Chapter 7 - Taxonomy and Systematics: Current Knowledge and Approaches on the Taxonomic Treatment of Myxomycetes

Abstract

Myxomycetes have been classified with the animal kingdom and with fungi. The major trophic stage, the plasmodium, is multinucleate and ingests food in an amoebalike manner. The amoeboflagellate cells that precede the formation of the plasmodium certainly hint at a connection with protozoan-like organisms in the animal kingdom. The plasmodium gives rise to spore-producing fruiting bodies, and the funguslike fruiting bodies with spores motivated a supposed relationship with the fungi. Presently, myxomycetes with protostelids and dictyostelids are regarded as phylogenetically closely related and represent a separate side-branch of an evolutionary line from amoeboid organisms. This side branch is separate from the line from which fungi and animals arose. Over the past 30 years, numerous papers with descriptions of new species of myxomycetes have been published and more than 380 new species have been described. In the present treatment, 64 genera and 980 species are recognized. A revision of the taxonomy and classification, as well as an update on the nomenclature of the group are presented. Recent phylogenetic approaches, based on molecular techniques, also have been taken into consideration. Thanks to the explosive development of the Internet during recent decades it has been possible to develop new tools and design online databases with the purpose to serve, favor, and facilitate taxonomic research by acting as global repositories for data on taxa and literature on myxomycetes. An enumeration of some useful databases, projects, virtual libraries, software, and other tools that facilitate the taxonomic work are included.