Invasion Biology - Science topic

I would approach this with logistic regression which I assume is what you did . After encountering your problem, I would guess that you might have rare cases. If so I would suggest Firth regression a modification that deals with this problem. Google Firth regression for full details.

Best wishes David Booth

Hello, Andrea

In Bulgaria, such a practice existed in the period of the 70s and 80s of the last century, when several hard-to-reach glacial lakes were stocked with brown trout (a native species for Bulgaria). These lakes are located at an altitude of over 2000 m (Rila and Pirin mountains, Balkan peninsula), and most of them until then had no natural ichthyofauna. Stocking was also carried out with the non-native species brook trout (Salvelinus fontinalis). Now, these practices (stocking of lakes and import of exotic species) are prohibited, but in these lakes, the fish population is increasing and this leads to acceleration of eutrophication processes in them. Of course, other factors such as pollution from the tourist, global warming, and others also contribute to this. Unfortunately, we are now in the stage of uncontrolled stocking, but now this is happening on more easily accessible sections of rivers and lower lakes.

Best regards,

Eliza

Health care appears to be well represented by both genders. Biological positions are being compromised since the beginning of the ongoing financial crises. I believe this is making it difficult for any new entrants to environment health related jobs, not any gender in particular.

In French Polynesia, to reduce the spread of Wasmannia auropunctata, they ask to clean the construction equipments (excavators, backhoe loaders) when they move to islands free of little fire ants. The dirt and soil you can find on the engines can bring a lot of invertebrates, of course a lot of invasive ants. And check the material such as the wood, to stop the spread of introduced saproxylic beetles.

Non-native species arrive from other continents with trade and internatonal travels. Ornamental trade of plants for planting including fruit trees play an important role in transporting non-native entomofauna. Some examples of such non-native entomofauna are the household Chinese cockroaches, Hemiptera and sap suckers. The hemipterans and the sap suckers colonized fruit trees in China whereas, in Europe, deciduous trees, shrubs and conifers were colonized.

If we are talking about "alien species", it seems clear to me that the "origin" is to be understood in a (bio) geographical sense. European examples are, among others, the Opuntia and Agave (American tropics), the invasive Robinia pseudoacacia (United States and Canada), Ailanthus (SE Asia). The ecological conditions for the survival and expansion of aliens must fall within the ecological potential of the invader

GBIF provides data worldwide https://www.gbif.org/

Look also to previous analogous question's answers

Additional papers have reported the presence of P. vivax in Duffy-negative individuals. See this 2019 publication on "Growing evidence of [the occurrence of] Plasmodium vivax across malaria-endemic Africa".

Can I suggest that you start with the absolutely classic book by Charles Elton. It is entitled 'The Ecology of Invasions by Animals and Plants', published in 1958 by Methuen, London

Hello Ms. Tatia Kuljanishvili,

First of all I would like to congratulate you on conjuring up a simple yet incredibly thought provoking question. But, the frame of mind you had while thinking about the subject as evident from you submission "I don't count most frequent cases like aquaculture, trade or ornamental and unintentional release as well", actually dims the brilliance of the question to a certain extent.

Almost any introduction, whether intentional or accidental, can be traced to one or all the avenues which you did not count. I wrote almost because the exceptions are very rare and negligible or otherwise not provided the attention they require because unless an introduced species is drastically changing the ecosystem for the natives, hardly any efforts are made to decipher their origins or on their control. And more often than naught, the result happens to be one of the issues mentioned above. Mass awareness or education also proved to be obstacles in preventing such spread of new (invasive) species as people wee not diligent enough to scrutinize changes and to associate such changes with their own ignorant activities; and even if they did, they failed to predict the impact anyway.

The Indo-Pacific lion fishes in the Atlantic, Burmese/African python and snake heads into the everglades, the release African honey bees in Brazil, Silver carps in Mississippi, Welsh Catfish in Spain, Pacu fishes in Papua New Guinea, loricarids and African catfish in India etc are all accidental or intentional releases that made the news because they are prominent and unmistakable. The introduction of rats and feral cats to far flung pacific islands and the ensuing devastation of endemic fauna are poignant examples of human ignorance, and have led to catastrophic decline in biodiversity, exemplified by the radical decline in sea bird populations, extinction of tuataras from their native mainlands. But in cases of introduction of plants, people hardly take stock of the situation before the introduced plants bring homogenization to the ecosystem and affects everything else depending on it for better or worse. Most of our crops are cases of accidental or intentional introductions. However, planktonic species are being introduced on a daily basis across the world without anyone getting a whiff of it unless the species survives the change and becomes dominant and starts to restructure the biomass pyramid from the ground up and this is far more important than any other introductions being discussed anywhere since not only it is capable of the change but it actually changes. To study the issue in-depth people need to have a serious understanding of how the earth works and there lies the limitation.

