to lithology and human disturbance while accounting for imperfect detection. Our results indicated that occurrence probability of cave crayfishes was negatively associated with human disturbance, whereas there was a weak positive relationship between cavefish occurrence and disturbance. Both cavefishes and cave crayfishes were more likely to occur in limestone rather than dolostone lithology. Our results indicate structuring factors are related to the distribution of these taxa, but with human disturbance as a prevalent modifier of distributions for cave crayfishes. Limiting human alteration near karst features may be warranted to promote the persistence of some stygobionts. Moreover, our results indicate current sampling efforts are inadequate to detect cryptic species; therefore, expanding sampling may be needed to develop effective conservation actions.
Topics: Animals; Humans; Astacoidea; Caves
PubMed: 36379975
DOI: 10.1038/s41598-022-21791-3 -
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 -
Journal of the Experimental Analysis of... May 2022Alcohol abuse remains one of the primary preventable sources of mortality in the United States. Model species can be used to evaluate behavioral and other biological...
Alcohol abuse remains one of the primary preventable sources of mortality in the United States. Model species can be used to evaluate behavioral and other biological changes associated with alcohol and to identify novel treatments. This report describes methods for evaluating the behavioral effects of ethanol (EtOH) in crayfish. Crayfish (Procambarus clarkii) were immersed in ethanol concentrations ranging from 0.1 to 1.0 molar, for 10-30 min. Studies evaluated hemolymph alcohol concentration, locomotion in an open field and anxiety-like behavior using a Light/Dark transfer approach. EtOH immersion produced dose-dependent increases in hemolymph EtOH (up to 249 mg/dL) and reductions in open field locomotion that depended on EtOH concentration or exposure duration. Untreated crayfish exhibit avoidance of the open parts of the locomotor arena and a preference for a covered portion. Acute EtOH immersion decreased time spent in the covered portion of the Light/Dark arena, consistent with a decrease in anxiety-like behavior. Daily EtOH immersion for 5 days did not alter locomotor responses, however, activity was increased 3 days after the repeated EtOH regimen. Overall, this study shows that this inexpensive, easily maintained species can be used for behavioral pharmacological experiments designed to assess the acute and repeated effects of EtOH.
Topics: Animals; Anxiety; Astacoidea; Ethanol; Locomotion
PubMed: 35261037
DOI: 10.1002/jeab.746 -
Diseases of Aquatic Organisms Feb 2022Morphological and molecular analyses were carried out to determine the causative agent of black gill disease in narrow-clawed crayfish Pontastacus leptodactylus...
Morphological and molecular analyses were carried out to determine the causative agent of black gill disease in narrow-clawed crayfish Pontastacus leptodactylus specimens collected from 6 lakes (Taşkısığı, Beyşehir, Karaidemir, Karataş, Manyas, and Gölhisar) in Turkey. Fungi were isolated from the tissues of crayfish displaying putative black gill disease symptoms. Morphological evaluation was conducted, and the isolates were determined to be similar to Fusarium oxysporum. Subsequent molecular cloning of the ITS region of nrDNA by PCR confirmed species identification; DNA sequences from all 6 isolates were 99% similar to those of F. oxysporum. An experimental infection trial was conducted in triplicate using 1 of the 6 isolates to fulfill Koch's postulates. Three groups of crayfish were used: (1) wounded and contaminated (WC), (2) wounded and not contaminated (WNC), and (3) non-wounded and contaminated (NWC). On Day 3, one individual died in the WC group. Throughout the total 74 d monitoring period, no other mortality was recorded. On Day 14, all crayfish in the WC group showed blackened gills, whereas all crayfish in the NWC displayed partial blackening and all crayfish in the WNC group displayed normal gill coloration. F. oxysporum was re-isolated in pure culture from the WC and NWC groups; thus, the disease was confirmed. Our results indicated that F. oxysporum causes black gill disease in P. leptodactylus crayfish. Moreover, we demonstrated that F. oxysporum can also infect non-wounded crayfish.
Topics: Animals; Astacoidea; Fusarium; Gills; Lakes
PubMed: 35142295
DOI: 10.3354/dao03643 -
Food Research International (Ottawa,... Sep 2022The risk of Procambarus clarkii eating safety attracts consumers' big concern, but it has not been addressed properly. Therefore, this study was aimed to investigate...
The risk of Procambarus clarkii eating safety attracts consumers' big concern, but it has not been addressed properly. Therefore, this study was aimed to investigate eating safety and quality of live and dead Procambarus clarkii at different stages by total volatile basic nitrogen (TVB-N), biogenic amines (BAs), total aerobic plate counts (TPC) and microbiota. The results showed that in live Procambarus clarkii, TVB-N and TPC values were below the limit despite vitality, while cadaverine in gills, intestines, and glands (GIG) exceeded in articulo-mortis Procambarus clarkii. For the dead, it showed that Procambarus clarkii posed a high risk in eating safety within one to two days after death; and BAs of high risk were putrescine and cadaverine. The dominant microorganisms threatening eating safety and quality were potentially pathogenic bacteria of Citrobacter and Acinetobacter from the environment; and spoilage bacteria of Shewanella from viscera.
Topics: Animals; Astacoidea; Biogenic Amines; Cadaverine; Fresh Water; Nitrogen; Seafood
PubMed: 35940814
DOI: 10.1016/j.foodres.2022.111630 -
Molecules (Basel, Switzerland) Aug 2022The effects of high hydrostatic pressure (treated with 200, 400 and 600 MPa) and storage temperatures (4 °C and −20 °C) on the fatty acids and flavor compounds of...
