author={Michael D. Guiry},
  journal={Journal of Phycology},
  • M. Guiry
  • Published 1 October 2012
  • Environmental Science, Biology
  • Journal of Phycology
Algae have been estimated to include anything from 30,000 to more than 1 million species. An attempt is made here to arrive at a more accurate estimate using species numbers in phyla and classes included in the on‐line taxonomic database AlgaeBase ( Despite uncertainties regarding what organisms should be included as algae and what a species is in the context of the various algal phyla and classes, a conservative approach results in an estimate of 72,500 algal species… 
How many species of Cyanobacteria are there? Using a discovery curve to predict the species number
The aim of this study was to understand the status of cyanobacterial biodiversity on a global scale and to estimate the number of still-unknown species, using a discovery curve.
AlgaeBase: An On-line Resource for Algae
AlgaeBase is an on-line database providing free access to authoritative taxonomic, distributional and nomenclatural information of more than 135,000 names of species and infraspecific taxa of algae set in the context of a taxonomic hierarchy.
Viruses of Microorganisms
Algae are photosynthetic organisms that drive aquatic ecosystems, e.g. fuelling food webs or forming harmful blooms. The discovery of viruses that infect eukaryotic algae has raised many questions
Algal taxonomy: a road to nowhere?
The widespread view of taxonomy as an essentially retrogressive and outmoded science unable to cope with the current biodiversity crisis stimulated us to analyze the current status of cataloguing
Red algal parasites: a synopsis of described species, their hosts, distinguishing characters and areas for continued research
A set of defining criteria for parasites is applied to a compiled list of all described red algal parasites to highlight the lack of knowledge of many key parasitic processes including early parasite development, host cell “control”, and parasite origin.
The number of known plants species in the world and its annual increase
Phytotaxa is currently contributing more than a quarter of the ca 2000 species that are described every year, showing that it has become a major contributor to the dissemination of new species discovery, but the rate of discovery is slowing down.
The widespread view of taxonomy as an essentially retrogressive and outmoded science unable to cope with the current biodiversity crisis stimulated us to analyze the current status of cataloguing
Progress in diatom research: from taxonomy to physiology
In this issue, morphological characteristics of diatoms are used to define new taxa in the Maritime Antarctic region of Canada and two new epiphytic species of Ulnaria are established.
Diversity of Viruses Infecting Eukaryotic Algae
This review summarizes current knowledge of algal viruses as diverse, dynamic, and ecologically important members of the biosphere and indicates that future investigations will continue to reveal the full extent of their diversity and impact.
An Inordinate Fondness? The Number, Distributions, and Origins of Diatom Species
The combination of very large species numbers and relatively rapid dispersal in diatoms is inconsistent with some versions of the “ubiquity hypothesis” of protist biogeography, and appears paradoxical, but population genetic data indicate geographical structure in all the (few) marine and freshwater species that have been examined in detail.


The Magnitude of Global Marine Species Diversity
How Many Species Are There on Earth and in the Ocean?
It is shown that the higher taxonomic classification of species follows a consistent and predictable pattern from which the total number of species in a taxonomic group can be estimated, and when applied to all domains of life, it predicts ∼8.7 million eukaryotic species globally.
The species concept in diatoms
  • D. Mann
  • Environmental Science, Geography
  • 1999
Abstract Diatoms are the most species-rich group of algae. They are ecologically widespread and have global significance in the carbon and silicon cycles, and are used increasingly in ecological
Dinoflagellate diversity and distribution
Dinoflagellates are common to abundant in both marine and freshwater environments. They are particularly diverse in the marine plankton where some cause “red tides” and other harmful blooms. More
Biodiversity, biogeography and conservation of diatoms
The present species classification of diatoms is too coarse and hides significant diversity, and it is recommended that such demes are recognized as separate species; the total number of diatom species worldwide may be at least 2 × 105.
The diversity and distribution of diatoms: from cosmopolitanism to narrow endemism
Evidence that challenges the ubiquity hypothesis for the most speciose group of microbial eukaryotes, the diatoms, and underscores the pressing need to continue research into diatom biology, ecology and the factors driving diatom species diversity and geographic distributions is reviewed is reviewed.
Prochlorococcus, a Marine Photosynthetic Prokaryote of Global Significance
The present review critically assesses the basic knowledge acquired about Prochlorococcus both in the ocean and in the laboratory to determine its adaptation to nutrient-deprived environments.
Global biodiversity patterns of marine phytoplankton and zooplankton
Biodiversity data for marine plankton assemblages from different areas of the world ocean shows a worldwide consistency, despite obvious differences in environmental conditions of the various oceanographic regions, and may serve as a new benchmark in the search for global biodiversity patterns of plants and herbivores.
DNA barcoding reveals multiple overlooked Australian species of the red algal order Rhodymeniales (Florideophyceae), with resurrection of Halopeltis J. Agardh and description of Pseudohalopeltis gen. nov
The DNA barcode (COI-5P) was used to investigate cryptic diversity among Rhodymenia spp. in southern Australia. Whereas eight species are currently recognized, we uncovered ca. 20 genetic species
DNA barcoding of Canadian Ahnfeltiales (Rhodophyta) reveals a new species – Ahnfeltia borealis sp. nov.
The authors' data indicate the presence of a third species of Ahnfeltia, A. borealis sp.