Publications

fusarium avenaceum causes burn spot disease syndrome in noble crayfish (astacus astacus).	burn spot disease has been causing epidemics both in the estonian mainland and in saaremaa island in the threatened noble crayfish (astacus astacus) stocks. to study the cause of the disease, we isolated several fusarium spp. from estonian noble crayfish (a. astacus) populations suffering from burn spot disease syndrome. we first identified fungi directly from melanised cuticle by their its sequences. then we isolated fusarium spp. from melanised spots of crayfish showing burn spot disease sympt ...	2013	23557716
effects of climate change, invasive species, and disease on the distribution of native european crayfishes.	climate change will require species to adapt to new conditions or follow preferred climates to higher latitudes or elevations, but many dispersal-limited freshwater species may be unable to move due to barriers imposed by watershed boundaries. in addition, invasive nonnative species may expand into new regions under future climate conditions and contribute to the decline of native species. we evaluated future distributions for the threatened european crayfish fauna in response to climate change, ...	2013	23531056
comparative ultrastructure of the spermatozoa of three crayfish species: austropotamobius torrentium, pacifastacus leniusculus, and astacus astacus (decapoda: astacidae).	this study reports about the spermatozoal ultrastructure of three species of astacid crayfish, i.e., the stone crayfish austropotamobius torrentium, signal crayfish pacifastacus leniusculus, and noble crayfish astacus astacus. the acrosome is a cup shaped and electron-dense structure at the anterior of the spermatozoon and comprises three layers of differing electron densities filled with parallel filaments that extend from the base to the apical zone. the acrosome was significantly longer in a. ...	2013	23475696
temporal dynamics of spore release of the crayfish plague pathogen from its natural host, american spiny-cheek crayfish (orconectes limosus), evaluated by transmission experiments.	the crayfish plague pathogen, aphanomyces astaci, is one of the most serious threats to indigenous european crayfish species. the north american invasive spiny-cheek crayfish, orconectes limosus, is an important source of this pathogen in central and western europe. we evaluated potential changes in a. astaci spore release rate from infected individuals of this species by experiments investigating the pathogen transmission to susceptible noble crayfish, astacus astacus. we filtered defined volum ...	2013	23425502
timing and quantifying aphanomyces astaci sporulation from the noble crayfish suffering from the crayfish plague.	aphanomyces astaci sporulation is crucial for the spreading potential of this disease agent. for the first time, we are reporting timing and quantity of a. astaci spores released from noble crayfish (astacus astacus) suffering from crayfish plague under practical aquatic conditions. we infected nine noble crayfish with a. astaci psi-genotype and maintained them in individual 8l tanks. spores (zoospores and cysts) were quantified from water samples (3 × 1 ml) taken every 12h over 10 d using a. as ...	2013	23102971
lunar-rhythmic molting in laboratory populations of the noble crayfish astacus astacus (crustacea, astacidea): an experimental analysis.	juvenile noble crayfish, astacusastacus (crustacea, astacidea) in the second year of age were kept in the laboratory for a twelve-month period under continuing "summer conditions" (ld 16:8, 19°c). molting processes in this population could be synchronized by artificial moonlight cycles. peaks of exuviations occurred at "new moons". males showed a slightly higher degree of synchronization than females. a phase-shift of the artificial lunar cycle in relation to the natural cycle resulted in a corr ...	2013	23840899
distribution and epidemiology of genotypes of the crayfish plague agent aphanomyces astaci from noble crayfish astacus astacus in finland.	the crayfish plague agent aphanomyces astaci was isolated from 69 noble crayfish astacus astacus samples in finland between 1996 and 2006. all isolates were genotyped using randomly amplified polymorphic dna-polymerase chain reaction (rapd-pcr). altogether, 43 isolates belonged to the genotype group of astacus strains (as), which is assumed to represent the genotype originally introduced into europe around 1860 and into finland in 1893. there were 26 crayfish plague isolates belonging to the gro ...	2013	23574706
aphanomyces astaci in wild crayfish populations in slovenia: first report of persistent infection in a stone crayfish austropotamobius torrentium population.	all 5 crayfish species inhabiting slovenian freshwaters, of which 3 are indigenous crayfish species (ics: astacus astacus, austropotamobius pallipes, and a. torrentium) and 2 are non-indigenous (nics: pacifastacus leniusculus and cherax quadricarinatus), were inspected for the presence of aphanomyces astaci, the causative agent of crayfish plague. wild crayfish populations showing no clinical signs of infection were inspected using a. astaci-specific real-time pcr. in addition, a conventional pc ...	2013	23548366
lc-ms analysis with thiol derivatization to differentiate [dhb(7)]- from [mdha(7)]-microcystins: analysis of cyanobacterial blooms, planktothrix cultures and european crayfish from lake steinsfjorden, norway.	kinetic studies showed that [asp(3), dhb(7)]mc-rr reacted with mercaptoethanol hundreds of times more slowly than mc-rr and a range of other [mdha(7)]-containing microcystin congeners. the difference in reaction rate was sufficiently large that derivatization of microcystin-containing samples with mercaptoethanol, followed by lc-ms analysis, clearly discriminated between microcystins containing the isobaric [dhb(7)]- and [mdha(7)]-groups. application of this approach, using lc-ms with both-ion t ...	2013	23531156