The last aspect of your question is the most important and to my knowledge any introduction of diazotrophs to improve arid land fertility or mass cultivation of biofuel producing plants/diatoms (although controlled but has the potential to be established as escaped species) or even the use of seaweeds or other macroalgae to combat issues of eutrophication of aquifer or wastewater where the species of algae as Nitella or Chara or other macrophytes such as Hydrilla, Egeria, Cabomba etc can all be classified as introduction of species in a targeted area.

I again thank you for such an interesting topic to be discussed.

With warm regards,

Dr. Abhishek Mukherjee

Dear Phil,

You can get a sense of how soil temperature varies with depth when exposed to fire by using the software FOFEM, which is physically based and produces graphs of temperature vs depth. Curious that a few years back I did simulations for Cistus ladanifer.

Ulmus pumila and U. minor hybridize freely, there's lots of literature on this.  Therefore, in any area where both occur there will be many hybrids, and backcrosses of hybrids. Individual elms in such areas will have mixtures of characteristics.  You'll find morphological 'pumila' that nevertheless have these corky 'wings' on twigs,  you'll also find morphological 'minor' that nevertheless have small buds.  These individuals cannot be assigned to any nominate species.  DNA sequencing shows individuals to be complex mixtures (e.g. Biological Invasions 15(12) · December 2013).  Indeed, where hybridization is so frequent, it's an open question whether nominate species like 'minor' or 'pumila' are really phylogentically distinct.  Incidentally, these corky outgrowths are common on U. minor in the areas I know (France, Germany, UK).  

Michael Usher is spot on with that recommendation. Simberloff has some good articles about the general theme of eradications of invasive species.  Here are some articles about this theme that I am fond of.

Thanks!

Did you already search the internet for seed catalogues (= Index seminum) from botanical gardens? A quick search now has resulted in a number of botanical gardens, which distributed Lythrum virgatum during the last years through their seed catalogues:

http://www.botanischer-garten.uni-erlangen.de/pdf/IS-2015-2016.pdf (Erlangen-Nürnberg, Gemany, who have got the plants from HB Paris)

http://www.linz.at/images/Samenliste_Botanischer_Garten_2015.pdf (Linz, Austria)

http://lepo.it.da.ut.ee/~jsild/ebgconsortiumindexseminum2014.pdf (Tartu, Estonia)

http://www.garten.uni-rostock.de/fileadmin/Mathnat_Bio_Garten/Index_Seminum_2015_BG_Rostock.pdf (Rostock, Germany)

http://phavi.umcs.pl/at/attachments/2014/0327/151101-index-seminum.pdf (Lublin, Poland)

http://www.obuam.robia.pl/uploaded4/Index_Seminum_2014_2015.pdf (Poznan, Poland)

http://botanicus.kiev.ua/Index-Seminum/index.pdf (Kyiv, Ukraine)

I suppose most or all of these got the seeds from plants cultivated in their garden.

Best wishes

Franz Starlinger

Arun:

Also have a look at this link for insights:

Best

Syed

I highly suggest you to read this, It may be a classic (made in 1966), but is one of the best papers about invasive species that I know. This paper basically shows how they used an invasive species of moth Cactoblastis cactorum on an invasive species of cactus Opuntia spp in the West Indies.

This paper highlights one of the unique uses of invasive species, which is biological control. When the invasive cactus was spreading in the area, they (the scientists) introduced a moth that fed specifically on those invasive cacti, and when the cacti had been completely eliminated, the moths died out. 

This offers a different perspective and opens new possibilities for your research.

Here is a link :)

Dear Reaearcher,

can read the following article to see if come with some information.

Int J Oncol. Author manuscript; available in PMC 2007 Dec 1.

Published in final edited form as:

Int J Oncol. 2006 Dec; 29(6): 1349–1357.

