Diluviocola capensis gen. and sp. nov., a freshwater ascomycete with unique polar caps on the ascospores

Abstract

Diluviocola capensis gen. and sp. nov. is described from wood submerged in a river in Brunei. The fungus is similar to species in Annulatascus, but it has unique ascospore appendages. In D. capensis ascospores have polar conical caps. After release from the ascus these polar caps detach from the tip, and a thread-like appendage unfurls from within the cap. EM micrographs indicate that the appendage comprises a network of inter-linked rod-like fibrils. This appendage structure is compared with the appendage structure in Annulatascus bipolaris and Halosarpheia species. Diluviocola is also compared to Annulatascus, Rivulicola and Proboscispora, genera which share some similar characteristics at the light and electron microscope levels.