Astreptonema gammari: An Eccrinid with Appendaged Spores

Astreptonema gammari (L. Léger & Duboscq) Manier (Trichomycetes, Eccrinaceae) grows obligately attached to the cuticle lining the hindgut of Gammarus pulex L. (Crustacea, Gammaridae) found in freshwater. The primary infestation sporangiospores possess polar mucilage-like appendages that are extensions of the outer layer of the sporangiospore wall. Appendage formation from dictyosome-derived vesicles is described for the first time and compared with spore appendage formation in other species of the Trichomycetes, particularly the Harpellales.