The Microsporidia, an often overlooked fungal lineage, exhibit increasing diversity and taxonomic understanding with the use of genomic techniques. They are obligate parasites infecting a diversity of hosts, including crustaceans. Crustacea are, in essence, ancient insects and their relationship with the Microsporidia is both diverse and convoluted. Relationships between crayfish and their microsporidian

Fungi represent one of the most diverse groups of organisms on the planet, with an essential role in ecosystem processes and functioning. The numbers of fungi have always been an intriguing topic with several review papers being written on the subject. Perhaps the starting point was that of paper of D.L. Hawksworth in 1991 in which he estimated that there were roughly 1.5 million species. In the last

In this article the author name Ana Alastruey-Izquierdo was incorrectly written as Ana Alastruey-Izquerdo.

In the section Biodiversity hotspots, the origin of most ascomycetous type collections was incorrectly worded. The original article has been corrected.

Species delimitation is one of the most fundamental processes in biology. Biodiversity undertakings, for instance, require explicit species concepts and criteria for species delimitation in order to be relevant and translatable. However, a perfect species concept does not exist for Fungi. Here, we review the species concepts commonly used in Basidiomycota, the second largest phylum of Fungi that contains

The increasing number of new fungal species described from all over the world along with the use of genetics to define taxa, has dramatically changed the classification system of early-diverging fungi over the past several decades. The number of phyla established for non-Dikarya fungi has increased from 2 to 17. However, to date, both the classification and phylogeny of the basal fungi are still unresolved

Biodiversity loss from disturbances caused by human activities means that species are disappearing at an ever increasing rate. The high number of species that have yet to be described have generated extreme crisis to the taxonomist. Therefore, more than in any other era, effective ways to discover and delimitate species are needed. This paper reviews the historically foremost approaches used to delimit