No abstract

Reports on fungi occurring on marine crabs have been mostly related to those causing infections/diseases. To better understand the potential role(s) of fungi associated with marine crabs, this study investigated the culturable diversity of fungi on carapace of the marine shallow-water hydrothermal vent crab Xenograpsus testudinatus collected at Kueishan Island, Taiwan. By sequencing the internal transcribed spacer regions (ITS), 18S and 28S of the rDNA for identification, 12 species of fungi were isolated from 46 individuals of X. testudinatus: Aspergillus penicillioides, Aspergillus versicolor, Candida parapsilosis, Cladosporium cladosporioides, Mycosphaerella sp., Parengyodontium album, Penicillium citrinum, Penicillium paxili, Stachylidium bicolor, Zasmidium sp. (Ascomycota), Cystobasidium calyptogenae and Earliella scabrosa (Basidiomycota). With additional data from other published reports, a total of 26 species of fungi (23 Ascomycota, three Basidiomycota) have been recorded from X. testudinatus. Aspergillus is the most speciose genus on the crab, followed by Penicillium and Candida. All but one species (Xylaria arbuscula) had been previously isolated from substrates in the marine environment, although many are typical terrestrial taxa. None of the recorded fungi on X. testudinatus are reported pathogens of crabs, but some have caused diseases of other marine animals. Whether the crab X. testudinatus is a vehicle of marine fungal diseases requires further study.

This study investigated the morphological diversity of arenicolous marine fungi (only those forming fruiting bodies on sand grains) at 11 sandy beaches in Taiwan. The species of Corollospora were identified by ascospore morphology and confirmed through a phylogenetic analysis of the 28S rDNA with other published sequences. The phylogenetic analysis revealed four previously unknown clades of Corollospora spp. related to C. portsaidica, while differences in ascospore morphology of the isolates in these four clades were observed. A total of 13 species of arenicolous marine fungi was identified from the 11 sandy beaches, including two Arenariomyces spp., nine Corollospora spp. (including four unknown Corollospora clades), Kohlmeyeriella crassa and Carbosphaerella cf sp. Taan Beach had the highest species richness (eight species), followed by Yongzhen Sea Park and Pisirian (five species each). The Shannon’s diversity index revealed the highest diversity at Taan Beach (1.51) over Pisirian (1.44), but the diversity was more even at the latter site (Pielou’s evenness index = 0.9) compared with the former (0.73). Non-metric multidimensional scaling suggests that there was generally a divide in the fungal community composition between the east and the west coasts of Taiwan.