PMCID: PMC1661847

NIHMSID: NIHMS12617

SPARC-Induced Migration of Glioblastoma Cell Lines via uPA-uPAR Signaling and Activation of Small GTPase RhoA

2.    Suppression of the uPAR–uPA System Retards Angiogenesis, Invasion, and In Vivo Tumor Development in Pancreatic Cancer Cells

Bharathi Gorantla1,

Swapna Asuthkar1,

Jasti S. Rao1,2,

Jitendra Patel3, and

Christopher S. Gondi1

 

3.      Urokinase Plasminogen Activator, uPAR, MMP-2, and MMP-9 in the C6-Glioblastoma Rat Model

PATRICK J. SCHULER1⇓,

MARTIN BENDSZUS2,

SIGLINDE KUEHNEL3,

SVEN WAGNER4,

THOMAS K. HOFFMANN1,

ROLAND GOLDBRUNNER5 and

GILES H. VINCE3

 

J Cell Mol Med. 2008 Jan-Feb;12(1):174-86. doi: 10.1111/j.1582-4934.2008.00220.x. Epub 2007 Jan 9.

In vivo detection of c-Met expression in a rat C6 glioma model.

Towner RA1, Smith N, Doblas S, Tesiram Y, Garteiser P, Saunders D, Cranford R, Silasi-Mansat R, Herlea O, Ivanciu L, Wu D, Lupu F

J Neurochem. 1998 May; 70(5): 1819–1825.

PMCID: PMC2571951

NIHMSID: NIHMS73238

Evidence for κ- and μ-Opioid Receptor Expression in C6 Glioma Cells

Laura M. Bohn, Mariana M. Belcheva, and Carmine J. Coscia

E. A. Doisy Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, St. Louis, Missouri, U.S.A.

Address correspondence and reprint requests to Dr. C. J. Coscia at Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, 1402 South Grand Blvd., St. Louis, MO 63104, U.S.A.

Author information ► Copyright and License information ►

Thanks,

PR Bollam, MD, MSChe

Manolo thank you for your response, That paper spells it out very clearly. 

Many Thanks 

Dear Melissa, Wegmann et al. (2007) recommend to apply bait to the forest canopy, which is not available to crabs, and consumption by rats of bait placed in the forest canopy has been observed. I think land crabs having about the same size of rats occupy the same ecological niche (opportunistic omnivores) and are impossible to exclude from baits applied to the ground. To exclude Birgus, metal tube traps may work. Good luck, Robert

VEHICLES: The issue is not when you get seeds ON YOU  while WITHIN the protected area, but people coming INTO protected areas with weed seeds on their VEHICLES, especially off-road vehicles.   Seeds on vehicles is what is spreading a new weed Saharan mustard across millions of acres of our desert iwthin only a decade., that you can see at http://www.ecoseeds.com/mustards.html

ROAD SIDES. How you manage the road sides at the edges of protected areas, and roads going through protected areas, and trails, railroads edges, and domesticated animal manures?  These alll help spread weeds into protected areas very much faster than any seeds carried in by humans on their clothing or shoes.   Even areas that have been protected 150 years ago like Yellowstone National Park or Yosemite National Park, weeds can travel along roadsides or by cattle in their manures, into those areas very easily. 

INTENTIONALLY SOWN SEEDS. Also intentionally sown exotic seeds, like along roadsides or in nearby agricultural areas, also can be a huge source of weeds.  If you look at my mile-by-mile survey of the western USA that I did in 1997, it was not weeds that were the big problem in most States, but intentionally sown exotic seeds along the roadsides or escapes from nearby exotic-sown pastures, at http://www.ecoseeds.com/megatransect.html. 

UNDERSTORY SPATIALLY EXTINCT OR DAMAGED, SO NOW VULNERABLE.  In 2015 most semi-arid to arid lands across the planet, the native plant understory is spatially extinct or severely damaged, to the degree that bare open spaces create vacancies for any new exotic plant to get established.  

That is how California became the most weedy spot on the planet 150 years ago, the cattle ate every bit of native under story during the 1864-65 drought, causing spatial extinction of the native under story, and the resulting bare land got colonized with close to 100% exotic cover within a few decades.

DO A VEGETATION TRANSECT.  If you have less than 100% local native cover (including native plant thatch) in your vegetation understory, then those areas will be eventually invaded by one or more weeds in the future, as open spaces have been created to let in the new invaders.  

