On species descriptions based on a single strain:: proposal to introduce the status species proponenda (sp pr.)

A survey of the descriptions of novel bacterial species published in the period 1996-2006 revealed that a large number of taxonomic descriptions are still based on one or a few strains. This situation determines that not only species descriptions, but also proposals to create higher ranks, are actually based on very few strains, which could produce a highly biased scenario. The encouragement to include a reasonable number of strains in species descriptions has been largely disregarded after its proposal, since acceptance of such descriptions relies mainly on editors' and reviewers' opinions. This observation and other considerations lead us to propose the creation of the status species proponenda (sp. pr.), as a compromise between the need for scientific description of biodiversity and exchange of data and the good taxonomic practice of including a sufficient number of strains in descriptions of species and higher taxonomic ranks.