[neutrophin ngf protects glial cells, but not stretch receptor neurons of the crayfish astacus astacus from photooxidative stress].		2014	18038644
recovery of hafnia alvei from diseased brown trout, salmo trutta l., and healthy noble crayfish, astacus astacus (l.), in bulgaria.	hafnia alvei was isolated in bulgaria from healthy noble crayfish, astacus astacus (l.), and then from farmed diseased brown trout, salmo trutta l., with signs of haemorrhagic septicaemia. the isolates were identified initially with conventional phenotyping and commercial merlin micronaut and api 20e rapid identification systems, followed by sequencing of the 16s rrna gene. hafnia alvei bt1, bt2 and aa4 were of low virulence to rainbow trout and brown trout, although cytotoxicity was demonstrate ...	2014	24422558
molecular detection and genotyping of aphanomyces astaci directly from preserved crayfish samples uncovers the norwegian crayfish plague disease history.	aphanomyces astaci causes crayfish plague in european freshwater crayfish, but most historical epizootics lack agent isolation and identification. although declared as crayfish plague outbreaks by the norwegian competent authorities, only presumptive diagnoses without agent isolation exist from norwegian epizootics until 2005. molecular methods now allow both a. astaci detection and genotype determination from preserved samples. we therefore aimed to (1) investigate molecularly if a. astaci was ...	2014	25124447
resistance to the crayfish plague pathogen, aphanomyces astaci, in two freshwater shrimps.	aphanomyces astaci, the causal agent of the crayfish plague, has recently been confirmed to infect also freshwater-inhabiting crabs. we experimentally tested the resistance of freshwater shrimps, another important decapod group inhabiting freshwaters, to this pathogen. we exposed individuals of two asian shrimp species, macrobrachium dayanum and neocaridina davidi, to zoospores of the pathogen strain isolated from procambarus clarkii, a known a. astaci carrier likely to get into contact with shr ...	2014	25064254
dose-dependent mortality of the noble crayfish (astacus astacus) to different strains of the crayfish plague (aphanomyces astaci).	several reports of the european crayfish species carrying a latent infection of the crayfish plague (aphanomyces astaci) have emerged and the discussion has focused especially on the lowered virulence of as-genotypes behind decreased mortality. the aim of this study was to compare the killing rate of different a. astaci strains in controlled infection experiments. two separate infection experiments with three a. astaci strains (ueft2b (as), evira6462/06 (as) and uef8866-2 (psi)) were made to com ...	2014	24184185
ultrastructure of egg activation and cortical reaction in the noble crayfish astacus astacus.	morphological changes in the gamete of female noble crayfish at four developmental stages were studied. mature ovarian oocytes are enclosed by the first envelope that consists of two layers. numerous pores are visible on the surface of the outer layer of this envelope and the inner layer contains bottlebrush-shaped objects. three types of vesicles, including some that are highly and moderately electron-dense and some multi-layered, occur in the cortex of the oocyte. in freshly ovulated eggs, the ...	2015	25464149
label-free protein quantification in freshly ejaculated versus post-mating spermatophores of the noble crayfish astacus astacus.	crayfish spermatophores are deposited on the body surface of the female during mating and remain there for a period of time before fertilization ensues. post-mating changes in protein expression level in the noble crayfish astacus astacus spermatophore were quantified. in-gel digestion and high resolution mass spectrometry were used for label-free protein quantification. one hundred twelve proteins were identified in the spermatophore of noble crayfish. after 7 days of storage on the body of the ...	2015	25871631
some like it hot: thermal tolerance and oxygen supply capacity in two eurythermal crustaceans.	thermal sensitivity of the cardiorespiratory oxygen supply capacity has been proposed as the cardinal link underlying the upper boundary of the temperature niche in aquatic ectotherms. here we examined the evidence for this link in two eurythermal decapods, the giant tiger shrimp (penaeus monodon) and the european crayfish (astacus astacus). we found that both species have a temperature resistant cardiorespiratory system, capable of maintaining oxygen delivery up to their upper critical temperat ...	2015	26030412
effect of experimental exposure to differently virulent aphanomyces astaci strains on the immune response of the noble crayfish astacus astacus.	european crayfish are sensitive to the crayfish plague pathogen, aphanomyces astaci, carried by north american crayfish species due to their less effective immune defence mechanisms against this disease. during a controlled infection experiment with a susceptible crayfish species astacus astacus using three a. astaci strains (representing genotype groups a, b, and e), we investigated variation in their virulence and in crayfish immune defence indicators (haemocyte density, phenoloxidase activity ...	2015	26410255
