Prorocentrum rivalis sp. nov. (Dinophyceae) and its phylogenetic affinities inferred from analysis of a mixed morphological and LSU rRNA data set

David Delmail (1) , Pascal Labrousse (1) , Philippe Crassous (2) , Philippe Hourdin (1) , Mathieu Guri (3)

1 GRESE - Groupement de Recherche Eau, Sol, Environnement
2 LEP - Laboratoire Environnement Profond
3 LM2E - Laboratoire de Microbiologie des Environnements Extrêmophiles

A new freshwater epiphytic Prorocentrum species, Prorocentrum rivalis, from the temperate region of the Haute-Vienne, France, is described. This species is the third freshwater species identified among approximately 60 marine Prorocentrum species. This new species is described using scanning electron microscope and phylogenetic analyses by a polyphasic approach (LSU rRNA sequences combined with 9 morphological characters). The phylogenetic analysis attests that P. rivalis is close to other planktonic freshwater species and the freshwater Prorocentrum clade is evolutionarily derived from an epiphytic freshwater prorocentroid ancestor. The unique marine species in the freshwater clade results from an ecophysiological reversion. P. rivalis differs from other epiphytic taxa by its rarity, its temperate distribution and its ecophysiological needs. The phylogeny confirms also that all planktonic Prorocentrum species are evolutionarily derived from epiphytic/benthic ancestors.

Mots clés: Prorocentrum rivalis; epiphytic microalgae; LSU; phylogeny; polyphasic approach; SEM

Domaines: Sciences de l'environnement; Biochimie [q-bio.BM]

David Delmail, Pascal Labrousse, Philippe Crassous, Philippe Hourdin, Mathieu Guri. Prorocentrum rivalis sp. nov. (Dinophyceae) and its phylogenetic affinities inferred from analysis of a mixed morphological and LSU rRNA data set. Biologia, 2011, 66 (3), pp.418-424. ⟨10.2478/s11756-011-0029-y⟩. ⟨hal-00654592⟩