Diseases of Freshwater Crayfish |
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Scientists have been interested in disease conditions in freshwater crayfish for at least 150 years. Scientific interest was stimulated in the mid 1800s when it was noticed that freshwater crayfish were disappearing from regions in Europe and that the "crayfish plague" seemed to be spreading. In the early 1900s it was shown that crayfish plague is caused by the fungus Aphanomyces astaci and it is now one of the best studied of invertebrate diseases. |
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This early and ongoing interest in disease conditions in freshwater crayfish has meant that, compared to many other invertebrates, scientists have gathered a considerable amount of information on the subject. Pathogens or potential pathogens known to affect freshwater crayfish include: |
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Several non-infectious diseases and diseases of unknown aetiology (cause) have also been reported. |
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Furthermore, freshwater crayfish have been used as a model for much of the work done on crustacean immunology. |
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Given the significance of controlling disease in farming systems, the development of freshwater crayfish aquaculture has increased interest in the field of freshwater crayfish pathology. Much of this new interest has been in Australian and/or on Australian species as these are the most commonly cultured in semi-intensive systems. However, freshwater crayfish have been farmed for a relatively short period of time compared with some other aquatic species, such as many fish species and shrimp. Moreover, industries based on culturing freshwater crayfish are much less economically significant than industries based on farming these other aquatic species. In relation to research done on freshwater crayfish pathology from an environmental perspective, ie. the work done in relation to disease outbreaks in Europe, much of it has concentrated on the crayfish plague fungus or other easily recognised diseases such as microsporidiosis or Psorospermium and bacterial infections. Consequently, our understanding of disease in freshwater crayfish is not as well developed as our understanding of diseases of fish and shrimp. As an illustration of this point, note that infections in freshwater crayfish by viruses and rickettsia-like organisms have been described only in the last decade. Considerable research is required to obtain an adequate understanding of disease in natural and farmed freshwater crayfish populations, to the benefit of industry and the environment. |
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To view photographs of many of the disease conditions discussed in this website, please visit my Freshwater Crayfish Pathology Gallery. |
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New: Techniques for fixation and preparation of freshwater crayfish for histopathological analyses |
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For a complete scientific review on this subject, please consult: |
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Edgerton BF, Evans LH, Stephens FJ, Overstreet RM (2002) Review of freshwater crayfish diseases and commensal organisms. Aquaculture Annual Review of Fish Diseases 206: 57-135; and |
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Evans L, Edgerton BF (2001) Pathogens, parasites and commensals. In: Biology of Freshwater Crayfish (ed. DM Holdich), Blackwell Science, Oxford, pp. 377-438 |
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Last updated: 10 September 2004 |