Isolation and characterization of a new fungal genus and species, Aphanoascella galapagosensis, from carapace keratitis of a Galapagos tortoise (Chelonoidis nigra microphyes)

A new fungal genus and species, Aphanoascella galapagosensis, recovered from carapace keratitis in a Galapagos tortoise residing in a south Texas zoological collection, is characterized and described. The presence of a pale peridium composed of textura epidermoidea surrounded by scarce Hülle cell-like chlamydospores, and the characteristic reticulate ascospores with an equatorial rim separates it from other genera within the Onygenales. The phylogenetic tree inferred from the analysis of D1/D2 sequences demonstrates that this fungus represents a new lineage within that order. As D1/D2 and ITS sequence data also shows a further separation of Aphanoascus spp. into two monophyletic groups, we propose to retain the generic name Keratinophyton for species whose ascospores are pitted and display a conspicuous equatorial rim, and thereby propose new combinations in this genus for four Aphanoascus species.