Coolia guanchica sp. nov. (Dinophyceae) a new epibenthic dinoflagellate from the Canary Islands (NE Atlantic Ocean)

Abstract

ABSTRACT A new warm-water benthic dinoflagellate species, Coolia guanchica sp. nov., is described from the Canary Islands (NE Atlantic Ocean), a subtropical archipelago with a rich benthic biodiversity. Samples of benthic microalgae were collected at Tenerife, and three strains of a previously unreported ribotype of the genus Coolia were found. Identification was carried out by combining morphological (light microscope, LM; and scanning electron microscope, SEM) and molecular (large subunit ribosomal gene, LSU rRNA; and internal transcribed spacer region, ITS1-5.8S-ITS2 rRNA) data from clonal cultures. Phylogenetic analyses revealed that the new strains formed a well-supported clade, sister to Coolia canariensis. The genetic distance of more than 0.20 for LSU and 0.30 for the ITS region (uncorrected p values) from the closest members of the genus (C. canariensis and C. cf. canariensis) showed species-level divergence to justify the description of a new species, Coolia guanchica sp. nov. A bioassay with Artemia salina was used to check the toxicity of the species, with negative results. Coolia guanchica has rounded cells, with plate 4′ as the largest plate of the epitheca and plate 6′′ about twice as wide as long, similar to C. canariensis and C. areolata. It differs morphologically from the other two ribotypes in the C. canariensis complex in having a lighter hypothecal ornamentation, larger thecal plate pores scattered randomly throughout the cell and higher pore density per thecal plate.