If you do a simplified Evens & Love (1957) Toe-point transect, where you walk 100 paces and each time you step, you note what plant your toe is touching, or you note when you hit bare earth--what percentage is native plants, exotic plants and what percentage is bare earth?  

PERCENTAGE OF VULNERABILITY. The percentage EXOTIC plants s your CURRENT vulnerability percentage and the BARE EARTH is the FUTURE vulnerability percentage of the area, for exotic plant invasion.  

Hope this information is helpful, and hope your land does not end up like California, a 99.999% weed-covered under-story. 

I agree with Julian about bracken, and would add that 'invasive' species would include any which spread onto, or within, habitats where they are not wanted.  In the UK this term is commonly used for various native species including Molinia caerulea and Ulex europaea as well as bracken, and even scrub (often including Betula, Salix, Quercus spp) invading open grassland and heathland can be considered invasive.

To some extent, our concern about these species derives from the semi-natural nature of much of our vegetation.  We value open habitats, like lowland heathland or grassland, but these can only be maintained by management - otherwise they will be 'invaded' by scrub. In the uplands, grazing pressure has led to loss of woodland (and other palatable plants) over large areas - as a result, unpalatable species, which are not used by grazing animals, come to predominate.  These particularly include bracken (as Julian says above), as well as Molinia and gorse.

A note on the terminology - it's quite usual for words to be used differently in different circumstances/ cultures, and in Britain 'invasive' is commonly used for native as well as non-native species.  I have never heard the term 'expansive' used here and, whilst 'weedy' might be used, this is usually for ruderal species (e.g. Epilobium or Digitalis) rather than the invasive ones referred to above.  Non-native problems are distinguished as INNS (Invasive Non-Native Species), although this term has only been in common use for a few years - before that it was 'aliens'.  I'm not sure how much the term matters though - we seem to be agreed that native species can be problematic.

These, for Europe though:

Guys running them may be able to help you.

Cheers

Hello Nelson.

The attached study used an ecologically based control strategy to try to reduce recolonization by an invasive grass after it had been removed by hand and herbicide. We tried to increase competition from native plants by re-establishing native species, in a semi-arid environment. The efforts largely failed, probably due to particularly low rainfall reducing seedling establishment.

Whatever typically limits seedling establishment in your ecosystem, a recommendation is to increase your chances of hitting a good year for establishment by seeding or planting in several years.

Also, watch out for strategies that may actually favour the invasive species or damage established native plants. We found that planting seedlings increased invasive seedling emergence and increased native forb mortality, probably due to the increased soil disturbance that is inevitable when you plant out.

Persistence is important. Best of luck to you.

steve woods

After prevention and early detection and eradication of incipient populations has failed, control is your last and least satisfying option when invasive plants are widespread. Control usually involves reducing impacts at important sites using chemical or manual control methods, for example on farms where the impacts are unacceptable or where there are high biodiversity values. Costs are usually too prohibitive to control the invader wherever it occurs. Biocontrol is the next option and has the potential to reduce the fitness (spread rate or growth rate) wherever the plant occurs. Modern biocontrol research involves extensive testing with coevolved invertebrate browsers or predadors (and sometimes diseases). Success rates in terms of achieving control and no unpredicted unacceptable non-target effects have been very high in the last 20-40 years.  The modern methods e.g. "centrifugal" testing involves testing for non-target effects using  many closely related taxa and fewer more distantly related species. This kind of introduction pales in comparison to the many unintentional introductions of plant pests and diseases that results from international trade, and has the potential to reduce important invader's impacts. An abundance of caution is warranted but I strongly disagree with the general thrust of   assessments of Applegate and Jaroszewicz. Dozens and dozens of agents have contributed controlling effects in multiple jurisdictions. The lessons from other locations can be applied to control where the invasive flora share taxa that already have had research into biocontrol and had good results. It is true that complete control would rarely if ever be achieved using any biocontrol but great improvements can be had in terms of mitigating impacts. One review of success rates from nearly two decades ago for one country that has implemented a lot of programs: Fowler et al Success and safety in the biological control of environmental weeds in New Zealand Austral Ecology 25 553-562

Suckling, D. M., & Sforza, R. F. H. (2014). What magnitude are observed non-target impacts from weed biocontrol?. PloS one, 9(1), e84847 say that " Our analysis shows (as far as is known), weed biological control agents have a biosafety track record of >99% of cases avoiding significant non-target impacts on plant populations."

