Mycoflora on the cuticle of the invasive crayfish Procambarus clarkii

A total of 18 genera and 22 fungal species was detected on adults of the red swamp crayfish Procambarus clarkii of both sexes collected in Lake Trasimeno from June 2007 to June 2008. The most frequent fungal species was Phoma glomerata, isolated from 67.82 % (N = 59) of the analyzed individuals. Cladosporium cladosporioides and Penicillium spp. occurred at prevalence greater than 20 % on P. clarkii. Other taxa frequently recorded were Fusarium spp. (17.24 %, N = 15), Aspergillus spp. (14.94 %, N = 13), F. oxysporum (13.79 %, N = 12), Alternaria alternata (12.64 %, N = 11), A. chlamydospora (11.49 %, N = 10), F. proliferatum (10.34 %, N = 9), Rhizopus stolonifer (9.20 %, N = 8), F. verticillioides (6.9 %, N = 6) and Paecilomyces lilacinus (3.45 %, N = 3). The presence of Chaetomella raphigera (9.20 %, N = 8) and of Graphium sp. (only found once) deserve to be mentioned as they are rarely isolated. The highest fungal diversity occurred in September 2007 and April 2008 with 15 species isolated, the lowest in July and August 2007 (4 species). During the mycological investigation, unidentified yeast and bacteria were also recorded. Fungal species did not differ between female and male crayfish. The ecological significance of the recorded fungi and their potential sanitary implications are discussed. The red-swamp crayfish may act as a vector for potentially dangerous fungi; a cause for concern as this is an invasive species.