Graminella bulbosa Leger & Gauthier, 1937 ex Manier, 1962.

Valle, Laia Guardia & Stoianova, Desislava, 2020, First record of Harpellales, Orphellales (Kickxellomycotina) and Amoebidiales (Mesomycetozoea) from Bulgaria, including a new species of Glotzia, MycoKeys 67, pp. 55-80 : 55

Graminella bulbosa Leger & Gauthier, 1937 ex Manier, 1962. Figs 11-13

Specimens examined.

Site 2: slide BUL-2-5; Site 8: slides BUL-8-1, BUL-8-2.

Notes.

This species is characterised by the unusual formation of vegetative propagules from the bulbous basal cells (Fig. 12 ), a feature only shared with the related genus Gauthieromyces ( Lichtwardt 1983). Graminella bulbosa was described from France ( Léger and Gauthier 1937; Manier 1962). The species is also known from Spain ( Valle 2007), Portugal ( Valle 2013a) and Italy ( Valle et al. 2013). Graminella bulbosa has been reported associated with various species of Baetis and related genera, very frequently within the hindgut of B. rhodani (Pictet). This species of mayfly is common and widespread in Europe and it also hosted Bulgarian specimens of G. bulbosa in the surveyed rivers, together with B. alpinus (Pictet). In fact, the genus Baetis bears different Harpellid species, including the more common Legeriomyces ramosus , occasionally sharing the same gut lumen with Graminella bulbosa . Bulgarian specimens of G. bulbosa show the typical small and numerous trichospores (Fig. 13 ), measuring 8 -11 × 2 µm in our collections. These measurements are midway between G. bulbosa and G. microsporus (see discussion for further information). Unfortunately, only immature zygospores were observed (Fig. 11 arrowhead).

Figures

Figures 11 - 16. Various species of Harpellales. 11 - 13 Graminella microspora from Baetidae nymphs: 11 thallus overview, with inflated basal cell structures from which propagules arise or are extruded (note: one empty basal cell which has extruded its cellular content, arrow); young zygospores can also be observed (arrowhead) 12 a cluster of basal cells 13 fertile branch with a long series of minute trichospores; 14, 15 Harpella melusinae from Simuliidae larvae: 14 generative cells and allantoids or curved trichospores 15 basal cell and small conic holdfast 16 Legeriomyces ramosus from Baetidae nymphs, zygospores and zygosporophores. Scale bars: 25 μm in all figures.