has resulted from crayfish plague (Kemp et al. 2003). The invasive crayfish, pallipes P. commonly acts as a reservoir for (the causative agent of leniusculus, Aphanomyces astaci crayfish plague), which is fatal to the native species (Holdich 2003). Also of interest are two further parasites. The microsporidian parasite Thelohania (Henneguy), infects causing porcelain disease and is contejeani Austropotamobius pallipes the most widely recorded parasitic infection of this species (Alderman and Polglase 1988). Whilst the pathology of is not as severe as that of crayfish plague it can be a T. contejeani serious threat within crayfish aquaculture (Edgerton et al. 2002) and may cause changes in the ecology of its host through changes in diet (Chartier and Chaisemartin 1983); however the consequences of infection by many pathogen groups in European freshwater crayfish are largely poorly understood (Edgerton et al. 2004). Microsporidia are widespread in crustacean hosts (Edgerton et al. 2002; Terry et al. 2004) and can cause significant mortality (Alderman and Polglase 1988). A second parasite, the protist (Haeckel) infects Psorospermium haeckeli crayfish and has recently been isolated from (Rogers et al. 2003) and A. pallipes Pacifastacus (Dieguez-Uribeondo et al. 1993). The influence of these parasites upon leniusculus native/invasive interactions in crayfish is unknown. In the UK, Yorkshire is a stronghold for although is present A. pallipes: P. leniusculus within the county in substantial numbers, it has not yet displaced many native populations and mixed populations do exist (Peay and Rogers 1999). Here we investigate possible competitive interactions by comparing the sizes of native and invading individuals in single species versus mixed species populations. Secondly we use PCR screening and sequence analysis to compare parasite diversity in the native and invasive crayfish, focusing on microsporidian parasites.
pallipes has resulted from crayfish plague (Kemp et al. 2003). The invasive crayfish, P. leniusculus, commonly acts as a reservoir for Aphanomyces astaci (the causative agent of crayfish plague), which is fatal to the native species (Holdich 2003). Also of interest are two further parasites. The microsporidian parasite Thelohania contejeani (Henneguy), infects Austropotamobius pallipes causing porcelain disease and is the most widely recorded parasitic infection of this species (Alderman and Polglase 1988). Whilst the pathology of T. contejeani is not as severe as that of crayfish plague it can be a serious threat within crayfish aquaculture (Edgerton et al. 2002) and may cause changes in the ecology of its host through changes in diet (Chartier and Chaisemartin 1983); however the consequences of infection by many pathogen groups in European freshwater crayfish are largely poorly understood (Edgerton et al. 2004). Microsporidia are widespread in crustacean hosts (Edgerton et al. 2002; Terry et al. 2004) and can cause significant mortality (Alderman and Polglase 1988). A second parasite, the protist Psorospermium haeckeli (Haeckel) infects crayfish and has recently been isolated from A. pallipes (Rogers et al. 2003) and Pacifastacus leniusculus (Dieguez-Uribeondo et al. 1993). The influence of these parasites upon native/invasive interactions in crayfish is unknown. In the UK, Yorkshire is a stronghold for A. pallipes: although P. leniusculus is present within the county in substantial numbers, it has not yet displaced many native populations and mixed populations do exist (Peay and Rogers 1999). Here we investigate possible competitive interactions by comparing the sizes of native and invading individuals in single species versus mixed species populations. Secondly we use PCR screening and sequence analysis to compare parasite diversity in the native and invasive crayfish, focusing on microsporidian parasites.
Crayfish%20paper%2021.01.08%20second%20revision.docx