Clewley, Gary D., et al. "The effectiveness of classical biological control of invasive plants." Journal of Applied Ecology 49.6 (2012): 1287-1295.

Paynter Q, Fowler SV, Gourlay AH, Peterson PG, Smith LA, Winks CJ. 2015. Relative performance on test and target plants in laboratory tests predicts the risk of non-target attack in the field for arthropod weed biocontrol agents. Biological Control 80(0): 133–142. DOI: 10.1016/j.biocontrol.2014.10.007.

Hi,

Our merozoite purification protocol is published in the open access publication "Methods in Malaria Research'  at MR4

See http://www.mr4.org/Publications/MethodsinMalariaResearch.aspx

We also published a detail protocol here:

There is a protocol in the supplementary material

We generally avoid high speed centrifugation

I hope these help

Cheers

James

Oh, yes, getting funds this is the question ;-) And, to be able to devote time in morphology and anatomy...when most devote it to molecular studies...I hope also to narrow the gap between molecular taxonomy and morphological and anatomical taxonomy...at the moment as a long term "hobby" study (considering I'm woriking without funds and depend on the good will of colleagues that will do the molecular part also as a "side" study of other projects). I suggest you to try then with traits relative to the reproductive biology, ontogeny, phenology. Differences in theses aspects are at least a good proxy to establish the existence of  cryptic species complexes in certain gastropods and alllow to separate species when morphologial and anatomical characters are not found (regardeless of whether this is due to the experience and skills of the researcher to find them or of whether they really don't exist).. Best wishes with your Protrura and hopefully in the long run you create your own school of "Proturology". I try to teach  my PhD students internal  anatomy (nervs system, reproductive system, digestive system...), and dissect together with them species to show them the differences so that later they can get data from sources other than DNA. Of course, this is time consuming but it is worth. Regards, Alexandra

Alexandra,

We have published several articles on this topic. We have many of the salmonids, which are native to the Northern Hemisphere in Chile. Below is a link where you can find this material. Feel free to ask for any papers you may be interested and I can send them to you.

Cheers,

Ivan

No, sorry.

hi Belinda,

 video - i know dirk very well and he has loads of films of Dik's actively killing and tearing apart other macroinvertebrates

calum

My troubleshooting questions would be 1) have you coated your membrane with ECM? what type? what is the pore size on the membrane used? how long you left your cells to migrate? have you used a negative control and a positive control. i.e. PDGF to ensure that the experiment actually works? are you sure you did not wipe out the face where the migrating cells are? Have you fixed your cells and stained them before counting?

I have worked with human airway smooth muscle cell (HASMC) migration toward different stimuli, I noticed that cells don't adhere or migrate when I don't coat my membranes ( I usually use 0.01% collagen I rat tail). Sometimes using high concentrations of ECM may hinder the cell migration. Using both negative control (medium alone) and positive control like PDGF-BB (10ng/ml) is essential in each experiment you run. It is advised to use 1 million cells/ml, but in occasions where I had limited number of cells I used less. The results were reproducible as long as I load the same number of cells in each well in a given experiment, since I calculate the fold increase compared to the negative control. For HASMCs migartion, 4-6hrs incubation time using 8-10uM pore size was sufficient to see difference in migration. Most importantly, once you optimize your conditions stick to them for better reproducibility.

I hope this helps.

Good luck,

Laila

Monterey pine (Pinus radiata) currently a rare species with three small California coastal populations and two Mexican island populations. Each population is suffering significant declines from human threats

But it is invasive in the South America and other southern hemisphere regions.

Hello Filip,

part of my research is to determine impact of Robinia pseudoacacia on vegetation and physical-chemical soil characteristics (see Vítková et Kolbek 2010, Phytocoenologia 40:205-241; full text in my profile). Currently, I'm writing an article about black locust adaptability to soil conditions based on my previous research on behavior of black locust in different habitats of the Czech Republic. 15 years ago, I also founded permanent plots on a transect across mesophilous and xerophilous black locust and pine stands to find out seasonal dynamics of chosen soil characteristics (soil moisture, pH, exchangeable cations, ammonium, nitrates, total C, N, extractable phosphorus, net N mineralisation, and nitrification rate) and differences in herb layer composition among plots. I repeated my measurements last year, but I have not evaluated all results yet. During last couple days I started to study decomposition of leaves of alien and native woody species – Robinia pseudoacacia, Quercus rubra, Prunus serotina, Quercus petraea, Fagus sylvatica, and Acer platanoides. I'm planning to collaborate with Microbiological Institute. Dealing with allelopathic potential of black locust would be very useful. I think, only evidences from the laboratory conditions are available (e. g. Nasir et al., 2005).

