Diversity of fungi isolated from carapace and gut of the marine crab Portunus sanguinolentus in northern waters of Taiwan

The fungal community associated with marine crabs is poorly known, except for the fungi causing diseases of marine animals of economic value. In this study we examined the diversity of fungi cultured from carapace and gut of the marine crab Portunus sanguinolentus, and the identification was based on nucleotide BLAST search results of the internal transcribed spacers of rDNA (ITS). A total of 256 fungal isolates representing 23 species were cultured from seven individuals of P. sanguinolentus including two unidentified species. The majority of the species belong to the Ascomycota, while three species of the Basidiomycota were isolated from the gut. Overall, Candida tropicalis (45.70%, percentage occurrence), Apiotrichum lignicola (8.98%) and Rhodotorula sp. (8.20%) were the dominant fungi on the crab. The most dominant fungi on the carapace were C. tropicalis (66.95%), Emericellopsis maritima (8.47%), A. lignicola and Purpureocillium lilacinum (both 4.24%). In the gut, C. tropicalis (27.54%), A. lignicola (16.67%), Rhodotorula sp. (15.22%) and Fusarium solani (14.49%) were dominant. The fungal diversity in the gut of P. sanguinolentus was higher than on the carapace according to the diversity indices. Although some of the isolated fungi were reported to be pathogenic, none were reported as pathogens of crabs, and no disease symptoms were noticed from the crab samples.