The effects of high hydrostatic pressure (treated with 200, 400 and 600 MPa) and storage temperatures (4 °C and −20 °C) on the fatty acids and flavor compounds of red claw crayfish were studied. HHP decreased the PUFA, GMP, IMP and AMP, citric and lactic acids, and PO43− contents, but the FAA, Ca2+ and Cl− contents increased in HHP-treated crayfish compared to untreated crayfish at 0 d. Storage at −20 °C could restrain the fatty acids and flavor contents compared to those stored at 4 °C. The GMP, AMP, citric acid and PO43− contents decreased, and Ca2+ and Cl− contents increased after storage at 4 °C for 15 d (p < 0.05). HHP at 200 and 400 MPa increased EUC on 0 d. No significant changes in EUC were observed after storage at −20 °C for 15 d, significant decreases were noted at 4 °C than the crayfish stored for 0 d (p < 0.05), except for the untreated group. Generally, HHP at 200 or 400 MPa, and storage at −20 °C is beneficial according to the shelling rates and EUC of crayfish.
Topics: Adenosine Monophosphate; Animals; Astacoidea; Fatty Acids; Hydrostatic Pressure; Taste; Temperature
PubMed: 36014342
DOI: 10.3390/molecules27165098 -
Fish & Shellfish Immunology Dec 2022Glycerol monolaurate (GML), one of the medium-chain fatty acid esters, is often used as an emulsifier or preservative. Its biological functions include antibacterial and...
Glycerol monolaurate (GML), one of the medium-chain fatty acid esters, is often used as an emulsifier or preservative. Its biological functions include antibacterial and antiviral activities. In this study, we examined the effects of dietary GML on the resistance of the red claw crayfish to WSSV infection. Crayfish fed with 4 g/kg GML showed higher survival rate and lower WSSV copy numbers than the control after WSSV infection. A RT-qPCR analysis showed that GML supplementation enhanced the expression of immune-related genes, especially JAK and caspase. Our data indicate that GML affects the immune parameters of crayfish, including the total hemocyte counts and phenoloxidase, acid phosphatase, superoxide dismutase, lysozyme, and peroxidase activities. After treatment with GML, the apoptosis of hemocytes increased significantly in both WSSV-infected and uninfected crayfish. In summary, GML reduced the mortality of WSSV-infected crayfish, perhaps by modulating the innate immunity of the crayfish. Our study shows that GML can be used to induce the innate immunity and enhance the immune protection of the red claw crayfish against WSSV infection, either therapeutically or as a preventive measure.
Topics: Animals; White spot syndrome virus 1; Astacoidea; Laurates; Monoglycerides; Immunity, Innate
PubMed: 36400368
DOI: 10.1016/j.fsi.2022.11.014 -
International Journal of Environmental... Dec 2022The aim of the present study was to evaluate the safety parameters, nutritional value and sensory profile of the meat from spiny-cheek crayfish (), captured from the...
The aim of the present study was to evaluate the safety parameters, nutritional value and sensory profile of the meat from spiny-cheek crayfish (), captured from the Danube River in Serbia. To achieve this, we determined their microbiological safety, chemical composition, minerals and heavy metals, fatty acid and amino acid profile, as well as a sensory profile of the meat. The obtained results showed that the meat from crayfish was microbiologically safe. Crayfish meat has a high nutritional quality, high protein content (18.12%) and a total of 17 detected amino acids, of which essential amino acids constituted 6.96 g/100 g sample. Additionally, the crayfish meat was characterized by high levels of essential polyunsaturated fatty acids (PUFA), particularly n-3 PUFA, at an optimal ratio of n-3/n-6 and with low values of atherogenic and thrombogenic indices. Predominant macrominerals in the meat are K, followed by Na, Ca, P and Mg, whereas the content of microminerals was in the following order: Zn > Cu > Fe > Mn. The concentrations of accumulated toxic metals (Cd, Pb, As and Hg) did not exceed the maximum allowed levels. Sensory analysis confirmed that the meat from spiny-cheek crayfish has the potential to become a new food source of essential nutrients.
Topics: Animals; Astacoidea; Meat; Seafood; Fatty Acids; Nutritive Value
PubMed: 36554699
DOI: 10.3390/ijerph192416819 -
Journal of Fish Diseases Mar 2022The freshwater crayfish Procambarus clarkii is native to North America and Mexico, and it was introduced to China in 1929. The production and consumption of P. clarkii...
The freshwater crayfish Procambarus clarkii is native to North America and Mexico, and it was introduced to China in 1929. The production and consumption of P. clarkii in China are the highest worldwide, reaching 208.96 million tons in 2020. The white spot syndrome virus (WSSV) is a major pathogen that affects shrimp, crayfish, crabs and lobsters, and it has caused widespread loss to the P. clarkii industry. Epigallocatechin-3-gallate (EGCG), a small-molecule compound, has a multitude of biological functions and the ability to bind to the 37 kDa/67 kDa laminin receptor (LamR). EGCG has potential antiviral effects against WSSV. In this study, we evaluated the potential anti-WSSV applications of EGCG in P. clarkii. We demonstrated that various concentrations (10 μg/g·bw, 20 μg/g·bw and 40 μg/g·bw) of EGCG can suppress WSSV infection in P. clarkii. Histopathological examination revealed no characteristic pathological changes due to EGCG administration in P. clarkii tissues. Furthermore, pharmacokinetics studies of EGCG in P. clarkii revealed its rapid absorption (T = 2 h), and the peak concentrations of EGCG were 73.78 µg/g in the liver and 24.87 µg/g in the muscle. Our results indicate the high potential applications of EGCG against WSSV in P. clarkii.
Topics: Animals; Astacoidea; Catechin; Fresh Water; Virus Replication; White spot syndrome virus 1
PubMed: 34927260
DOI: 10.1111/jfd.13573