The microorganisms of cryoconite holes (algae, Archaea, bacteria, cyanobacteria, fungi, and Protista): a review

We provide a comprehensive list of microorganisms (algae, Archaea, bacteria, cyanobacteria, fungi, and Protista) inhabiting cryoconite holes on glaciers throughout the world, giving an updated taxonomy accompanied by geographic coordinates and localities. The list consists of 370 taxa reported from cryoconite holes (mostly from Arctic and Antarctic regions and European Alps). However, most of the taxa were not identified to the species level. Until now only 39 identified species or subspecies of bacteria and Archaea, 11 fungi, 17 cyanobacteria, 62 algae, and 13 Protista are known from cryoconite holes, which are only about 38% of total number of taxa reported from these ephemeral environments. Almost 62% of the taxa were marked ascf.(confer) or were identified only to the genera or even to the higher taxonomic units (such as families or orders). This wide and detailed review assists other scientists to identify the gaps in our knowledge about cryobionts and indicates directions for further zoogeographical and taxonomical studies in this unique freshwater habitat.