Myrmecia Printz.

Veselá, Veronika, Malavasi, Veronica & Škaloud, Pavel, 2024, A synopsis of green-algal lichen symbionts with an emphasis on their free-living lifestyle, Phycologia 63 (3), pp. 317-338 : 320

Myrmecia Printz.

Myrmecia is a coccoid alga with spherical, ovoid, or pear-shaped cells that can form multicellular aggregates. The cell wall may be locally thickened. The chloroplast is parietal, cup-shaped, wavy at the edges, and usually divided into 2–4 lobes ( Fig. 2 ). It reproduces asexually by zoospores, aplanospores or autospores (Ettl & Gärtner 2013). From the nine taxonomically accepted species ( Guiry & Guiry 2022) only two ( M. biatorellae and M. israelensis ) have so far been confirmed as photobionts of Psora , Placidium and Heteroplacidium from the family Verrucariaceae ( Thüs et al. 2011; Moya et al. 2018).

Free-living M. biatorellae is often reported from arid regions ( Flechtner et al. 1998; Vinogradova et al. 2004; Flechtner et al. 2008; Venter et al. 2015). However, there are also records from the tundra in north-eastern Russia ( Andreyeva 2005). This species has been reported quite frequently from caves ( Roldán et al. 2004; Vinogradova et al. 2009). For instance, Roldán & Hernández-Mariné (2009) isolated M. biatorellae from a biofilm on the surface of stalactite in Collbató Cave ( Spain). The granite walls of historic buildings in Galicia ( Spain) are also a substrate inhabited by this alga ( Rifón-Lastra & Noguerol-Seoane 2001). In addition to rocks ( Vinogradova et al. 2004), this species often inhabits soil ( Khaybullina et al. 2010; Bakieva et al. 2012), tree bark ( Khaybullina et al. 2010), sand ( Schulz et al. 2016) and survives on serpentinite soils ( Venter et al. 2015).

Figures

Figs 1–18. Lichen photobiont genera (including nonlichenized species) belonging to classes Trebouxiophyceae and Chlorophyceae. Fig. 1. Asterochloris lobophora. Fig. 10. Prasiola crispa. Fig. 2. Myrmecia incisa. Fig. 11. Pseudochlorella pringsheimii. Fig. 3. Trebouxia impressa. Fig. 12. Stichococcus sp. Fig. 4. Vulcanochloris symbiontica. Fig. 13. Auxenochlorella protothecoides. Fig. 5. Chloroidium saccharophilum. Fig. 14. Apatococcus sp. Fig. 6. Jaagichlorella luteoviridis. Fig. 15. Leptosira sp. Fig. 7. Coccomyxa sp. Fig. 16. Symbiochloris tschermakiae. Fig. 8. Elliptochloris subsphaerica. Fig. 17. Uvulifera verrucariae (Lorenz 2016). Fig. 9. Diplosphaera chodatii. Fig. 18. Bracteacoccus. sp. Scale bars: 10 μm (Figs 1-9, 11-18), 200 μm (Fig. 10).