Ejectosporus, an Unusual New Genus of Harpellales in Winter-Emerging Stonefly Nymphs (Capniidae) and a New Species of Paramoebidium (Amoebidiales)

Abstract

Ejectosporus magnus belongs to a new monotypic genus of Harpellales (Trichomycetes) found in the hindgut of Allocapnia spp. nymphs (Plecoptera, Capniidae). The mature sporangiospore is forcefully ejected from the trichospore, a monosporous sporangium, while the sporangial wall remains attached to the generative cell. Trichospores apparently do not break away from the thallus as in most other genera of Harpellales. No trichospore appendages were observed. Another new hindgut species from Allocapnia spp. nymphs, Paramoebidium corpulentum (Amoebidiales), is also described. The first axenic isolations of Simuliomyces spica (Harpellales) from these stonefly hosts are reported.