Algal taxonomy: a road to nowhere?

Abstract

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 global algal diversity. Contrary to this largely pessimistic belief, species description rates of algae through time and trends in the number of active taxonomists, as revealed by the web resource AlgaeBase, show a much more positive picture. More species than ever before are being described by a large community of algal taxonomists. The lack of any decline in the rate at which new species and genera are described, however, is indicative of the large proportion of undiscovered diversity and bears heavily on any prediction of global algal species diversity and the time needed to catalogue it. The saturation of accumulation curves of higher taxa (family, order, and classes) on the other hand suggest that at these taxonomic levels most diversity has been discovered. This reasonably positive picture does not imply that algal taxonomy does not face serious challenges in the near future. The observed levels of cryptic diversity in algae, combined with the shift in methods used to characterize them, have resulted in a rampant uncertainty about the status of many older species. As a consequence, there is a tendency in phycology to move gradually away from traditional names to a more informal system whereby clade-, specimen- or strain-based identifiers are used to communicate biological information. Whether these informal names for species-level clades represent a temporary situation stimulated by the lag between species discovery and formal description, or an incipient alternative or parallel taxonomy, will be largely determined by how well we manage to integrate historical collections into modern taxonomic research. Additionally, there is a pressing need for a consensus about the organizational framework to manage the information about algal species names. An eventual strategy should preferably come out of an international working group that includes the various databases as well as the various phycological societies. In this strategy, phycologists should link up to major international initiatives that are currently being developed, such as the compulsory registration of taxonomic and nomenclatural acts and the introduction of Life Science Identifiers.

Update of the Brazilian floristic list of Algae and Cyanobacteria

“…On the other hand, in the case of algae and cyanobacteria, Brazil continues to face obstacles for the advancement in the knowledge of phycological diversity, be it because of global issues, such as the shortage of taxonomists specializing in this area (Guiry 2012;De Clerck et al 2013) or, in the regional scale, such as the lack of laboratory facilities and nonavailability of biological collections where the diversity is higher (Grieneisen et al 2014). Strategic policies have already been launched by the Brazilian government in order to accelerate the study of the country's biodiversity, however, these need to be strengthened and widened to ensure its mapping is more homogeneous and complete.…”

A Community of Clones: Snow Algae Are Diverse Communities of Spatially Structured Clones

“…Previous queries into the ecology of snow algae have been limited mainly to community composition (Yoshimura et al 1997;Takeuchi 2013). The increasing use of DNA meta-bar-coding tools has elucidated the hidden diversity of algae and presents an opportunity to integrate these new discoveries with traditional taxonomy (De Clerck et al 2013). Snow algae have been described as simple communities that consist of few species (Takeuchi 2001) and are generally considered to occur in closed ecosystems (Hoham and Duval 2001).…”

Kallymenia crouaniorum(Kallymeniaceae, Rhodophyta), a new red algal species from theLaminaria hyperboreaunderstorey community

“…Nonetheless, the advent of molecular systematics has demonstrated that the vegetative and reproductive characteristics traditionally used for species delimitation are not always consistent with the results of molecular phylogenetic approaches because of both convergence leading to cryptic diversity, and phenotypic plasticity causing variation in morphological characters (e.g. Saunders, 2005;Le Gall & Saunders, 2010;De Clerck et al, 2013). Reliable identification of seaweeds, based solely on morphological characters, is therefore a challenging task.…”