founder event and its effect on genetic variation in translocated populations of noble crayfish (astacus astacus).	establishing translocated populations is a common process to preserve and maintain genetic diversity of threatened species. in 2001, three translocated populations of noble crayfish (astacus astacus) were established in the czech republic, founded by either adult or juvenile individuals from three particular source populations. we assessed genetic diversity at seven microsatellite loci after one decade (assumed three generations) from establishment. although the translocated populations exhibite ...	2016	26077200
prevalence of the pathogen aphanomyces astaci in freshwater crayfish populations in croatia.	the oomycete aphanomyces astaci is an obligate crayfish parasite that co-evolved with american crayfish species, and they therefore generally live in a balanced relationship. on the contrary, european native crayfish are highly susceptible to a. astaci, and infestation with it causes development of the lethal disease termed crayfish plague. until now, 5 a. astaci strains have been described from the freshwater crayfish present in europe. in this study we aimed to investigate the occurrence of th ...	2016	26865234
subcellular localization of calcium deposits in the noble crayfish astacus astacus spermatophore: implications for post-mating spermatophore hardening and spermatozoon maturation.	the freshly ejaculated spermatophore of crayfish undergoes a hardening process during post-mating storage on the body surface of female. the ultrastructural distribution of calcium deposits were studied and compared in freshly ejaculated and post-mating noble crayfish spermatophores, using the oxalate-pyroantimonate technique, to determine possible roles of calcium in post-mating spermatophore hardening and spermatozoon maturation. small particles of sparsely distributed calcium deposits were vi ...	2016	26817519
high-resolution structural and elemental analyses of calcium storage structures synthesized by the noble crayfish astacus astacus.	during premolt, crayfish develop deposits of calcium ions, called gastroliths, in their stomach wall. the stored calcium is used for the calcification of parts of the skeleton regularly renewed for allowing growth. structural and molecular analyses of gastroliths have been primarily performed on three crayfish species, orconectes virilis, procambarus clarkii, and more recently, cherax quadricarinatus. we have performed high-resolution analyses of gastroliths from the native noble crayfish, astac ...	2016	27612582
the significance of droughts for hyporheic dwellers: evidence from freshwater crayfish.	freshwater biodiversity is globally threatened by various factors while severe weather events like long-term droughts may be substantially devastating. in order to remain in contact with the water or stay in a sufficiently humid environment at drying localities, the ability to withstand desiccation by dwelling in the hyporheic zone, particularly through vertical burrowing is crucial. we assessed the ability of three european native and five non-native crayfish as models to survive and construct ...	2016	27225308
de novo assembly and annotation of the freshwater crayfish astacus astacus transcriptome.	we generated rna-seq data to assemble the transcriptome of the noble crayfish (astacus astacus) from four combined tissues (abdominal muscle, hepatopancreas, ovaries, green glands). a total of 194 million read pairs with a length of 100 bp were generated. the transcriptome was assembled de novo using trinity software, producing 158,649 non-redundant transcripts. lowly expressed transcripts were filtered out leaving 45,415 transcripts of which 14,559 were found to contain open reading frames with ...	2016	26988698
toxic and heavy metals as a cause of crayfish mass mortality from acidified headwater streams.	mining activities are responsible for high concentrations of metals in river networks in many parts of the world. mining activities and the resulting high loads of heavy metals interact with intensive acid rain, and often have great consequences for biodiversity. however, considering the frequently episodic nature of these heavy acid rains, there is little detailed evidence of direct impacts. in 2011 we observed a massive mortality of noble crayfish and stone crayfish in padrťsko special area of ...	2017	28108890
aphanomyces astaci isolate from latently infected stone crayfish (austropotamobius torrentium) population is virulent.	aphanomyces astaci infection is the cause of crayfish plague in european crayfish. here the virulence of an a. astaci as strain isolated from apparently healthy stone crayfish (austropotamobius torrentium) from slovenia was compared to that of the psl-puujärvi a. astaci isolate in 3 crayfish species: noble crayfish (astacus astacus), signal crayfish (pacifastacus leniusculus) from finland and stone crayfish from slovenia. all 3 crayfish species were challenged with psi-puujärvi a. astaci and suc ...	2017	28716442
monitoring of noble, signal and narrow-clawed crayfish using environmental dna from freshwater samples.	for several hundred years freshwater crayfish (crustacea-decapoda-astacidea) have played an important ecological, cultural and culinary role in scandinavia. however, many native populations of noble crayfish astacus astacus have faced major declines during the last century, largely resulting from human assisted expansion of non-indigenous signal crayfish pacifastacus leniusculus that carry and transmit the crayfish plague pathogen. in denmark, also the non-indigenous narrow-clawed crayfish astac ...	2017	28654642