Such information exists in order to calculate the propagule pressure required to develop a new population. There are the introductions of known numbers of amphipods to Russian and Lithuanian lakes, the introduction of Paralithodes to the Barents sea and striped bass to the Californian coast. AS far as I know no study has been made on such translocations but may be worthwhile.

Hi Jaimie,

I published a study on D. villosus last year for which I had to compile all of its known occurrences in Europe. The map is available in Appendix 1 (Gallardo et al. 2012, Biological Invasions, 14: 1265-1278).

Another version of the map in Appendix B of a one of our publications this year (Gallardo and Aldridge 2013, Ecological Applications 23: 352-364.

I can only send one here, but you can download the others from my profile.

Dear Josè, as far as i know there is not so much info on the invasive status of Casuarina equisetifolia in Europe. C. equisetifolia is planted as ornamental in many Med. countries. The MEPA Guidelines on managing non-native plant invaders and restoring native plant communities in terrestrial settings in the Maltese Islands promotes actions to control C. equisetifolia. You might also try to contact expert from Cyprus and Azores, but I do not know if published literature is already available on that. C. equisetifolia is cited also by Ramon Vallejo in his work(s) on Restoring Mediterranean Forests. Another useful info source is the EPPO site, in the EPPO reporting service and on ISSG on-line data-base. Hope it helps, best wishes, Giuseppe

Hello Jamie,

here is an article that may interest you. It deals with corridors in the Ponto-Caspian region and macroinvetbrates.

Bij de Vaate, A., Jazdzewski, K., Ketelaars, H.A.M., Gollasch, S.,

and der Velde, G. 2002. Geographical patterns in range extension

of Ponto-Caspian macroinvertebrate species in Europe.

Can. J. Fish. Aquat. Sci. 59: 1159–1174.

MacIsaac, H.J., Grigorovich, I.A., and Ricciardi, A. 2001. Reassessment

of species invasions concepts: the Great Lakes basin as

a model. Biol. Invasions, 3: 405–416.

Ricciardi, A., and Rasmussen, J.B. 1998. Predicting the identity

and impact of future biological invaders: a priority for aquatic

resource management. Can. J. Fish. Aquat. Sci. 55: 1759–1765.

Hi Dana:

First of all, i think its important to note that this suggested intervention is not an immediate process, but a gradual but more natural approach to solving this problem, and more importantly is subject to research.

Although i don't have references directly reporting such successes, but i've in times past come across literature on the incidence of hybridization among some fish species (including cichlids) and the inference was that a number of species have conspecifics (ecological neighbors) in nature which are not their species but look like their species and hybridizing with these species result in hybrids which are often sterile.

The good part of hybridization is that it produces offspring which are most times better adapted to the environment than the parent species leading to a natural selection of the hardier breed. This means that with a hardier breed the original species (fertile population) are more likely to be out-survived thus resulting in a reduction in their population.

it is also important to note that in nature conspecifics are unlikely to be avoided by the fertile population especially if the prevalent reproductive cues are visual cues, thus creating a near-equal probability of being mated with.

You could also check the European Alien Species Information Network (http://easin.jrc.ec.europa.eu/). Try the 'combined criteria search' in 'Tools/Services' and select 'Terrestrial' 'Plantae' and 'High Impact'. Apart from the list of high-impact plants (based on DAISIE, NOBANIS, SEBI and CABI) you can also produce distribution maps of one or more species. By pressing the green buttons next to each species you will get relevant information (e.g. links to the factsheets of DAISIS, NOBANIS, CABI.

P.S. Visual inspection for the disease is unreliable. You may look for melanised spots but these are general immune response and are not necessarily associated with infection by A. astaci. Thus, some individuals with melanisation are actually uninfected, and the pathogen DNA may be detected also in animals where macroscopic melanisation is not apparent.