Impact of microsporidia on Pacifastacus leniusculus: a study of Astathelohania contejeani infection
1
ipartimento di Scienze della Terra e dell’Ambiente, Università di Pavia, Ferrata 1, Pavia, Pavia - 27100, Italia
2
Istituto Zooprofilattico Sperimentale delle Venezie, Centro Specialistico Ittico, Viale dell’Università 10, Legnaro, PD - 35020, Italia
The microsporidian parasite Astathelohania contejeani is the causative agent of porcelain disease, a
chronic infection affecting populations of the endangered European crayfish Austropotamobius
pallipes complex and the vulnerable noble crayfish Astacus astacus across Europe. The disease is
characterized by progressive tissue degeneration and whitening of the abdominal muscles,
ultimately leading to the death of infected individuals. Porcelain disease has been implicated in
significant crayfish population declines and past mass mortality events, posing a serious threat to
the conservation of native crayfish species. The aim of the present study is to assess the horizontal
transmission of this parasite from A. pallipes to Pacifastacus leniusculus and to evaluate the
development of the disease in this invasive crayfish.
A total of 60 P. leniusculus were collected and divided into two groups: a treatment group
consisting of 20 females and 20 males, and a control group consisting of 10 females and 10 males.
All crayfish were housed individually in separate tanks, each equipped with a shelter and an aerator.
Animals were fed weekly and standard housing conditions were maintained throughout the study.
The infection process consisted of feeding the treatment group three times with fresh muscle tissue
derived from A. pallipes heavily infected by A. contejeani. Infection status was periodically
monitored using non-invasive sampling techniques in combination with molecular biology analyses.
A low infection rate was observed, which did not align with findings from previous studies. The
first infected individual was detected three months after the beginning of the experiment and the
final infected crayfish was recorded after five months. Interestingly, no additional infections were
detected by the end of the nine-month monitoring period.
Keywords: Pacifastacus leniusculus, experiment of infection, microsporidian
Acknowledgement:
This study was supported by EU LIFE Programme: LIFE-CLAW, Crayfish Lineages Conservation in North-
western Apennine (LIFE18 NAT/IT/000806).
Conservazione e gestione di specie e habitat minacciati